IFR Checkride Guide
Chair flying / Partial Panel — Approach Without Primary Instruments

Partial Panel — Approach Without Primary Instruments

Recognize a primary flight instrument failure, transition to backup references, and fly a non-precision approach without the failed displays.

Guided rehearsal is PremiumACS VII.D — Approach with Loss of Primary Flight Instrument Indicators

Pre-Approach (Five A's)

  1. ATIS/AWOS — weather, runway in use, expect which approach
  2. Altimeter — set current setting; cross-check altimeters
  3. Avionics — tune and IDENTIFY navaids, set courses, load the procedure
    Confirm the correct approach is loaded and the sequence matches the chart — waypoints, courses, altitudes.
  4. Approach briefing — brief the chart aloud
    Approach name and runway, final approach course, FAF and glidepath intercept altitude, DA or MDA, required visibility, missed approach point and first two steps of the miss, notes and lighting.
  5. Aircraft — descent/approach checklist complete, fuel pump and mixture per checklist

Setup

  1. Recognize the failure — instruments disagree; identify WHICH is lying
    Cross-check: two instruments agreeing outvote the third. Vacuum failure takes attitude and heading slowly; a stuck attitude indicator with normal airspeed/altimeter trends is the classic trap.
  2. Cover or ignore the failed displays; switch to backups
    Glass: revert to standby instruments. Conventional: timed turns on the magnetic compass and turn coordinator, pitch on airspeed/altimeter/VSI trends.
  3. Advise ATC — declare, state capabilities, request the simplest approach“Confess”

Execution

  1. Fly the airplane on backups first — small attitude changes, trim, known power settings
    Pitch: airspeed and altimeter trends. Bank: turn coordinator standard-rate. Power: 2,100–2,200 RPM level at 90 KIAS, 1,700–1,800 RPM descending.
  2. Compass turns: undershoot/overshoot rules, or timed standard-rate turns
    Standard rate = 3°/second — 30° of heading change is a 10-second turn. UNOS: Undershoot North, Overshoot South on the magnetic compass.
  3. Request and fly a non-precision approach using the working guidance
  4. Standard non-precision gates: FAF — descend, MDA +100/−0, ¾-scale tracking

Recovery

  1. Land from the approach, or miss and re-assess — divert to VMC if able
  2. Debrief: what failed, what told you, how fast did you catch it?

ACS tolerances

  • Non-precision approach standards using remaining instruments
  • MDA +100/−0 ft, ¾-scale CDI, airspeed ±10 kt

Common errors

  • Chasing a failed instrument instead of isolating it
  • Large attitude changes without the attitude indicator
  • Not telling ATC — help (vectors, no-gyro turns, simpler approach) is free
  • Skipping trim and known power settings — workload explodes