AIM ¶ 4-4-9 — VFR to IFR Clearance
AIM 4-4-9 explains pilot responsibility for terrain clearance when picking up an IFR clearance en route below MEA/MIA/MVA/OROCA. Study guide for checkride prep.
When you depart VFR and plan to (or need to) pick up an IFR clearance en route, you must stay aware of your aircraft's position relative to terrain and obstructions. ATC may issue a clearance at an altitude below the published minimums — and when that happens, you are responsible for your own terrain and obstruction clearance until you climb to the:
- MEA — Minimum En Route Altitude
- MIA — Minimum IFR Altitude
- MVA — Minimum Vectoring Altitude
- OROCA — Off-Route Obstruction Clearance Altitude
If you can't maintain safe clearance from terrain or obstacles at the assigned altitude, tell the controller and state your intentions (e.g., request a higher altitude or a different routing).
About OROCA: It provides 1,000 ft of terrain/obstruction clearance (2,000 ft in designated mountainous areas). However, OROCA is not evaluated for NAVAID signal coverage, ATC radar surveillance, or communications coverage. It's published for situational awareness, flight planning, and in-flight contingencies — not as a guaranteed IFR routing altitude.
This matters operationally because picking up IFR in the air, especially in marginal VFR or near rising terrain, can place you in IMC below safe altitudes if you're not actively monitoring your position.
Five FAA-written-style questions. Instant explanations, every answer cites its source — no account needed.
You are flying VFR in Class E airspace at 8,500 feet MSL during the day. What are your minimum visibility and cloud clearance requirements?