Major or Minor: That is the question

Major or Minor? That is the question Joe Hertzler A repair is maintenance that takes place to restore a typecertificated product to "condition for safe operation." And, an alteration is maintenance that is performed that adds to and/or...


65.95 Inspection authorization: Privileges and limitations
"(a) The holder of an inspection authorization may -
(1) Inspect and approve for return to service any aircraft or related part or appliance (except any aircraft maintained in accordance with a continuous airworthiness program under Part 121 of this chapter) after a major repair or major alteration to it in accordance with Part 43 of this chapter, if the work was done in accordance with technical data approved by the Administrator . . ."

145.51 Privileges of certificates
". . . However, a certificated repair station may not approve for return to service any aircraft, airframe, aircraft engine, propeller, or appliance after major repair or major alteration unless the work was done in accordance with technical data approved by the Administrator."

There is a misleading statement in Appendix A of Part 43 that begs a question. Notice it states "For major repairs made in accordance with a manual or specifications acceptable to the Administrator, a certificated repair station may . . ." I have several times approached the FAA with this statement to justify the use of data that has not yet been approved and that is not the intent. Let's look again at 14 CFR Part 145.51:

145.51 Privileges of certificates
" . . . However, a certificated repair station may not approve for return to service any aircraft, airframe, aircraft engine, propeller, or appliance after major repair or major alteration unless the work was done in accordance with technical data approved by the Administrator."

Very clearly, a repair station must use approved data for major repairs even when it elects to approve for return to service in accordance with 14 CFR Part 43 Appendix B (b).

I believe the intent of this statement stems from this. Back when this old rule was written, approved data for repairs was rare and the common practice was to use AC 43.13-1A as data to support the repair. You may be surprised to find out that you can use AC 43.13-1B (revised about five years ago) as approved data for major repairs.

AC43.13-1B introduction
1. Purpose

"This advisory circular (AC) contains methods, techniques, and practices acceptable to the Administrator for the inspection and repair of nonpressurized areas of civil aircraft, only when there are no manufacturer repair or maintenance instructions. This data generally pertains to minor repairs. The repairs identified in this AC may also be used as a basis for FAA approval for major repairs. The repair data may also be used as approved data, and the AC chapter, page, and paragraph listed in block 8 of FAA Form 337 when:

a. The user has determined that it is appropriate to the product being repaired;
b. It is directly applicable to the repair being made; and
c. It is not contrary to manufacturer's data."

This is why the Appendix uses the term accepted rather than approved, what I see as another opportunity for revision. The AC is simply acceptable data and can only be used as approved data under these clearly defined conditions.

So there you have it. The person performing the work is to determine whether or not the alteration or repair is major in nature using 14 CFR Part 43 Appendix A as a guide. Once that has been decided, if it is major, the work must be performed in accordance with FAA approved data and the person performing the work must execute an FAA Form 337 as defined by 14 CFR Part 43 Appendix B (a). A repair station may provide the owner or operator with a signed copy of the work order as detailed in 14 CFR Part 43 Appendix B (b). Develop for yourself, clear boundaries around Part 43 Appendix A so that you will not find yourself on the fence when deciding between major and minor.

Joe Hertzler is the president of AVTRAK Inc., an Aurora, Colorado-based company. He is an A&P mechanic with Inspection Authorization and also a private pilot

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