IFR Aircraft & Equipment Requirements
Key instruments, inspection intervals, VOR checks, and database currency rules for legal IFR flight.
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Questions Covered in This Set
10 cards to master
What does the GRABCARD mnemonic cover?
The instruments required for IFR under §91.205(d), in addition to VFR day and night equipment: Generator/alternator, Radios, Altimeter (sensitive/adjustable), Ball, Clock, Attitude indicator, Rate-of-turn indicator, Directional gyro.
Does a wristwatch or phone satisfy the IFR clock requirement?
No — the clock must be installed in the aircraft, displaying hours, minutes and seconds with a sweep-second pointer or digital presentation.
How often must the altimeter/static system be inspected for IFR?
Every 24 calendar months, by an appropriately rated shop (§91.411).
How often must a VOR receiver be checked for IFR use?
Within the preceding 30 days (§91.171) — required only if you use VOR for IFR navigation.
What must be logged after a VOR check?
Date, place, bearing error, and the signature of the person making the check. 'VOR ck OK' alone is not compliant.
What are the allowable VOR check tolerances?
VOT ±4°, ground checkpoint ±4°, airborne checkpoint ±6°, airway centerline over a landmark within 20 NM ±6°, dual-VOR cross-check within 4° of each other.
Transponder and ELT inspection intervals?
Transponder every 24 calendar months (§91.413); ELT every 12 calendar months, battery replaced at 1 hour cumulative use or 50% of useful life (§91.207).
Can you fly an RNAV (GPS) approach with an expired database?
Not for the final approach segment — a current database is required. Expired databases with waypoint verification against current charts may be workable en route/terminal only.
Does a handheld GPS or tablet satisfy 'nav appropriate to the ground facilities to be used'?
No — only a panel-mounted, IFR-approved GPS installation satisfies the requirement.
Why does the KOEL matter in glass-cockpit aircraft?
An integrated system means one ADAHRS failure can remove attitude, heading and turn rate at once, so the AFM's Kinds of Operations Equipment List and standby instruments govern what's legal and safe.
