AIM ¶ 5-4-18 — RNP AR Procedures
AIM 5-4-18 explains RNP AR (Authorization Required) approach and departure procedures, RNP values, RF legs, and FAA authorization requirements for pilots.
RNP AR (Authorization Required) procedures are advanced RNAV approaches and departures requiring specific FAA authorization — similar to Cat II/III ILS. Authorization comes via OpSpec, MSpec, or LOA, with no exceptions. Detailed guidance lives in AC 90-101.
Key characteristics:
- Chart title: U.S. charts read "RNAV (RNP) RWY XX" and always state "Authorization Required."
- Lateral OEA: Obstacle Evaluation Area is 2 × RNP with no secondary buffers.
- Minimum RNP: 0.30 lateral accuracy is the floor; each line of minima has its own RNP value.
- Radius-to-Fix (RF) legs: common on RNP AR IFPs; aircraft must be eligible.
- Missed approach RNP <1.00: some procedures require sub-1.00 NM accuracy in the missed; the operator's authorization specifies if this is permitted.
- Non-standard speeds/climb gradients: pilots must verify capability before commencing the approach.
- RNP AR Departures: require prior RNP AR approach authorization, may use RNP 0.30, RF turns starting at the DER, and steeper climb gradients.
Why it matters: flying an RNP AR procedure without authorization, eligible aircraft, and trained crew is prohibited — these procedures place tighter obstacle margins and demand precise navigation performance.
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?