SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-Q
             QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                  For the quarterly period ended June 30, 1998
                         Commission file number 0-23044

                      AMERICAN MOBILE SATELLITE CORPORATION
             (Exact name of registrant as specified in its charter)

                      DELAWARE              93-0976127
                  (State or other        (I.R.S. Employer
                  jurisdiction of       Identification No.)
                  incorporation or
                    organization)

             10802 Parkridge Boulevard
                     Reston, VA              20191-5416
               (Address of principal         (Zip Code)
                  executive offices)

                                 (703) 758-6000
                         (Registrant's telephone number,
                              including area code)


Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  registrant  was
required  to file  such  report(s)),  and (2) has been  subject  to such  filing
requirements for the past 90 days. Yes X No

Number of shares of Common Stock outstanding at July 31, 1998: 32,129,163






                          PART I--FINANCIAL INFORMATION

                          Item 1. Financial Statements

             AMERICAN MOBILE SATELLITE CORPORATION AND SUBSIDIARIES
                    CONSOLIDATED CONDENSED STATEMENTS OF LOSS
                      (in thousands, except per share data)
                                   (Unaudited)





                                                         Three Months Ended                 Six Months Ended
                                                               June 30,                          June 30,
                                                       1998             1997              1998             1997
                                                    ----------        ---------         ---------       ---------
                                                                                            
REVENUES
   Services                                           $16,670           $4,979           $23,088          $9,132
   Sales of equipment                                   5,740            5,774             9,344          10,306
                                                    ----------        ---------         ---------       ---------
   Total Revenue                                       22,410           10,753            32,432          19,438

COSTS AND EXPENSES
   Cost of service and operations                      16,918            8,201            24,646          17,074
   Cost of equipment sold                               5,415            7,140             9,296          12,582
   Sales and advertising                                4,711            3,059             7,733           6,280
   General and administrative                           5,773            2,937             9,404           7,805
   Depreciation and amortization                       14,457           11,083            24,620          21,020
                                                       ------           ------            ------          ------
   Operating Loss                                     (24,864)         (21,667)          (43,267)        (45,323)

INTEREST EXPENSE                                      (15,706)          (5,281)          (22,344)         (9,651)
INTEREST AND OTHER INCOME                               1,607              106             1,748           1,051
EQUITY IN LOSS OF AMRC                                     --               --              (342)             --
                                                       ------           ------            ------          ------

NET LOSS                                             ($38,963)        ($26,842)         ($64,205)       ($53,923)
                                                    ==========        =========         =========       =========

BASIC AND DILUTED NET LOSS PER SHARE OF
COMMON STOCK                                           ($1.23)          ($1.07)           ($2.25)         ($2.15)
                                                    ==========        =========         =========       =========

WEIGHTED AVERAGE COMMON SHARES
OUTSTANDING DURING THE PERIOD (000'S)                  31,719           25,120            28,502          25,115
                                                    ==========        =========         =========       =========


See notes to consolidated financial statements.









                          PART I-FINANCIAL INFORMATION
                    Item 1. Financial Statements (continued)
             AMERICAN MOBILE SATELLITE CORPORATION AND SUBSIDIARIES
                      CONSOLIDATED CONDENSED BALANCE SHEETS
                                 (In thousands)
                                   (Unaudited)




                                                            June 30,           December 31,
                                                              1998                1997
                                                              ----                ----
ASSETS
CURRENT ASSETS:
                                                                             
   Cash and cash equivalents                                 $8,944               $2,106
   Inventory                                                 37,887               40,321
   Accounts receivable-trade, net                            13,279                8,140
   Restricted cash-current portion                           41,038                   --
   Prepaid in-orbit insurance                                 1,993                4,564
   Other current assets                                      20,602                9,608
                                                             ------                -----
   Total current assets                                     123,743               64,739

PROPERTY AND EQUIPMENT - NET                                265,788              233,174
GOODWILL AND INTANGIBLES - NET                               54,347                   --
DEFERRED CHARGES AND OTHER ASSETS                            34,554               13,534
RESTRICTED CASH - NON-CURRENT                                83,970                   --
                                                             ------             --------
   Total assets                                            $562,402             $311,447
                                                           ========             ========

LIABILITIES AND STOCKHOLDERS' EQUITY
CURRENT LIABILITIES:
   Accounts payable and accrued expenses                    $40,725              $35,861
   Obligations under capital leases due within one year       3,687                  798
   Current portion of long-term debt                          3,006               15,254
   Other current liabilities                                  7,673                7,520
                                                              -----                -----
   Total current liabilities                                 55,091               59,433
LONG-TERM LIABILITIES:
   Obligations under Bank Financing                         122,000              198,000
   Obligations under Senior Notes, net of discount          326,722                   --
   Capital lease obligations                                 10,163                3,147
   Net assets acquired in excess of purchase price            2,376                2,725
   Other long-term debt                                       1,003                1,364
   Other long-term liabilities                                  563                  647
                                                            -------              -------
   Total long-term liabilities                              462,827              205,883
                                                            -------              -------
   Total liabilities                                        517,918              265,316
                                                            -------              -------
STOCKHOLDERS' EQUITY
   Preferred Stock, par value $0.01;  no shares issued           --                   --
   Common Stock, voting, par value $0.01                        318                  252
   Additional paid-in capital                               502,228              451,892
   Common Stock purchase warrants                            62,547               36,338
   Unamortized guarantee warrants                           (37,640)             (23,586)
   Retained loss                                           (482,969)            (418,765)
                                                           ---------            ---------
   Total stockholders' equity                                44,484               46,131
                                                             ------            ---------
   Total liabilities and stockholders' equity              $562,402             $311,447
                                                           ========             ========


See notes to consolidated financial statements.








                          PART I-FINANCIAL INFORMATION

                    Item 1. Financial Statements (continued)

             AMERICAN MOBILE SATELLITE CORPORATION AND SUBSIDIARIES
                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (in thousands)
                                   (Unaudited)




                                                                          Six Months Ended
                                                                               June 30
                                                                      ------------------------

                                                                           1998        1997

CASH FLOWS FROM OPERATING ACTIVITIES:
                                                                                       
Net loss                                                                ($64,205)    ($53,923)  
Adjustments to reconcile net loss to net cash used
in operating activities:
  Amortization of guarantee warrants, debt discount and issuance costs     5,877        4,297
  Depreciation and amortization                                           24,220       21,020
  Equity in loss from AMRC                                                   341           --
  Amortization of interest rate swap                                       1,491           --
  Changes in assets and liabilities:
     Inventory                                                             1,889       (7,426)
     Prepaid in-orbit insurance                                            2,571        3,387
     Trade accounts receivable                                             1,941       (2,142)
     Other current assets                                                     67        5,565
     Accounts payable and accrued expenses                                 1,245       (8,558)
     Deferred trade payables                                              (7,680)          --
     Deferred items - net                                                   (124)         285
                                                                        ---------    ---------
Net cash used in operating activities                                    (32,367)     (37,495)

CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to property and equipment                                       (5,558)      (5,804)
Acquisition of ARDIS                                                     (51,440)          --
Purchase of long-term, restricted cash securities                       (141,899)          --
Investment in AMRC                                                            --       (1,500)
                                                                       ----------    ---------
Net cash used in investing activities                                   (198,897)      (7,304)

CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of Common Stock                                       236          141
Principal payments under capital leases                                   (1,234)      (1,882)
Proceeds from Bank Financing                                              24,000           --
Repayment of Bank Financing                                             (100,000)          --
Proceeds from bridge financing                                            10,000           --
Repayment of bridge financing                                            (10,000)          --
Proceeds from Senior Notes and Warrants                                  335,000           --
Payments on long-term debt                                                (4,933)      (5,225)
Proceeds from long-term debt                                                  --       53,000
Debt issuance costs                                                      (14,967)        (611)
                                                                         --------      -------
Net cash provided by financing activities                                238,102       45,423

Net increase (decrease) in cash and cash equivalents                       6,838          624

CASH AND CASH EQUIVALENTS, beginning of period                             2,106        2,182
                                                                          ------       ------  


CASH AND CASH EQUIVALENTS, end of period                                  $8,944       $2,806
                                                                          ======       ======


See notes to consolidated financial statements.









                          PART I-FINANCIAL INFORMATION

                    Item 1. Financial Statements (continued)
             AMERICAN MOBILE SATELLITE CORPORATION AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

                                  June 30, 1998
                                   (Unaudited)


1. Organization and Business
   -------------------------

American Mobile Satellite Corporation (with its subsidiaries,  "American Mobile"
or the  "Company")  was  incorporated  on May 3, 1988,  by eight of the  initial
applicants for the mobile satellite services license,  following a determination
by the Federal Communications  Commission ("FCC") that the public interest would
be best served by granting the license to a consortium of all willing, qualified
applicants.  The FCC has authorized  American Mobile to construct,  launch,  and
operate a mobile satellite services system (the "Satellite Network ") to provide
a full range of mobile voice and data  services via  satellite to land,  air and
sea-based  customers  in a service area  consisting  of the  continental  United
States,  Alaska,  Hawaii,  Puerto Rico, the U.S.  Virgin Islands,  U.S.  coastal
waters,  international  waters and airspace and any foreign  territory where the
local  government  has  authorized  the  provision  of  service.  In March 1991,
American Mobile Satellite Corporation  transferred the mobile satellite services
license ("MSS license") to a wholly owned subsidiary, American Mobile Subsidiary
Corporation  ("AMSC  Subsidiary").  On April 7, 1995,  the Company  successfully
launched its first satellite ("MSAT-2"), from Cape Canaveral, Florida.

On  March  31,  1998  the  Company  (through  its   newly-formed,   wholly-owned
subsidiary,  AMSC Acquisition Company,  Inc.  ("Acquisition  Company")) acquired
ARDIS Company  ("ARDIS"),  a wholly-owned  subsidiary of Motorola Inc. that owns
and operates a two-way  wireless  data  communications  network,  for a purchase
price of  approximately  $50  million in cash and $50  million in the  Company's
Common Stock and  warrants  (the  "Purchase  Price").  The Company,  through the
acquisition of ARDIS,  becomes a nationwide provider of wireless  communications
services,  including data, dispatch,  and voice services,  primarily to business
customers in the United States.

On October 16, 1997,  American Mobile Radio Corporation,  an indirect subsidiary
of American  Mobile through its subsidiary  AMRC Holdings,  Inc.  (together with
American Mobile Radio Corporation,  "AMRC"), was awarded a license by the FCC to
provide  satellite-based  Digital Audio Radio Service  ("DARS")  throughout  the
United States, following its successful $89.9 million bid at auction on April 2,
1997.  AMRC has and will  continue to receive  funding for this business from an
independent  source  in  exchange  for  debt  and an  equity  interest  in AMRC.
Accordingly,  it is not expected that the development of this business will have
a material impact on the Company's financial position, results of operations, or
cash flows.

American Mobile is devoting its efforts to expanding a developing business. This
effort involves  substantial risk,  including  successfully  integrating  ARDIS.
Specifically,  future operating results will be subject to significant business,
economic,    regulatory,    technical,   and   competitive   uncertainties   and
contingencies. Depending on their extent and timing, these factors, individually
or in the  aggregate,  could have an adverse  effect on the Company's  financial
condition and future results of operations.









2.  Significant Accounting Policies
    -------------------------------

Basis of Presentation
The unaudited  consolidated  condensed financial statements included herein have
been  prepared  pursuant  to the rules and  regulations  of the  Securities  and
Exchange  Commission.  Certain  information  and footnote  disclosures  normally
included in financial  statements prepared in accordance with generally accepted
accounting principles have been condensed or omitted. While the Company believes
that the  disclosures  made are adequate to make the information not misleading,
these consolidated  financial  statements should be read in conjunction with the
consolidated  financial  statements  and related notes included in the Company's
1997 Annual Report on Form 10-K

The  consolidated  balance  sheet  as of June  30,  1998,  and the  consolidated
statements of loss and cash flows for the three months and six months ended June
30,  1998 and 1997,  have been  prepared by the Company  without  audit.  In the
opinion  of  management,   all  adjustments   (consisting  of  normal  recurring
adjustments)  necessary  to present  fairly the  financial  position,  result of
operations and cash flows at June 30, 1998,  and for all periods  presented have
been  made.  The  balance  sheet at  December  31,  1997 has been taken from the
audited financial statements.


Acquisition
- -----------

The Company acquired ARDIS for a purchase price of approximately  $50 million in
cash and $50  million in the  Company's  Common  Stock (the  "Purchase  Price").
Approximately  1.5  million  of  the  shares  that  were  issuable  to  Motorola
(representing  approximately  $11.5 million) were  contingent  upon  stockholder
approval at the May 20, 1998 annual meeting of  shareholders.  Such approval was
duly received and the remaining shares issued. The purchase method of accounting
for business  combinations  was used for the recording of the  acquisition.  The
operating results of ARDIS have only been included in the Company's consolidated
statements  of loss  from the date of  acquisition.  The  Company's  preliminary
estimate of the excess of the  purchase  price over the fair market value of net
assets  acquired  is  $54.3  million.  The  Company  has  not  yet  specifically
identified amounts to assign to certain intangibles and licenses; changes in the
amounts  allocated  to such  assets  could  result in  changes  to the amount of
goodwill recorded.  A preliminary  amortization  period of twenty years has been
selected, which is expected in all material respects to be representative of the
amortization  expense  that will  result  from the  ultimate  allocation  to the
specific intangible assets.

The  unaudited pro forma  results give effect to (i) the  Acquisition,  (ii) the
Offering  and  (iii) the New Bank  Financing  as if such  transactions  had been
consummated on January 1 of each of the periods presented.




                                                      Six Months Ended
                                                           June 30,
(dollars in thousands, except per share data)        1998           1997
                                                     ----           ----

                                                           
Revenues                                           $42,364        $41,239
Net loss                                          ($77,812)      ($81,770)
Loss per share                                      ($2.45)        ($2.58)
Weighted-average shares outstanding                 31,708         31,636



Net Loss Per Share
- ------------------

Basic and diluted loss per common share is based on the weighted-average  number
of shares of Common  Stock  outstanding  during the  period.  Stock  options and
common stock  purchase  warrants are not  reflected  since their effect would be
antidilutive.

Recently Adopted Accounting Pronouncements
- ------------------------------------------

In June 1997, the Financial Accounting Standards Board ("FASB") issued Statement
of Financial  Accounting  Standards ("SFAS") No. 130,  "Reporting  Comprehensive
Income," and SFAS No. 131,  "Disclosures  about  Segments of an  Enterprise  and
Related Information." The Company adopted both of these standards during the six
month period ended June 30, 1998.





SFAS No.  130  requires  "comprehensive  income"  and the  components  of "other
comprehensive  income" to be reported in the financial  statements  and/or notes
thereto.  Since the Company does not have any components of "other comprehensive
income," reported net income is the same as "total comprehensive income" for the
three months and six months ended June 30, 1997 and 1998.

SFAS  No.  131  requires  an  entity  to  disclose   financial  and  descriptive
information  about  its  reportable  operating  segments.  It  also  establishes
standards for related disclosures about products and services, geographic areas,
and  major  customers.  SFAS  No.  131 is not  required  for  interim  financial
reporting  purposes  during 1998. The Company is in the process of assessing the
additional disclosures, if any, required by SFAS No. 131. However, such adoption
will not impact the Company's results of operations or financial position, since
it relates only to disclosures.

Other
- -----

The Company paid  approximately  $9.4 million and $1.6 million in the  six-month
periods  ended June 30,  1998 and 1997,  respectively,  to related  parties  for
capital  assets,  service-related  obligations,  and  payments  under  financing
agreements.  Payments  from  related  parties  for  communication  services  and
equipment  purchases totaled $2.5 million in the six-month period ended June 30,
1998 and $1.2  million  in  the  six-month  period  ended June 30,  1997.  Total
indebtedness to related parties as of June 30, 1998 approximated $1.3 million.

3.  Liquidity and Financing
    -----------------------

$335 Million Unit Offering
- --------------------------

In connection with the acquisition of ARDIS, discussed above, the Company issued
$335 million of Units (the "Units")  consisting of 12 1/4% Senior Notes due 2008
(the "Notes"),  and Warrants to purchase  shares of Common Stock of the Company.
Each Unit  consists  of $1,000  principal  amount  of Notes and one  Warrant  to
purchase  3.75749  shares of Common  Stock at an  exercise  price of $12.51  per
share.  A value of $8.5 million was assigned to the Warrants and is reflected in
the balance sheet as a debt discount.  A portion of the net proceeds of the sale
of the Units were used to finance the Acquisition. In connection with the Notes,
the Company has purchased  approximately  $112.3  million of pledged  securities
that are intended to provide for the payment of the first six interest  payments
on the Notes. The Company incurred approximately $15 million in costs associated
with the placement of the Notes and the Acquisition.

Interest payments are due semi-annually, in arrears, beginning October 1, 1998.

Acquisition  Company  consummated  its  offer  to  exchange  up to $335  million
aggregate  principal  amount of its  registered 12 1/4 percent Senior Notes (due
2008,  Series B) (the "New Notes") for  outstanding  unregistered 12 1/4 percent
Senior Notes (due 2008,  Series A) (the "Old  Notes").  The exchange  expired at
5:00 p.m. (New York City time) on Friday,  August 7, 1998.  Holders tendered for
exchange $334.75 million  aggregate  principal amount of the Old Notes as of the
expiration of the offer. The Old Notes tendered for exchange  constituted 99.93%
of the Old Notes outstanding.

The Notes  contain  covenants  that,  among other  things,  limit the ability of
Acquisition Company, Inc. and its Subsidiaries to incur additional indebtedness,
pay  dividends  or make other  distributions,  repurchase  any capital  stock or
subordinated indebtedness, make certain investments, create certain liens, enter
into certain  transactions  with  affiliates,  sell  assets,  enter into certain
mergers and consolidations, and enter into sale and leaseback transactions.


New Bank Financing
- ------------------

In connection with the Acquisition, the Company, the Acquisition Company and its
subsidiaries  restructured  the existing $200 million Bank  Financing (the "Bank
Financing") to provide for two facilities:  (i) the Revolving Credit Facility, a
$100 million unsecured  five-year reducing  revolving credit facility,  and (ii)
the Term Loan Facility, a $100 million five-year,  term loan facility with up to
three  additional  one-year  extensions  subject to the lenders'  approval.  The
Revolving Credit Facility bears an interest rate, generally,  of 50 basis points
above  LIBOR and is  unsecured,  with a  negative  pledge  on the  assets of the
Acquisition Company and its subsidiaries  ranking pari passu with the Notes. The
Revolving  Credit  Facility will be reduced $10 million each quarter,  beginning
with the quarter ending June 30, 2002, with the balance due on maturity of March
31, 2003.  Borrowings under the Revolving Credit Facility are subject to certain
conditions  beginning in the fourth quarter of 1998. In the event the Company is
unable to borrow amounts under the Revolving Credit Facility, the Company's cash
needs will  significantly  exceed its  available  resources,  which would have a
material adverse effect on the Company. The revolving Credit Facility ranks pari
passu with the  Notes.  The Term Loan  Facility  is secured by the assets of the
Company,  principally its stockholdings in AMRC and the Acquisition Company, and






will be effectively subordinated to the Revolving Credit Facility and the Notes.
The New Bank Financing is severally guaranteed by Hughes Electronics Corporation
("Hughes"),  Singapore  Telecommunications  Ltd. ("Singapore Telecom") and Baron
Capital  Partners,  L.P. (the "Bank Facility  Guarantors").  In exchange for the
additional risks  undertaken by the Bank Facility  Guarantors in connection with
the New Bank  Financing,  the Company  agreed to  compensate  the Bank  Facility
Guarantors,  principally  in the  form  of 1  million  additional  warrants  and
re-pricing of 5.5 million warrants  previously issued (together,  the "Guarantee
Warrants").  The Guarantee  Warrants  have an exercise  price of $12.51 and have
been valued at approximately $17.7 million. As of July 31, 1998, the Company had
outstanding borrowings of $100 million of the Term Loan Facility at 6.1875%, and
$27 million under the Revolving Credit Facility at 6.1875%.

In connection with the New Bank Financing,  the Company entered into an interest
rate swap  agreement,  with an implied annual rate of 6.51%.  The swap agreement
reduces the impact of interest  rate  increases on the Term Loan  Facility.  The
Company paid a fee of approximately $17.9 million for the swap agreement.  Under
the swap  agreement,  the Company  will receive an amount equal to LIBOR plus 50
basis points,  paid on a quarterly  basis,  on a notional amount of $100 million
until the  termination  date of March 31, 2001.  The Company has reflected as an
asset  the  unamortized  fee  paid for the swap  agreement  in the  accompanying
financial  statements.  The  Company is exposed to a credit loss in the event of
non performance by the counter party under the swap agreement.  The Company does
not believe there is a significant  risk of non performance as the counter party
to the swap agreement is a major financial institution.


Motorola Vendor Financing
- -------------------------

Motorola has entered into an agreement with a subsidiary of Acquisition Company,
the ARDIS Company, to provide up to $10 million of vendor financing (the "Vendor
Financing  Commitment"),  which  will be  available  to finance up to 75% of the
purchase price of additional  network base  stations.  Loans under this facility
will bear  interest at a rate equal to LIBOR plus 7.0% and will be guaranteed by
the Company and each  subsidiary of the  Acquisition  Company.  The terms of the
facility  require that amounts  borrowed be secured by the  equipment  purchased
therewith. No amounts were outstanding under this facility as of July 31, 1998.

Financing Summary
- -----------------

The Company  believes the proceeds  from the issuance of the Notes,  net of cash
used for the  Acquisition,  together  with  the  borrowings  under  the New Bank
Financing  and the  Vendor  Financing  Commitment,  will be  sufficient  to fund
operating losses, capital expenditures, working capital, and scheduled principal
and interest payments on debt through 1998 and beyond;  however, there can be no
assurance  that the Company's  current  projections  regarding the timing of its
ability to achieve positive  operating cash flow will be accurate,  and that the
Company will not need additional financing in the future.

AMRC
- ----

As previously  mentioned (see  "Organization and Business"),  AMRC was a winning
bidder for, and on October 16, 1997,  was awarded an FCC license to provide DARS
throughout the United States.  AMRC has and will continue to receive funding for
this  business  from an  independent  source in exchange  for debt and an equity
interest in AMRC.  Accordingly,  it is not expected that the development of this
business  will have a  material  impact  on the  Company's  financial  position,
results of operations, or cash flows. The Company's equity interest in AMRC may,
however, even on a fully diluted basis, become a material asset of the Company.

Summarized unaudited financial information for AMRC as of June 30, 1998, and for
the six month  periods  ended June 30,  1998 and 1997,  and for the period  from
December 15, 1992 (date of inception) through June 30, 1998 is set forth below.











                                                                                December 15, 1992
                                                      Six Months                     through
dollars in thousands                                Ended June 30,                   June 30,
                                                    --------------                   --------
                                                     (unaudited)                   (unaudited)

                                                 1998            1997                  1998
                                                 ----            ----                  ----
                                                                               
Gross sales                                    $   --          $   --                $   --
Operating expenses                              8,132              51                 9,242
Loss from operations                            8,132              51                 9,242
Interest expense                                 ----             219                   549
Net loss                                        8,132             270                 9,791






                                                                                      As of
                                                            As of June 30,         December 31,
                                                                 1998                  1997
                                                                 ----                  ----
                                                              (unaudited)           (unaudited)

                                                                                  
Current assets                                               $    598               $    --
Noncurrent assets                                             114,929                91,933
Current liabilities                                           108,584                82,949
Noncurrent liabilities                                          6,091                    --
Total stockholders' equity                                        852                 8,983




Deferred Trade Payables
- -----------------------

In the last quarter of 1997 and the first quarter of 1998, the Company  arranged
the financing of certain trade  payables,  and as of June 30, 1998, $4.0 million
of deferred trade  payables were  outstanding at rates ranging from 6.23% to 12%
and are generally payable by the end of 1998.

Purchase and Lease Agreement
- ----------------------------

As  previously  disclosed,  the Company has entered into certain  agreements  to
acquire a one-half ownership interest in TMI Communications and Company, Limited
Partnership's ("TMI") satellite, MSAT-1, at a cost of $60 million payable over a
five-year  period,  as well as entered into a five-year  lease of the  Company's
satellite,  MSAT-2,  with  African  Continental   Telecommunications  Ltd.  that
provides for aggregate lease payments to the Company of $182.5 million.  Closing
under  the  agreements  is  subject  to a number  of  conditions,  including:  a
successful financing by ACTEL of at least $120 million and completion of certain
satellite testing, inversion and relocation activities with respect to AMSC-1.
 It is anticipated that the closing under both the purchase and lease agreements
will occur simultaneously in the third quarter of 1998.

Other
- -----

On July 2, 1998,  American  Mobile filed an application  for authority to launch
and operate its  second-generation  mobile satellite  system.  This satellite is
intended to support the Company's existing satellite services and also allow the
provision of an expanded  array of services,  such as higher data rate  services
and services to  lower-power  terminals.  There can be no assurance that the FCC
will grant this  application.  If the Company  proceeds with  deployment of this
second-generation  satellite  system,  the  Company  would be  required to raise
substantial additional capital to finance this project.








4. Legal and Regulatory Matters
   ----------------------------

Like other mobile  service  providers in the  telecommunications  industry,  the
Company is subject to substantial domestic, foreign and international regulation
including the need for regulatory  approvals to operate and expand the Satellite
Network and operate and modify subscriber equipment.

The  ownership  and  operation  of  American  Mobile's  MSS  system  and  ARDIS'
ground-based  two-way  wireless  data  system  are  subject  to  the  rules  and
regulations of the FCC, which acts under authority granted by the Communications
Act and related federal laws. Among other things,  the FCC allocates portions of
the radio  frequency  spectrum to certain  services  and grants  licenses to and
regulates  individual  entities  using the spectrum.  American  Mobile and ARDIS
operate pursuant to various licenses granted by the FCC.

The  successful  operation of the Satellite  Network is dependent on a number of
factors,  including the amount of L-band  spectrum made available to the Company
pursuant  to  an  international  coordination  process.  The  United  States  is
currently  engaged in an  international  process of  coordinating  the Company's
access to the  spectrum  that the FCC has  assigned  to the  Company.  While the
Company  believes that  substantial  progress has been made in the  coordination
process and expects that the United  States  government  will be  successful  in
securing the necessary spectrum,  the process is not yet complete. The inability
of the United States  government  to secure  sufficient  spectrum  could have an
adverse effect on the Company's  financial  position,  results of operations and
cash flows.

The Company has the necessary regulatory  approvals,  some of which are pursuant
to  special  temporary  authority,  to  continue  its  operations  as  currently
contemplated.  The  Company has filed  applications  with the FCC and expects to
file applications in the future with respect to the continued operations, change
in  operation  and  expansion  of the Network and  certain  types of  subscriber
equipment.  Certain of its  applications  pertaining to future service have been
opposed.  While the Company, for various reasons,  believes that it will receive
the necessary  approvals on a timely basis,  there can be no assurance  that the
requests  will be granted,  will be granted on a timely basis or will be granted
on  conditions  favorable  to  the  Company.  Any  significant  changes  to  the
applications resulting from the FCC's review process or any significant delay in
their approval could adversely affect the Company's financial position,  results
of operations and cash flows.

There are applications now pending before the FCC to use the Inmarsat system and
TMI's Canadian-licensed system, both of which operate in the MSS L-band and have
satellite  footprints  covering  the United  States,  to provide  service in the
United  States.  American  Mobile has  opposed  these  filings.  In  addition to
providing  additional  competition  to  American  Mobile,  a grant  of  domestic
authority by the FCC to use any of these foreign systems may increase the demand
by these  systems for  spectrum in the  international  coordination  process and
could  adversely  affect  American  Mobile's  ability to coordinate its spectrum
access.

On July 20, 1998, the International Bureau of the FCC granted an application for
Special  Temporary  Authority to use TMI's space segment to conduct market tests
in the U.S. for the next six months using up to 500 mobile  terminals.  American
Mobile  has  asked the full  Commission  to review  this  decision  and stay the
effectiveness of the temporary authorization. There can be no assurance that the
FCC will stay the  effectiveness  of this decision or rescind the  International
Bureau's grant of Special Temporary Authority.

American Mobile is authorized to build, launch, and operate three geosynchronous
satellites in accordance  with a specific  schedule.  American  Mobile is not in
compliance with the schedule for commencement and construction of its second and
third satellites and has petitioned the FCC for changes to the schedule. Certain
of these extension requests have been opposed by third parties.  The FCC has not
acted on American  Mobile's  requests.  The FCC has the  authority to revoke the
authorizations  for the second and third  satellites and in connection with such
revocation  could exercise its authority to rescind American  Mobile's  license.
American  Mobile  believes  that the  exercise of such  authority to rescind the
license is unlikely. The term of the license for each of American Mobile's three
authorized  satellites is ten years,  beginning when American  Mobile  certifies
that the respective  satellite is operating in compliance with American Mobile's
license.  The ten-year term of MSAT-2 began August 21, 1995.  Although  American
Mobile  anticipates that the authorization to MSAT-2 is likely to be extended in
due course to  correspond  to the useful life of the satellite and a new license
granted for any replacement satellites,  there is no assurance of such extension
or grants.







On July 2, 1998,  American  Mobile filed an application  for authority to launch
and operate its  second-generation  mobile satellite  system.  This satellite is
intended to support the Company's  existing  satellite services and, also, allow
the  provision  of an  extended  array of  services,  such as  higher  data rate
services and services to lower-power  terminals.  There is no guarantee that the
FCC will grant this  application.  The filing of the application does not commit
the Company to expend any  resources  toward this project;  however,  should the
Company decide to proceed with the construction of the follow-on satellite,  the
Company would be required to raise substantial  additional  capital to fund this
project.

As a provider of interstate telecommunications services, the Company is required
to contribute to the FCC's  universal  service fund for certain of its services,
which supports the provision of  telecommunication  services to high-cost areas,
and  establishes  funding  mechanisms  to support  the  provision  of service to
schools,  libraries  and rural  health care  providers.  The  regulation  became
effective  on January 1, 1998.  This cost generally is not borne by the Company,
but passed on to its customers.

On June 5, 1996,  the FCC  waived  its  one-year  construction  requirement  and
granted ARDIS  extensions  of time to complete  buildouts of  approximately  190
sites,  as  required to  maintain  previously  granted  licenses.  The  extended
construction  deadlines  vary by site until  March 31,  1999.  While  management
believes  that all buildouts  will continue to be completed in a timely  manner,
there can be no  assurances  that  future  delays  will not  occur.  Failure  to
complete the buildouts in a timely manner could result in a loss of licenses for
such sites from the FCC.

In 1992, a former director of American Mobile filed an Amended Complaint against
the Company alleging  violations of the  Communications Act of 1934, as amended,
and of the Sherman Act and breach of  contract.  The suit seeks  damages for not
less than $100 million  trebled under the antitrust laws plus punitive  damages,
interest,  attorneys fees and costs. In mid-1992, the Company filed its response
denying all  allegations.  The Company's motion for summary  judgment,  filed on
March  31,  1994,  was  denied on April 18,  1996.  The trial in this  matter is
currently scheduled for late 1998. Management believes that the ultimate outcome
of this matter will not be material to the Company's financial position, results
of operations or cash flows.


5.  Other Matters
    -------------

At June 30, 1998, the Company had remaining contractual  commitments to purchase
both  mobile data  terminal  inventory  and mobile  telephone  inventory  in the
maximum amount of $3.6 million over the next year. Additionally, the Company had
remaining  contractual  commitments  in the  amount  of  $1.7  million  for  the
development of certain next generation data terminal inventory.  Contingent upon
the  successful  research  and  development  efforts,  the  Company  would  have
additional  contractual  commitments  for mobile  communications  data  terminal
inventory in the amount of $31.2 million over a three-year  period.  The Company
has the right to terminate the research and development and inventory commitment
by paying cancellation fees of between $1 million and $2.5 million, depending on
when the termination option is exercised during the term of the contract.

6.  AMSC Acquisition Company Financial Statements
    ---------------------------------------------

In connection with the Acquisition and related  financing  discussed  above, the
Company formed a new wholly-owned subsidiary, AMSC Acquisition Company, Inc. The
Company  transferred all of its inter-company  notes receivables and its rights,
title and interests in AMSC Subsidiary  Corporation,  American Mobile  Satellite
Sales  Corporation,  and  AMSC  Sales  Corp.  Ltd.  (together  with  ARDIS,  the
"Subsidiaries") to AMSC Acquisition Company, Inc., and AMSC Acquisition Company,
Inc.  was the  acquirer  of ARDIS and the  issuer of the $335  million of Senior
Notes.  American Mobile Satellite  Corporation  ("Parent") is a guarantor of the
Senior Notes. The Senior Notes contain covenants that, among other things, limit
the  ability  of  Acquisition  Company,  Inc.  and  its  Subsidiaries  to  incur
additional indebtedness,  pay dividends or make other distributions,  repurchase
any capital stock or subordinated indebtedness, make certain investments, create
certain liens,  enter into certain  transactions  with affiliates,  sell assets,
enter into certain mergers and consolidations, and enter into sale and leaseback
transactions.

Acquisition Company is a holding company with no material  operations.  It holds
the Senior  Notes and  Revolving  Credit  Facility,  both of which are fully and
unconditionally  guaranteed  on  a  joint  and  several  basis  by  all  of  its
Subsidiaries.






Separate company financial  statements for AMSC Acquisition  Company,  Inc. have
not been  prepared,  as  management  believes  the  differences  between the two
statements  to be  immaterial,  and therefore  not material  information  to the
investors.

Major  differences  between the financial  statements of Parent and  Acquisition
Company include (i) the Term Loan Facility which, as of the  Acquisition,  is an
obligation of Parent and, as such,  the related debt and interest  costs are not
included in the Acquisition  Company financial  statements for the periods ended
and as of June 30, 1998,  as  discussed  in Note 3, and (ii) certain  immaterial
intercompany  management  fees and expenses  between the Parent and  Acquisition
Company are not eliminated at the Acquisition Company level.

The combined condensed financial statements of Acquisition Company are set forth
below.








                         AMSC Acquisition Company, Inc.
                    Consolidated Condensed Statements of Loss
                             (dollars in thousands)
                                   (Unaudited)




                                                          Three Months Ended               Six Months Ended
                                                                June 30,                        June 30,

                                                           1998           1997             1998              1997
                                                          ------         -------          -------        --------


REVENUES

                                                                                                  
       Services                                           $16,670        $4,979            $23,088           $9,132
       Sales of equipment                                   5,740         5,774              9,344           10,306
                                                           ------        ------             ------           ------

       Total Revenues                                      22,410        10,753             32,432           19,438


COSTS AND EXPENSES:

       Cost of service and operations                      16,918         8,201             24,646           17,074
       Cost of equipment sold                               5,415         7,123              9,296           12,565
       Sales and advertising                                4,693         3,042              7,686            6,263
       General and administrative                           5,807         2,858              9,466            7,635
       Depreciation and amortization                       14,457        11,609             25,146           22,072
                                                          -------       -------           --------         --------

       Operating Loss                                     (24,880)      (22,080)           (43,808)         (46,171)


INTEREST AND OTHER  INCOME                                  1,491            86              1,632            1,031
INTEREST EXPENSE                                          (12,793)      (12,650)           (26,619)         (24,272)
                                                          --------      --------           --------         --------


NET LOSS                                                 $(36,182)     $(34,644)          $(68,795)        $(69,412)
                                                         =========     =========          =========        =========




















                         AMSC Acquisition Company, Inc.
                      Consolidated Condensed Balance Sheets
                             (dollars in thousands)
                                   (Unaudited)




                                                                                 June 30,     December 31,
ASSETS                                                                            1998            1997
                                                                                  ----            ----


CURRENT ASSETS:

                                                                                            
   Cash and cash equivalents                                                     $8,944          $2,106
   Inventory                                                                     37,887          40,321
   Accounts receivable-trade, net of allowance for doubtful accounts             13,279           8,140
   Restricted cash-current portion                                               41,038              --
   Prepaid in-orbit insurance                                                     1,993           4,564
   Other current assets                                                          14,638           9,608
                                                                                --------        -------
      Total current assets                                                      117,779          64,739

PROPERTY AND EQUIPMENT - NET                                                    282,422         250,335
GOODWILL AND INTANGIBLE - NET                                                    54,347              --
RESTRICTED CASH - Non-Current                                                    63,157              --
DEFERRED CHARGES AND OTHER ASSETS - NET                                          49,371          36,722
                                                                                --------        -------

       Total assets                                                            $567,076        $351,796
                                                                               =========       =========

LIABILITIES AND STOCKHOLDERS' EQUITY


CURRENT LIABILITIES:

   Accounts payable and accrued expenses                                        $40,644         $35,825
   Obligations under capital leases due within one year                           3,687             798
   Current portion of long-term debt                                              3,006          15,254
   Other current liabilities                                                      7,673           7,520
                                                                                --------        --------
      Total current liabilities                                                  55,010          59,397


DUE TO PARENT                                                                        --         441,836



LONG-TERM LIABILITIES:

   Obligations under Bank Financing                                              22,000         198,000
   Senior Notes, net of discount                                                326,722              --
   Capital lease obligations                                                     10,163           3,147
   Other long-term debt                                                           1,003           1,364
   Net assets acquired in excess of purchase price                                2,376           2,725
   Other long-term liabilities                                                      563             647
                                                                                --------        --------

      Total long-term liabilities                                               362,827         205,883

      Total liabilities                                                         417,837         707,116
                                                                                --------        -------


STOCKHOLDERS' EQUITY                                                            149,239        (355,320)
                                                                                --------       ---------


      Total liabilities and stockholders' equity                               $567,076        $351,796
                                                                               ==========      ========









                         AMSC Acquisition Company, Inc.
                 Consolidated Condensed Statements of Cash Flows
                             (dollars in thousands)
                                   (Unaudited)





                                                                      Six Months Ended
                                                                          June 30,
                                                                ------------------------------
                                                                          1998           1997
                                                                      --------      ---------

CASH FLOWS USED IN OPERATING ACTIVITIES:
                                                                                    
Net loss                                                              $(68,795)       ($69,412)
Adjustments to reconcile net loss to net cash used in
operating activities:
             Amortization of debt discount                               5,318           4,297
             Depreciation and amortization                              24,747          22,072
             Changes in assets and liabilities:
                 Inventory                                               1,889          (7,426)
                 Prepaid in-orbit insurance                              2,571           3,387
                 Trade accounts receivable                               1,941          (2,142)
                 Other current assets                                      (48)          5,565
                 Accounts payable and accrued expenses                   1,201          (8,536)
                 Deferred trade payables                                (7,680)             --
                 Deferred items - net                                     (124)            305
                                                                          -----         -------

Net cash used in operating activities                                  (38,980)        (51,890)


CASH FLOWS USED IN INVESTING ACTIVITIES:

Additions to property and equipment                                     (5,558)         (5,804)
Acquisition of ARDIS                                                   (51,440)             --
Purchase of long-term restricted cash securities                      (113,747)             --
                                                                      ---------        -------

Net cash used in investing activities                                 (170,745)         (5,804)

CASH FLOWS FROM FINANCING ACTIVITIES:

Funding (to) from Parent                                               (21,303)         13,035
Principal payments under capital leases                                 (1,234)         (1,882)
Proceeds from Bank Financing                                            24,000          53,000
Repayment of Bank Financing                                           (100,000)             --
Proceeds from bridge financing                                          10,000              --
Repayment of bridge financing                                          (10,000)             --
Proceeds from Senior Notes                                             335,000              --
Payments on long-term debt                                              (4,933)         (5,225)
Debt issuance costs                                                    (14,967)           (611)
                                                                       --------         -------

Net cash provided by  financing activities                             216,563          58,317

Net increase (decrease) in cash and cash equivalents                     6,838             623

CASH AND CASH EQUIVALENTS, beginning of period                           2,106           2,182
                                                                         ------         ------
CASH AND CASH EQUIVALENTS, end of period                                $8,944          $2,805
                                                                        =======         ======











                           PART I-FINANCIAL STATEMENTS

                 Item 2. Management's Discussion and Analysis of
              Interim Financial Condition and Results of Operations

This Quarterly Report on Form 10-Q includes "forward-looking  statements" within
the meaning of Section 27A of the  Securities Act of 1933 and Section 21E of the
Securities  Exchange Act of 1934.  Such  statements are identified by the use of
forward-looking  words or phrases  including,  but not limited  to,  "believes,"
"intended,"   "will  be   positioned,"   "expects,"   "expected,"   "estimates,"
"anticipates" and "anticipated." These  forward-looking  statements are based on
the Company's  current  expectations.  All statements  other than  statements of
historical  facts included in this Annual Report,  including those regarding the
Company's financial position,  business strategy,  projected costs and financing
needs,  and plans and  objectives  of  management  for  future  operations,  are
forward-looking statements.  Although the Company believes that the expectations
reflected in such  forward-looking  statements are  reasonable,  there can be no
assurance  that  such  expectations  will  prove to have been  correct.  Because
forward-looking statements involve risks and uncertainties, the Company's actual
results  could  differ  materially.  Important  factors  that could cause actual
results  to  differ  materially  from the  Company's  expectations  ("Cautionary
Statements")  are disclosed under  "Business" and  "Management's  Discussion and
Analysis of Financial  Condition  and Results of  Operations,"  and elsewhere in
this  Form  10-Q,  including,   without  limitation,  in  conjunction  with  the
forward-looking  statements  included in this Form 10-Q.  These  forward-looking
statements  represent the  Company's  judgment as of the date hereof and readers
are cautioned not to place undue reliance on these  forward-looking  statements.
All subsequent written and oral forward-looking  statements  attributable to the
Company or persons  acting on behalf of the Company are  expressly  qualified in
their entirety by the Cautionary Statements. Readers should carefully review the
risk factors  described in other  documents  the Company files from time to time
with the  Securities  and Exchange  Commission,  including  the Form 10-K Annual
Report  and  Form  10-Q  Quarterly  Reports  filed by the  Company  prior to and
subsequent to this Form 10-Q  Quarterly  Report and any Current  Reports on Form
8-K and registration statements filed by the Company.


General
- -------

The following  discussion and analysis  provides  information  which  management
believes  is  relevant  to an  assessment  and  understanding  of the  financial
condition and  consolidated  results of operations of American Mobile  Satellite
Corporation  (with its subsidiaries,  "American  Mobile" or the "Company").  The
discussion  should  be read  in  conjunction  with  the  consolidated  financial
statements and notes thereto.

American Mobile  Satellite  Corporation was  incorporated in May 1988 and, until
1996,  was a  development  stage  company,  engaged  primarily  in  the  design,
development,  construction,  deployment  and  financing  of a  mobile  satellite
communication  system.  On March 31, 1998 the Company (through its newly-formed,
wholly-owned subsidiary,  AMSC Acquisition Company, Inc.) acquired ARDIS Company
("ARDIS"),  a wholly-owned  subsidiary of Motorola Inc. that owns and operates a
two-way  wireless  data  communications   network,   for  a  purchase  price  of
approximately  $50 million in cash and $50 million in the Company's Common Stock
and warrants (the "Purchase Price").  With the acquisition of ARDIS, the Company
becomes a leading  provider  of  nationwide  wireless  communications  services,
including data, dispatch and voice services,  primarily to business customers in
the United  States.  The  Company  offers a broad range of  end-to-end  wireless
solutions utilizing a seamless network consisting of the nation's largest,  most
fully-deployed  terrestrial  wireless  data network (the "ARDIS  Network") and a
satellite  in  geosynchronous  orbit  (the  "Satellite  Network")(together,  the
"Network").

In connection with the  Acquisition,  the Company and its  subsidiaries  entered
into agreements with respect to the following  financings and refinancings:  (1)
$335  million of Units;  (2) the  restructuring  of its  existing  $200  million
Revolving  Credit Facility and Term Loan Facility  (collectively,  the "New Bank
Financings");  and (3) $10 million  commitment  with respect to Motorola  vendor
financing.  See "Management's Discussion and Analysis of Financial Condition and
Results of  Operations  - Liquidity  and Capital  Resources."  Additionally,  in
connection with the Acquisition and related financing,  the Company  transferred
all of its rights, title and interests in AMSC Subsidiary Corporation,  American
Mobile  Satellite  Sales  Corporation,  and AMSC  Sales  Corp.  Ltd.  (together,
"American Mobile Subsidiaries") to Acquisition Company.







On October 16, 1997,  American Mobile Radio Corporation,  an indirect subsidiary
of American  Mobile through its subsidiary  AMRC Holdings,  Inc.  (together with
American Mobile Radio Corporation,  "AMRC"), was awarded a license by the FCC to
provide  satellite-based  Digital Audio Radio Service  ("DARS")  throughout  the
United States, following its successful $89.9 million bid at auction on April 2,
1997. The  operations  and financing of AMRC are  maintained  separate and apart
from the  operations  and  financing  of  American  Mobile (see  "Liquidity  and
Financing").

Management  believes the period to period comparison of the Company's  financial
results  are not  necessarily  meaningful  and should  not be relied  upon as an
indication of future  operating  performance  due to the Company's  historically
high growth rate and the acquisition of ARDIS.


Overview
- --------

Each of American  Mobile and ARDIS  incurred  significant  operating  losses and
negative cash flows in each year since it commenced operations, due primarily to
start-up  costs,  the costs of developing and building each network and the cost
of developing,  selling and providing its respective products and services.  The
Company is, and will continue to be, highly leveraged.  As of June 30, 1998, the
Company had indebtedness of approximately $466.6 million.

The Company's future operating  results could be adversely  affected by a number
of uncertainties and factors, including (i) the timely completion and deployment
of  future  products  and  related  services,   including  among  other  things,
availability of mobile telephones, data terminals and other equipment to be used
with the Network  ("Subscriber  Equipment") being  manufactured by third parties
over which the Company has limited control,  (ii) the market's acceptance of the
Company's  services,  (iii) the  ability  and the  commitment  of the  Company's
distribution channels to market and distribute the Company's services,  (iv) the
Company's  ability to modify  its  organization,  strategy  and  product  mix to
maximize the market  opportunities in light of changes therein,  (v) competition
from existing  companies that provide  services  using  existing  communications
technologies  and the  possibility  of  competition  from  companies  using  new
technology  in  the  future,   (vi)  capacity   constraints   arising  from  the
reconfiguration of MSAT-2,  subsequent anomalies affecting MSAT-2 and MSAT-1, or
the power management  recommendation affecting both MSAT-2 and MSAT-1 previously
reported,  (vii)  additional  technical  anomalies  that may  occur  within  the
Satellite  Network,  including those relating to MSAT-1 and MSAT-2,  which could
impact, among other things, the operation of the Satellite Network and the cost,
scope  or  availability  of  in-orbit  insurance,  (viii)  subscriber  equipment
inventory  responsibilities and liabilities assumed by the Company including the
ability of the Company to realize the value of its inventory in a timely manner,
(ix) the Company's ability to secure  additional  financing as may be necessary,
(x) the  Company's  ability to respond and react to changes in its  business and
the  industry  as a result of being  highly  leveraged,  (xi) the ability of the
Company  to  successfully  integrate  ARDIS  and  to  achieve  certain  business
synergies, and (xii) the ability of the Company to manage growth effectively.

As of June 30, 1998, there were approximately 91,700 units on the Network.


Quarter Ended June 30, 1998 and 1997
- ------------------------------------

Service  revenues,  which  include both the Company's  voice and data  services,
approximated  $16.7 million and $23.1 million for the  three-month and six-month
periods ended June 30, 1998,  respectively,  which  constitutes an $11.7 million
and $14.0 million increase over the three-month and six-month periods ended June
30, 1997,  respectively.  The significant increase in service revenues year over
year is primarily  attributable to the income of the ARDIS data service.  Absent
the acquisition of ARDIS on March 31, 1998, service revenues for the three-month
and six-month  period ended June 30, 1998,  respectively,  increased 36% and 44%
year to year,  from $5.0  million and $9.1  million for the three and  six-month
periods ended June 10, 1997, to $6.7 million and $13.2 million for the three and
six-month periods ended June 30, 1998, respectively.  Service revenue from voice
services  increased 39% and 54% from approximately $2.4 million and $4.3 million
in the second quarter and  six-months of 1997,  respectively,  to  approximately
$3.5 million and $6.7 million in the  comparable  periods of 1998. The increases
were  primarily a result of a 54% increase in voice  customers  during the first
half of 1998 as compared to the same period in 1997.  Service  revenue  from the
Company's  data  services  approximated  $12.3 million and $14.5 million for the
three-month and six-month periods ended June 30, 1998, respectively, as compared
to $1.9 million and $3.5 million for the comparable  periods of 1997. The dollar
increases  of $10.4  million and $11.0  million are  primarily a result of a 33%
increase  in mobile  data units  during the first half of 1998 and $9.9  million







from the ARDIS data service. Service revenue from capacity resellers, who handle
both voice and data  services,  approximated  $852,000 in the second  quarter of
1998 and $1.6 million for the  six-months  ended June 30,  1998,  as compared to
$608,000 and $1.1 million for the same periods of 1997,  an increase of $244,000
and $531,000, or 40% and 47%, respectively.

Revenue from the sale of mobile data terminals and mobile  telephones  decreased
10% from $10.3  million  in the first half of 1997 to $9.3  million in the first
half of 1998 and,  similarly,  by 2% from $5.8  million  to $5.7  million in the
second  quarter  of 1997 and 1998,  respectively.  The  decrease  was  primarily
attributable  to  reduced  sales of voice  products,  as well as  certain  price
reductions  made in the first  quarter of 1998.  ARDIS  equipment  sales for the
second quarter were $384,000.

Cost of service and operations  for the  three-months  and the six-months  ended
June 30, 1998,  which includes costs to support  subscribers  and to operate the
Network,  was $16.9 million and $24.7 million compared to $8.2 million and $17.1
million  for the same  periods of 1997.  Cost of service  and  operations,  as a
percentage  of revenues,  was 76% for the second  quarters of both 1998 and 1997
and 76% and 88% for the first  six-months  of 1998 and 1997,  respectively.  The
increase in cost of service and  operations  was primarily  attributable  to (i)
$9.1 million of ARDIS costs (ii) increased  interconnect charges associated with
increased  service usage offset by (iii) a reduction in  information  technology
costs  affected by reducing the  dependence on outside  consultants.  Absent the
acquisition  of ARDIS on March 31, 1998,  cost of service and operations for the
three-month  and six-month  period ended June 30, 1998,  respectively,  was $7.9
million and $15.6 million, and represented approximately 35% and 48% of revenue,
compared to $8.2 million and $17.1 million for the same periods in 1997.

The cost of equipment sold decreased 24% from $7.1 million for the  three-months
ended June 30, 1997, to $5.4 million for the  three-months  ended June 30, 1998,
and 26% from $12.6 million for the six-month period ended June 30, 1997, to $9.3
million  for the  same  period  in  1998.  The  dollar  decrease  in the cost of
equipment sold was primarily  attributable  to (i) a  corresponding  decrease in
voice equipment sales and (ii) the impact of the inventory  valuation  allowance
recorded in the fourth quarter of 1997.

Sales and  advertising  expenses  were $4.7  million  and $7.7  million  for the
three-months and the six-months ended June 30, 1998,  respectively,  compared to
$3.0  million  and  $6.3  million  for the  same  periods  in  1997.  Sales  and
advertising  expenses as a percentage  of revenue were 21% and 24% in the second
quarter and first half of 1998, respectively,  as compared to 28% and 32% during
the same  periods of 1997.  The increase in sales and  advertising  expenses was
primarily  attributable  to ARDIS.  Absent the acquisition of ARDIS on March 31,
1998,  sales and advertising  expenses for the three-month and six-month  period
ended  June 30,  1998 were $3.2  million  and $6.3  million,  respectively,  and
represented 15% and 20% of revenue,  respectively,  compared to $3.0 million and
$6.3 million, or 28% and 32% of revenue, for the same periods in 1997.

General and  administrative  expenses for the  three-months  and the  six-months
ended June 30, 1998, were $5.8 million and $9.4 million, respectively,  compared
to $2.9 million and $7.8 million in the same periods of 1997. As a percentage of
revenue,  general and  administrative  expenses  represented  26% and 29% in the
second quarter and first half of 1998, respectively,  compared to 27% and 40% in
the same periods of 1997.  The increase in general and  administrative  expenses
for 1998  compared to 1997 was primarily  attributable  to $2.1 million of ARDIS
costs  offset by a  $741,000  reduction  in  personnel  expenses  as a result of
reduced  headcount.  Absent the acquisition of ARDIS on March 31, 1998,  general
and administrative  expenses for the three-month and six-month period ended June
30, 1998 were $3.6 million and $7.3 million, respectively, approximating 16% and
22% of revenue, compared to $2.9 million and $7.8 for the same periods in 1997.

Depreciation  and  amortization  expense was $14.4 million and $24.6 million for
the  three-months  and  the  six-months  ended  June  30,  1998,   respectively,
representing  approximately  65% and 76% of revenue for the respective  periods.
During the same periods of 1997 depreciation and amortization  expense was $11.1
million and $21.0 million,  approximating 103% and 108% of revenue. The increase
in  depreciation  and  amortization  expense was primarily  attributable  to the
addition of ARDIS assets and amortization of goodwill  associated with the ARDIS
acquisition. Absent the acquisition of ARDIS on March 31, 1998, depreciation and
amortization  expense for the  three-month  and six-month  period ended June 30,
1998 was $10.4 million and $20.5 million,  respectively,  approximating  46% and
63% of revenue, compared to $11.1 million and $21.0 million for the same periods
in 1997.

Interest  and other  income was $1.6  million  and $1.7  million  for the second
quarter  and first half of 1998,  respectively,  as compared to $86,000 and $1.0
million for the same periods in 1997.  The  increase  was  primarily a result of
interest  earned on escrows  required  under the terms of the $335  million debt
offering at the end of the first quarter. The Company incurred $15.7 million and
$22.3 million of interest  expense in the second  quarter and first half of 1998







compared to  $5.3 million  and  $9.7  million  for the  same  periods  in  1997,
reflecting (i) the  amortization of debt discount and debt offering costs in the
amount of $5.9 million in 1998, compared to $4.3 million in 1997 and (ii) higher
outstanding loan balances as compared to 1997.

Interest  expense  in the  first  half of 1998 was  significant  as a result  of
borrowings  under  the Bank  Financing,  the  amortization  of  borrowing  costs
incurred in conjunction with securing the facility,  and interest accrual on the
Notes issued in the ARDIS  acquisition . It is  anticipated  that interest costs
will  continue  to be  significant  as a result  of the Bank  Financing,  Bridge
Financing, and Acquisition, (see "Liquidity and Capital Resources").

Net capital expenditures,  for the first half of 1998 for property and equipment
were $5.6 million compared to $5.8 million for the same period in 1997.

Liquidity and Capital Resources
- -------------------------------

$335 Million Unit Offering
- --------------------------

In connection with the  Acquisition,  discussed  above,  the Company issued $335
million of Units (the "Units")  consisting of 12 1/4% Senior Notes due 2008 (the
"Notes"),  and Warrants to purchase shares of Common Stock of the Company.  Each
Unit  consists of $1,000  principal  amount of Notes and one Warrant to purchase
3.75749  shares of Common  Stock at an exercise  price of $12.51 per share.  The
Warrants were valued at $8.5 million and are reflected in the balance sheet as a
debt discount.  A portion of the net proceeds of the sale of the Units were used
to finance  the  Acquisition.  In  connection  with the Notes,  the  Company has
purchased  approximately  $112.3 million of pledged securities that are intended
to provide for the payment of the first six interest  payments on the Notes. The
Company  incurred  approximately  $15  million  in  costs  associated  with  the
placement  of  the  Notes  and  the  Acquisition.   Interest  payments  are  due
semi-annually, in arrears, beginning October 1, 1998.

Acquisition  Company  consummated  its  offer  to  exchange  up to $335  million
aggregate  principal  amount of its  registered 12 1/4 percent Senior Notes (due
2008,  Series B) (the "New Notes") for  outstanding  unregistered 12 1/4 percent
Senior Notes (due 2008,  Series A) (the "Old  Notes").  The exchange  expired at
5:00 p.m. (New York City time) on Friday,  August 7, 1998.  Holders tendered for
exchange $334.75 million  aggregate  principal amount of the Old Notes as of the
expiration of the offer. The Old Notes tendered for exchange  constituted 99.93%
of the Old Notes outstanding.

The Notes  contain  covenants  that,  among other  things,  limit the ability of
Acquisition Company, Inc. and its Subsidiaries to incur additional indebtedness,
pay  dividends  or make other  distributions,  repurchase  any capital  stock or
subordinated indebtedness, make certain investments, create certain liens, enter
into certain  transactions  with  affiliates,  sell  assets,  enter into certain
mergers and consolidations, and enter into sale and leaseback transactions.


New Bank Financing
- ------------------

In connection with the Acquisition, the Company, the Acquisition Company and its
subsidiaries  restructured  the existing $200 million Bank  Financing (the "Bank
Financing") to provide for two facilities:  (i) the Revolving Credit Facility, a
$100 million unsecured  five-year reducing  revolving credit facility,  and (ii)
the Term Loan Facility, a $100 million five-year,  term loan facility with up to
three  additional  one-year  extensions  subject to the lenders'  approval.  The
Revolving Credit Facility bears an interest rate, generally,  of 50 basis points
above  LIBOR and is  unsecured,  with a  negative  pledge  on the  assets of the
Acquisition Company and its subsidiaries  ranking pari passu with the Notes. The
Revolving  Credit  Facility will be reduced $10 million each quarter,  beginning
with the quarter ending June 30, 2002, with the balance due on maturity of March
31, 2003.  Borrowings under the Revolving Credit Facility are subject to certain
conditions  beginning in the fourth quarter of 1998. In the event the Company is
unable to borrow amounts under the Revolving Credit Facility, the Company's cash
needs will  significantly  exceed its  available  resources,  which would have a
material adverse effect on the Company. The revolving Credit Facility ranks pari
passu with the  Notes.  The Term Loan  Facility  is secured by the assets of the
Company,  principally its stockholdings in AMRC and the Acquisition Company, and
will be effectively subordinated to the Revolving Credit Facility and the Notes.
The New Bank Financing is severally guaranteed by Hughes Electronics Corporation
("Hughes"),  Singapore  Telecommunications  Ltd. ("Singapore Telecom") and Baron
Capital  Partners,  L.P. (the "Bank Facility  Guarantors").  In exchange for the
additional risks  undertaken by the Bank Facility  Guarantors in connection with
the New Bank  Financing,  the Company  agreed to  compensate  the Bank  Facility
Guarantors,  principally  in the  form  of 1  million  additional  warrants  and
re-pricing of 5.5 million warrants  previously issued (together,  the "Guarantee
Warrants").  The Guarantee  Warrants  have an exercise  price of $12.51 and have
been valued at approximately $17.7 million. As of July 31, 1998, the Company had
outstanding borrowings of $100 million of the Term Loan Facility at 6.1875%, and
$27 million under the Revolving Credit Facility at 6.1875%.







In connection with the New Bank Financing,  the Company entered into an interest
rate swap  agreement,  with an implied annual rate of 6.51%.  The swap agreement
reduces the impact of interest  rate  increases on the Term Loan  Facility,  and
fixes  The  Company  paid a fee of  approximately  $17.9  million  for the  swap
agreement. Under the swap agreement, the Company will receive an amount equal to
LIBOR plus 50 basis points,  paid on a quarterly  basis, on a notional amount of
$100  million  until the  termination  date of March 31,  2001.  The Company has
reflected  as an asset the  unamortized  fee paid for the swap  agreement in the
accompanying  financial  statements.  The Company is exposed to a credit loss in
the event of non performance by the counter party under the swap agreement.  The
Company does not believe there is a significant  risk of non  performance as the
counter party to the swap agreement is a major financial institution.

Motorola Vendor Financing
- -------------------------

Motorola has entered into an agreement with a subsidiary of Acquisition Company,
the ARDIS Company, to provide up to $10 million of vendor financing (the "Vendor
Financing  Commitment"),  which  will be  available  to finance up to 75% of the
purchase price of additional  network base  stations.  Loans under this facility
will bear  interest at a rate equal to LIBOR plus 7.0% and will be guaranteed by
the Company and each  subsidiary of the  Acquisition  Company.  The terms of the
facility  require that amounts  borrowed be secured by the  equipment  purchased
therewith. No amounts were outstanding under this facility as of July 31, 1998.

Financing Summary
- -----------------

The Company  believes the proceeds  from the issuance of the Notes,  net of cash
used for the  Acquisition,  together  with  the  borrowings  under  the New Bank
Financing  and the  Vendor  Financing  Commitment,  will be  sufficient  to fund
operating losses, capital expenditures, working capital, and scheduled principal
and interest payments on debt through 1998 and beyond;  however, there can be no
assurance  that the Company's  current  projections  regarding the timing of its
ability to achieve positive  operating cash flow will be accurate,  and that the
Company will not need additional financing in the future.

AMRC
- ----

As previously  mentioned (see  "Organization and Business"),  AMRC was a winning
bidder for, and on October 16, 1997,  was awarded an FCC license to provide DARS
throughout the United States.  AMRC has and will continue to receive funding for
this  business  from an  independent  source in exchange  for debt and an equity
interest in AMRC.  Accordingly,  it is not expected that the development of this
business  will have a  material  impact  on the  Company's  financial  position,
results of operations, or cash flows. The Company's equity interest in AMRC may,
however, even on a fully diluted basis, become a material asset of the Company.

Deferred Trade Payables
- -----------------------

In the last quarter of 1997 and the first quarter of 1998, the Company  arranged
the financing of certain trade  payables,  and as of June 30, 1998, $4.0 million
of deferred trade  payables were  outstanding at rates ranging from 6.23% to 12%
and are generally payable by the end of 1998.

Purchase and Lease of Satellite
- -------------------------------

As  previously  disclosed,  the Company has entered into certain  agreements  to
acquire a one-half ownership interest in TMI Communications and Company, Limited
Partnership's ("TMI") satellite, MSAT-1, at a cost of $60 million payable over a
five-year  period,  as well as entered  into  five-year  lease of the  Company's
satellite,  MSAT-2,  with  African  Continental   Telecommunications  Ltd.  that
provides for aggregate lease payments to the Company of $182.5 million.  Closing
under  the  agreements  is  subject  to a number  of  conditions,  including:  a
successful financing by ACTEL of at least $120 million and completion of certain
satellite testing, inversion and relocation activities with respect to AMSC-1.
It is  anticipated that the closing under both the purchase and lease agreements
will occur simultaneously in the third quarter of 1998.

Other
- -----

At June 30, 1998, the Company had remaining contractual  commitments to purchase
both  mobile data  terminal  inventory  and mobile  telephone  inventory  in the
maximum amount of $3.6 million over the next year. Additionally, the Company had
remaining  contractual  commitments  in the  amount  of  $1.7  million  for  the






development of certain next generation data terminal inventory.  Contingent upon
the  successful  research  and  development  efforts,  the  Company  would  have
additional  contractual  commitments  for mobile  communications  data  terminal
inventory in the amount of $31.2 million over a three-year  period.  The Company
has the right to  terminate  this the  research and  development  and  inventory
commitment by paying  cancellation  fees of between $1 million and $2.5 million,
depending on when the  termination  option is  exercised  during the term of the
contract.

On  July  2,  1998,   the  Company  filed  an   application   with  the  Federal
Communications   Commission   ("FCC")  to  construct   and  launch  a  follow-on
geostationary  mobile satellite for its business.  The filing of the application
does not  commit  the  Company  to expend any  resources  toward  this  project;
however,  should the  Company  decide to proceed  with the  construction  of the
follow-on  satellite,  the  Company  would  be  required  to  raise  substantial
additional capital to fund this project.

Cash used in  operating  activities  for the first six  months of 1998 was $32.4
million as compared to $37.5  million for the same period of 1997.  The decrease
in cash used in  operating  activities  was  primarily  attributable  to reduced
inventory spending. Cash used by investing activities was $198.9 million for the
first six months of 1998 compared to $7.3 million during the first six months of
1997. The increase was primarily  attributable  to the  acquisition of ARDIS and
the funding of certain  escrows  required in connection with the Acquisition and
issuance of Notes.  Cash  provided by financing  activities  was $238.1  million
during  the first six months of 1998 as  compared  to $45.4  million  during the
first six months of 1997,  reflecting (i) the proceeds from the Notes, offset by
(ii) the  repayment  of a portion  of the Bank  Financing  and (iii)  payment of
financing fees  associated  with the  acquisition  of the Notes.  As of June 30,
1998,  the Company  had $8.9  million of cash and cash  equivalents  and working
capital of $68.7 million.


Other Matters
- -------------

In June 1997, the Financial Accounting Standards Board ("FASB") issued Statement
of Financial  Accounting  Standards ("SFAS") No. 130,  "Reporting  Comprehensive
Income," and SFAS No. 131,  "Disclosures  about  Segments of an  Enterprise  and
Related Information." The Company adopted both of these standards during the six
month periods ended June 30, 1998.

SFAS No.  130  requires  "comprehensive  income"  and the  components  of "other
comprehensive  income" to be reported in the financial  statements  and/or notes
thereto.  Since the Company does not have any components of "other comprehensive
income," reported net income is the same as "total comprehensive income" for the
three months and six months ended June 30, 1997 and 1998.

SFAS  No.  131  requires  an  entity  to  disclose   financial  and  descriptive
information  about  its  reportable  operating  segments.  It  also  establishes
standards for related disclosures about products and services, geographic areas,
and  major  customers.  SFAS  No.  131 is not  required  for  interim  financial
reporting  purposes  during 1998. The Company is in the process of assessing the
additional disclosures, if any, required by SFAS No. 131. However, such adoption
will not impact the Company's results of operations or financial position, since
it relates only to disclosures.





                           PART II - OTHER INFORMATION

                Item 2. Changes in Securities and Use of Proceeds

The Company  believes the proceeds  from the issuance of the Notes,  net of cash
used for the  Acquisition,  together  with  the  borrowings  under  the New Bank
Financing  and the  Vendor  Financing  Commitment,  will be  sufficient  to fund
operating losses, capital expenditures, working capital, and scheduled principal
and interest payments on debt through 1998 and beyond;  however, there can be no
assurance  that the Company's  current  projections  regarding the timing of its
ability to achieve positive  operating cash flow will be accurate,  and that the
Company will not need additional financing in the future.


                          PART II -- OTHER INFORMATION

           Item 4. Submission of Matters to a Vote of Security Holders

(a) At the annual meeting of the  stockholders of AMSC held on May 20, 1998, the
matters described under (b) and (c) below were voted upon.

(b) The following nominees,  constituting all of the Company's  directors,  were
elected to the Company's board of directors:




                                                     Individual
                                    Votes For        Votes Withheld             Withheld

                                                                             
Douglas I. Brandon                  28,215,889           1,201                  1,163,388
Ho Siaw Hong                        28,216,389             701                  1,162,888
Pradeep P. Kaul                     28,216,389             701                  1,162,888
Billy J. Parrott                    28,216,469             621                  1,162,808
Gary M. Parsons                     28,216,314             776                  1,162,963
Andrew A. Quartner                  28,215,989           1,101                  1,163,288
Jack A. Shaw                        28,216,669             421                  1,162,608
Roderick M. Sherwood, III           27,986,600         230,490                  1,392,677
Michael T. Smith                    28,216,689             401                  1,162,588
Yap Chee Keong                      27,986,265         230,825                  1,393,012


On June 5, 1998 the Company reported on its Report on 8K dated June 1, 1998 that
Mr. Yap had resigned his position as director of the Company in connection  with
his  resignation  of  employment  from  Singapore  Telecommunications,  Ltd.  As
indicated in that Report,  the position  vacated by Mr. Yap remains vacant until
such time as filled by a vote of the Board of Directors or the stockholders.

(c)(1)  The vote on the  ratification  of  Arthur  Andersen  LLP as  independent
accountants  for the Company for 1998 was 29,371,445  for,  7,732  against,  100
abstaining.

     (2) The vote on the approval of an amendment  to the  Company's  1989 Stock
Option  Plan to  increase  the  number of shares  authorized  for  issuance  was
27,587,129 for, 1,787,564 against, 4,584 abstaining.

     (3) The vote on the  approval of the  issuance  of shares of the  Company's
Common  Stock to  Motorola  Inc.  was  22,128,875  for,  28,195  against,  3,220
abstaining  and  7,218,987  not voting  (including  the shares  held by Motorola
Inc.).





                           PART II - OTHER INFORMATION

                            Item 5. Other Information



If the Company does not receive notice at its principal  executive offices on or
before March 13, 1999 of a stockholder  proposal for  consideration  at the 1999
annual  meeting of  stockholders,  the proxies named by the  Company's  Board of
Directors with respect to the meeting shall have discretionary  voting authority
with respect to such proposal.




                           PART II - OTHER INFORMATION

                    Item 6. Exhibits and Reports on Form 8-K

          (a) Exhibits

3.1      -     Restated  Certificate  of  Incorporation  of  AMSC  (as  restated
               effective May 1, 1996)  (Incorporated by reference to Exhibit 3.1
               to the Company's Annual Report on Form 10-K for the period ending
               December 31,1997 (File No. 0-23044))

3.2      -     Amended and  Restated  Bylaws of AMSC (as  amended  and  restated
               effective May 20, 1998) (Incorporated by reference to Exhibit 3.2
               to the  Company's  Annual Report on Form 10-K for the fiscal year
               ending December 31, 1997 (File No. 0-23044))

10.13    -     Amended and Restated Stock Option Plan (as amended  effective May
               20, 1998)  (Incorporated  by  reference  to Exhibit  10.13 to the
               Company's   Registration   Statement   on  Form  S-8  (Reg.   No.
               333-53253))

10.67    -     Credit  Agreement by and between  Motorola Inc. and ARDIS Company
               dated June 17, 1998 (filed herewith)

11.1     -     Computations of Earnings Per Common Share (filed herewith)

27.0     -     Financial Data Schedule (filed herewith)


          (b) Reports on Form 8-K:

On June 5, 1998, the Company filed a Current  Report on Form 8-K,  describing in
response to Item 5-Other Events, the resignation of director Yap Chee Keong.








                                    SIGNATURE

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.

                                    AMERICAN MOBILE SATELLITE CORPORATION
                                                (Registrant)


Date: August 14, 1998               By:/s/Stephen D. Peck
                                       -------------------------------------
                                                 Stephen D. Peck
                                    Vice President and Chief Financial Officer
                                    (principal financial and accounting officer)











                                  EXHIBIT INDEX



Number            Description

3.1      -     Restated  Certificate  of  Incorporation  of  AMSC  (as  restated
               effective May 1, 1996)  (Incorporated by reference to Exhibit 3.1
               to the Company's Annual Report on Form 10-K for the period ending
               December 31,1997 (File No. 0-23044))

3.2      -     Amended and  Restated  Bylaws of AMSC (as  amended  and  restated
               effective May 20, 1998) (Incorporated by reference to Exhibit 3.2
               to the  Company's  Annual Report on Form 10-K for the fiscal year
               ending December 31, 1997 (File No. 0-23044))

10.13    -     Amended and Restated Stock Option Plan (as amended  effective May
               20, 1998)  (Incorporated  by  reference  to Exhibit  10.13 to the
               Company's   Registration   Statement   on  Form  S-8  (Reg.   No.
               333-53253))

10.67    -     Credit  Agreement by and between  Motorola Inc. and ARDIS Company
               dated June 17, 1998 (filed herewith)

11.1     -     Computations of Earnings Per Common Share (filed herewith)

27.0     -     Financial Data Schedule (filed herewith)