FAA Instrument Rating Airplane (IRA)IFR Procedures and ChartsMedium
A pilot is filing an IFR flight plan from Airport A to Airport B. The direct route between the two airports crosses an area where an OROCA of 12,500 feet is depicted. The pilot wishes to cruise at 11,000 feet. What is the significance of the OROCA in this scenario?
- AIt is the minimum altitude for radar coverage in that area.
- BIt is the minimum altitude the pilot must maintain over that area.
- CIt indicates the highest usable altitude for IFR flight in that area.
- DIt provides obstacle clearance but does not guarantee navigation signal coverage or communications.
Show answer & explanationAnswer & explanation
Correct answer: D. It provides obstacle clearance but does not guarantee navigation signal coverage or communications.
An Off-Route Obstacle Clearance Altitude (OROCA) provides a guaranteed 1,000 feet (2,000 feet in mountainous terrain) of obstacle clearance. However, it does not assure navigation signal reception or ATC communications, which is why it's typically higher than an MEA or MOCA.
Why the other options are wrong
- A. Incorrect. OROCA does not guarantee radar coverage or communications.
- B. Incorrect. OROCA is an obstacle clearance altitude, but not necessarily the *minimum* altitude to be maintained if an MEA or MOCA is lower and applicable.
- C. Incorrect. OROCA is a minimum for obstacle clearance, not a highest usable altitude.
OROCA (Off-Route Obstacle Clearance Altitude)
OROCA is an off-route altitude that provides obstacle clearance with a 1,000-foot buffer (2,000 feet in mountainous terrain) but does not guarantee navigation signal coverage or ATC communications.
- Provides obstacle clearance only.
- Minimum 1,000 ft (non-mtn) or 2,000 ft (mtn) above obstacles.
- Does not guarantee NAVAID reception.
- Does not guarantee ATC radio communications.
Memory trick: OROCA: Obstacle-safe but No Radio Or Communications Available.