Subject: ELIGIBILITY AND EVALUATION

OF U.S. MILITARY SURPLUS FLIGHT

SAFETY CRITICAL AIRCRAFT PARTS,

ENGINES, AND PROPELLERS

Date: 2/25/00

Initiated By: AFS-300

AC No: 20-142

Change:

1. PURPOSE. This advisory circular (AC) provides information and guidance for use in evaluating

and determining the eligibility of U.S. military surplus flight safety critical aircraft parts (FSCAP),

engines, and propellers for installation on Federal Aviation Administration (FAA) type-certificated

products. This AC is applicable to all U.S. military surplus FSCAP, engines, and propellers,

irrespective of when and by what process these products or parts became available. In the absence of

FSCAP classification of military surplus parts by the Department of Defense (DoD), such parts should

be identified and classified as FSCAP using the guidance contained in this AC. For information and

guidance on determining the eligibility of parts other than FSCAP, refer to AC 20-62, Eligibility,

Quality, and Identification of Aeronautical Replacement Parts. Like all AC material, this AC is not

mandatory and does not constitute a regulation. It is issued for guidance purposes and to outline one

method of compliance with the rules. In lieu of following the method(s) prescribed herein without

deviation, a person may elect to follow an alternative method, provided the FAA finds the alternative

method to be an acceptable means of complying with the applicable requirements of Title 14 of the

Code of Federal Regulations (14 CFR).

2. RELATED 14 CFR PARTS.

a. Part 1, Definitions and Abbreviations.

b. Part 21, Certification Procedures for Products and Parts.

c. Part 23, Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter Category

Airplanes.

d. Part 25, Airworthiness Standards: Transport Category Airplanes.

e. Part 27, Airworthiness Standards: Normal Category Rotorcraft.

f. Part 29, Airworthiness Standards: Transport Category Rotorcraft.

g. Part 33, Airworthiness Standards: Aircraft Engines.
AC 20-142 2/25/00

Page 2 Par 2

h. Part 35, Airworthiness Standards: Propellers.

i. Part 39, Airworthiness Directives.

j. Part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration.

k. Part 45, Identification and Registration Marking.

l. Part 91, General Operating and Flight Rules.

3. DEFINITIONS. The following terms have the meaning listed when used in this AC:

a. Critical Characteristic. Any feature throughout the life cycle of a FSCAP which, if

nonconforming, missing, or degraded, could cause a catastrophic failure resulting in loss or

serious damage to the aircraft or an uncommanded engine shutdown resulting in an unsafe

condition. A characteristic can be critical in terms of a dimension, tolerance, finish, or material;

an assembly, manufacturing, or inspection process; or an operational, field maintenance, or depot

overhaul requirement.

(1) A manufacturing critical characteristic is produced during the manufacturing process.

(2) An installation critical characteristic is critical in terms of assembly or installation

(e.g., torque).

b. DoD CAGE Code. The DoD Commercial and Government Entity (CAGE) code

identifies the manufacturer of the part or product produced under government contract.

c. Dual Use Product/Part. Any product or part manufactured for civil application by a

Production Approval Holder (PAH) authorized by the FAA which is also procured under a

U.S. military contract. The product or part has the identical part number and configuration as its civil

counterpart; it was manufactured using the same FAA-approved design, materials, and manufacturing

processes. These could also include any product (or part thereof) originally produced for the military

which currently holds a normal, utility, acrobatic, or transport type certificate (TC) issued under

section 21.27.

d. Flight Safety Critical Aircraft Part (FSCAP). Any part, assembly, or installation

containing a critical characteristic whose failure, malfunction or absence could cause a

catastrophic failure resulting in loss or serious damage to the aircraft or an uncommanded engine

shutdown resulting in an unsafe condition.

e. Military Surplus Product/Part. A product or part that has been originally released as

surplus by the U.S. military, even if subsequently resold by a manufacturer, owner/operator, repair

facility, or any other parts supplier.

f. Military Unique FSCAP. Any FSCAP specifically and uniquely designed and

manufactured for the U.S. military, for which there is no corresponding FAA-approved type

design or PAH engine, propeller or part produced for civil application. “Breakout” products or
2/25/00 AC 20-142

Par 3 Page 3

parts, produced specifically for military use by a manufacturer other than an FAA PAH using

military-provided designs/drawings and specifications, are also considered military unique.

g. Part Out. To remove a part from, or disassemble, an aircraft, engine, propeller, or

assembly of parts.

4. RELATED READING MATERIAL.

a. Copies of the current edition of FAA Order 8300.10, Airworthiness Inspector’s

Handbook, may be purchased by check or money order payable to the Superintendent of

Documents, PO Box 371954, Pittsburgh, PA 15250-7954.

b. Copies of current editions of the following documents may be obtained free of charge from

the U.S. Department of Transportation, Subsequent Distribution Office, Ardmore East Business

Center, 3341 Q 75th Avenue, Landover, MD 20785:

(1) FAA Order 8110.4, Type Certification Process.

(2) FAA Order 8110.42, Parts Manufacturer Approval Procedures.

(3) FAA Order 8130.2, Airworthiness Certification of Aircraft and Related Products.

(4) FAA Order 8130.21, Procedures for Completion and Use of FAA Form 8130-3,

Airworthiness Approval Tag.

(5) AC 20-62, Eligibility, Quality, and Identification of Aeronautical Replacement Parts.

(6) AC 20-96, Surplus Military Aircraft: A Briefing for Prospective Buyers.

(7) AC 21-13, Standard Airworthiness Certification of Surplus Military Aircraft and

Aircraft Built from Spare and Surplus Parts.

(8) AC 21-23, Airworthiness Certification of Civil Aircraft Engines, Propellers, and

Related Products.

(9) AC 21-29, Detecting and Reporting Suspected Unapproved Parts.

5. BACKGROUND.

a. The Federal Property and Administrative Services Act of 1949 (Public Law 81-152), as

amended, requires the DoD to dispose of its surplus property. However, DoD is prevented from

destroying property with economic value. Consequently, since the end of World War II various

U.S. manufactured, DoD surplus military aircraft of the U.S. Armed Forces, and their parts, have

been available for sale to or within the civil sector. Depending on the aircraft type and/or whether

or not these surplus military products have had civilian counterpart models for which an FAA type

certificate had been issued, such aircraft may have eligibility for either “standard” airworthiness

certification under section 21.183(d), or “special” airworthiness certification under section
AC 20-142 2/25/00

Page 4 Par 5

21.185. With the “downsizing” of military requirements, increasing quantities of surplus DoD

aviation products and their parts have become available for civil purchase.

b. In 1993 and 1994, various concerns regarding military surplus aircraft parts, specifically

those parts designated by the proponent military service as FSCAP, entering into the civil market

place led to the forming of a joint DoD and FAA FSCAP Process Action Team (PAT). This

team, representing the Defense Logistics Agency, the Departments of the Army, Navy and Air

Force, and the FAA, produced recommendations related to the identification, disposition and

control of FSCAP. The DoD and the FAA accepted the PAT recommendations and jointly signed

the implementation plan memorandum in 1995. This AC is part of the FSCAP PAT

implementation plan and provides guidance that is pertinent to the aviation community regarding

the potential installation of military surplus FSCAP on FAA type-certificated products.

6. DISCUSSION.

a. Any military surplus FSCAP may have the potential to be considered for approval to be

installed on an aircraft which holds a special or standard airworthiness certificate.

b. While many military parts may appear to be the same as their FAA-approved civil

counterparts, they are not automatically FAA-approved for installation. Typically, the procuring

military service specifies requirements for the design, production, and acquisition of its parts,

which may not meet the requirements of 14 CFR; however, certain parts procured by DoD also

have the potential to be approved for civil use. In fact, certain military unique FSCAP are

currently part of FAA-certificated, restricted category military surplus products. These military

unique parts sometimes have no replacement source other than the military surplus stocks

originally procured solely for U.S. Armed Forces use.

c. DoD makes no representation as to a part’s eligibility for installation on FAA type-certificated

products. Therefore, prior to installing the part on a type-certificated product, the receiving person,

organization, or installer must determine that the part is eligible for installation and is airworthy.

Failure to comply with FAA requirements can subject the owner and/or installer to enforcement

actions. Since the FSCAP may not meet FAA type design and/or may have been operated outside the

limitations specified by 14 CFR, additional inspections and/or FAA approval may be needed to

determine the part's condition for safe operation or eligibility for installation on civil aircraft.

d. In order to maintain the airworthiness of any aircraft, parts used to maintain the aircraft

must meet that aircraft's applicable airworthiness requirements. Section 43.13 requires the

installer of a part on an FAA type-certificated product to ensure that the condition of the product

is at least equal to that product’s original or properly altered condition.

e. There are certain unique design considerations and FAA certification requirements for

engines and propellers. Therefore, the eligibility and evaluation processes for military surplus

engines, propellers, accessories, and their parts, whether dual use or military unique, are described

separately from other FSCAP in paragraphs 9 through 11.
2/25/00 AC 20-142

Par 6 Page 5

f. Military surplus FSCAP, whether new, used, or parted out, should not be presumed to be

eligible for installation on FAA type-certificated products. As shown in Figure 1 and discussed in

paragraphs 7 through 11, pertinent accompanying historical records/documentation are essential

for the Defense Reutilization Marketing Office (DRMO) public sale of FSCAP, engines, and

propellers, and subsequently for categorizing FSCAP, engines, or propellers as either dual use or

military unique, to establish installation eligibility, and to evaluate for airworthiness in accordance

with this AC. With appropriate documentation, the installer should be able to determine that the

installation of that FSCAP will maintain the aircraft in compliance with the pertinent regulation(s)

and in condition for safe operation.

PART CODED

SCRAP AND

MUTILATED

NEW/USED MILITARY

AIRCRAFT PARTS

DECLARED EXCESS

IS THE PART

CODED

FSCAP?

IS HISTORICAL

RECORDS

DOCUMENTATION

AVAILABLE? YES

PART GOES TO DRMO (NO

DOD DOCUMENTATION

REQUIREMENT)

FSCAP AND

DOCUMENTATION

GO TO DRMO

DRMO DISPOSITION

PRIORITIES:

 1. OTHER DOD ACTIVITIES

 2. GSA

 3. STATE, LOCAL GOVT.

 4. PUBLIC SALE (SURPLUS)

DRMO DISPOSITION

PRIORITIES:

1. OTHER DOD ACTIVITIES

 2. GSA

 3. STATE, LOCAL GOVT.

 4. PUBLIC SALE (SURPLUS)

PERSON

PURCHASES PART

PERSON

PURCHASES

FSCAP

FOR ELIGIBILITY &

EVALUATION USE

AC 20-62

FOR ELIGIBILITY &

EVALUATION USE

FSCAP AC

 NO

NO YES

FIGURE 1. MILITARY SURPLUS PROCESS
AC 20-142 2/25/00

Page 6 Par 7

7. DUAL USE FSCAP. The process for eligibility screening and airworthiness evaluation of

dual use FSCAP by individuals authorized under section 43.7 is illustrated in Figure 2 and

described in paragraphs 7a through 7e. The authorized individual completing the eligibility

screening and/or the airworthiness evaluation should make a record entry to document the

result(s).

DUAL USE FSCAP

(NEW OR USED)

DO NOT INSTALL

INSTALL

 7e

INSTALL

 7e

DO NOT

INSTALL

(FOR

STD A/W

CERT)

EVALUATION

7b or 7d

EVALUATION

7c or 7d

ELIGIBILITY

7a

 NO

YES

YES STD SPEC YES

NO

 STD

OR

SPEC

AWC

A/C

DO NOT

INSTALL

NO

FIGURE 2. DUAL USE FSCAP (NEW OR USED)
2/25/00 AC 20-142

Par 7 Page 7

a. Eligibility. New or used dual use FSCAP, as defined in paragraph 3c, may be considered

eligible for installation on FAA type-certificated products based upon the requisite evaluation

findings when accompanied by pertinent DoD historical records detailing the following

information:

(1) part identification - part number, DoD National Stock Number and serial number;

(2) manufacturer, DoD CAGE code, and date of manufacture;

(3) total time-in-service;

(4) current status of life-limited parts;

(5) time since the last overhaul of each part which is required to be overhauled on a

specified time basis;

(6) identification of current inspection status, including time since last required inspection

or maintenance performed;

(7) current status of applicable airworthiness directives (AD) and DoD directives (i.e.,

engineering change, technical order, maintenance work order, etc.), including the date, method,

and compliance requirement; if the AD involves recurring action, time and date when the next

action is required;

(8) a list of current major alterations, repairs or modifications for each part;

(9) date any work was accomplished; and

(10) work authentication.

b. Evaluation of New Dual Use FSCAP for Installation on Products with Standard

Airworthiness Certificates. In addition to verifying that the part is eligible for installation using

pertinent items listed in paragraph 7a, the evaluation shall determine that the part conforms to its FAAapproved type design, and that the part is in condition for safe operation.

c. Evaluation of New Dual Use FSCAP for Installation on Products with Special

Airworthiness Certificates. In addition to verifying that the part is eligible for installation by

reviewing applicable records listed in paragraph 7a, the evaluation should ensure that the part is

cited in the FAA-accepted maintenance manual and illustrated parts catalog (IPC) specified on the

applicable aircraft type certificate data sheet (TCDS), and that the part is in condition for safe

operation.

d. Evaluation of Used Dual Use FSCAP for Installation on Products with Standard or

Special Airworthiness Certificates. In addition to successfully completing the eligibility

screening by reviewing applicable records listed in paragraph 7a, plus those evaluation procedures
AC 20-142 2/25/00

Page 8 Par 7

specified for new dual use FSCAP in either paragraph 7b (standard) or 7c (special), to establish

used dual use FSCAP airworthiness in accordance with section 43.13, further evaluation should

be performed by persons authorized under section 43.7 (a), (c), (d), or (e) using the following

applicable methods, means or data sources:

(1) differences between military and civil version (possible DoD modification, alteration,

repair, etc. performed);

(2) current manufacturer’s or DoD technical data and procedures to perform tests and

inspections including current life limited parts list;

(3) comparison of military time and/or cycle count for accumulated operational time

versus civil (e.g., “Did the military use a different method than civil operators to account for

accumulated operational time?”);

(4) non-destructive tests, as required;

(5) bench testing or functional test, as required;

(6) results of tests and inspection recorded;

(7) complete historical and modification/alterations/repair records;

(8) manufacturer’s identification plate;

(9) flight, maintenance, and/or structural manual(s), and illustrated parts catalog; and

(10) instructions for continued airworthiness.

e. Approval for Installation of Dual Use FSCAP. Persons authorized under section

43.7 may approve for installation dual use FSCAP that have successfully completed airworthiness

evaluation in accordance with paragraph 7b, 7c, or 7d. The installer must be able to determine

that the installation of the FSCAP will leave the product in compliance with all regulations and in

condition for safe operation.

8. MILITARY UNIQUE FSCAP. The process of eligibility screening and airworthiness

evaluation of military unique FSCAP by individuals authorized under section 43.7 is illustrated in

Figure 3 and described in paragraphs 8a through 8d. The authorized individual completing the

eligibility screening and/or the airworthiness evaluation should make a record entry to document the

result(s).
2/25/00 AC 20-142

Par 8 Page 9

MILITARY

UNIQUE FSCAP

(SPECIAL USE

ONLY)

DO NOT

INSTALL

INSTALL

8d

INSTALL

 8d

DO NOT

INSTALL

NEW

OR

USED

 EVALUATION

 8b

EVALUATION

8c

ELIGIBILITY

8a

NO

YES

 YES NEW USED YES

NO NO

FIGURE 3. MILITARY UNIQUE FSCAP (SPECIAL USE ONLY)
AC 20-142 2/25/00

Page 10 Par 8

a. Eligibility. Military unique FSCAP may be eligible for installation on civil products with

special airworthiness certificates under either subsection 21.305(c) in conjunction with type

certification procedures for a product, or in accordance with a TCDS. Military unique FSCAP is not

eligible for installation on a civil product with a standard airworthiness certificate. At a minimum, the

accompanying historical records for military unique FSCAP should contain the following pertinent

information:

(1) part identification - part number, DoD National Stock Number and serial number;

(2) manufacturer, DoD CAGE code, and date of manufacture;

(3) total time-in-service;

(4) current status of life-limited parts;

(5) time since the last overhaul of each part which is required to be overhauled on a specified

time basis;

(6) identification of current inspection status, including time since last required inspection

or maintenance performed;

(7) current status of applicable ADs and DoD directives, (i.e., engineering change,

technical order, maintenance work order, etc.) including the date, method, and compliance

requirement; if the AD involves recurring action, time, and date when the next action is required;

(8) a list of current major alterations, repairs, or modifications for each part;

(9) date any work was accomplished; and

(10) work authentication.

b. Evaluation of New Military Unique FSCAP for Installation on Products with Special

Airworthiness Certificates. In addition to verifying that the part is eligible for installation by

reviewing applicable records listed in paragraph 8a, the evaluation should ensure that the part is

cited in the FAA-accepted, military-approved maintenance manual and IPC specified on the

applicable aircraft TCDS, and that the part is in condition for safe operation.

c. Evaluation of Used Military Unique FSCAP for Installation on Products with Special

Airworthiness Certificates. In addition to verifying that the part is eligible for installation by

reviewing applicable records listed in paragraph 8a, the evaluation should ensure that the part is

cited in the FAA-accepted, military-approved maintenance manual and IPC specified on the

applicable aircraft TCDS, and that the part is in condition for safe operation. To establish the

airworthiness of used military unique FSCAP in accordance with section 43.13, further evaluation

should be performed using the following applicable methods, means, or data sources:
2/25/00 AC 20-142

Par 8 Page 11

(1) special equipment or test apparatus, as required;

(2) current manufacturer’s or DoD technical data and procedures to perform tests and

inspections;

(3) comparison of military time and/or cycle count for accumulated operational time

versus civil (e.g., “Did the military use a different method than civil operators to account for

accumulated operational time?”);

(4) non-destructive tests, as required;

(5) bench testing or functional test, as required;

(6) results of tests and inspection recorded;

(7) complete historical and modification/alterations/repair records;

(8) manufacturer’s identification plate;

(9) flight, maintenance, and/or structural manual(s), and illustrated parts catalog; and

(10) instructions for continued airworthiness.

d. Approval for Installation of Military Unique FSCAP. Persons authorized under

section 43.7 may approve for installation military unique FSCAP that have successfully completed

airworthiness evaluation in accordance with paragraph 8b or 8c. The installer must be able to

determine that the installation of the FSCAP will leave the product in compliance with the TCDS,

and in condition for safe operation.

9. MILITARY SURPLUS ENGINES, PROPELLERS, ACCESSORIES, AND THEIR

PARTS.

a. Military surplus engines, propellers, accessories, and their parts, whether new, used, or

parted out, should not be presumed to be eligible for installation on FAA type-certificated aircraft.

The pertinent accompanying historical records documentation is essential for the DRMO public sale

of engines, propellers, accessories, and their parts, for subsequently categorizing them as either dual

use or military unique, and for establishing their eligibility and airworthiness in accordance with

either paragraph 10 or 11.

b. Military engines and propellers may be type-certificated under 14 CFR, section 21.17,

which requires issuance of a new TC and compliance with the applicable requirements, such as

part 33 for engines and part 35 for propellers. For a military aircraft issued a TC under section

21.25 or 21.27, the applicable engine or propeller is not required to be issued a separate TC .
AC 20-142 2/25/00

Page 12 Par 9

 However, it should be noted that the engine and propeller cannot be certificated separately under

these two sections. Any eligible military surplus engines or propellers will be referenced on the

aircraft’s TCDS.

c. Dual use military surplus engines and propellers which hold a TC, and their accessories and

parts, may be eligible for installation on civil aircraft, engines, or propellers, respectively, in

accordance with the applicable regulations. However, military unique engines, propellers,

accessories, or their military unique parts, may be eligible for installation only on civil military

surplus aircraft with special airworthiness certificates.

d. Engines, propellers, accessories, or their parts are deemed flight safety critical if their

failure, malfunction or absence could cause a catastrophic failure resulting in loss or serious

damage to the aircraft or an uncommanded engine shutdown resulting in an unsafe condition.

Such conditions include, but are not limited to:

(1) release of engine or propeller debris, or propeller separation; and

(2) in rotorcraft, a transient or continuous power loss, or loss of power response.

e. Examples of flight safety critical engine and propeller parts are life-limited parts, rotating

parts, and for rotorcraft, actuating parts.

10. DUAL USE MILITARY SURPLUS ENGINES, PROPELLERS, ACCESSORIES,

AND THEIR PARTS. The process of eligibility screening and airworthiness evaluation of dual

use military surplus engines, propellers, accessories, or their parts, by individuals authorized under

section 43.7, or other airworthiness evaluation by individuals specified, is shown in Figure 4 and

described in paragraphs 10a through 10g. The authorized individual completing the eligibility

screening and/or the airworthiness evaluation should make a record entry to document the

result(s).

a. Eligibility of New Dual Use Engines, Propellers, Accessories, or Their Parts for

Installation on Aircraft with Standard or Special Airworthiness Certification. A U.S. TC

must have been issued for a corresponding civil model engine or propeller under section 21.21 at

the time of manufacture (standard or special), or a U.S. aircraft TC must have been issued and the

engines or propellers referenced in the aircraft TCDS under section 21.27 (standard) or section

21.25 (special). New dual use engines, propellers, accessories, or their parts, as defined in

paragraph 3c may be considered eligible for installation on FAA type-certificated surplus military

aircraft or civil aircraft with standard airworthiness certification or special airworthiness

certification, based upon the requisite favorable findings from reviewing pertinent historical

records detailing the following applicable information:
2/25/00 AC 20-142

Par 10 Page 13

DUAL USE ENGINES,

PROPELLERS, ACCESSORIES,

OR THEIR PARTS

(NEW OR USED)

DO NOT INSTALL

INSTALL

10g

INSTALL

10g

DO NOT

INSTALL

(FOR

STD A/W

CERT)

STD

OR

SPEC EVALUATION

10b or 10e

EVALUATION

10c or 10f

ELIGIBILITY

10a or 10d

NO

 YES

YES STD SPEC YES

NO

DO NOT

INSTALL

NO

FIGURE 4. DUAL USE ENGINES, PROPELLERS, ACCESSORIES, OR THEIR PARTS

(NEW OR USED)
AC 20-142 2/25/00

Page 14 Par 10

(1) engine, propeller, accessories, and part identification - assembly part number and

serial number and manufacturer;

(2) contract or purchase order number manufactured under;

(3) evidence of engine, propeller, accessory, and part status (i.e., serviceable or

unserviceable, per DD Form 1574-1 or DD Form 2410);

(4) complete historical records maintained by the military, the manufacturer, and any

other prior owner(s), pertaining to inspection, modification, repair, alteration, maintenance, and

operation of the engine from the time of acceptance by the military, including, but not limited to,

DD Form 2408-5 and DD Form 2408-16. The maintenance records should also include the date

that the work was accomplished, and work authentication; and

(5) current status of applicable ADs and DoD directives (i.e., engineering change, technical

order, maintenance work order, etc.), including the date, method, and compliance requirement; if the

AD involves recurring action, time and date when the next action is required.

b. Evaluation of New Dual Use Engines, Propellers, Accessories, or Their Parts for

Aircraft with Standard Airworthiness Certification. After reviewing the applicable items

listed in paragraph 10a and establishing that the product/part is eligible for installation on an

FAA type-certificated civil aircraft, the evaluation should ensure that each engine, propeller,

accessory and associated part conforms to the approved TC, was manufactured under an FAAapproved production system, and is in condition for safe operation.

c. Evaluation of New Dual Use Engines, Propellers, Accessories, or Their Parts for

Aircraft with Special Airworthiness Certification. After reviewing the applicable items listed in

paragraph 10a of this AC to ensure that the engine, propeller, accessory or part is eligible, the

evaluation should verify that the engine, propeller, accessory, or associated part is listed in the

FAA-accepted, military-approved maintenance manual or FAA-accepted civil maintenance manual

and IPC specified on the TCDS, and that the product/part is in condition for safe operation.

d. Eligibility of Used Dual Use Engines, Propellers, Accessories, or Their Parts for

Aircraft with Standard or Special Airworthiness Certification. A U.S. TC must have been

issued for a corresponding civil model engine or propeller under section 21.21 at the time of

manufacture (standard or special), or a U.S. aircraft TC must have been issued and the engine or

propeller referenced in the aircraft TCDS under section 21.27 (standard) or section 21.25

(special). The used engines, propellers, accessories, or parts may be considered eligible for

installation on FAA type-certificated civil or surplus military aircraft with standard or special

airworthiness certification when accompanied by pertinent historical records in accordance with

the items listed in paragraph 10a.

e. Evaluation of Used Dual Use Engines, Propellers, Accessories, or Their Parts for

Aircraft with Standard Airworthiness Certification. After establishing eligibility by reviewing

the applicable items listed in paragraph 10a, the evaluation should be performed by an FAA
2/25/00 AC 20-142

Par 10 Page 15

Engineer or an appropriately authorized designated engineering representative (DER). When a

DER is used, ensure that the DER substantiates recommendations or decisions in writing using

FAA Form 8110-3, Statement of Compliance, including supporting document(s). The evaluation

should ensure that each engine, propeller, accessory, and associated part conforms to the

approved TC, was manufactured under an FAA-approved production system, and is in condition

for safe operation. In addition, the following should be evaluated:

(1) Operational differences between military and civil versions (e.g., possible DoD

modification, alteration, repair, etc. performed), in performance standards as listed in the TCDS

(e.g., thrust, shaft horsepower, RPM and ratings), and in specifications, as listed in the TCDS and

the maintenance manuals (e.g., fuel type, oil, weight);

(2) Complete historical operational records, i.e., extreme operational conditions such as

accidents, fires or engine operating limit exceedances;

(3) Complete historical maintenance records, i.e., modifications, alterations, and repairs, and

complete documentation of work performed by an FAA approved facility that was properly rated for

the work performed and which conformed to the FAA approved data;

(4) Instructions for Continued Airworthiness;

(5) Emission requirements as stated in the TCDS (engine only);

(6) Comparison of military time and/or cycle count for accumulated operational time and

cycle versus civil (e.g., “Did the military use a different method than civil operators to account for

accumulated operational time and what are the expended equivalent civil cycles of the parts,

taking into account their past operational history and mission profile?”);

(7) Current manufacturer’s technical data to perform tests or inspections;

(8) Written results of inspections performed (e.g., maintenance record entry,

FAA Form 8130-3, Airworthiness Approval Tag, or FAA Form 337, Repair/Alteration Data

Form, for approval for return to service) and a completed FAA Form 8130-9, Statement of

Conformity, signed by the person who approved the item for return to service, as applicable;

(9) The application of the identifying marking requirements per sections 45.11 and 45.13,

as applicable;

(10) Engine, propeller, accessory, or part overhaul records, including overhaul in

accordance with civil engine/propeller manuals (e.g., “Is the engine, propeller, accessory or part in

a newly overhauled condition?”); and

(11) Verification that engine, propeller, accessory, or part was produced by an FAA PAH.

f. Evaluation of Used Dual Use Engines, Propellers, Accessories, or Their Parts for Aircraft

with Special Airworthiness Certification. After eligibility is established, the evaluation should be

performed by an FAA Engineer or an appropriately authorized DER. When a DER is used, ensure
AC 20-142 2/25/00

Page 16 Par 10

that the DER substantiates recommendations or decisions in writing using FAA Form 8110-3,

Statement of Compliance, including supporting document(s). The evaluation should verify that the

engine, propeller, accessory, or associated part is listed in the FAA-accepted, military-approved

maintenance manual or FAA-accepted maintenance manual and IPC specified on the TCDS, and that

the product/part is in condition for safe operation. In addition, the following should be evaluated:

(1) Complete historical operational records, i.e., extreme operational conditions such as

accidents, fires, or engine operating limit exceedances;

(2) Complete historical maintenance records, i.e., modifications, alterations, and repairs,

and complete documentation of the work performed;

(3) Instructions for Continued Airworthiness;

(4) Emission requirements as stated in the TCDS (engine only);

(5) Comparison of military time and/or cycle count for accumulated operational time and

cycle versus civil (e.g., “Did the military use a different method than civil operators to account for

accumulated operational time and what are the expended equivalent civil cycles of the parts,

taking into account their past operational history and mission profile?”);

(6) Current manufacturer’s technical data to perform tests or inspections;

(7) Written results of inspections performed (e.g., maintenance record entry,

FAA Form 8130-3 or FAA Form 337 for “Return-to-Service”) and a completed FAA Form 8130-9,

signed by the person who approved the “Return-to-Service”, as applicable;

(8) The application of the identifying marking requirements per sections 45.11 and 45.13,

as applicable;

(9) Engine, propeller, accessory, or part overhaul records, including overhaul in

accordance with civil engine/propeller manuals (e.g., “Is the engine, propeller, accessory or part in

a newly overhauled condition?”); and

(10) Verification that engine, propeller, accessory, or part was produced by an FAA PAH.

g. Approval for Installation of Dual Use Engines, Propellers, Accessories, and Parts.

Persons authorized under section 43.7 may approve for installation dual use engines, propellers,

accessories, or parts that have successfully completed airworthiness evaluation in accordance with

paragraph 10b, 10c, 10e, or 10f. The installer must be able to determine that the use of the engine

or propeller, and/or the installation of the accessory or part, will leave the aircraft in compliance

with pertinent regulations and in condition for safe operation.

11. MILITARY UNIQUE ENGINES, PROPELLERS, ACCESSORIES, AND THEIR

MILITARY UNIQUE PARTS. Military unique engines, propellers, accessories, and parts are

FSCAP that were specifically and uniquely designed and manufactured for the U.S. military for

which there was originally no corresponding FAA-approved PAH engine, propeller, accessory or
2/25/00 AC 20-142

Par 11 Page 17

part for civil application. The process of eligibility screening and airworthiness evaluation of

military unique engines and propellers by individuals authorized under section 43.7, or other

airworthiness evaluation by individuals specified, is shown in Figure 5 and described in paragraphs

11a through d. The authorized individual completing the eligibility screening and/or the

airworthiness evaluation should make a record entry to document the result(s).

a. Eligibility. Military unique engines, propellers, accessories, and parts may be eligible for

installation on surplus U.S. military aircraft with special airworthiness type certification under

subsection 21.25(a) and 21.305(c). The accompanying historical records for military unique engines,

propellers, accessories, or parts should contain the pertinent information in accordance with the

items listed in paragraph 10a.

MILITARY UNIQUE ENGINES, PROPELLERS,

ACCESSORIES, OR THEIR MILITARY UNIQUE

PARTS (SPECIAL USE ONLY)

DO NOT INSTALL

INSTALL

11d

INSTALL

 11d

DO NOT

INSTALL

NEW

OR

USED

EVALUATION

11b

EVALUATION

11c

ELIGIBILITY

11a

 NO

YES

 YES NEW USED YES

 NO NO

FIGURE 5. MILITARY UNIQUE ENGINES, PROPELLERS, ACCESSORIES, OR THEIR

MILITARY UNIQUE PARTS (SPECIAL USE ONLY)
AC 20-142 2/25/00

Page 18 Par 11

b. Evaluation of New Military Unique Engines, Propellers, Accessories, and Their Parts

for Installation on Surplus Military Aircraft with Special Airworthiness Certification. After

reviewing applicable records listed in paragraph 10a of this AC to ensure that the engine,

propeller, accessory, or part is eligible, the evaluation should verify that the engine, propeller,

accessory, or associated part is listed in the FAA-accepted, military-approved maintenance manual

or FAA-accepted civil maintenance manual and IPC specified on the TCDS, and ensure that the

engine, propeller, accessory, or part is in condition for safe operation.

c. Evaluation of Used Military Unique Engines, Propellers, Accessories, and Their Parts

for Installation on Surplus Military Aircraft with Special Airworthiness Certification. After

the applicable records listed in paragraph 10a are reviewed to ensure that the engine, propeller,

accessory, or part is eligible, the evaluation should be performed by an FAA Engineer or an

appropriately authorized DER. When a DER is used, ensure that the DER substantiates

recommendations or decisions in writing using FAA Form 8110-3, including supporting

document(s). The evaluation should verify that the engine, propeller, accessory, or associated part

is listed in the FAA-accepted, military-approved maintenance manual or FAA-accepted civil

maintenance manual and the IPC specified on the TCDS, and ensure that the product/part is in

condition for safe operation.

d. Approval for Installation of Military Unique Engines, Propellers, Accessories, and

Parts. Persons authorized under section 43.7 may approve for installation military unique

engines, propellers, accessories, or parts that have successfully completed airworthiness

evaluation in accordance with paragraph 11b or 11c. The installer must be able to determine that

the use of the engine or propeller, and/or the installation of the accessory or part, will leave the

product in compliance with the TCDS and in condition for safe operation.

12. SUMMARY. To ensure continued safety in civil aviation, it is essential that appropriate data

is used when determining the eligibility for installation on an FAA type-certificated aircraft of all

U.S. military surplus FSCAP, engines, and propellers. The airworthiness evaluation should be

performed by an authorized person reviewing the applicable records and performing appropriate

tests and inspections as specified, and shall ensure that each FSCAP, engine or propeller conforms

to its approved type design and is in condition for safe operation.

/s/

Ava L. Mims

for

L. Nicholas Lacey

Director, Flight Standards Service