FAA Part 135 audit preparation checklist

Inspectors usually start with the manuals because everything else hangs off them: §135.21 requires a manual, §135.23 dictates much of what it must contain, and the training program, MEL usage, and operational control procedures all have to be consistent with it. The classic findings here are not missing manuals — they are revision-control failures: a procedure that changed in practice but not on paper, a revision that never reached a crew room, or two manuals that quietly disagree with each other.

• General Operations Manual (GOM) current and reflecting actual practice

  The most damaging finding in an audit is a manual that describes an operation you don't actually run. Walk the manual against a real trip: does dispatch, fueling, and de-icing happen the way §135.23's required procedures say it does?

• Flight Operations Manual / SOPs consistent with the GOM and OpSpecs

  Cross-document contradictions read as loss of control. If the SOP says one stabilized-approach gate and the training manual says another, expect the inspector to ask which one crews actually fly.

• Revision control: revision numbers, dates, and distribution records current

  §135.21 requires keeping the manual up to date and making it available. Distribution records are the proof — an unacknowledged revision is, from the FAA's side of the table, an undistributed one.

• Required manuals accessible to the crews and personnel who use them

  Accessible means where the work happens: EFB, crew room, dispatch. If a line pilot can't produce the current fueling procedure on request, availability has failed regardless of what the master copy says.

• Each manual section traceable to the Part 135 requirements it satisfies

  A requirement-to-procedure map turns audit questions from archaeology into lookup. This is precisely the mapping Navlyt maintains automatically — but a spreadsheet version beats nothing.

Your OpSpecs are the contract between the certificate and the operation — the aircraft, areas, and kinds of operations you are actually authorized to fly. Findings in this area are usually drift: the operation grew a capability (new aircraft type, new area, RVSM, international) faster than the paperwork, or a special authorization exists on paper with no supporting procedure in the manuals.

• OpSpecs on file, current, and signed

  Sounds trivial; isn't. Amendments accumulate, and the working copy in dispatch has to match what the FSDO holds.

• Authorized areas, aircraft, and kinds of operations match what you actually fly

  Every trip outside the authorization is a violation regardless of how safely it was flown. Reconcile the schedule of a sample month against the OpSpecs authorizations.

• Special authorizations supported by required procedures in the manuals

  An authorization (e.g., specific approach minima, international ops) normally presumes procedures, training, and sometimes equipment. The authorization without its supporting procedure is a standing finding.

This is where audits are most commonly lost, because the requirements are individually simple and collectively relentless: every pilot, every 12 months (or 6, for §135.297 instrument proficiency where applicable), with records that prove it under §135.63. Inspectors typically verify §135.293 competency, §135.297 IPC, and §135.299 line checks first, because those connect directly to whether a pilot was legal to fly a revenue trip.

• Pilot certificates and ratings current for the operations flown

  Match each pilot's certificates and type ratings against the aircraft and operations they were assigned — §135.243 sets PIC qualification floors that vary by operation type.

• Medical certificates on file and unexpired

  A lapsed medical makes every intervening flight a finding. Track expiries with margin, not calendar luck — this is exactly what Navlyt's medical tracking flags as current, expiring, or expired.

• Recurrent testing and checks current: §135.293 competency, §135.297 IPC, §135.299 line checks

  The 12-calendar-month clocks run per pilot, per requirement. A training program that ran 'roughly annually' produces exactly the gaps inspectors are trained to find.

• Recent experience (§135.247) verifiable for the operations flown

  Night currency and the 90-day landing requirements have to be reconstructable from records, not memory.

• Duty and rest records retained and consistent with §135.267 limits

  Duty/rest findings compound: one bad record suggests a bad system, and the sample size expands accordingly.

• Training records complete and traceable to the approved training program

  §135.63(a)(4) requires records that show compliance — the record must name the curriculum item, the date, and the instructor or check pilot, and match the program the FSDO approved.

The maintenance side of a Part 135 audit turns on whether the paperwork regime matches the fleet — §135.411 splits the world at nine passenger seats, and everything from inspection programs to who may approve work flows from that split. MEL discipline is the other reliable probe: an MEL is an authorization to fly with something broken under conditions, and inspectors check whether those conditions were actually met and closed out.

• Airworthiness status and required inspections current for each aircraft

  Reconcile each airframe's inspection status against the applicable program — and confirm the program itself is the one your OpSpecs and §135.411 category require.

• MEL approved, current, and used correctly (§135.179)

  Deferred items need the MEL's conditions met, placarding done, repair intervals respected, and closure recorded. An open deferral past its category interval is a self-documenting finding.

• Airworthiness directives tracked with method of compliance recorded (Part 39)

  AD compliance must be demonstrable per aircraft: the AD, the method, the date, the next action if recurring. Gaps here ground airplanes on the spot.

• Maintenance records complete and retained for required periods

  The records prove the airworthiness chain. Missing entries break the chain even when the work was done.

• Weight and balance data current for each aircraft

  Repainting, interior changes, and equipment swaps all move empty weight. Stale W&B data quietly invalidates every load manifest computed from it.

With the FAA's SMS mandate extending Part 5 to Part 135 operators, safety management is moving from best practice to requirement — and it is audited as a system, not a binder: does hazard reporting actually happen, do reports become corrective actions, and do those actions close? Recordkeeping is the connective tissue of the whole audit: §135.63 sets what must exist, and retrievability is what separates a pass from a scramble.

• Safety reporting process in use — reports flowing, not just a form existing

  An empty hazard register at an operator flying real trips reads as a reporting culture problem, not a safety achievement.

• Hazard reports and audit findings tracked to closure with owners and dates

  The corrective-action loop is what SMS auditors probe: identified, assessed, assigned, closed, verified. An action without an owner or past its date is a live finding.

• SMS documentation scaled to the operation and consistent with practice

  Under the Part 5 framework the system must fit the operator's size and complexity — a copied big-carrier manual that nobody follows is worse than a thin one that is actually used.

• Required records retained for their applicable retention periods

  Retention periods vary by record type; a purge policy that outran a retention requirement converts good history into a finding.

• Evidence organized and retrievable per requirement — minutes, not days

  The practical test of the whole system: pick any requirement and produce its evidence while the inspector waits. If that takes a filing expedition, the audit will feel like one.