Document:

<PAGE>

                                                                   Exhibit 10.43

CERTAIN PORTIONS OF THIS EXHIBIT HAVE BEEN OMITTED AND FILED SEPARATELY WITH THE
    SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL
                                    TREATMENT

                          LETTER AGREEMENT COM 0029-06

                              **Material Redacted**

                                  **12 pages**<PAGE>

                                                                   Exhibit 10.44

          CERTAIN PORTIONS OF THIS EXHIBIT HAVE BEEN OMITTED AND FILED
         SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT
                     TO A REQUEST FOR CONFIDENTIAL TREATMENT

                          Supplemental Agreement No. 9

                                       to

                           Purchase Agreement No. 2191

                                     between

                               The Boeing Company

                                       and

                            COPA Holdings, S.A., Inc.

                      Relating to Boeing Model 737 Aircraft

     THIS SUPPLEMENTAL AGREEMENT entered into as of March 16, 2006 by and
between THE BOEING COMPANY, a Delaware corporation with its principal office in
Seattle, Washington, (Boeing) and COPA HOLDINGS, S.A., INC. (Customer);

     WHEREAS, the parties hereto entered into Purchase Agreement No. 2191 dated
November 25, 1998 (the Agreement), as amended and supplemented, relating to
Boeing Model 737-7V3 and 737-8V3 aircraft (the Aircraft); and

     WHEREAS, Customer and Boeing have come to agreement on the purchase and
sale of one 737-8V3 Aircraft with a scheduled delivery month of October 2009;
and

     WHEREAS, Boeing and Buyer have mutually agreed to amend the Agreement to
incorporate the effect of these and certain other changes;

NOW THEREFORE, in consideration of the mutual covenants herein contained, the
parties agree to amend the Agreement as follows:

1.   Table of Contents, Tables and Exhibits:

     1.1. Remove and replace, in its entirety the "Table of Contents", with the
          "Table of Contents" attached hereto and hereby made a part of the
          Agreement, to reflect the changes made by this Supplemental Agreement.

     1.2. Table 1-5 entitled "Aircraft Information Table for Model 737-8V3
          Aircraft" is attached hereto to reflect the scheduled delivery months
          for the 737 Aircraft with schedule delivery month of October 2009.

<PAGE>

                                                                               2

2.   Letter Agreements: No. 6-1162-LAJ-982R2 entitled **Material Redacted** to
     include our agreement on Electronic Flight Bag and extension of first
     advance payment date to April 3, 2006 and Letter Agreement No.
     6-1162-RLL-3852 entitled "737-800 Aircraft Performance Guarantees" are
     attached hereto and hereby made a part of the Agreement.

The Purchase Agreement will be deemed to be supplemented to the extent herein
provided as of the date hereof and as so supplemented will continue in full
force and effect.

Boeing and Customer have each caused this Supplemental Agreement to be duly
executed as of the day and year first written above.

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                            SA
                                                                          NUMBER
                                                                          ------
<S>                                                                       <C>
ARTICLES
1.        Quantity, Model and Description                                  SA 3
2.        Delivery Schedule
3.        Price
4.        Payment                                                          SA 3
5.        Miscellaneous

TABLE
1-1       Aircraft Information Table for Model 737-7V3 Aircraft            SA 4
1-2       Aircraft Information Table for Model 737-8V3 Aircraft            SA 5
1-3       Aircraft Information Table for Model 737-7V3 Aircraft            SA 7
1-4       Aircraft Information Table for Model 737-7V3 Aircraft            SA 8
1-5       Aircraft Information Table for Model 737-8V3 Aircraft            SA 9

EXHIBIT
A-1       Aircraft Configuration for Model 737-7V3 Aircraft                SA 3
A-2       Aircraft Configuration for Model 737-8V3 Aircraft                SA 3

B.        Aircraft Delivery Requirements and Responsibilities              SA 3

SUPPLEMENTAL EXHIBITS
BFE1.     BFE Variables                                                    SA 3
CS1.      Customer Support Variables                                       SA 3
EE1.      Engine Escalation/Engine Warranty and Patent Indemnity
SLP1.     Service Life Policy Components

LETTER AGREEMENTS
2191-01   Demonstration Flight Waiver
2191-02   Escalation Sharing
2191-03   Seller Purchased Equipment

RESTRICTED LETTER AGREEMENTS
6-1162-DAN-0123    Performance Guarantees
6-1162-DAN-0124    **Material Redacted**
6-1162-DAN-0155    **Material Redacted**
6-1162-DAN-0156    Year 2000 Ready Software, Hardware and Firmware
6-1162-DAN-0157    Miscellaneous Matters
61162-MJB-0017     **Material Redacted**
</TABLE>

                                        i

<PAGE>

<TABLE>
<S>                                                                       <C>
6-1162-MJB-0030    **Material Redacted**
6-1162-LAJ-874R    **Material Redacted**
6-1162-LAJ-874R1   **Material Redacted**
6-1162-LAJ-874R2   **Material Redacted**
6-1162-LAJ-982     **Material Redacted**
6-1162-LAJ-982R2   **Material Redacted**
6-1162-RLL-3852    737-800 Performance Guarantees                          SA 9
</TABLE>

<TABLE>
<CAPTION>
SUPPLEMENTAL AGREEMENTS        DATED AS OF:
-----------------------        ------------
<S>                            <C>
Supplemental Agreement No. 1   June 29, 2001
Supplemental Agreement No. 2   December 21, 2001
Supplemental Agreement No. 3   June 14, 2002
Supplemental Agreement No. 4   December 20, 1002
Supplemental Agreement No. 5   October 31, 2003
Supplemental Agreement No. 6   September 9, 2004
Supplemental Agreement No. 7   December 9, 2004
Supplemental Agreement No. 8   April 15, 2005
Supplemental Agreement No. 9   March 16, 2006
</TABLE>

                                       ii

<PAGE>

                               THE BOEING COMPANY
                                  P.O. Box 3707
                             Seattle, WA 98124-2207

6-1162-LAJ-982R2

COPA HOLDINGS, S.A.
Apartado 1572
Avenida Justo Arosemena y Calle 39
Panama 1, Panama

Subject: **Material Redacted**

Reference: Purchase Agreement No. 2191 (the Purchase Agreement) between The
           Boeing Company (Boeing) and COPA HOLDINGS, S.A. (Customer) relating
           to Model 737 aircraft (the Aircraft)

This Letter Agreement amends and supplements the Purchase Agreement. This Letter
Agreement supersedes and replaces in its entirety Letter Agreement
6-1162-MJB-0017. All terms used but not defined in this Letter Agreement have
the same meaning as in the Purchase Agreement. In consideration of the Aircraft
orders, Boeing provides the following to Customer.

1.   **Material Redacted**

     **Material Redacted**

2.   **Material Redacted**

3.   **Material Redacted**

4.   **Material Redacted**

5.   **Material Redacted**

6.   **Material Redacted**

7.   **Material Redacted**

8.   **Material Redacted**

9.   **Material Redacted**

10.  **Material Redacted**

11.  **Material Redacted**

12.  **Material Redacted**

13.  **Material Redacted**

<PAGE>

14.  **Material Redacted**

15.  **Material Redacted**

16.  **Material Redacted**

17.  Confidentiality. Customer understands that certain commercial and financial
     information contained in this Letter Agreement are considered by Boeing as
     confidential. Customer agrees that it will treat this Letter Agreement and
     the information contained herein as confidential and will not, without the
     prior written consent of Boeing, disclose this Letter Agreement or any
     information contained herein to any other person or entity.

                                        2
<PAGE>

                               THE BOEING COMPANY
                                  P.O. Box 3707
                             Seattle, WA 98124-2207

6-1162-RLL-3852

COPA HOLDINGS, S.A.
Apartado 1572
Avenida Justo Arosemena y Calle 39
Panama 1, Panama

Subject: 737-800 Aircraft Performance Guarantees

Reference: Purchase Agreement No. 2191 (the Purchase Agreement) between The
           Boeing Company (Boeing) and COPA HOLDINGS, S.A. (Customer) relating
           to Model 737 aircraft (the Aircraft)

This letter agreement (Letter Agreement) amends and supplements the Purchase
Agreement. All terms used but not defined in this Letter Agreement have the same
meaning as in the Purchase Agreement.

Boeing agrees to provide Customer with the performance guarantees in the
Attachment. These guarantees are exclusive and expire upon delivery of the
Aircraft to Customer.

Customer agrees not to disclose this Letter Agreement, attachments, or any other
information related to this Letter Agreement without prior written consent by
Boeing.

                                        3

<PAGE>

                               BOEING PROPRIETARY

                                        4

<PAGE>

Attachment to Letter Agreement
No. 6-1161-RLL-3852
CFM56-7B26 Engines
Page 1

                      MODEL 737-800 PERFORMANCE GUARANTEES

                  FOR COPA (COMPANIA PANAMENA DE AVIACION S.A.)

<TABLE>
<CAPTION>
SECTION             CONTENTS
-------             --------
<S>       <C>
   1      AIRCRAFT MODEL APPLICABILITY
   2      FLIGHT PERFORMANCE
   3      MANUFACTURER'S EMPTY WEIGHT
   4      AIRCRAFT CONFIGURATION
   5      GUARANTEE CONDITIONS
   6      GUARANTEE COMPLIANCE
   7      EXCLUSIVE GUARANTEES
</TABLE>

<PAGE>

Attachment to Letter Agreement
No. 6-1161-RLL-3852
CFM56-7B26 Engines
Page 2

1    AIRCRAFT MODEL APPLICABILITY

     The guarantees contained in this Attachment (the "Performance Guarantees")
     are applicable to the 737-800 Aircraft equipped with Boeing furnished
     CFM56-7B26 engines.

2    FLIGHT PERFORMANCE

     CRUISE RANGE

     The still air range at an initial cruise altitude of 35,000 feet on a
     standard day at 0.78 Mach number, starting at a gross weight of 169,000
     pounds and consuming 35,000 pounds of fuel, and using not more than maximum
     cruise thrust (except maximum climb thrust may be used during a step climb)
     and using the conditions and operating rules defined below, shall not be
     less than the following guarantee value:

               NOMINAL:   2,805 Nautical Miles
               TOLERANCE: -55 Nautical Miles
               GUARANTEE: 2,750 Nautical Miles

     Conditions and operating rules:

          A step climb or multiple step climbs of 4,000 feet altitude may be
          used when beneficial to minimize fuel burn.

3    MANUFACTURER'S EMPTY WEIGHT

     The Manufacturer's Empty Weight (MEW) is guaranteed not to exceed the value
     in Section 03-60-00 of Detail Specification D6-38808-43-1, Revision C plus
     two percent.

4    AIRCRAFT CONFIGURATION

4.1  The guarantees contained in this Attachment are based on the Aircraft
     configuration as defined in Revision C of Detail Specification
     D6-38808-43-1 (hereinafter referred to as the Detail Specification).
     Appropriate adjustment shall be made for changes in such Detail
     Specification approved by the Customer and Boeing or otherwise allowed by
     the Purchase Agreement which cause changes to the flight performance and/or
     weight and balance of the Aircraft. Such adjustment shall be accounted for
     by Boeing in its evidence of compliance with the guarantees.

4.2  The Manufacturer's Empty Weight guarantee of Section 3 will be adjusted by
     Boeing for the following in its evidence of compliance with the guarantees:

<PAGE>

Attachment to Letter Agreement
No. 6-1161-RLL-3852
CFM56-7B26 Engines
Page 3

     (1) Changes to the Detail Specification or any other changes mutually
     agreed upon between the Customer and Boeing or otherwise allowed by the
     Purchase Agreement.

     (2) The difference between the component weight allowances given in
     Appendix IV of the Detail Specification and the actual weights.

5    GUARANTEE CONDITIONS

5.1  All guaranteed performance data are based on the International Standard
     Atmosphere (ISA) and specified variations therefrom; altitudes are pressure
     altitudes.

5.2  The FAA Regulations (FAR) referred to in this Attachment are, unless
     otherwise specified, the 737-800 Certification Basis regulations specified
     in the Type Certificate Data Sheet A16WE, Revision 33, dated March 8, 2002.

5.3. In the event a change is made to any law, governmental regulation or
     requirement, or in the interpretation of any such law, governmental
     regulation or requirement that affects the certification basis for the
     Aircraft as described in Paragraph 5.2, and as a result thereof, a change
     is made to the configuration and/or the performance of the Aircraft in
     order to obtain certification, the guarantees set forth in this Attachment
     shall be appropriately modified to reflect any such change.

5.4  The cruise range guarantee includes allowances for normal power extraction
     and engine bleed for normal operation of the air conditioning system.
     Normal electrical power extraction shall be defined as not less than a 50
     kilowatts total electrical load. Normal operation of the air conditioning
     system shall be defined as pack switches in the "Auto" position, the
     temperature control switches in the "Auto" position that results in a
     nominal cabin temperature of 75 degrees F, and all air conditioning systems
     operating normally. This operation allows a maximum cabin pressure
     differential of 8.35 pounds per square inch at higher altitudes, with a
     nominal Aircraft cabin ventilation rate of 3,300 cubic feet per minute
     including passenger cabin recirculation (nominal recirculation is 47
     percent). The APU is turned off unless otherwise specified.

5.5  The cruise range guarantee is based on an Aircraft center of gravity
     location of 26.2 percent of the mean aerodynamic chord.

5.6  Performance, where applicable, is based on a fuel Lower Heating Value (LHV)
     of 18,580 BTU per pound.

<PAGE>

Attachment to Letter Agreement
No. 6-1161-RLL-3852
CFM56-7B26 Engines
Page 4

6    GUARANTEE COMPLIANCE

6.1  Compliance with the guarantees of Sections 2 and 3 shall be based on the
     conditions specified in those sections, the Aircraft configuration of
     Section 4 and the guarantee conditions of Section 5.

6.2  Compliance with the cruise range guarantee shall be established by
     calculations based on flight test data obtained from an aircraft in a
     configuration similar to that defined by the Detail Specification.

6.3  Compliance with the Manufacturer's Empty Weight guarantee shall be based on
     information in the "Weight and Balance Control and Loading Manual -
     Aircraft Report."

6.4  The data derived from tests shall be adjusted as required by conventional
     methods of correction, interpolation or extrapolation in accordance with
     established engineering practices to show compliance with these guarantees.

6.5  Compliance shall be based on the performance of the airframe and engines in
     combination, and shall not be contingent on the engine meeting its
     manufacturer's performance specification.

7    EXCLUSIVE GUARANTEES

     The only performance guarantees applicable to the Aircraft are those set
     forth in this Attachment.

<PAGE>

                                    TABLE 1-5
           AIRCRAFT DELIVERY, DESCRIPTION, PRICE AND ADVANCE PAYMENTS

<TABLE>
<S>                                               <C>                 <C>
AIRFRAME MODEL/MTOW:                              737-8V3                 174,200 pounds
ENGINE MODEL/THRUST:                              CFM56-7B26               26,400 pounds
AIRFRAME PRICE:                                                       $58,854,000
OPTIONAL FEATURES:                                                    $ 3,635,800
                                                                      -----------
SUB-TOTAL OF AIRFRAME AND FEATURES:                                   $62,489,800
                                                                      -----------
ENGINE PRICE (PER AIRCRAFT):                                          $         0
AIRCRAFT BASIC PRICE (EXCLUDING BFE/SPE):                             $62,489,800
                                                                      ===========
BUYER FURNISHED EQUIPMENT (BFE) ESTIMATE:                             $         0
SELLER PURCHASED EQUIPMENT (SPE) ESTIMATE:                            $ 1,900,000
REFUNDABLE DEPOSIT/AIRCRAFT AT PROPOSAL ACCEPT:                       $    90,000

DETAIL SPECIFICATION:                             D6-38808-1 Rev C,
                                                  dated 5-4-05
AIRFRAME PRICE BASE YEAR/ESCALATION FORMULA:      Jul-04              ECI-MFG/CPI
ENGINE PRICE BASE YEAR/ESCALATION FORMULA:        N/A                         N/A

AIRFRAME ESCALATION DATA:
BASE YEAR INDEX (ECI):                                                      166.1
BASE YEAR INDEX (CPI):                                                      184.1
</TABLE>

<TABLE>
<CAPTION>
                                                                                  ADVANCE PAYMENT PER AIRCRAFT
                                                                               (AMTS. DUE/MOS. PRIOR TO DELIVERY):
                     ESCALATION                 ESCALATION ESTIMATE  ------------------------------------------------------
DELIVERY  NUMBER OF    FACTOR    MANUFACTURER     ADV PAYMENT BASE   AT SIGNING    24 MOS.   21/18/12/9/6 MOS.     TOTAL
  DATE     AIRCRAFT  (AIRFRAME)  SERIAL NUMBER     PRICE PER A/P         1%          4%              5%             30%
--------  ---------  ----------  -------------  -------------------  ----------  ----------  -----------------  -----------
<S>       <C>        <C>         <C>            <C>                  <C>         <C>         <C>                <C>
Oct-2009      1        1.1921        36550          $76,759,000       $677,590   $3,070,360      $3,837,950     $23,027,700
Total:        1
</TABLE>

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00105-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00105-of-00352.parquet"}]]