Deciding, finding, and recording

Eight procedures, in the order the work actually happens: decide what kind of job it is, find the data that governs it, do the work, record it.

Same five-part form as GEN-H Procedures.

Procedure 1 — Determine whether a repair or alteration is major or minor (S15)

The first decision on any job, because everything downstream depends on it.

Method

1. Describe the change in one sentence — what is being altered or repaired, and to what.
2. Ask what it affects. Weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness. Appreciably?
3. Ask whether it can be done by elementary operations with ordinary practices.
4. Check part 43 appendix A — if the work is named there, the answer is settled.
5. If appendix A does not name it, reason from step 2. The list is not exhaustive.
6. Record why you decided as you did, not only what you decided.

Check — state the consequence out loud. "This is minor, so acceptable data is sufficient and no 337 is required." If you cannot complete that sentence confidently, you have not made the determination yet.

Failure — reasoning from the list alone, so an unlisted alteration that appreciably affects airworthiness is called minor because appendix A does not mention it (GEN-I Concepts §1).

Procedure 2 — Determine applicability of approved data (S16)

Given — a major repair to design. Sought — data that is approved, and approved for this aircraft.

Method

1. Identify candidate data: the structural repair manual, an STC, a manufacturer's approved repair, an FAA field approval, a DER-approved repair.
2. Check the approval status. Is this document approved data, or acceptable data? Manuals contain both, and the distinction is often stated in the front matter rather than on the page you are reading.
3. Check applicability: model, serial-number effectivity, configuration, and whether prior alterations affect it.
4. Check currency — the revision, as in GEN-B Procedures Procedure 1.
5. If nothing approved covers it, that is a finding, not an obstacle: the routes are a field approval, DER approval, or the manufacturer.

Check — name the document, its revision and the approval basis. "The SRM, revision 12, section 51-40, approved data" is an answer. "The manual" is not.

Failure — using a manufacturer's repair scheme written for a different model because the structure looks the same.

Procedure 3 — Determine AD applicability (S8)

Method

1. Search the AD database by aircraft, engine, propeller and appliance — all four. An AD against an appliance applies to whatever it is fitted to.
2. For each AD, read the applicability paragraph: model, serial numbers, part numbers, configuration.
3. Determine whether it applies to this aircraft as configured today, including any STCs fitted.
4. Determine the compliance time: one-time, recurring, or before further flight — and whether any recurring interval is now due.
5. Check the maintenance records for prior compliance, and whether an AMOC was approved (K10).

Check — an AD is either applicable or it is not, and you must be able to say which paragraph makes it so. "It does not apply because our serial number is outside the range in paragraph (c)" is an answer.

Failure — searching by airframe only and missing an AD against the engine, propeller or an appliance.

Procedure 4 — Determine an aircraft's inspection status from its records (S3)

Method

1. Establish what inspections this aircraft requires — annual, 100-hour, progressive, or a program — and under which rule it operates.
2. Find the most recent entry for each.
3. Compare against current time in service, and against the calendar where the interval is calendar-based.
4. Check for life-limited parts and recurring AD intervals, which run on their own clocks.
5. State the status and the next due point.

Check — time in service, not tach time, not Hobbs time, unless the record establishes the relationship. K6 and § 1.1 define the term, and the definition is doing real work here.

Failure — finding the last annual and stopping. A current annual with an overdue recurring AD is not an airworthy aircraft.

Procedure 5 — Use an illustrated parts catalog (S10, with K21, K22)

Method

1. Find the figure for the assembly, and the item number on the illustration.
2. Read across to the part number.
3. Read the usable-on or effectivity code. This is the step that is skipped.
4. Confirm the code covers your aircraft's serial number or configuration.
5. Check for supersession notes — the part number may have been replaced.

Check — say which effectivity code your aircraft falls under. If the catalog has a code column and you did not read it, you have found a part number, not the part number.

Failure — ordering and fitting a part that appears in the right figure under the wrong effectivity. It fits (GEN-I Concepts §4).

Procedure 6 — Make a maintenance record entry for return to service (S7)

Given — work completed satisfactorily. Sought — an entry meeting § 43.9(a).

Method — four items, and only four:

1. A description of the work performed, or a reference to acceptable data describing it.
2. The date of completion.
3. The name of the person who performed the work, if different from the person approving it.
4. Signature, certificate number and kind of certificate of the person approving for return to service.

Then: state what data you worked to, including revision, and record what you found where finding is part of the job.

Check — read the entry as though you are the next mechanic, a year from now, with no memory of this aircraft. Can you tell what was done, to which component, to what data, and whether anything was left outstanding? If not, item 1 is not yet satisfied.

Failure — "Complied with AD 2019-XX-XX." Which method? Which revision? What was found? A compliance claim with no substance behind it is the most common defective entry there is.

Your signature is an approval for return to service for that work only — not for the aircraft as a whole, and not for anyone else's work.

Procedure 7 — Make a 100-hour inspection record entry (S18)

Different from Procedure 6, because the claim is different.

Method

1. State the type and scope of the inspection — a 100-hour inspection, performed in accordance with part 43 appendix D.
2. State the date and time in service.
3. State the finding: that the aircraft was determined to be airworthy, or a statement that it was found unairworthy together with the list of discrepancies given to the owner.
4. Signature, certificate number, kind of certificate.

Check — an inspection entry must state a conclusion about airworthiness. A maintenance entry says what you did; an inspection entry says what you found. If your entry does not contain a determination, it is not an inspection entry.

Failure — recording an inspection as though it were maintenance, so the record never says whether the aircraft was airworthy.

Procedure 8 — Complete a Form 337 (S1)

Given — a completed major repair or alteration and the approved data it was done to.

Method

1. Identify the aircraft, engine, propeller or appliance exactly — make, model, serial, registration.
2. Mark repair or alteration, and the unit affected.
3. In the description block, state what was done, in what location, to what data — naming the approved data and its revision.
4. Attach the sketch where the description needs one (GEN-B Procedures Procedure 7).
5. Sign as the person who performed the work, and obtain the approval for return to service from a person authorized to give it for the class of work.
6. Make the corresponding maintenance record entry as well. The 337 does not replace it.
7. File it as required.

Check — could an inspector, in ten years, reconstruct what was done and confirm it was permissible? The 337 exists for that reader, not for you.

Failure — a description that says what was replaced but not what data authorized it. Step 3's data reference is what makes the repair defensible; without it the form records an undocumented major alteration in writing.

The checks, collected

Six of the eight checks are the same test: can someone who was not there work out what happened? That is what a maintenance record is, and it is why this unit is the one every other unit ends in.

License

CC BY-SA 4.0 (Licensing).