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Instrument rating · ACS IR.VIII.A · lesson pack

Checking Instruments and Equipment

Why this one matters

An instrument that flickered on the approach today is an instrument that may fail in cloud for the next pilot. The postflight write-up is how one pilot’s warning reaches the next. Skipping it to save five minutes passes the risk on.

1 · Know these cold

  • •After an IFR flight, go through every flight instrument and every nav and comm system, using the POH/AFM as the list, and compare each with how it behaved in flight; note anything that misbehaved, even briefly. Then document it. The walk-around supplements this; it doesn't replace it.(Instrument Flying Handbook (FAA-H-8083-15B); Your airplane's POH/AFM)
  • •Write discrepancies in the operator's squawk system, where maintenance and the next pilot will see them. The owner or operator keeps the airplane airworthy and has discrepancies fixed (91.403, 91.405); maintenance makes the maintenance-record entries; you, as PIC, decide whether it's airworthy for your next flight (91.7).(14 CFR 91.403(a), 91.405, 91.7(b))
  • •Inoperative equipment is repaired or formally deferred before the next flight. Placarding alone never defers anything. With an approved MEL and its letter of authorization, follow the MEL. Without one, 91.213(d): not required by the type certificate, the equipment list or KOEL, 91.205 or another rule, or an AD; then removed or deactivated with a maintenance-record entry, placarded "Inoperative", and judged no hazard. Deferred items are repaired at the next required inspection (91.405(c)).(14 CFR 91.213; 91.405(c))
  • •VOR check: for IFR use, within the preceding 30 days (±4° VOT or ground checkpoint, ±6° airborne, 4° between two receivers), normally done before the IFR flight; log the date, place, bearing error and signature. Stale or out of tolerance means no VOR use under IFR.(14 CFR 91.171)
  • •Note servicing needs: fuel, oil, and anything that needs a mechanic’s look.(Your airplane's POH/AFM)

2 · The lesson

The postflight check and write-up
  • The systematic review first: each flight instrument, nav receiver, comm radio, the autopilot and the transponder, against what it did in flight. Then the walk-around: damage, leaks, ice or anything loose; the antennas and the pitot and static ports.(Instrument Flying Handbook (FAA-H-8083-15B); Your airplane's POH/AFM)
  • Note anything that misbehaved in flight: a navaid flag, a flickering display, a radio that cut out, a gyro that drifted.(Instrument Flying Handbook (FAA-H-8083-15B))
  • Record discrepancies in the aircraft’s maintenance records or squawk system, per the owner or operator.(14 CFR 91.405)
  • Placarding "Inoperative" is one step of the formal deferral, done with deactivation or removal and a maintenance-record entry, not a routine personal postflight action. Your job is the write-up and telling the operator.(14 CFR 91.213(d))

Want it all on one page, with scenarios? Read the full lesson.

On the flight

ACS standards

  • Conduct a postflight inspection and document discrepancies and servicing requirements, if any.(Instrument Rating ACS (FAA-S-ACS-8C), IR.VIII.A.S1)

What your instructor is watching for

Your instructor watches for a real walk-around, honest notes on anything that misbehaved, and a write-up the next pilot can use.

3 · Say it out loud

Answer each one out loud, then check yourself and mark how it went.

  1. Remember Recall it

    “Where do you record a discrepancy after a flight?”

  2. Understand Explain why

    “Why write up a problem that fixed itself?”

  3. Apply Use it on a flight

    “Your glideslope flagged twice on the approach and then worked. What do you do after landing?”

4 · Common mistakes

  • Telling only a friend.

    Maintenance never hears.

    Instead: Write it in the official system.

  • Vague write-ups.

    Maintenance can’t find it.

    Instead: Say what, when and where.

5 · Quick check

Answer, then reveal. Flag anything you want to see again.

  1. 1. Who is responsible for keeping the airplane airworthy?

  2. 2. What goes in a VOR check log?

  3. 3. What happens to inoperative equipment before the next flight?

  4. 4. Name two things to check on the postflight walk-around for IFR.

  5. 5. Why record an intermittent fault?

  6. Scenario6. Your turn coordinator flag came on briefly on the approach. What do you do after landing?

Trained it? Now prove it: practice checking instruments and equipment out loud with our examiner.

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Study aid, not FAA guidance. Sources: 14 CFR; Instrument Flying Handbook (FAA-H-8083-15B); Instrument Rating ACS (FAA-S-ACS-8C). Checked against current sources 2026-11-13.