Checking Instruments and Equipment

Anything the flight caused or revealed — especially things that only show up under IFR workload:

• Nav and comm behavior: intermittent flags, a glideslope that dropped out, a CDI that centered late
• Gyro health: an attitude indicator slow to erect or that precessed in the turns, a heading indicator that needed frequent resets
• Autopilot disconnects or mode weirdness
• Electrical and vacuum/pressure trends you noticed on the gauges
• Ordinary servicing: fuel, oil, oxygen, tires and brakes

Capture it while it's fresh — a squawk you can't remember by the time you reach the FBO desk never gets fixed (IR.VIII.A.S1).

Document it in whatever discrepancy system the operator uses — squawk sheet, maintenance log, a call to the shop — with enough detail to be useful to a technician: what happened, when, in what conditions, which frequency and approach. The owner or operator must have defects repaired between required inspections as prescribed by Part 43, but that machinery only starts when the defect is written down (91.405(a)). The unwritten half: an undocumented squawk becomes the next pilot's in-flight surprise — and in this airplane the next pilot may be shooting an ILS to minimums.

The owner or operator, who must:

• Have discrepancies repaired between required inspections as prescribed in Part 43 (91.405(a))
• Ensure maintenance personnel make the return-to-service entries in the maintenance records (91.405(b))
• Have any item deferred inoperative under 91.213(d)(2) repaired, replaced, removed, or inspected at the next required inspection (91.405(c))
• Ensure a placard is installed when listed discrepancies include inoperative instruments or equipment (91.405(d))

You still own the pilot half: deciding whether the airplane is airworthy for the next flight.

Yes, if every step of the deferral test passes (91.213(d)):

1. Eligible aircraft — a rotorcraft, non-turbine airplane, glider, lighter-than-air aircraft, powered parachute, or weight-shift-control aircraft with no Master MEL, or a small rotorcraft, non-turbine small airplane, glider, or lighter-than-air aircraft that has one
2. The item is not required by the aircraft's VFR-day type certification, its equipment list or Kinds of Operations Equipment List, 91.205 or any other rule for the specific kind of flight operation, or an airworthiness directive
3. The item is removed (cockpit control placarded, maintenance recorded under 43.9) or deactivated and placarded "Inoperative" (deactivation involving maintenance is done and recorded per Part 43)
4. A pilot or maintenance person certificated and appropriately rated determines it's no hazard to the aircraft

The IFR wrinkle in that "specific kind of flight operation" clause: equipment 91.205(d) requires for IFR can't be deferred for an IFR flight. The full airworthiness decision ladder is covered under Task II.C.

A Minimum Equipment List is an FAA-approved, aircraft-specific list providing for operation with certain items inoperative. Operating under one requires a letter of authorization from the Flight Standards office carried in the aircraft — the MEL and letter together constitute a supplemental type certificate. The aircraft records available to the pilot must include an entry describing the inoperable items, and you must observe every condition and limitation in the MEL and letter (91.213(a)).

Most light trainers have no MEL — they run on the 91.213(d) deferral method instead. Be ready to say that plainly.

A special flight permit — an aircraft with inoperable instruments or equipment may be operated under one, issued in accordance with 21.197 and 21.199, to get it to where repairs can be made (91.213(e)).

Three piles:

• Work records — for each maintenance, alteration, and inspection: a description of the work, the date completed, and the signature and certificate number of the person approving return to service. Kept 1 year or until the work is repeated or superseded.
• Permanent status records — total time in service, current status of life-limited parts, time since overhaul of time-limited items, current inspection status, AD compliance status (method and date), and copies of the 43.9(d) major-alteration forms. Retained and transferred with the aircraft when it's sold.
• Inspection defect lists — a list of defects furnished under 43.11, kept until the defects are repaired and the aircraft is approved for return to service (91.417(b)(3)).

All of it must be made available to the FAA or NTSB on request (91.417(c)). Your postflight squawk is the first link in that paper trail.

The VOR operational check. To use the VOR under IFR it must have been checked within the preceding 30 days, and whoever does the check enters the date, place, bearing error, and signature in the aircraft log or other record (91.171(d)). It's the one recurring IFR record that's pilot-made rather than mechanic-made — check methods and error limits are covered under Task II.C.

Because the failures that matter most under IFR are invisible on the ramp. A gyro that precesses under load, a glideslope receiver that drops out intermittently, an altimeter that sticks — all of them pass a ground check and then resurface in IMC, where partial panel is a genuine emergency rather than a hood exercise. The only thing standing between that airplane and the next low-IMC departure is your written squawk. Same logic for servicing trends: a slowly sagging vacuum reading or an ammeter drifting low is a report, not a shrug.