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                                                                 EXHIBIT 10.4.16

                            SECOND AMENDMENT TO LOAN
                             AND SECURITY AGREEMENT


         THIS SECOND AMENDMENT TO LOAN AND SECURITY AGREEMENT (this "Amendment")
is made and entered into as of the 21 day of December, 1999, by and among the
financial institutions party to the below-described Loan Agreement (the
"Lenders"), BANK OF AMERICA, N.A., formerly NationsBank, N.A., as agent for the
Lenders (the "Agent"), AMERICAN AIRCARRIERS SUPPORT, INCORPORATED, a Delaware
corporation ("AAS"), and the Subsidiaries of AAS party hereto as borrowers
(together with AAS, the "Borrowers").

                              W I T N E S S E T H :

         WHEREAS, the Agent, the Lenders and the Borrowers entered into that
certain Loan and Security Agreement, dated as of May 25, 1999 (as amended from
time to time, the "Loan Agreement"), pursuant to which the Agent and the Lenders
agreed to extend certain financial accommodations to the Borrowers; and

         WHEREAS, the Agent, the Lenders and the Borrowers desire to amend the
Loan Agreement as set forth herein.

         NOW, THEREFORE, in consideration of the foregoing premises, and other
good and valuable consideration, the receipt and legal sufficiency of which are
hereby acknowledged, the parties hereto hereby agree as follows:

         1. All capitalized terms used herein and not otherwise expressly
defined herein shall have the respective meanings given to such terms in the
Loan Agreement.

         2. Subject to the provisions of SECTION 5.3 of the Loan Agreement and
the maximum principal amount of the Revolving Credit Facility, each Lender
hereby agrees severally (but not jointly) to make Overadvances, on a Ratable
basis, of up to $1,000,000 in aggregate outstanding principal amount to the
Borrowers to and including the earlier of (a) March 31, 2000, and (b) the
funding of the Subordinated Indebtedness described below (the "Overadvance
Termination Date"), at which time all Overadvances outstanding shall be repaid
in full. As used herein, "Overadvance" shall mean, as of any date of
determination, the amount by which the outstanding principal balance of
Revolving Credit Loans exceeds the Borrowing Base, without regard to the minimum
Availability required at such time pursuant to SECTION 11.17 of the Loan
Agreement. Each Borrower acknowledges and agrees that all Overadvances
constitute Secured Obligations under the Loan Agreement and are secured by the
Collateral. Accordingly, the Agent reserves the right to (and, upon the written
request of the Required Lenders, shall) immediately declare all Overadvances due
and payable and to immediately terminate the Borrowers' right to receive


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Overadvances prior to the Overadvance Termination Date upon the occurrence of an
Event of Default or upon any Borrower's failure to comply with the terms and
provisions of this Amendment. All Overadvances shall constitute Prime Rate
Revolving Credit Loans under the Loan Agreement, and nothing contained in this
Amendment shall require any Lender to make Revolving Credit Loans in excess of
such Lender's Commitment.

         3. The effectiveness of this Amendment is expressly conditioned upon
the receipt by the Agent of (a) a fully executed copy of this Amendment, and (b)
a fully executed engagement letter or similar agreement (in form and substance
acceptable to the Agent) between a financial institution acceptable to the Agent
and AAS with respect to Subordinated Indebtedness to be incurred by AAS. The
Agent shall notify AAS and the Lenders in writing of the receipt of such an
acceptable engagement letter or similar agreement, and this Amendment shall
become effective on the date the Agent sends such notice.

         4. To and including the Overadvance Termination Date, (a) the Agent and
the Lenders hereby agree to waive the requirements of SECTION 11.17 of the Loan
Agreement, and (b) the Agent, the Lenders and the Borrowers agree that SECTION
4.7(D)(I) shall be of no force and effect.

         5. As amended hereby, the Loan Agreement shall be and remain in full
force and effect.

         6. To induce the Agent and each Lender to enter into this Amendment,
the Borrowers agree to pay to the Agent (a) for the Ratable benefit of the
Lenders, a fee of $15,000 on the date hereof, and (b) on demand all costs and
expenses of the Agent in connection with the preparation, execution and delivery
of this Amendment, including, without limitation, the fees and out-of-pocket
expenses of legal counsel to the Agent. Such fees are constitute compensation
for services and are not, nor shall they be deemed to be, interest or a charge
for the use of money.

         7. To induce the Agent and each Lender to enter into this Amendment,
the Borrowers hereby (a) represent and warrant that, as of the date hereof, and
after giving effect to the terms hereof, there exists no Default or Event of
Default, and (b) acknowledge and agree that no right of offset, defense,
counterclaim, claim, causes of action or objection in favor of the Borrowers
against the Agent or any Lender exists arising out of or with respect to any of
the Secured Obligations or any of the Loan Documents.

         8. To induce the Agent and the Lenders to enter into this Amendment and
grant the accommodations set forth herein, each Obligor agrees that (a) except
as expressly set forth herein, neither the Agent nor any Lender has agreed to
(and has no obligation whatsoever to discuss, negotiate or agree to) any other
restructuring, modification, amendment, waiver or forbearance with respect to
the Secured Obligations or the Loan Agreement, (b) no understanding with respect
to any other restructuring, modification, amendment, waiver or forbearance with
respect to the Secured Obligations or the Loan Agreement shall constitute a
legally binding agreement or contract, or have any force or effect whatsoever,
unless and until reduced to writing and signed by authorized representatives of
each party hereto, and (c) the execution and delivery of this Amendment has not



                                      -2-
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established any course of dealing between the parties hereto or created any
obligation or agreement of the Agent or any Lender with respect to any future
restructuring, modification, amendment, waiver or forbearance with respect to
the Secured Obligations or the Loan Agreement.

         9. This Amendment may be executed in any number of counterparts and by
different parties hereto in separate counterparts, each of which, when so
executed and delivered, shall be deemed to be an original and all of which
counterparts, taken together, shall constitute but one and the same instrument.

         10. This Amendment shall be binding upon and inure to the benefit of
the successors and permitted assigns of the parties hereto.

         11. This Amendment shall be governed by, and construed in accordance
with, the laws of the State of Georgia, other than its laws respecting choice of
law.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



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         IN WITNESS WHEREOF, the Borrowers, the Agent and the Lenders have
caused this Amendment to be duly executed by their authorized officers in
several counterparts, all as of the date first above written.

                                      BORROWERS:

                                      American Aircarriers Support, Incorporated

                                      By: /s/ J. E. Civiletto
                                          --------------------------------------
                                          Joseph E. Civiletto
                                          President



                                      AAS Engine Services, Inc.

                                      By: /s/ J. E. Civiletto
                                          --------------------------------------
                                          Joseph E. Civiletto
                                          President



                                      AAS Landing Gear Services, Inc.

                                      By: /s/ J. E. Civiletto
                                          --------------------------------------
                                          Joseph E. Civiletto
                                          President



                                      AAS Complete Controls, Inc.

                                      By: /s/ J. E. Civiletto
                                          --------------------------------------
                                          Joseph E. Civiletto
                                          President


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                                      AAS-Amjet, Inc.

                                      By: /s/ Joseph E. Civiletto
                                          --------------------------------------
                                          Joseph E. Civiletto
                                          President



                                      LENDERS:

                                      BANK OF AMERICA, N.A., formerly
                                      NationsBank, N.A.

                                      By: /s/ Byron J. Turner III
                                          --------------------------------------
                                          Byron J. Turner III
                                          Vice President



                                      NATIONAL BANK OF CANADA, a Canadian
                                      chartered bank

                                      By: /s/ Dan Shaw        /s/ C Collie
                                          --------------------------------------
                                          Name: Dan Shaw      Charles Collie
                                          Title: AVP          VP & Manager



                                      THE CIT GROUP / CREDIT FINANCE, INC.

                                      By: /s/ Jay Nomina
                                          --------------------------------------
                                          Name: Jay Nomina
                                          Title: Vice President

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                                      AGENT:

                                      BANK OF AMERICA, N.A., formerly
                                      NationsBank, N.A.

                                      By: /s/ Byron J. Turner III
                                          --------------------------------------
                                          Byron J. Turner III
                                          Vice President


<PAGE>   7


                          NOTARY JURAT FOR EXECUTION OF
                        WRITTEN OBLIGATIONS TO PAY MONEY
                              BY FLORIDA BORROWERS


         On this the 21st day of December, 1999, before me, the undersigned, a
Notary Public in and for the State of South Carolina, County of York, Joseph E.
Civiletto personally appeared, personally known to me or proved to me on the
basis of satisfactory evidence to be the President of each of American
Aircarriers Support, Incorporated, AAS Engine Services, Inc., AAS-Amjet, Inc.,
AAS Landing Gear Services, Inc. and AAS Complete Controls, Inc., who, being by
me first duly sworn, stated that:

1.       He executed the foregoing Second Amendment to Loan and Security
         Agreement on behalf of such corporations pursuant to their by-laws or
         resolutions of their boards of directors, said execution taking place
         in the State of South Carolina, County of York;
         and

2.       He has this day delivered the foregoing instrument to Bank of America,
         N.A. at Fulton County, Georgia.


                                           Signature of Borrowers' Officer:


                                           By: /s/ Joseph E. Civiletto
                                               ---------------------------------
                                           Name:  Joseph E. Civiletto



Sworn to and subscribed before me this 21st day of December, 1999:

/s/ Angela C. Gaskins
----------------------------------
        Notary Signature

My Commission Expires:

Nov. 26, 2006
---------------------------------

     [Affix Notarial Seal]


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                          AFFIDAVIT REGARDING DELIVERY

         On this the 27th day of December, 1999, before me, the undersigned, a
Notary Public in and for the State of Georgia, County of Fulton, Byron
J. Turner III personally appeared, personally known to me or proved to me on the
basis of satisfactory evidence to be a Vice President of Bank of America, N.A.,
who, being by me first duly sworn, stated that Bank of America, N.A., as Agent,
has received delivery of the foregoing Second Amendment to Loan and Security
Agreement in the State of Georgia, County of Fulton.

                                   /s/ Byron J. Turner III
                                   ---------------------------------------------
                                   Signature of Officer of Agent



Sworn to and subscribed before me this 27th day of December, 1999:

/s/ ? ? Bean
----------------------------------
          Notary Signature

My Commission Expires:

5/5/00
---------------------------------

     [Affix Notarial Seal]