IFR Quick Reference
Updated July 2026 · by Jeff, pilot and builder of Zeekin Around
The numbers the oral turns on: currency, alternates, fuel, equipment checks, and the memory hooks that hold them together. Built for the night before, and the run-up area on a low ceiling.
Instrument currency (61.57(c)–(d))
| Situation | Rule |
|---|---|
| Current | Within the preceding 6 calendar months: six instrument approaches, holding, and intercepting/tracking (66-HIT), flown in an aircraft or a sim/FTD/ATD representing the category |
| Lapsed, within the next 6 months | Regain currency yourself (safety pilot or device); no IPC needed |
| Lapsed more than 6 months | Instrument proficiency check (61.57(d)) with an examiner, authorized instructor, or check pilot |
| Safety pilot flight | Simulated instrument requires a view-limiting device and a rated safety pilot in the other control seat (91.109(c)) |
Alternate planning (91.169)
| Question | Rule |
|---|---|
| Need an alternate? | Yes, unless the destination has an instrument approach and from 1 hour before to 1 hour after ETA the forecast is at least 2,000 ft ceiling and 3 SM (the 1-2-3 rule) |
| Alternate minima (precision approach) | 600-2 (600 ft ceiling, 2 SM) at ETA, unless the chart publishes nonstandard alternate minima |
| Alternate minima (non-precision) | 800-2 at ETA |
| Alternate with no instrument approach | Ceiling and visibility must allow descent from the MEA, approach, and landing under basic VFR |
| Fuel (91.167) | Destination + alternate + 45 minutes at normal cruise |
Equipment and system checks
| Check | Interval | Tolerance |
|---|---|---|
| VOR: VOT or ground checkpoint (91.171) | 30 days | ±4° |
| VOR: airborne checkpoint | 30 days | ±6° |
| VOR: dual cross-check | 30 days | 4° between indications |
| Altimeter / pitot-static (91.411) | 24 calendar months | Shop-certified for IFR |
| Transponder (91.413) | 24 calendar months | n/a |
Holding and approach speeds
| Block | Numbers |
|---|---|
| Max holding speeds (AIM 5-3-8) | ≤6,000 ft: 200 KIAS · 6,001–14,000 ft: 230 KIAS · above 14,000 ft: 265 KIAS |
| Holding legs | 1 minute inbound at or below 14,000 ft; 1½ minutes above |
| Approach categories (97.3, by 1.3 Vso) | A: less than 91 kt · B: 91–120 · C: 121–140 · D: 141–165 |
| Standard rate | 3°/second: 30° of heading change ≈ 10 seconds |
Memory acronyms
Study strategy (the written, 61.65 experience, spaced repetition, and chair-flying procedures) lives on the How to Prepare page.