PLEDGE AND SECURITY AGREEMENT


               PLEDGE AND SECURITY  AGREEMENT,  dated as of April 1, 1997, among
Triton  Aviation  Services  II  LLC,  a  California  limited  liability  company
("Borrower"),  Triton Aviation Services Limited, a Bermuda corporation ("TASL"),
the other parties  executing the signature  pages hereto as pledgors  (Borrower,
TASL,  and  such  other  parties,  collectively,  "Pledgors"  and  each  of them
individually  a  "Pledgor")  and Polaris  Aircraft  Income Fund II, a California
limited partnership ("Lender").

                                R E C I T A L S:

               WHEREAS, Pledgors are the sole members of Borrower; and

               WHEREAS,  Pledgors  are the record and  beneficial  owners of the
membership  interests described in Schedule I hereto (the "Pledged Interests" of
each such Pledgor) issued by Borrower; and

               WHEREAS,   Borrower  has  executed  and  delivered  to  Lender  a
Promissory Note (as the same may be amended,  modified or supplemented from time
to time,  the  "Note"),  pursuant to the  Purchase,  Assignment  and  Assumption
Agreement, dated as of April 1, 1997 (the "Purchase Agreement"),  between Lender
and Borrower; and

               WHEREAS,  Pledgors, as the sole members of Borrower,  will derive
substantial   direct  and  indirect   economic  benefit  from  the  transactions
contemplated  by the Purchase  Agreement and the delivery of the Note to Lender;
and

               WHEREAS,  in connection with the making of the Purchase Agreement
and the delivery of the Note and as security for all of the Obligations,  Lender
is requiring  that Pledgors  shall have  executed and delivered  this Pledge and
Security Agreement and granted the security interest contemplated hereby;

               NOW,  THEREFORE,   in  consideration  of  the  premises  and  the
covenants  hereinafter contained the receipt and sufficiency of which are hereby
agreed and  acknowledged  and to induce  Lender to provide the seller  financing
evidenced by the Note, it is agreed as follows:













1. Definitions.  Unless otherwise defined herein,  terms defined in the Note are
used herein as therein defined,  and the following shall have (unless  otherwise
provided  elsewhere in this Agreement) the following  respective  meanings (such
meanings  being  equally  applicable to both the singular and plural form of the
terms defined):

               "Additional  Holder" shall have the meaning assigned to such term
in Section 7(d) hereof.

               "Agreement"  shall  mean  this  Pledge  and  Security  Agreement,
including all  amendments,  modifications  and  supplements  and any exhibits or
schedules to any of the foregoing, and shall refer to this Agreement as the same
may be in effect at the time such reference becomes operative.

               "Ancillary  Agreements"  shall have the meaning assigned to it in
the Purchase Agreement.

               "Bankruptcy  Code" shall mean title 11,  United  States Code,  as
amended from time to time, and any successor statute thereto

               "Equity  Dividend  Amount" means, (i) for any calendar month that
ends prior to the first Effective Time to occur under the Purchase Agreement, an
amount  equal to  $19,612  and (ii) for the  calendar  month in which  the first
Effective  Time occurs under the Purchase  Agreement and for each calendar month
thereafter,  the Purchase  Agreement,  an amount  equal to $32,687,  and for any
period  that is less than a  calendar  month,  a  proportionate  amount  thereof
calculated  using the same  proportion  that the  number of days in such  period
bears to thirty days.

               "General  Intangibles"  shall mean all "general  intangibles"  as
such term is defined in Section 9-106 of the Uniform  Commercial Code, now owned
or hereafter  acquired by any Pledgor relating to the collateral of such Pledgor
pledged hereby.

               "Governmental  Authority"  shall  mean  (a) any  federal,  state,
provincial or similar government,  and any body, board, department,  commission,
court,  tribunal,  author  ity,  agency  or  other  instrumentality  of any such
government  or  otherwise  exercising  any  executive,  legislative,   judicial,
administrative  or  regulatory  functions  of such  government  or (b) any other
government  entity  having  jurisdiction  over any matter  contemplated  by this
Agreement,  the Purchase Agreement or any other Ancillary Agreements or relating
to the observance or performance of the obligations of any of the parties hereto
or thereto.



                                        2







               "Interests" shall mean all shares, options,  warrants, general or
limited partnership  interests,  membership  interests,  participations or other
equivalents (regardless of how designated) of or in a corporation,  partnership,
limited  liability  company or equivalent  entity  whether  voting or nonvoting,
including,  without  limitation,  common stock,  preferred  stock,  or any other
"equity  security"  (as such term is defined in Rule 3a11-1 of the General Rules
and Regulations  promulgated by the Securities and Exchange Commission under the
Securities Exchange Act of 1934, as amended).

               "Keep Well" shall mean that certain Keep Well Agreement, dated as
of the date hereof, among TASL, Borrower and Lender.

               "Keep Well  Guaranty"  shall  mean that  certain  Guaranty  (Keep
Well), dated as of the date hereof, among TIL, Lender and Borrower.

               "Loan   Guaranty"   shall  mean  that   certain   Guaranty   (SPV
Indebtedness), dated as of the date hereof, between TIL and Borrower.

               "Obligations"  shall  mean  (i)  all  loans,   advances,   debts,
liabilities and  obligations,  for monetary amounts (whether or not such amounts
are liquidated or determinable)  owing by Borrower to Lender,  and all covenants
and duties  regarding  such amounts,  of any kind or nature,  present or future,
whether or not  evidenced by any note,  agreement or other  instrument,  arising
under the Purchase  Agreement or the Note  including,  without  limitation,  all
interest, fees, charges, expenses,  attorneys' fees and any other sum chargeable
to Borrower under the Purchase  Agreement or the Note,  (ii) all  obligations of
any kind or nature,  present or future,  of TASL under the Keep Well,  (iii) all
obligations of any kind or nature, present or future, of TIL under the Keep Well
Guaranty and (iv) all obligations of any kind or nature,  present or future,  of
TIL under the Loan Guaranty.

               "Person"  shall  mean  any   individual,   sole   proprietorship,
partnership,  limited liability company,  joint venture,  trust,  unincorporated
organization, association, corporation, institution, public benefit corporation,
entity or  government  (whether  Federal,  state,  county,  city,  municipal  or
otherwise, including, without limitation, any instrumentality, division, agency,
body or department thereof).


               "Pledged Collateral" shall have the meaning assigned to such term
in Section 2 hereof.



                                        3







               "Pledged  Interests" shall have the meaning assigned to such term
in the recitals hereof.

               "Secured  Obligations"  shall have the  meaning  assigned to such
term in Section 3 hereof.

               "Termination  Date" shall mean the date on which all determinable
and liquidated Obligations have been completely discharged.

               "TIL"  shall  mean   Triton   Investments   Limited,   a  Bermuda
corporation.

               "Transferee"  shall  have the  meaning  assigned  to such term in
Section 7(d) hereof.

               "Uniform  Commercial Code" shall mean the Uniform Commercial Code
as the same  may,  from time to time,  be in effect in the State of  California;
provided,  however, in the event that, by reason of mandatory provisions of law,
any or all of the  attachment,  perfection  or  priority  of  Lender's  security
interest in any  Collateral  is governed  by the Uniform  Commercial  Code as in
effect in a jurisdiction other than the State of California,  Uniform Commercial
Code  shall  mean  the  Uniform  Commercial  Code as in  effect  in  such  other
jurisdiction for purposes of the provisions  hereof relating to such attachment,
perfec  tion or  priority  and  for  purposes  of  definitions  related  to such
provisions.

               2. Pledge.  Each Pledgor hereby pledges to Lender,  and grants to
Lender,  a first  priority  security  interest  in,  all of the  following  (the
"Pledged Collateral"):

               (a) in the case of each Pledgor other than Borrower,  the Pledged
Interests of such Pledgor and all dividends,  distributions,  cash,  instruments
and other  property  or  proceeds  from  time to time  received,  receivable  or
otherwise distributed by Borrower in respect of or in exchange for any or all of
the  Pledged  Interests  of  such  Pledgor;  provided,   however,  that  Pledged
Collateral  shall not  include  any  distributions  made by  Borrower  which are
permitted to be made by it under Section 7(b) hereof;

               (b)  in the  case  of  each  Pledgor  other  than  Borrower,  all
additional  Interests  issued by Borrower  to such  Pledgor or from time to time
acquired by such Pledgor in any manner  (which  Interests  shall be deemed to be
part of the Pledged Interests), and the certificates,  if any, representing such
additional Interests,  and all dividends,  distributions,  cash, instruments and
other property or proceeds from time to



                                        4







time received,  receivable or otherwise distributed in respect of or in exchange
for any or all of such Interests;

               (c) in the case of Borrower,  all rights under the Keep Well, the
Keep Well Guaranty and the Loan Guaranty;

               (d)    in the case of each Pledgor, all General Intangibles; and

               (e)    all proceeds of any of the foregoing.

               3. Security for  Obligations.  This  Agreement  secures,  and the
Pledged Collateral is security for, the prompt payment in full when due, whether
at stated  maturity,  by  acceleration  or  otherwise,  and  performance  of the
Obligations, whether for principal, premium, interest, fees, costs and expenses,
and all  obligations of Pledgors now or hereafter  existing under this Agreement
(collectively, the "Secured Obligations").

               4.  Delivery of Pledged  Collateral.  All  certificates,  if any,
representing or evidencing the Pledged  Interests shall be delivered to and held
by or on behalf of  Lender  pursuant  hereto  and shall be  accompanied  by duly
executed  instruments  of  transfer  or  assignment  in  blank,  all in form and
substance  satisfactory  to Lender.  Lender shall have the right, at any time in
its discretion and without notice to Pledgors,  to transfer to or to register in
the  name of  Lender  or any of its  nominees,  as  pledgees,  any or all of the
Pledged  Interests.  In  addition,  Lender  shall  have the right at any time to
exchange   certificates  or  instruments   representing  or  evidencing  Pledged
Interests for certificates or instruments of smaller or larger denominations.

               5.  Representations  and Warranties.  Each Pledgor represents and
warrants to Lender that:

               (a) Such  Pledgor  is, and at the time of delivery of the Pledged
Interests  to Lender  pursuant  to Section 4 hereof  will be, the sole holder of
record and the sole beneficial owner of the Pledged  Collateral  pledged by such
Pledgor  free and clear of any Lien  thereon  or  affecting  the title  thereto,
except for the Lien created by this Agreement.

               (b) All of the Pledged  Interests  of such Pledgor have been duly
authorized, validly issued and are fully paid and nonassessable.



                                        5







               (c) Such Pledgor has the right and requisite authority to pledge,
assign,  transfer,  deliver, deposit and set over the Pledged Collateral pledged
by such Pledgor to Lender as provided herein.

               (d) None of the Pledged Interests of such Pledgor has been issued
or  transferred  in  violation  of  the  securities   registration,   securities
disclosure  or  similar  laws of any  jurisdiction  to which  such  issuance  or
transfer may be subject.

               (e) As of the date hereof, the authorized, issued and outstanding
Interests  of  Borrower  consist  solely of the  membership  interests  that are
described  in Schedule I hereto.  As of the date  hereof,  there are no existing
options,  warrants, calls or commitments of any character whatsoever relating to
any Interests of Borrower other than as set forth on Exhibit A hereto.

               (f) No  consent,  approval,  authorization  or other order of any
Person  and no  consent,  authorization,  approval,  or other  action by, and no
notice to or filing  with,  any  Governmental  Authority,  other than as already
obtained,  given or filed,  is required by Pledgor  either (i) for the pledge by
such  Pledgor of the Pledged  Collateral  pursuant to this  Agreement or for the
execution, delivery or performance of this Agreement or the Ancillary Agreements
to which such  Pledgor is a party,  by such  Pledgor or (ii) for the exercise by
Lender of the  voting or other  rights  provided  for in this  Agreement  or the
remedies in respect of the Pledged Collateral pursuant to this Agreement, except
as may be required in connection  with such  disposition  by laws  affecting the
offering and sale of securities generally.

               (g) The pledge, assignment and delivery of the Pledged Collateral
pursuant to this  Agreement  will create a valid  first  priority  lien on and a
first priority  perfected security interest in the Pledged Collateral pledged by
such  Pledgor,  and the  proceeds  thereof,  securing the payment of the Secured
Obligations.

               (h) This  Agreement  and the  Ancillary  Agreements to which such
Pledgor is a party have been duly  authorized,  executed  and  delivered by such
Pledgor and  constitute  legal,  valid and binding  obligations  of such Pledgor
enforceable  in accordance  with their terms,  except as  enforceability  may be
limited by bankruptcy, insolvency, or other similar laws affecting the rights of
creditors generally or by the application of general equity principles.

               (i)    Borrower has no subsidiaries.



                                        6







               The  representations  and  warranties set forth in this Section 5
shall survive the execution and delivery of this Agreement.


               6.     Covenants.

               (a) Each Pledgor jointly and severally  covenants and agrees that
until the Termination Date:

                      (i) Subject to Section  7(d),  without  the prior  written
        consent of Lender, such Pledgor will not sell, assign, transfer,  pledge
        or otherwise  encumber any of its rights in or to the Pledged Collateral
        pledged by such Pledgor or any unpaid  dividends or other  distributions
        or payments with respect thereto or grant a Lien in any therein.

                      (ii) Such Pledgor will, at its expense,  promptly execute,
        acknowledge and deliver all such instruments and take all such action as
        Lender  from time to time may  reasonably  request in order to ensure to
        Lender  the  benefits  of the  Liens  in and to the  Pledged  Collateral
        intended to be created by this  Agreement,  including  the filing of any
        necessary  Uniform  Commercial Code financing  statements,  which may be
        filed by Lender with or without the signature of such Pledgor,  and will
        cooperate  with Lender,  at such  Pledgor's  expense,  in obtaining  all
        necessary  governmental approvals and making all necessary filings under
        federal  or  state  law in  connection  with  such  Liens or any sale or
        transfer of the Pledged Collateral.

                      (iii) Such  Pledgor  has and will  defend the title to the
        Pledged  Collateral and the Liens of Lender thereon against the claim of
        any  Person  and  will  maintain  and  preserve  such  Liens  until  the
        Termination Date.

                      (iv) Each of them  will,  upon  obtaining  any  additional
        Interest of Borrower,  which Interest is not already Pledged Collateral,
        promptly  (and in any event within three (3) business  days)  deliver to
        Lender  a  Pledge   Amendment,   duly  executed  by  such  Pledgor,   in
        substantially the form of Schedule II hereto (a "Pledge Amendment"),  in
        respect  of the  additional  Pledged  Interests  which are to be pledged
        pursuant to this  Agreement.  Each Pledgor hereby  authorizes  Lender to
        attach  each  Pledge  Amendment  to this  Agreement  and agrees that all
        Pledged  Interests  listed on any Pledge  Amendment  delivered to Lender
        shall for all purposes hereunder be considered Pledged Collateral.




                                        7







                      (v) None of them will take any  action to amend,  alter or
        change Borrower's articles of organization or operating agreement (other
        than amendments  permitted under the Note), the Keep Well, the Keep Well
        Guaranty or the Loan Guaranty or permit  Borrower to repeal its articles
        of organization.

                      (vi)  None  of  them  will  take  any  action  that  would
        authorize  or permit  Borrower to take any of the actions  specified  in
        Paragraph 2.4 of its operating agreement.

                      (vii)  TASL  covenants  and  agrees  that  it  will  cause
        Borrower  to  comply  with the  terms of and  limitations  contained  in
        Borrower's articles of organization or in its operating agreement.

               (b) TASL  shall  deliver  to  Lender  written  notice  of (i) any
payments made by it to Borrower  pursuant to the Keep Well and (ii) any dividend
or distribution received by it from Borrower other than Equity Dividend Amounts,
in each case no later than three (3) business days after disbursing such payment
or the receipt of any such dividend or distribution, as applicable.

               (c) TASL  covenants  and agrees that it will at all times  during
the term of this Agreement maintain  management  personnel who are qualified and
competent to manage and direct the business and  operations  of Borrower and who
have experience in the commercial aviation industry.

               (d) TASL covenants and agrees that, at all times,  Triton Members
shall hold,  in the  aggregate,  at least fifty  percent  (50%) of the  Economic
Interests of Borrower. TASL covenants and agrees that, at all times, it shall be
the sole  manager of  Borrower  and shall have all  responsibilities  and duties
allocated  to TASL as manager  of  Borrower  pursuant  to  Borrower's  operating
agreement  or  articles of  organization  and shall not make any  delegation  or
assignment  to any  other  Person  of  such  responsibility  or duty  except  as
permitted thereby.

               7.  Pledgors'  Rights.  (a) As long as no  Default  or  Event  of
Default shall have occurred and be continuing  and until written notice shall be
given to each Pledgor in accordance with Section 8(a) hereof, such Pledgor shall
have the right, from time to time, to vote and give consents with respect to the
Pledged  Collateral or any part thereof for all purposes not  inconsistent  with
the provisions of this Agreement, the Note or any Ancillary Agreement; provided,
however,  that no vote shall be cast,  and no  consent  shall be given or action
taken,  which  would have the effect of  impairing  the  position or interest of



                                        8







Lendor in respect of the Pledged  Collateral or which would  authorize or effect
(i) the dissolution or liquidation,  in whole or in part, of Borrower,  (ii) the
consolidation  or merger of  Borrower  with any other  Person,  (iii)  except as
permitted under this Agreement or the Note, the sale, disposition or encumbrance
of all or substantially all of the assets of Borrower,  (iv) except as permitted
by Section 7(d) hereof and Section 4.4 of the Note, any change in the authorized
number of  Interests  or the stated  capital of Borrower and the issuance of any
additional  Interests,  (v) the  alteration of the voting rights with respect to
the Interests of Borrower,  or (vi) any change,  alteration or  modification  of
Borrower's articles of organization,  operating agreement (other than amendments
permitted  under the Note,  the Keep Well,  the Keep Well  Guaranty  or the Loan
Guaranty.

               (b) No Pledgor  shall be  entitled  to collect  and  receive  any
dividend or other  distribution paid in respect of the Pledged Interests whether
paid or payable in cash,  instruments or other property other than (1) beginning
as of April 1, 1997,  payable in the next calendar  month,  the Equity  Dividend
Amount  and any  accrued  and  unpaid  Equity  Dividend  Amount  for each  month
thereafter, (2) with respect to TASL only, amounts equal to equity contributions
made by TASL pursuant to the Keep Well which have not been  previously  recouped
through the payment of any dividend or  distribution by Borrower and (3) amounts
equal to any  reduction  of the Cash Amount  pursuant to Section 4(c) or Section
4(d)(ii) of the Purchase Agreement; provided, however, that during any period in
which any  payment  under the Note is overdue or a Default has  occurred  and is
continuing,  no Pledgor shall be entitled to collect and receive any dividend or
other  distribution  whatsoever  but Borrower may continue to accrue a liability
equal to the Equity  Dividend  Amount  during such period and  Borrower may make
payments in respect of any such accrued  liability so long as no amounts due and
payable under the Note are overdue and no Default thereunder is continuing,  and
provided,  further,  that any permitted dividends or distributions in respect of
the Pledged  Interests shall be paid only to the extent  permitted by applicable
law.

               (c)  Other  than  dividends  and  distributions  permitted  to be
received by a Pledgor  pursuant to subsection (b) above,  all dividends or other
distributions paid in respect of any of the Pledged Interests,  whenever paid or
made,  shall be delivered to Lender to hold as Pledged  Collateral and shall, if
received by such  Pledgor,  be  received in trust for the benefit of Lender,  be
segregated  from the other  property or funds of such Pledgor,  and be forthwith
delivered to Lender as Pledged  Collateral in the same form as so received (with
any necessary endorsement).



                                        9







               (d) (i) Borrower shall be permitted to issue additional Interests
to any Person (each,  an  "Additional  Holder") and (ii) each member of Borrower
shall be permitted to sell or otherwise transfer Pledged Interests to any Person
(each, a "Transferee");  provided,  in each case that after giving effect to any
such  issuance  or transfer  (A) the number of members of  Borrower  who are not
Triton  Members  shall not exceed three (3) as a result of any such  issuance or
transfer,  (B) the Triton Members shall hold, in the aggregate,  at least 50% of
the Economic  Interests of Borrower,  (C) the Additional Holder or Transferee of
such equity interest shall be a Qualified Holder,  (D) such Additional Holder or
Transferee  shall  expressly  agree to the pledge of such  Interests  under this
Agreement  and to be bound by the terms and  conditions  hereof by delivery of a
duly executed Pledge Amendment, and (E) after notice to Lender by the applicable
Pledgor,  pursuant to the terms of Section 19 hereof,  Lender  shall  consent to
such  transfer  or  issuance,  such  consent  not to be  unreasonably  withheld;
provided,  however,  that if Lender does not  respond to such notice  within ten
(10) days after  receipt by Lender of such notice,  such consent shall be deemed
granted.  Notwithstanding  the foregoing,  no such issuance or transfer shall be
permitted if such issuance or transfer would violate any applicable law or cause
the Aircraft owned,  directly or indirectly,  by Borrower then registered  under
the Act to no longer be eligible for registration under the Act.

               8. Defaults and Remedies.  (a) Upon the occurrence of an Event of
Default and during the  continuation  of such Event of  Default,  then or at any
time  after  the  declaration  of such  Event of  Default  (provided  that  such
declaration  is not  rescinded by Lender) and following  written  notice to each
Pledgor,  Lender  (personally  or  through  an agent) is hereby  authorized  and
empowered to transfer and register in its name or in the name of its nominee the
whole or any part of the Pledged Collateral,  to exercise the voting rights with
respect  thereto,  to collect and receive all dividends and other  distributions
made  thereon,  to sell in one or more sales after seven (7) days' notice of the
time and place of any public sale or of the time after  which a private  sale is
to take place (which notice each Pledgor agrees is commercially reasonable), but
without  any  previous  notice  or  advertisement,  the whole or any part of the
Pledged  Collateral and to otherwise act with respect to the Pledged  Collateral
as though Lender was the outright owner thereof, each Pledgor hereby irrevocably
constituting  and appointing  Lender as the proxy and  attorney-in-fact  of such
Pledgor,  with full power of substitution to do so;  provided,  however,  Lender
shall not have any duty to exercise  any such right or to preserve  the same and
shall not be liable  for any  failure to do so or for any delay in doing so. Any
sale shall be made at a public or private sale at Lender's place of business, or
at any public  building in the City and County of San  Francisco or elsewhere to
be named in the  notice of sale,  either  for cash or upon  credit or for future
delivery at such price as Lender may deem fair,  and Lender may be the purchaser
of the  whole or any part of the  Pledged  Collateral  so sold and hold the same



                                       10








thereafter  in its own right free from any claim of such Pledgor or any right of
redemption.  Each sale shall be made to the highest bidder,  but Lender reserves
the right to reject any and all bids at such sale which, in its  discretion,  it
shall  deem  inadequate.  Demands of  performance,  except as  otherwise  herein
specifically  provided for, notices of sale,  advertisements and the presence of
property at sale are hereby waived and any sale hereunder may be conducted by an
auctioneer or any officer or agent of Lender.

               (b) If, at the original  time or times  appointed for the sale of
the whole or any part of the Pledged  Collateral,  the highest  bid, if there be
but  one  sale,  shall  be  inadequate  to  discharge  in full  all the  Secured
Obligations, or if the Pledged Collateral be offered for sale in lots, if at any
of such sales,  the  highest bid for the lot offered for sale would  indicate to
Lender, in its discretion,  the unlikelihood of the proceeds of the sales of the
whole of the Pledged  Collateral  being  sufficient to discharge all the Secured
Obligations,  Lender  may,  on  one or  more  occasions  and in its  discretion,
postpone  any of said  sales by public  announcement  at the time of sale or the
time of previous  postponement of sale, and no other notice of such postponement
or  postponements  of sale need be given,  any other notice being hereby waived;
provided,  however, that any sale or sales made after such postponement shall be
after seven (7) days' notice to Pledgors.

               (c) In the  event of any  sales  hereunder  Lender  shall,  after
deducting all costs or expenses of every kind (including  reasonable  attorneys'
fees and disbursements) for care,  safekeeping,  collection,  sale,  delivery or
otherwise,  apply the  residue of the  proceeds  of the sales to the  payment or
reduction,  either in whole or in part, of the Secured Obligations in accordance
with the agreements and instruments  governing and evidencing such  Obligations,
returning the surplus, if any, to Pledgors.

               (d) If, at any time when Lender  shall  determine to exercise its
right to sell the whole or any part of the Pledged  Collateral  hereunder,  such
Pledged  Collateral  or the part  thereof to be sold  shall not,  for any reason
whatsoever,  be  effectively  registered  under the  Securities  Act of 1933, as
amended (or any similar statute then in effect) (the "Act"),  Lender may, in its
discretion  (subject only to applicable  requirements of law), sell such Pledged
Collateral  or part  thereof  by  private  sale in such  manner  and under  such
circumstances  as Lender may deem  necessary  or  advisable,  but subject to the
other  requirements  of this Section 8, and shall not be required to effect such
registration  or  to  cause  the  same  to be  effected.  Without  limiting  the
generality of the foregoing, in any such event Lender in its discretion (x) may,
in accordance with applicable securities laws, proceed to make such private sale
notwithstanding  that a  registration  statement for the purpose of  registering
such Pledged Collateral or part thereof could be or shall have been  filed under



                                       11







the Act, (y) may  approach and  negotiate  with a single  possible  purchaser to
effect  such  sale  and (z) may  restrict  such  sale to a  purchaser  who  will
represent and agree that such purchaser is purchasing  for its own account,  for
investment  and not  with a view  to the  distribution  or sale of such  Pledged
Collateral or part thereof.  In addition to a private sale as provided  above in
this  Section  8,  if  any  of  the  Pledged  Collateral  shall  not  be  freely
distributable  to the public without  registration  under the Act at the time of
any proposed  sale pursuant to this Section 8, then Lender shall not be required
to  effect  such  registration  or cause  the same to be  effected  but,  in its
discretion  (subject only to applicable  requirements  of law), may require that
any sale  hereunder  (including  a sale at  auction)  be  conducted  subject  to
restrictions  (i) as to the financial  sophistication  and ability of any Person
permitted to bid or purchase at any such sale, (ii) as to the content of legends
to be placed upon any certificates  representing the Pledged  Collateral sold in
such sale,  including  restrictions on future transfer thereof,  (iii) as to the
representations required to be made by each Person bidding or purchasing at such
sale relating to that Person's  access to financial  information  about Pledgors
and such Person's intentions as to the holding of the Pledged Collateral so sold
for  investment,  for its own account,  and not with a view to the  distribution
thereof,  and (iv) as to such other  matters as Lender may,  in its  discretion,
deem  necessary  or  appropriate  in order that such sale  (notwithstanding  any
failure so to register) may be effected in compliance  with the Bankruptcy  Code
and other laws affecting the  enforcement  of creditors'  rights and the Act and
all applicable state securities laws.

               (e) Each Pledgor recognizes that any such private sale may result
in prices and other terms less  favorable to the seller than if such sale were a
public  sale  and,  notwithstanding  such  circumstances,  agrees  that any such
private  sale  shall be deemed to have  been made in a  commercially  reasonable
manner.  Lender  shall  be  under  no  obligation  to delay a sale of any of the
Pledged  Collateral for the period of time necessary to permit the registrant to
register  such  securities  for public sale under the Act,  or under  applicable
state securities laws, even if any Pledgor would agree to do so.

               (f) Each Pledgor  agrees that following the occurrence and during
the  continuance of an Event of Default it will not at any time plead,  claim or
take the benefit of any appraisal,  valuation,  stay,  extension,  moratorium or
redemption  law now or  hereafter  in force in order  to  prevent  or delay  the
enforcement of this Agreement,  or the absolute sale of the whole or any part of
the Pledged  Collateral or the  possession  thereof by any purchaser at any sale
hereunder, and each Pledgor waives the benefit of all such laws to the extent it
lawfully  may do so. Each  Pledgor  agrees that it will not  interfere  with any
right,  power and  remedy of Lender  provided  for in this  Agreement  or now or
hereafter  existing  at law or in  equity or by  statute  or  otherwise,  or the




                                       12








exercise  or  beginning  of the  exercise  by  Lender of any one or more of such
rights,  powers  or  remedies.  No  failure  or delay on the part of  Lender  to
exercise  any such right,  power or remedy and no notice or demand  which may be
given to or made upon any  Pledgor by Lender with  respect to any such  remedies
shall operate as a waiver thereof, or limit or impair Lender's right to take any
action or to exercise any power or remedy  hereunder,  without notice or demand,
or prejudice its rights as against any Pledgor in any respect.

               (g) Each  Pledgor  further  agrees  that a  breach  of any of the
covenants  contained in this Section 8 will cause irreparable  injury to Lender,
that  Lender has no  adequate  remedy at law in respect of such breach and, as a
consequence,  agrees that each and every  covenant  contained  in this Section 8
shall be specifically  enforceable against such Pledgor, and such Pledgor hereby
waives  and agrees not to assert  any  defenses  against an action for  specific
performance of such covenants except for a defense that the Secured  Obligations
are not then due and payable in accordance  with the agreements and  instruments
governing and evidencing such obligations.

               9.  Application  of Proceeds.  Any cash held by Lender as Pledged
Collateral  and all cash proceeds  received by Lender in respect of any sale of,
liquidation  of,  or  other  realization  upon  all or any  part of the  Pledged
Collateral  or  pursuant to Section  8(g)  hereof  shall be applied by Lender as
follows:

               (a) First, to the payment of the costs and expenses of such sale,
including reasonable  compensation to Lender and its agents and counsel, and all
expenses,  liabilities  and  advances  made or incurred by Lender in  connection
therewith;

               (b)    Next, to the payment of the Secured Obligations; and

               (c) Finally, after payment in full of all Secured Obligations, to
the payment to Pledgors, or their successors or assigns, or to whomsoever may be
lawfully  entitled to receive the same or as a court of  competent  jurisdiction
may direct, of any surplus then remaining from such proceeds.

               10. Waiver.  No delay on Lender's part in exercising any power of
sale, Lien,  option or other right hereunder,  and no notice or demand which may
be given to or made upon  Pledgors by Lender with  respect to any power of sale,
Lien,  option or other right hereunder,  shall  constitute a waiver thereof,  or
limit or impair  Lender's  right to take any action or to exercise  any power of
sale, Lien,  option, or any other right hereunder,  without notice or demand, or
prejudice Lender's rights as against Pledgors in any respect.


                                       13







               11.  Assignment.  Lender  may  assign,  endorse or  transfer  any
instrument evidencing all or any part of the Secured Obligations as provided in,
and in accordance  with, the Note, the Keep Well, the Keep Well Guaranty and the
Loan  Guaranty,  as  applicable,  and the  holder  of such  instrument  shall be
entitled to the benefits of this Agreement.

               12. Termination. Immediately following the payment of all Secured
Obligations, Lender shall deliver to each Pledgor the Pledged Collateral pledged
by such Pledgor at the time subject to this  Agreement  and all  instruments  of
assignment executed in connection therewith,  free and clear of the Liens hereof
and, except as otherwise provided herein, all of Pledgors' obligations hereunder
shall at such time terminate.

               13.  Lien  Absolute.  All  rights  of Lender  hereunder,  and all
obligations  of  Pledgors   hereunder,   shall  be  absolute  and  unconditional
irrespective of:

               (a) any lack of  validity  or  enforceability  of the  Note,  the
Purchase Agreement,  the Keep Well, the Keep Well Guaranty, the Loan Guaranty or
any  other   agreement  or  instrument   governing  or  evidencing  any  Secured
Obligations;

               (b) any change in the time,  manner or place of payment of, or in
any other  term of,  all or any part of the  Secured  Obligations,  or any other
amendment or waiver of or any consent to any departure  from the Note,  the Keep
Well,  the Keep Well  Guaranty,  the Loan  Guaranty  or any other  agreement  or
instrument governing or evidencing any Secured Obligations;

               (c)  any  exchange,   release  or   nonperfection  of  any  other
collateral,  or any release or  amendment  or waiver of or consent to  departure
from any guaranty, for all or any of the Secured Obligations; or

               (d) any other  circumstance  which might  otherwise  constitute a
defense available to, or a discharge of, any Pledgor.

               14. Release.  Each Pledgor consents and agrees that Lender may at
any time, or from time to time, in its  discretion  (a) renew,  extend or change
(pursuant to any right to do so provided in the relevant  agreement) the time of
payment,  and/or the manner, place or terms of payment of all or any part of the
Secured Obligations and (b) exchange, release and/or surrender all or any of the
Pledged Collateral,  or any part thereof, by whomsoever deposited,  which is now
or may hereafter be held by Lender in connection  with all or any of the Secured
Obligations;  all in such manner and upon such terms as Lender may deem  proper,


                                       14







and without  notice to or further  assent  from such  Pledgor,  it being  hereby
agreed  that  such  Pledgor  shall be and  remain  bound  upon  this  Agreement,
irrespective  of the  existence,  value  or  condition  of  any  of the  Pledged
Collateral,   and  notwithstanding  any  such  change,   exchange,   settlement,
compromise,  surrender,  release, renewal or extension, and notwithstanding also
that the Secured  Obligations may, at any time,  exceed the aggregate  principal
amount thereof set forth in the Note, the Keep Well, the Keep Well Guaranty, the
Loan Guaranty or any other  agreement  governing any Secured  Obligations.  Each
Pledgor  hereby  waives  notice  of  acceptance  of  this  Agreement,  and  also
presentment,  demand,  protest  and  notice  of  dishonor  of any and all of the
Secured Obligations,  and promptness in commencing suit against any party hereto
or liable  hereon,  and in giving any notice to or of making any claim or demand
hereunder  upon such  Pledgor.  No act or omission of any kind on Lender's  part
shall in any event affect or impair this Agreement.

               15. Indemnification. Each Pledgor jointly and severally agrees to
indemnify  and hold Lender  harmless  from and  against any taxes,  liabilities,
claims and damages, including reasonable attorney's fees and disbursements,  and
other  expenses  incurred  or arising by reason of the taking or the  failure to
take action by Lender,  in good faith,  in respect of any  transaction  effected
under  this  Agreement  or in  connection  with the Lien  provided  for  herein,
including, without limitation, any taxes payable in connection with the delivery
or  registration  of any of the  Pledged  Collateral  as provided  herein.  Each
Pledgor jointly and severally agrees to promptly reimburse Lender for all actual
reasonable  out-of-pocket  costs and expenses,  including,  without  limitation,
reasonable   counsel  fees,   incurred  by  Lender,   in  connection   with  the
administration  and  enforcement  of this  Agreement  and all  reasonable  fees,
expenses and disbursements,  including the reasonable fees of Lender's agents or
representatives,  incurred in connection with any lien searches and filings made
by Lender, any amendments hereto or waivers or modifications  hereof;  provided,
however,  that  Pledgors  shall not be  obligated  to pay any costs or  expenses
(including attorney's fees) incurred by Lender in connection with preparation of
this Agreement or any other Ancillary  Agreement or any ordinary  administrative
costs and expenses of Lender in the absence of a Default by Borrower  under this
Agreement, the Note or any other Ancillary Agreement or a Default by any Pledgor
under this Agreement or any other Ancillary  Agreement;  and provided,  further,
that  nothing  contained  herein  shall limit or be deemed to limit any right of
Borrower under Section 13 of the Purchase Agreement. The obligations of Pledgors
under this Section 15 shall survive the termination of this Agreement.

               16. Reinstatement.  This Agreement shall remain in full force and
effect and continue to be  effective  should any petition be filed by or against
any  Pledgor  for  liquidation  or  reorganization,  should any  Pledgor  become



                                       15







insolvent  or make an  assignment  for the  benefit  of  creditors  or  should a
receiver  or  trustee  be  appointed  for  all or any  significant  part  of any
Pledgor's  assets,  and shall continue to be effective or be reinstated,  as the
case may be, if at any time payment and performance of the Secured  Obligations,
or any part thereof,  is,  pursuant to applicable  law,  rescinded or reduced in
amount,  or must otherwise be restored or returned by any obligee of the Secured
Obligations,  whether as a "voidable  preference,"  "fraudulent  conveyance," or
otherwise,  all as though such payment or performance  had not been made. In the
event that any payment, or any part thereof, is rescinded,  reduced, restored or
returned, the Secured Obligations shall be reinstated and deemed reduced only by
such amount paid and not so rescinded, reduced, restored or returned.

               17.  Miscellaneous.  (a)  Lender  may  execute  any of its duties
hereunder by or through  agents or employees  and shall be entitled to advice of
counsel concerning all matters pertaining to its duties hereunder.

               (b) Neither Lender nor any of its officers, directors, employees,
agents or counsel shall be liable for any action lawfully taken or omitted to be
taken by it or them hereunder or in connection herewith, except for its or their
own gross negligence or willful misconduct.

               (c) This  Agreement  shall be  binding  upon  Pledgors  and their
successors  and assigns,  and shall inure to the benefit of, and be  enforceable
by,  Lender  and its  successors  and  assigns,  and shall be  governed  by, and
construed  and enforced in accordance  with,  the internal laws in effect in the
State of  California  without  giving effect to principles of conflicts of laws,
and none of the terms or  provisions of this  Agreement may be waived,  altered,
modified  or amended  except in writing  duly signed for and on behalf of Lender
and Pledgors.

               18.  Severability.  If for any reason any provision or provisions
hereof are  determined to be invalid and contrary to any existing or future law,
such  invalidity  shall not impair the operation of or affect those  portions of
this Agreement which are valid.

               19. Notices.  Except as otherwise provided herein, whenever it is
provided herein that any notice, demand, request, consent, approval, declaration
or  other  communication  shall or may be  given  to or  served  upon any of the
parties by any other party,  or whenever  any of the parties  desires to give or
serve upon any other a communication  with respect to this Agreement,  each such
notice, demand, request, consent,  approval,  declaration or other communication
shall be in  writing  and  either  shall be  delivered  in person  with  receipt



                                       16







acknowledged or sent by registered or certified mail, return receipt  requested,
postage prepaid, or by telecopy and confirmed by telecopy  answerback  addressed
as follows:

               (a)    If to Lender, at

                      c/o Polaris Investment Management Corporation
                      201 Mission Street, 27th Floor
                      San Francisco, CA  94105
                      Attention:   President
                      Telecopy Number:  (415) 284-7460

                      With copies to

                      c/o Polaris Investment Management Corporation
                      201 Mission Street, 27th Floor
                      201 High Ridge Road, 1st Floor
                      Stamford, CT  06927-4900
                      Attention:  Portfolio Management
                      Telecopy Number:  (203) 357-4585


               (b)    If to any Pledgor, at

                      c/o Triton Aviation Services Limited
                      55 Green Street, Suite 500
                      San Francisco, CA  94111
                      Attention:  President
                      Telecopy Number:  (415) 398-9184


or at such  other  address  as may be  substituted  by  notice  given as  herein
provided.  The giving of any notice required  hereunder may be waived in writing
by the party  entitled to receive such notice.  Every notice,  demand,  request,
consent, approval,  declaration or other communication hereunder shall be deemed
to have been duly  given or  served on the date on which  personally  delivered,
with receipt  acknowledged,  telecopied and confirmed by telecopy  answerback or
three (3) business  days after the same shall have been  deposited in the United
States  mail.  Failure  or delay in  delivering  copies of any  notice,  demand,
request,  consent,  approval,  declaration or other communication to the persons



                                       17







designated  above  to  receive  copies  shall  in no way  adversely  affect  the
effectiveness of such notice, demand, request, consent, approval, declaration or
other communication.

               20. Confidentiality. Lender agrees that it will keep confidential
all  information  regarding  Pledgors that it may receive in connection with the
transactions  contemplated  hereunder  and  agrees  that it will  only  use such
information in connection  with such  transactions  and will not disclose any of
such information other than (i) to its directors, officers, employees, advisors,
auditors,  agents or  representatives  who are or are expected to be involved in
the evaluation of such information in connection with such  transactions and who
are  advised  of the  confidential  nature  of such  information  (and for whose
compliance  Lender  shall  be  liable),  (ii)  to the  extent  such  information
presently is or  hereafter  becomes  available  to Lender on a  non-confidential
basis from a source other than a Pledgor,  (iii) to the extent such  information
has been independently  acquired or developed by Lender without violating any of
its obligations under the Purchase Agreement or any Ancillary Agreement, or (iv)
to the extent disclosure is required by law, regulation or judicial order.

               21.  Section  Titles.   The  Section  titles  contained  in  this
Agreement  are and shall be without  substantive  meaning or content of any kind
whatsoever and are not a part of the agreement between the parties hereto.

               22. Counterparts. This Agreement may be executed in any number of
counterparts,   which  shall,   collectively  and  separately,   constitute  one
agreement.



                                       18







               IN WITNESS  WHEREOF,  the parties  hereto have caused this Pledge
and Security Agreement to be duly executed as of the date first written above.


                                  TRITON AVIATION SERVICES II LLC
                                  By:  Triton Aviation Services Limited, its
                                         Manager

                                  By: /S/ JOHN E. FLYNN
                                      -----------------------------------------
                                      Title: JOHN E. FLYNN, PRESIDENT


                                  TRITON AVIATION SERVICES LIMITED


                                  By: /S/ JOHN E. FLYNN
                                      -----------------------------------------
                                      Title: JOHN E. FLYNN, PRESIDENT


                                  TRITON AVIATION LIMITED


                                  By: /S/ STEVEN C. WIGHT
                                      -----------------------------------------
                                      Title: STEVEN C. WIGHT, MANAGING DIRECTOR


Accepted and Acknowledged by:

POLARIS AIRCRAFT INCOME FUND II
By:  Polaris Investment Management
       Corporation, General Partner

By: /S/ MARC A. MEICHES
    --------------------------------------
    Title: MARC A. MEICHES, VICE PRESIDENT



                                       19













                                   SCHEDULE I

                Attached  to and  forming  a part of  that  certain  Pledge  and
Security  Agreement dated as of April 1, 1997 among Triton Aviation  Services II
LLC, a  California  limited  liability  compa y  ("Borrower"),  Triton  Aviation
Services Limited,  a Bermuda  corporation  ("TASL"),  Triton Aviation Limited, a
Bermuda  corporation  (collectively,  "Pledgors" and each of them individually a
"Pledgor") to Polaris Aircraft Income Fund II, a California limited partnership.

Name and
Address of
Pledgor                                                             Interests
- -------                                                             ---------

Triton Aviation Services Limited                                       99%
55 Green Street, Suite 500
San Francisco, California 94111

Triton Aviation Limited                                                 1%
55 Green Street, Suite 500
San Francisco, California 94111







                                   SCHEDULE II
                      to the Pledge and Security Agreement

                                PLEDGE AMENDMENT

                This Pledge Amendment,  dated ______, 19__ is delivered pursuant
to [Section 6(a)(iv)/Section 7(d)] of the Pledge and Security Agreement referred
to below.  The  undersigned  hereby  agrees  that this Pledge  Amendment  may be
attached to that certain Pledge and Security Agreement,  dated ________ __, 1997
among the undersigned and others,  as Pledgors,  to Polaris Aircraft Income Fund
II, a California limited partnership,  that the Pledged Interests listed on this
Pledge Amendment shall be and become a part of the Pledged  Collateral  referred
to  in  said  Pledge  and  Security  Agreement  and  shall  secure  all  Secured
Obligations  referred  to in said  Pledge and  Security  Agreement  and that the
undersigned  shall be deemed to be a Pledgor  under  said  Pledge  and  Security
Agreement.

                                                    [Name of Pledgor]

                                                    By: _______________________
                                                       Title:


Name and
Address of
Pledgor                                                            Interests
- -------                                                            ---------







                                       EXHIBIT A


None