Approach Fundamentals
The structure that every IFR approach shares. Four segments, five aircraft categories, the helicopter visibility halving rule, SHARPTT (the seven cases when a procedure turn is NOT required), and INCRAM (the brief you run before the IAF). These fundamentals apply to every approach type — VOR, ILS, RNAV, radar — and knowing them cold makes every chart easier to read.
The four approach segments
- Initial approach — From the Initial Approach Fix (IAF) to the Intermediate Fix (IF), or to the point where the aircraft is established on the intermediate or final approach course. 1,000 ft terrain clearance. May be skipped if vectored to final.
- Intermediate approach — From the IF to the Final Approach Fix (FAF). Normally aligned within 30° of the final approach course. This is where you stabilize speed and altitude.
- Final approach — From the FAF to the runway, airport, or Missed Approach Point (MAP). If the runway is not in sight at the MAP, you must execute a missed approach.
- Missed approach — From the MAP (or DA/DH on a precision approach) to the missed approach fix at the prescribed altitude. Always plan it before the FAF.
Approach categories — speed-based
Determined by the aircraft's approach speed at maximum certified gross landing weight. Determines which approach minimums apply.
- Category A: 90 knots or less (most helicopters and light singles)
- Category B: 91-120 knots
- Category C: 121-140 knots
- Category D: 141-165 knots
- Category E: 166 knots or more
Most helicopter approaches use Category A minimums. If you're flying outside Category A speed range (rare for civil helicopters), use the higher category's minimums.
Helicopter visibility reduction (AIM 10-1-2)
Helicopters flying conventional (non-Copter) IAPs may reduce the published Category A landing visibility minima to not less than half, or to 1/4 SM (1,200 RVR), whichever is greater — unless the chart is annotated "Visibility Reduction by Helicopters NA".
Examples:
- Cat A approach with 1 SM published minimum → 1/2 SM for a helicopter.
- Cat A approach with 1/2 SM published → 1/4 SM for a helicopter (the floor).
- Cat A approach with 1/4 SM published → 1/4 SM (already at floor).
This is one of the genuine helicopter advantages over fixed-wing in the IFR system. Use it where it applies — and notice "Visibility Reduction by Helicopters NA" before assuming.
SHARPTT — when a procedure turn is NOT required
The procedure turn (or hold-in-lieu-of-PT) is required when depicted on the approach chart, except in any of these cases:
- S — Straight-in approach
- H — Hold-in-lieu when ATC clears you straight in
- A — Arc (DME arc transition)
- R — Radar vectored to the final approach course
- P — NoPT (initial segment marked "No PT")
- T — Teardrop (when teardrop course reversal is the published transition)
- T — Timed approach from a holding fix
If your scenario isn't on this list, the procedure turn is required.
Approach brief — INCRAM
Run before reaching the IAF. Verbalize each item — even single-pilot. Briefing forces you to find anything you missed.
- I — ID: Have you tuned and identified the navigation station(s)?
- N — NAVAID: GPS or VLOC source selected correctly?
- C — Communication: Tower / approach / CTAF frequencies set?
- R — Radio: Backup nav, audio panel, ident verified.
- A — Altitude: Step-down altitudes called out, current altitude set in altimeter.
- M — Missed approach: Briefed before the FAF — what you'll do, where you'll go, with what frequency.
The briefing isn't ceremonial — it's the catch for the thing you forgot. Pilots who skip the brief catch fewer of their own errors.