EXHIBIT 99.1
 
                           OFFSHORE LOGISTICS, INC.
 
                             LETTER OF TRANSMITTAL
                                      FOR
                               OFFER TO EXCHANGE
                     7 7/8% SERIES B SENIOR NOTES DUE 2008
                              FOR ALL OUTSTANDING
                     7 7/8% SERIES A SENIOR NOTES DUE 2008
 
       THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME,
                    ON           , 1998, UNLESS EXTENDED BY
               OFFSHORE LOGISTICS, INC. (THE "EXPIRATION DATE").
 
                              THE EXCHANGE AGENT
                          FOR THE EXCHANGE OFFER IS:
 
                      STATE STREET BANK AND TRUST COMPANY
 
  By Registered or Certified Mail:            By Hand or Overnight Delivery
                                                        Service:
      Corporate Trust Services
                                                Corporate Trust Services
 
 
 
          By Facsimile Transmission (for Eligible Institutions only):
                                (   )
 
                           (Facsimile Confirmation)
 
                                (   )
 
                                      or
 
                                (   )
 
(Originals of all documents sent by facsimile should be sent promptly by
registered or certified mail, by hand, or by overnight delivery service.)
 
  DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH
ABOVE OR TRANSMISSION OF INSTRUCTIONS VIA A FACSIMILE TRANSMISSION TO A NUMBER
OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY. THE
INSTRUCTIONS CONTAINED HEREIN SHOULD BE READ CAREFULLY BEFORE THIS LETTER OF
TRANSMITTAL IS COMPLETED.
 
  The undersigned hereby acknowledges receipt and review of the Prospectus
dated         , 1998 (the "Prospectus") of Offshore Logistics, Inc., a
Delaware corporation (the "Company"), Air Logistics, L.L.C., a Louisiana
limited liability company, Air Logistics of Alaska, Inc., an Alaska
corporation, Grasso Corporation, a Delaware corporation, Grasso Production
Management, Inc., a Texas corporation, Medic Systems, Inc., a Delaware
corporation, and Pumpkin Air, Inc., a Texas corporation (collectively, the
"Guarantors"), and this Letter of Transmittal (the "Letter of Transmittal"),
which together describe the Company's offer (the "Exchange Offer") to exchange
its 7 7/8% Series B Senior Notes due 2008 (the "New Notes"), which have been
registered under the Securities Act of 1933, as amended (the "Securities
Act"), for a like principal amount of its issued and outstanding 7 7/8% Series
A Senior Notes due 2008 (the "Old Notes"). Capitalized terms used but not
defined herein have the respective meaning given to them in the Prospectus.
 
                                       1

 
  The Company reserves the right, at any time or from time to time, to extend
the Exchange Offer at its discretion, in which event the term "Expiration
Date" shall mean the latest date to which the Exchange Offer is extended. The
Company shall notify the Exchange Agent and each registered holder of the Old
Notes of any extension by oral or written notice prior to 9:00 a.m., New York
City time, on the next business day after the previously scheduled Expiration
Date.
 
  This Letter of Transmittal is to be used by a holder of Old Notes if
original Old Notes, if available, are to be forwarded herewith. An Agent's
Message (as defined in the next sentence) is to be used if delivery of Old
Notes is to be made by book-entry transfer to the account maintained by the
Exchange Agent at the Depository Trust Company (the "Book-Entry Transfer
Facility") pursuant to the procedures set forth in the Prospectus under the
caption "The Exchange Offer--Terms of the Exchange Offer--Procedures for
Tendering Old Notes." The term "Agent's Message" means a message, transmitted
by the Book-Entry Transfer Facility and received by the Exchange Agent and
forming a part of the confirmation of a book-entry transfer ("Book-Entry
Confirmation"), which states that the Book-Entry Transfer Facility has
received an express acknowledgment from a participant tendering Old Notes
which are the subject of such Book-Entry Confirmation and that such
participant has received and agrees to be bound by the terms of the Letter of
Transmittal and that the Company may enforce such agreement against such
participant. Holders of Old Notes whose Old Notes are not immediately
available, or who are unable to deliver their Old Notes and all other
documents required by this Letter of Transmittal to the Exchange Agent on or
prior to the Expiration Date, or who are unable to complete the procedure for
book-entry transfer on a timely basis, must tender their Old Notes according
to the guaranteed delivery procedures set forth in the Prospectus under the
caption "The Exchange Offer--Terms of the Exchange Offer--Guaranteed Delivery
Procedures." See Instruction 2. Delivery of documents to the Book-Entry
Transfer Facility does not constitute delivery to the Exchange Agent.
 
  The term "holder" with respect to the Exchange Offer means any person in
whose name Old Notes are registered on the books of the Company or any other
person who has obtained a properly completed bond power from the registered
holder. The undersigned has completed, executed and delivered this Letter of
Transmittal to indicate the action the undersigned desires to take with
respect to the Exchange Offer. Holders who wish to tender their Old Notes must
complete this Letter of Transmittal in its entirety.
 
  PLEASE READ THE ENTIRE LETTER OF TRANSMITTAL AND THE PROSPECTUS CAREFULLY
BEFORE CHECKING ANY BOX BELOW.
 
  THE INSTRUCTIONS INCLUDED WITH THIS LETTER OF TRANSMITTAL MUST BE FOLLOWED.
QUESTIONS AND REQUESTS FOR ASSISTANCE OR FOR ADDITIONAL COPIES OF THE
PROSPECTUS AND THIS LETTER OF TRANSMITTAL MAY BE DIRECTED TO THE EXCHANGE
AGENT.
 
                                       2

 
  List below the Old Notes to which this Letter of Transmittal relates. If the
space below is inadequate, list the registered numbers and principal amount on
a separate signed schedule and affix the list to this Letter of Transmittal.
  
 
- ------------------------------------------------------------------------------------------------------------------------------  
                                              DESCRIPTION OF OLD NOTES TENDERED
- ------------------------------------------------------------------------------------------------------------------------------  
 NAME(S) AND ADDRESS(ES) OF REGISTERED  OWNER(S)
AS (IT/THEY) APPEAR(S) ON THE 7 1/8% SERIES A SENIOR NOTES 
      DUE 2008 (THE "OLD NOTES")                                   AGGREGATE PRINCIPAL AMOUNT REPRESENTED BY OLD NOTES
- ------------------------------------------------------------------------------------------------------------------------------ 
                                                                                                    
                                                             CERTIFICATE NUMBER(S)        AMOUNT OF         PRINCIPAL AMOUNT 
                                                                 OF OLD NOTES*        OLD NOTES TENDERED       TENDERED     
                                                           ------------------------------------------------------------------- 
                                                           ------------------------------------------------------------------- 
                                                           ------------------------------------------------------------------- 
                                                           ------------------------------------------------------------------- 
                                                           ------------------------------------------------------------------- 
                                                           ------------------------------------------------------------------- 
- ------------------------------------------------------------------------------------------------------------------------------  
                                                              TOTAL PRINCIPAL** 
- ------------------------------------------------------------------------------------------------------------------------------ 
  * Need not be completed by book-entry holders.
 ** Unless otherwise indicated, any tendering holder of Old Notes will be deemed to have tendered the entire aggregate 
    principal amount represented by such Old Notes. All tenders must be in integral multiples of $1,000.
- ------------------------------------------------------------------------------------------------------------------------------ 
 
(If additional space is required, attach a continuation sheet in substantially
                               the above form.)
 
                              METHOD OF DELIVERY
 
[_]Check here if tendered Old Notes are enclosed herewith.
 
[_]Check here if tendered Old Notes are being delivered by book-entry transfer
   made to an account maintained by the Exchange Agent with a Book-Entry
   Transfer Facility and complete the following:
 
  Name of Tendering Institution: _____________________________________________
  Account Number: ____________________________________________________________
  Transaction Code Number: ___________________________________________________
 
[_]Check here if tendered Old Notes are being delivered pursuant to a Notice
   of Guaranteed Delivery and complete the following:
 
  Name(s) of Registered Holder(s): ___________________________________________
  ----------------------------------------------------------------------------
  ----------------------------------------------------------------------------
  ----------------------------------------------------------------------------
  Date of Execution of Notice of Guaranteed Delivery: ________________________
  Window Ticket Number (if available): _______________________________________
  Name of Eligible Institution that guaranteed delivery: _____________________
  Account Number (If delivered by book-entry transfer): ______________________
 
                                       3

 
                       SIGNATURES MUST BE PROVIDED BELOW
              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY
 
Ladies and Gentlemen:
 
  1. The undersigned hereby tenders to the Company the Old Notes described
above pursuant to the Company's offer of $1,000 principal amount of registered
New Notes, in exchange for each $1,000 principal amount of the Old Notes, upon
the terms and subject to the conditions contained in the Prospectus, receipt
of which is hereby acknowledged, and this Letter of Transmittal.
 
  2. The undersigned hereby represents and warrants that it has full authority
to tender, exchange, assign and transfer the Old Notes described above. The
undersigned will, upon request, execute and deliver any additional documents
deemed by the Exchange Agent or the Company to be necessary or desirable to
complete the exchange, assignment and transfer of Old Notes.
 
  3. The undersigned understands that the tender of the Old Notes pursuant to
all of the procedures set forth in the Prospectus will constitute an agreement
between the undersigned and the Company as to the terms and conditions set
forth in the Prospectus.
 
  4. The undersigned acknowledge(s) that this Exchange Offer is being made in
reliance upon interpretations contained in no-action letters issued to third
parties by the staff of the Securities and Exchange Commission (the "SEC"),
including Exxon Capital Holdings Corporation, SEC No-Action (available April
13, 1989), Morgan Stanley & Co. Inc., SEC No-Action Letter (available June 5,
1991) (the "Morgan Stanley Letter") and Mary Kay Cosmetics, Inc., SEC No-
Action Letter (available June 5, 1991), that the Exchange Notes issued in
exchange for the Old Notes pursuant to the Exchange Offer may be offered for
resale, resold and otherwise transferred by holders thereof (other than a
broker-dealer who purchased Old Notes exchanged for such Exchange Notes
directly from the Company to resell pursuant to Rule 144A or any other
available exemption under the Securities Act and any such holder that is an
"affiliate" of the Company within the meaning of Rule 405 under the Securities
Act), without compliance with the registration and prospectus delivery
provisions of the Securities Act, provided that such Exchange Notes are
acquired in the ordinary course of such holders' business and such holders are
not participating in, and have no arrangement with any person to participate
in, the distribution of such Exchange Notes.
 
  5. Unless the box under the heading "Special Registration Instructions" is
checked, the undersigned hereby represents and warrants that:
 
    (i) the New Notes acquired pursuant to the Exchange Offer are being
  obtained in the ordinary course of business of the holder;
 
    (ii) the holder is not engaging in and does not intend to engage in a
  distribution of such New Notes;
 
    (iii) the holder does not have an arrangement or understanding with any
  person to participate in the distribution of such New Notes; and
 
    (iv) the holder is not an "affiliate," as such term is defined under Rule
  405 promulgated under the Securities Act, of the Company.
 
  6. The undersigned may, if, and only if, unable to make all of the
representations and warranties contained in Item 5 above, elect to have its
Old Notes registered in the shelf registration statement described in the
registration rights agreement (the "Registration Rights Agreement") dated as
of January 22, 1998 among the Company, the Guarantors and the Initial
Purchaser. Such election may be made by checking the box under "Special
Registration Instructions" on page 6. By making such election, the undersigned
agrees, as a holder of Transfer Restricted Securities participating in a shelf
registration, to indemnify and hold harmless the Company, each of the
Guarantors and each person, if any, who controls the Company or any of the
Guarantors within the meaning of either Section 15 of the Securities Act or
Section 20 of the Securities Exchange Act of 1934, as
 
                                       4

 
amended (the "Exchange Act"), and each of their respective officers,
directors, employees, partners, representatives and agents from and against
any and all losses, liabilities, claims, damages and expenses whatsoever
(including but not limited to reasonable attorneys' fees and any and all
reasonable expenses whatsoever incurred in investigating, preparing or
defending against any investigation or litigation, commenced or threatened, or
any claim whatsoever, and any and all amounts paid in settlement of any claim
or litigation), joint or several, to which they or any of them may become
subject under the Securities Act, the Exchange Act or otherwise, insofar as
such losses, liabilities, claims, damages or expenses (or actions in respect
thereof) arise out of or are based upon any untrue statement or alleged untrue
statement of a material fact contained in any Registration Statement or
Prospectus, or in any supplement thereto or amendment thereof, or arise out of
or are based upon the omission or alleged omission to state therein a material
fact required to be stated therein or necessary to make the statements
therein, in the light of the circumstances under which they were made, not
misleading; but only with respect to information relating to the undersigned
furnished in writing by or on behalf of the undersigned expressly for use in
the Registration Statement, the Prospectus or any amendments or supplements
thereto. Any such indemnification shall be governed by the terms and subject
to the conditions set forth in the Registration Rights Agreement, including,
without limitation, the provisions regarding notice, retention of counsel,
contribution and payment of expenses set forth therein. The above summary of
the indemnification provision of the Registration Rights Agreement is not
intended to be exhaustive and is qualified in its entirety by the Registration
Rights Agreement.
 
  7. If the undersigned is not a broker-dealer, the undersigned represents
that it is not engaged in, and does not intend to engage in, a distribution of
New Notes. If the undersigned is a broker-dealer that will receive New Notes
for its own account in exchange for Old Notes that were acquired as a result
of market-making activities or other trading activities, it acknowledges that
it will deliver a prospectus in connection with any resale of such New Notes;
however, by so acknowledging and delivering a prospectus, the undersigned will
not be deemed to admit that it is an "underwriter" within the meaning of the
Securities Act. If the undersigned is a broker-dealer and Old Notes held for
its own account were not acquired as a result of market-making or other
trading activities, such Old Notes cannot be exchanged pursuant to the
Exchange Offer.
 
  8. Any obligation of the undersigned hereunder shall be binding upon the
successors, assigns, executors, administrators, trustees in bankruptcy and
legal and personal representatives of the undersigned.
 
  9. Unless otherwise indicated herein under "Special Delivery Instructions,"
please issue the certificates for the New Notes in the name of the
undersigned.
 
                                       5

 
- ------------------------------------       -------------------------------------
 
 SPECIAL ISSUANCE INSTRUCTION                SPECIAL DELIVERY INSTRUCTIONS
  (SEE INSTRUCTIONS 5 AND 6)                   (SEE INSTRUCTIONS 5 AND 6)
 
 
  To be completed only (i) if Old           To be completed ONLY if the New
 Notes in a principal amount not           Notes are to be issued or sent to
 tendered, or New Notes issued in          someone other than the under-
 exchange for Old Notes accepted           signed or to the undersigned at
 for exchange, are to be issued in         an address other than as indi-
 the name of someone other than            cated above.
 the undersigned, or (ii) if Old           ----------------------------------
 Notes tendered by book-entry              Mail  [_]  Issue [_] (check ap-   
 transfer which are not exchanged          propriate boxes) Certificates to: 
 are to be returned by credit to           Name______________________________
 an account maintained at the                       (TYPE OR PRINT)          
 Book-Entry Transfer Facility. Is-         Address __________________________
 sue Exchange Notes and/or Old             __________________________________
 Notes to:                                             (ZIP CODE)            
- ------------------------------------                                         
 Name _____________________________        __________________________________
          (TYPE OR PRINT)                  (TAX IDENTIFICATION OR SOCIAL     
 Address __________________________               SECURITY NUMBER)
 __________________________________        __________________________________
             (ZIP CODE)                                                   
 __________________________________                                       
   (TAX IDENTIFICATION OR SOCIAL                                          
          SECURITY NUMBER)                                                
   (COMPLETE SUBSTITUTE FORM W-9)                                         
                                                                          
    CREDIT UNEXCHANGED OLD NOTES                                          
  DELIVERED BY BOOK-ENTRY TRANSFER                                        
     TO THE BOOK-ENTRY TRANSFER                                           
     FACILITY SET FORTH BELOW:                                            
 __________________________________                                       
    BOOK-ENTRY TRANSFER FACILITY                                          
          ACCOUNT NUMBER:                                                 
 __________________________________  
___________________________________  
                                     
                                     
                                     
                                     
                                     
                                     
                                     
                                     
 
 
                                       6

 
                       SPECIAL REGISTRATION INSTRUCTIONS
 
  To be completed ONLY if (i) the undersigned satisfies the conditions set
forth in Item 6 above, (ii) the undersigned elects to register its Old Notes
in the shelf registration statement described in the Registration Rights
Agreement and (iii) the undersigned agrees to indemnify certain entities and
individuals as set forth in Item 6 above. (See Item 6).
 
[_]By checking this box the undersigned hereby (i) represents that it is
   unable to make all of the representations and warranties set forth in Item
   5 above, (ii) elects to have its Old Notes registered pursuant to the shelf
   registration statement described in the Registration Rights Agreement and
   (iii) agrees to indemnify certain entities and individuals identified in,
   and to the extent provided in, Item 6 above.
 
                      SPECIAL BROKER-DEALER INSTRUCTIONS
 
[_]Check here if you are a broker-dealer and wish to receive 10 additional
   copies of the Prospectus and 10 copies of any amendments or supplements
   thereto.
 
  Name _______________________________________________________________________
  Address ____________________________________________________________________
  (Zip Code) _________________________________________________________________
 
                                   IMPORTANT
                        PLEASE SIGN HERE WHETHER OR NOT
                OLD NOTES ARE BEING PHYSICALLY TENDERED HEREBY
          (Complete Accompanying Substitute Form W-9 on Reverse Side)
 
  (Signature(s) of Registered Holders of Old Notes) __________________________
  ----------------------------------------------------------------------------
  ----------------------------------------------------------------------------
 
  Dated                , 1998
 
  (The above lines must be signed by the registered holder(s) of Old Notes as
name(s) appear(s) on the Old Notes or on a security position listing, or by
person(s) authorized to become registered holder(s) by a properly completed
bond power from the registered holder(s), a copy of which must be transmitted
with this Letter of Transmittal. If Old Notes to which this Letter of
Transmittal relate are held of record by two or more joint holders, then all
such holders must sign this Letter of Transmittal. If signature is by a
trustee, executor, administrator, guardian, attorney-in-fact, officer of a
corporation or other person acting in a fiduciary or representative capacity,
then such person must (i) set forth his or her full title below and (ii)
unless waived by the Company, submit evidence satisfactory to the Company of
such person's authority so to act. See Instruction 5 regarding completion of
this Letter of Transmittal, printed below.)
 
  Name(s) ____________________________________________________________________
                             (PLEASE TYPE OR PRINT)
  Capacity: __________________________________________________________________
  Address: ___________________________________________________________________
                               (INCLUDE ZIP CODE)
  Area Code and Telephone Number: ____________________________________________
 
 
                                       7

 
                         MEDALLION SIGNATURE GUARANTEE
                        (If Required by Instruction 5)
 
  Certain signatures must be Guaranteed by an Eligible Institution.
 
  Signature(s) Guaranteed by an Eligible Institution:.
 
  (Authorized Signature) _____________________________________________________
  (Title) ____________________________________________________________________
  (Name of Firm) _____________________________________________________________
  (Address, Include Zip Code) ________________________________________________
  (Area Code and Telephone Number) ___________________________________________
  Dated:                            , 1998
 
                                 INSTRUCTIONS
        FORMING PART OF THE TERMS AND CONDITIONS OF THE EXCHANGE OFFER
 
1. DELIVERY OF THIS LETTER OF TRANSMITTAL AND OLD NOTES OR BOOK-ENTRY
CONFIRMATIONS.
 
  All physically delivered Old Notes or any confirmation of a book-entry
transfer to the Exchange Agent's account at the Book-Entry Transfer Facility
of Old Notes tendered by book-entry transfer (a "Book-Entry Confirmation"), as
well as a properly completed and duly executed copy of this Letter of
Transmittal or Agent's Message or facsimile hereof, and any other documents
required by this Letter of Transmittal, must be received by the Exchange Agent
at its address set forth herein prior to 5:00 p.m., New York City time, on the
Expiration Date. The method of delivery of the tendered Old Notes, this Letter
of Transmittal and all other required documents to the Exchange Agent is at
the election and risk of the holder and, except as otherwise provided below,
the delivery will be deemed made only when actually received or confirmed by
the Exchange Agent. If such delivery is by mail, it is recommended that
registered mail, properly insured, with return receipt requested, be used.
Instead of delivery by mail, it is recommended that the holder use an
overnight or hand delivery service. In all cases, sufficient time should be
allowed to assure delivery to the Exchange Agent before the Expiration Date.
No Letter of Transmittal or Old Notes should be sent to the Company.
 
2. GUARANTEED DELIVERY PROCEDURES.
 
  Holders who wish to tender their Old Notes and whose Old Notes are not
immediately available or who cannot deliver their Old Notes, this Letter of
Transmittal or any other documents required hereby to the Exchange Agent prior
to the Expiration Date or who cannot complete the procedure for book-entry
transfer on a timely basis and deliver an Agent's Message, must tender their
Old Notes according to the guaranteed delivery procedures set forth in the
Prospectus. Pursuant to such procedures a tender may be effected if the
Exchange Agent has received at its office, on or prior to the Expiration Date,
a letter, telegram or facsimile transmission from an Eligible Institution
setting forth the name and address of the tendering holder, the name(s) in
which the Old Notes are registered and the certificate number(s) of the Old
Notes to be tendered, and stating that the tender is being made thereby and
guaranteeing that, within three Nasdaq National Market trading days after the
date of execution of such letter, telegram or facsimile transmission by the
Eligible Institution, such Old Notes, in proper form for transfer (or a
confirmation of book-entry transfer of such Old Notes into the Exchange
Agent's account at DTC), will be delivered by such Eligible Institution
together with a properly completed and duly executed Letter of Transmittal
(and any other required documents). Unless Old Notes being tendered by the
above-described method are deposited with the Exchange Agent within the time
period set forth above (accompanied or preceded by a properly completed Letter
of Transmittal and any other required documents), the Company may, at its
option, reject the tender.
 
                                       8

 
  Any holder of Old Notes who wishes to tender Old Notes pursuant to the
guaranteed delivery procedures described above must ensure that the Exchange
Agent receives the Notice of Guaranteed Delivery prior to 5:00 p.m., New York
City time, on the Expiration Date. Upon request of the Exchange Agent, a
Notice of Guaranteed Delivery will be sent to holders who wish to tender their
Old Notes according to the guaranteed delivery procedures set forth above. See
"The Exchange Offer--Terms of the Exchange Offer--Guaranteed Delivery
Procedures" section of the Prospectus.
 
3. TENDER BY HOLDER.
 
  Only a holder of Old Notes may tender such Old Notes in the Exchange Offer.
Any beneficial holder of Old Notes who is not the registered holder and who
wishes to tender should arrange with the registered holder to execute and
deliver this Letter of Transmittal on his behalf or must, prior to completing
and executing this Letter of Transmittal and delivering his Old Notes, either
make appropriate arrangements to register ownership of the Old Notes in such
holder's name or obtain a properly completed bond power from the registered
holder.
 
4. PARTIAL TENDERS.
 
  Tenders of Old Notes will be accepted only in integral multiples of $1,000.
If less than the entire principal amount of any Old Notes is tendered, the
tendering holder should fill in the principal amount tendered in the third
column of the box entitled "Description of Old Notes Tendered" above. The
entire principal amount of Old Notes delivered to the Exchange Agent will be
deemed to have been tendered unless otherwise indicated. If the entire
principal amount of all Old Notes is not tendered, then Old Notes for the
principal amount of Old Notes not tendered and New Notes issued in exchange
for any Old Notes accepted will be sent to the holder at his or her registered
address, unless a different address is provided in the appropriate box on this
Letter of Transmittal, promptly after the Old Notes are accepted for exchange.
 
5. SIGNATURES ON THIS LETTER OF TRANSMITTAL; BOND POWERS AND ENDORSEMENTS;
GUARANTEE OF SIGNATURES.
 
  If this Letter of Transmittal (or facsimile hereof) is signed by the record
holder(s) of the Old Notes tendered hereby, the signature must correspond with
the name(s) as written on the face of the Old Notes without alteration,
enlargement or any change whatsoever. If this Letter of Transmittal (or
facsimile hereof) is signed by a participant in the Book-Entry Transfer
Facility, the signature must correspond with the name as it appears on the
security position listing as the holder of the Old Notes.
 
  If this Letter of Transmittal (or facsimile hereof) is signed by the
registered holder or holders of Old Notes listed and tendered hereby and the
New Notes issued in exchange therefor are to be issued (or any untendered
principal amount of Old Notes is to be reissued) to the registered holder, the
said holder need not and should not endorse any tendered Old Notes, nor
provide a separate bond power. In any other case, such holder must either
properly endorse the Old Notes tendered or transmit a properly completed
separate bond power with this Letter of Transmittal, with the signatures on
the endorsement or bond power guaranteed by an Eligible Institution.
 
  If this Letter of Transmittal (or facsimile hereof) is signed by a person
other than the registered holder or holders of any Old Notes listed, such Old
Notes must be endorsed or accompanied by appropriate bond powers, in each case
signed as the name of the registered holder or holders appears on the Old
Notes.
 
  If this Letter of Transmittal (or facsimile hereof) or any Old Notes or bond
powers are signed by trustees, executors, administrators, guardians,
attorneys-in-fact, officers of corporations or others acting in a fiduciary or
representative capacity, such persons should so indicate when signing, and,
unless waived by the Company, evidence satisfactory to the Company of their
authority to act must be submitted with this Letter of Transmittal.
 
  Endorsements on Old Notes or signatures on bond powers required by this
Instruction 5 must be guaranteed by an Eligible Institution.
 
 
                                       9

 
  No signature guarantee is required if (i) this Letter of Transmittal (or
facsimile hereof) is signed by the registered holder(s) of the Old Notes
tendered herein (or by a participant in the Book-Entry Transfer Facility whose
name appears on a security position listing as the owner of the tendered Old
Notes) and the New Notes are to be issued directly to such registered
holder(s) (or, if signed by a participant in the Book-Entry Transfer Facility,
deposited to such participant's account at such Book-Entry Transfer Facility)
and neither the box entitled "Special Delivery Instructions" nor the box
entitled "Special Registration Instructions" has been completed, or (ii) such
Old Notes are tendered for the account of an Eligible Institution. In all
other cases, all signatures on this Letter of Transmittal (or facsimile
hereof) must be guaranteed by an Eligible Institution.
 
6. SPECIAL REGISTRATION AND DELIVERY INSTRUCTIONS.
 
  Tendering holders should indicate, in the applicable box or boxes, the name
and address (or account at the Book-Entry Transfer Facility) to which New
Notes or substitute Old Notes for principal amounts not tendered or not
accepted for exchange are to be issued or sent, if different from the name and
address of the person signing this Letter of Transmittal. In the case of
issuance in a different name, the taxpayer identification or social security
number of the person named must also be indicated.
 
  Tax law requires that a holder of any Old Notes which are accepted for
exchange must provide the Company (as payor) with its correct taxpayer
identification number ("TIN"), which, in the case of a holder who is an
individual is his or her social security number. If the Company is not
provided with the correct TIN, the holder may be subject to a $50 penalty
imposed by Internal Revenue Service. (If withholding results in an over-
payment of taxes, a refund may be obtained). Certain holders (including, among
others, all corporations and certain foreign individuals) are not subject to
these backup withholding and reporting requirements. See the enclosed
"Guidelines for Certification of Taxpayer Identification Number on Substitute
Form W-9" for additional instructions.
 
  To prevent backup withholding, each tendering holder must provide such
holder's correct TIN by completing the Substitute Form W-9 set forth herein,
certifying that the TIN provided is correct (or that such holder is awaiting a
TIN), and that (i) the holder has not been notified by the Internal Revenue
Service that such holder is subject to backup withholding as a result of
failure to report all interest or dividends or (ii) the Internal Revenue
Service has notified the holder that such holder is no longer subject to
backup withholding. If the Old Notes are registered in more than one name or
are not in the name of the actual owner, see the enclosed "Guidelines for
Certification of Taxpayer Identification Number of Substitute Form W-9" for
information on which TIN to report.
 
  The Company reserves the right in its sole discretion to take whatever steps
are necessary to comply with the Company's obligations regarding backup
withholding.
 
7. VALIDITY OF TENDERS.
 
  All questions as to the validity, form, eligibility (including time of
receipt), acceptance, and withdrawal of tendered Old Notes will be determined
by the Company, in its sole discretion, which determination will be final and
binding. The Company reserves the absolute right to reject any or all tenders
not in proper form or the acceptance for exchange of which may, in the opinion
of counsel for the Company, be unlawful. The Company also reserves the
absolute right to waive any of the conditions of the Exchange Offer or any
defect or irregularity in the tender of any Old Notes. The Company's
interpretation of the terms and conditions of the Exchange Offer (including
the instructions in the Letter of Transmittal) will be final and binding on
all parties. Unless waived, any defects or irregularities in connection with
tenders of Old Notes must be cured within such time as the Company shall
determine. Although the Company intends to notify holders of defects or
irregularities with respect to tenders of Old Notes, neither the Company, the
Exchange Agent, nor any other person shall be under any duty to give
notification of any defects or irregularities in tenders or incur any
liability for failure to give such notification. Tenders of Old Notes will not
be deemed to have been made until such defects or irregularities
 
                                      10

 
have been cured or waived. Any Old Notes received by the Exchange Agent that
are not properly tendered and as to which the defects or irregularities have
not been cured or waived will be returned by the Exchange Agent to the
tendering holders, unless otherwise provided in the Letter of Transmittal, as
soon as practicable following the Expiration Date.
 
8. WAIVER OF CONDITIONS.
 
  The Company reserves the absolute right to waive, in whole or part, any of
the conditions to the Exchange Offer set forth in the Prospectus.
 
9. NO CONDITIONAL TENDER.
 
  No alternative, conditional, irregular or contingent tender of Old Notes on
transmittal of this Letter of Transmittal will be accepted.
 
10. MUTILATED, LOST, STOLEN OR DESTROYED OLD NOTES.
 
  Any holder whose Old Notes have been mutilated, lost, stolen or destroyed
should contact the Exchange Agent at the address indicated above for further
instructions.
 
11. REQUESTS FOR ASSISTANCE OR ADDITIONAL COPIES.
 
  Requests for assistance or for additional copies of the Prospectus or this
Letter of Transmittal may be directed to the Exchange Agent at the address or
telephone number set forth on the cover page of this Letter of Transmittal.
Holders may also contact their broker, dealer, commercial bank, trust company
or other nominee for assistance concerning the Exchange Offer.
 
12. WITHDRAWAL.
 
  Tenders may be withdrawn only pursuant to the limited withdrawal rights set
forth in the Prospectus under the caption "The Exchange Offer--Terms of the
Exchange Offer--Withdrawal Rights."
 
IMPORTANT: THIS LETTER OF TRANSMITTAL OR A MANUALLY SIGNED FACSIMILE HEREOF
(TOGETHER WITH THE OLD NOTES DELIVERED BY BOOK-ENTRY TRANSFER OR IN ORIGINAL
HARD COPY FORM) MUST BE RECEIVED BY THE EXCHANGE AGENT, OR THE NOTICE OF
GUARANTEED DELIVERY MUST BE RECEIVED BY THE EXCHANGE AGENT, PRIOR TO THE
EXPIRATION DATE.
 
                                      11

 
- -------------------------------------------------------------------------------
                        PART 1--PLEASE PROVIDE YOUR    Social Security Number
                        TIN IN THE BOX AT RIGHT AND          OR Employer
                        CERTIFY BY SIGNING AND          Identification Number
                        DATING BELOW.
 
 SUBSTITUTE
 FORM W-9
 DEPARTMENT OF
 THE TREASURY--                                        ----------------------
 INTERNAL REVENUE      --------------------------------------------------------
 SERVICE                PART 2--Certification Under penalties of perjury, I
                        certify that:
 
                        (1) The number shown on this form is my correct
                            Taxpayer Identification Number (or I am waiting
                            for a number to be issued to me) and
 
 PAYER'S REQUEST        (2) I am not subject to backup withholding either    
 FOR TAXPAYER               because I have not been notified by the Internal 
 IDENTIFICATION             Revenue Service ("IRS") that I am subject to     
 NUMBER (TIN)               backup withholding as a result of failure to     
                            report all interest or dividends, or the IRS has 
                            notified me that I am no longer subject to backup 
                            withholding.                                      
 
                        Certificate Instructions--You must cross out item (2)
                        in Part 2 above if you have been notified by the IRS
                        that you are subject to backup withholding because of
                        under reporting interest or dividends on your tax
                        return. However, if after being notified by the IRS
                        that you were subject to backup withholding you
                        received another notification from the IRS stating
                        that you are no longer subject to backup withholding,
                        do not cross out item (2).
                       --------------------------------------------------------
                        NOTE: FAILURE TO COMPLETE AND RETURN    PART 3 --
                            THIS FORM MAY RESULT IN BACKUP      Awaiting TIN [_]
                            WITHHOLDING OF 31% OF ANY PAY-              
                            MENTS MADE TO YOU PURSUANT TO THE  Please         
                            OFFER. PLEASE REVIEW THE ENCLOSED  complete the     
                            GUIDELINES FOR CERTIFICATION OF    Certificate      
                            TAXPAYER IDENTIFICATION NUMBER ON  of Awaiting      
                            SUBSTITUTE FORM W-9 FOR ADDI-      Taxpayer         
                            TIONAL DETAILS.                    Identification   
                                                               Number           
                                                               below.           
 
                        SIGNATURE ______________  DATE _ ,1998
- -------------------------------------------------------------------------------
YOU MUST COMPLETE THE FOLLOWING CERTIFICATE IF YOU CHECKED THE BOX IN PART 3
OF THE SUBSTITUTE FORM W-9
 
                                      12

 
            CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER
 
  I certify under penalties of perjury that a taxpayer identification number
has not been issued to me, and either (a) I have mailed or delivered an
application to receive a taxpayer identification number to the appropriate
Internal Revenue Service Center or Social Security Administration Office or
(b) I intend to mail or deliver an application in the near future. I
understand that if I do not provide a taxpayer identification number to the
payor within 60 days, 31% of all reportable payments made to me thereafter
will be withheld until I provide a number.
 
- ------------------------------------------  ____________________________ , 1998
                Signature                                Date
 
CERTIFICATE FOR FOREIGN RECORD HOLDERS
 
  Under penalties of perjury, I certify that I am not a United States citizen
or resident (or I am signing for a foreign corporation, partnership, estate or
trust).
 
- ------------------------------------------  ____________________________ , 1998
                Signature                                Date
 
                                      13

 
                           OFFSHORE LOGISTICS, INC.
 
                               LETTER TO CLIENTS
                                      FOR
                           TENDER OF ALL OUTSTANDING
                     7 7/8% SERIES A SENIOR NOTES DUE 2008
                                IN EXCHANGE FOR
                     7 7/8% SERIES B SENIOR NOTES DUE 2008
 
  THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON
          , 1998, UNLESS EXTENDED (THE "EXPIRATION DATE").
 
  NOTES TENDERED IN THE EXCHANGE OFFER MAY BE WITHDRAWN AT ANY TIME PRIOR TO
5:00 P.M., NEW YORK CITY TIME, ON THE BUSINESS DAY PRIOR TO THE EXPIRATION
DATE UNLESS PREVIOUSLY ACCEPTED FOR EXCHANGE.
 
To Our Clients:
 
  We are enclosing herewith a Prospectus, dated         , 1998, of Offshore
Logistics, Inc., a Delaware corporation (the "Company"), and a related Letter
of Transmittal, which together constitute the Company's offer (the "Exchange
Offer") to exchange its 7 7/8% Series B Senior Notes due 2008 (the "New
Notes"), which have been registered under the Securities Act of 1933, as
amended (the "Securities Act"), for a like principal amount of its issued and
outstanding 7 7/8% Series A Senior Notes due 2008 (the "Old Notes"), upon the
terms and subject to the conditions set forth in the Exchange Offer.
 
  The Exchange Offer is not conditioned upon any minimum number of Old Notes
being tendered.
 
  We are the holder of record of Old Notes held by us for your own account. A
tender of such Old Notes can be made only by us as the record holder and
pursuant to your instructions. The Letter of Transmittal is furnished to you
for your information only and cannot be used by you to tender Old Notes held
by us for your account.
 
  We request instructions as to whether you wish to tender any or all of the
Old Notes held by us for your account pursuant to the terms and conditions of
the Exchange Offer. We also request that you confirm that we may on your
behalf make the representations and warranties contained in the Letter of
Transmittal.
 
                                          Very truly yours,
 
PLEASE RETURN YOUR INSTRUCTIONS TO US IN THE ENCLOSED ENVELOPE WITHIN AMPLE
TIME TO PERMIT US TO SUBMIT A TENDER ON YOUR BEHALF PRIOR TO THE EXPIRATION
DATE.
 
                                      14

 
                 INSTRUCTION TO REGISTERED HOLDER AND/OR BOOK
                          ENTRY TRANSFER PARTICIPANT
 
  To Registered Holder and/or Participant of the Book-Entry Transfer Facility:
 
  The undersigned hereby acknowledges receipt of the Prospectus dated        ,
1998 (the "Prospectus") of Offshore Logistics, Inc., a Delaware corporation
(the "Company"), and the accompanying Letter of Transmittal (the "Letter of
Transmittal"), that together constitute the Company's offer (the "Exchange
Offer") to exchange its 7 7/8% Series B Senior Notes due 2008 (the "New
Notes"), for all of its outstanding 7 7/8% Series A Senior Notes due 2008 (the
"Old Notes"). Capitalized terms used but not defined herein have the meanings
ascribed to them in the Prospectus.
 
  This will instruct you, the registered holder and/or book-entry transfer
facility participant, as to the action to be taken by you relating to the
Exchange Offer with respect to the Old Notes held by you for the account of
the undersigned.
 
  The aggregate face amount of the Old Notes held by you for the account of
the undersigned is (FILL IN AMOUNT):
 
  $               of the 7 7/8% Series A Senior Notes due 2008.
 
  With respect to the Exchange Offer, the undersigned hereby instructs you
(CHECK APPROPRIATE BOX):
 
[_]To TENDER the following Old Notes held by you for the account of the
   undersigned (INSERT PRINCIPAL AMOUNT OF OLD NOTES TO BE TENDERED) (IF ANY):
   $                     .
 
[_]NOT to TENDER any Old Notes held by you for the account of the undersigned.
 
  If the undersigned instructs you to tender the Old Notes held by you for the
account of the undersigned, it is understood that you are authorized to make,
on behalf of the undersigned (and the undersigned by its signature below,
hereby makes to you), the representations and warranties contained in the
Letter of Transmittal that are to be made with respect to the undersigned as a
beneficial owner, including but not limited to the representations, that (i)
the New Notes acquired in exchange for Old Notes pursuant to the Exchange
Offer are being acquired in the ordinary course of business of the person
receiving such New Notes, whether or not the undersigned, (ii) the undersigned
is not engaging in and does not intend to engage in a distribution of the New
Notes, (iii) the undersigned does not have any arrangement or understanding
with any person to participate in the distribution of New Notes, and (iv)
neither the undersigned nor any such other person is an "affiliate" (within
the meaning of Rule 405 under the Securities Act of 1933, as amended) of the
Company. If the undersigned is a broker-dealer that will receive New Notes for
its own account in exchange for Old Notes, it acknowledges that it will
deliver a prospectus in connection with any resale of such New Notes.
 
                                   SIGN HERE
 
Name of beneficial owner(s):___________________________________________________
                                 SIGNATURE(S)
Name(s): ______________________________________________________________________
    ------------------------------------------------------------------------
    ------------------------------------------------------------------------
                                 (PLEASE PRINT)
 
Address: ______________________________________________________________________
Telephone number: _____________________________________________________________
Taxpayer Identification or Social Security Number: ____________________________
Date: _________________________________________________________________________
 
                                      15

 
                           OFFSHORE LOGISTICS, INC.
 
                       LETTER TO REGISTERED HOLDERS AND
                     DEPOSITORY TRUST COMPANY PARTICIPANTS
                                      FOR
                           TENDER OF ALL OUTSTANDING
                     7 7/8% SERIES A SENIOR NOTES DUE 2008
                                IN EXCHANGE FOR
                     7 7/8% SERIES B SENIOR NOTES DUE 2008
 
  THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON
           , 1998, UNLESS EXTENDED (THE "EXPIRATION DATE").
 
OLD NOTES TENDERED IN THE EXCHANGE OFFER MAY BE WITHDRAWN AT ANY TIME PRIOR TO
  5:00 P.M., NEW YORK CITY TIME, ON THE BUSINESS DAY PRIOR TO THE EXPIRATION
                 DATE UNLESS PREVIOUSLY ACCEPTED FOR EXCHANGE.
 
To Registered Holders and Depository Trust Company Participants:
 
  We are enclosing herewith the material listed below relating to the offer by
Offshore Logistics, Inc., a Delaware corporation (the "Company"), to exchange
its 7 7/8% Series B Senior Notes due 2008 (the "New Notes"), which have been
registered under the Securities Act of 1933, as amended (the "Securities
Act"), for a like principal amount of its issued and outstanding 7 7/8% Series
A Senior Notes due 2008 (the "Old Notes") upon the terms and subject to the
conditions set forth in the Company's Prospectus, dated          , 1998, and
the related Letter of Transmittal (which together constitute the "Exchange
Offer").
 
  Enclosed herewith are copies of the following documents:
 
    1. Prospectus dated             , 1998;
 
    2. Letter of Transmittal (together with accompanying Substitute Form W-9
  Guidelines);
 
    3. Notice of Guaranteed Delivery;
 
    4. Letter which may be sent to your clients for whose account you hold
  Old Notes in your name or in the name of your nominee; and
 
    5. Letter which may be sent from your clients to you with such client's
  instruction with regard to the Exchange Offer.
 
  We urge you to contact your clients promptly. Please note that the Exchange
Offer will expire on the Expiration Date unless extended.
 
  The Exchange Offer is not conditioned upon any minimum number of Old Notes
being tendered.
 
  Pursuant to the Letter of Transmittal, each holder of Old Notes will
represent to the Company that (i) the New Notes acquired in exchange for Old
Notes pursuant to the Exchange Offer are being acquired in the ordinary course
of business of the person receiving such New Notes, whether or not the
undersigned, (ii) the undersigned is not engaging in and does not intend to
engage in a distribution of the New Notes, (iii) the undersigned does not have
any arrangement or understanding with any person to participate in the
distribution of New Notes, and (iv) neither the undersigned nor any such other
person is an "affiliate" (within the meaning of Rule 405 under the Securities
Act of 1933, as amended) of the Company. If the holder is a broker-dealer that
will receive New Notes for its own account in exchange for Old Notes, it
acknowledges that it will deliver a prospectus in connection with any resale
of such New Notes.
 
                                      16

 
  The enclosed Letter to Clients contains an authorization by the beneficial
owners of the Old Notes for you to make the foregoing representations.
 
  The Company will not pay any fee or commission to any broker or dealer to
any other persons (other than the Exchange Agent) in connection with the
solicitation of tenders of Old Notes pursuant to the Exchange Offer.
 
  Additional copies of the enclosed material may be obtained from the
undersigned.
 
                                          Very truly yours,
 
                                          OFFSHORE LOGISTICS, INC.
 
                                      17