Night VFR, Illusions, and the Decision to Continue
You are flying a light helicopter VFR at night toward a coastal aerodrome. The approach is over water with few ground lights, and the runway has only edge lighting. You have been flying for 2.5 hours, your last meal was 6 hours ago, and you are wearing no night-vision equipment. On final, the runway appears higher and closer than your altimeter and vertical-speed indicator suggest. You feel a strong urge to push the nose down. The aerodrome is 4 NM ahead, fuel is adequate, and the weather is VMC.
1. Explain the visual illusion you are experiencing and the correct response.
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This is a black-hole approach illusion. Over water with few ground references, the eye lacks cues between the aircraft and the runway, so the pilot perceives the runway as higher and closer than it is. The natural response is to fly a lower and steeper approach than intended, which risks an undershoot or a hard landing.
The correct response is to trust the instruments - altimeter, vertical-speed indicator, and airspeed - and to fly a published or planned approach profile with a stable descent rate and airspeed. Do not push the nose down to match the visual picture. If available, use the approach lighting or a visual glide slope indicator. If the illusion is strong and you cannot stabilize, go around.
2. Assess the fatigue and physiological factors and state whether you should continue to land.
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Several factors degrade performance:
- 2.5 hours of flight with no recent food - low blood glucose reduces attention and reaction time.
- Night flight without night-vision equipment increases the risk of spatial disorientation.
- Featureless over-water approach removes the horizon reference that helps maintain orientation.
The combination makes a visual illusion more likely and harder to override. The safe decision is to continue only if you can stabilize on instruments. If you cannot, go around, climb to a safe altitude, and either re-approach with a stabilized profile or divert to an aerodrome with better lighting. Do not press on simply because the aerodrome is close and fuel is adequate - those are not the limiting factors. After landing, report the fatigue and review your personal minimums for night flight.