Flight History
On 7 May 1995, a privately owned Cessna Skylane F182Q, registration HB-CQH, was involved in an accident at Speck-Fehraltorf airfield. The pilot, a Swiss citizen born in 1945, held a valid private pilot license with 279 total flight hours, none in the previous 90 days. His last flight in a Cessna 182 was on 8 December 1994.
The pilot arrived at the airfield around 1045 local time to resume training after a winter break. During the pre-flight inspection, he noted the electric fuel gauges indicated between 1/4 and 1/2 for the left tank and slightly less than 1/4 for the right, which rose above 1/4 during taxi. He considered refueling but concluded the fuel was sufficient for the planned flight.
At 1105, the pilot departed alone from runway 30 and flew south to the Grüningen-Mönchaltorf area, where he performed two simulated circuits to familiarize himself with the aircraft. Returning to Speck-Fehraltorf, he reduced engine manifold pressure to 18 inches and propeller RPM to 2100 while west of Pfäffikon. During the approach, he felt the engine power decrease twice and, suspecting carburetor icing or fuel starvation, applied carburetor heat and moved the manifold pressure control without effect.
Realizing the aircraft had descended to 2000 ft QNH over a forest south of the runway, the pilot declared an emergency via radio and initiated a wide left turn. He noticed a floodlight mast in the approach path and fully extended the landing flaps to clear it, causing the stall warning to activate. He lowered the nose to regain speed, then raised it to avoid a fence. To avoid colliding with gliders parked near the runway threshold, he again lowered the nose and landed in a field short of the runway.
During landing, the nose wheel dug in and broke off; the aircraft then nosed over a field path, overturned, and came to rest inverted in a cultivated field. No fire broke out. The pilot, suffering a head injury but conscious, switched off the master switch with his foot. The accident occurred at 1122.
Investigation Findings
- The pilot's license was valid, and no physical impairment was found. Shoulder belts were not used.
- The aircraft was certified for VFR day and night operations. Takeoff weight and center of gravity were within limits.
- The last 200-hour inspection was on 21 October 1994; the engine had 831 hours since overhaul at the time of the accident.
- The pilot checked fuel quantity only via electric gauges, not using the T-stick gauge that was part of the aircraft's equipment. Total fuel capacity is 151 liters per tank (40 USG). Average fuel consumption is 54-60 l/h (14-16 USG/h).
- After the accident, fuel was drained: 37 liters from the left tank and 20 liters from the right, totaling 57 liters. An unknown amount likely leaked during recovery and while inverted. The fuel selector was found in the "off" position, but a flight instructor had moved it there for safety; it was on "both" before.
- The engine, spark plugs, carburetor, and magnets were examined and tested, revealing no malfunctions. Two ground runs with full systems showed proper operation.
- Weather at the time: scattered clouds at 2200 m, visibility >20 km, wind SW 5 kt, temperature 21°C, dew point 7°C, QNH 1018 hPa, sun azimuth 131°, elevation 51°.
Technical Aspects
No technical defects were found that could explain a power loss. Fuel starvation was excluded, as 57 liters remained in the tanks, and the selector was on "both." The engine operated correctly during post-accident tests.
Operational Aspects
The pilot's decision to fly after a five-month break was necessary, but his pre-flight fuel check was inadequate. He relied solely on electric gauges, which are often inaccurate, and did not use the available T-stick gauge. This uncertainty about fuel quantity contributed to his stress.
During the return flight, the pilot perceived engine power loss and immediately suspected fuel starvation or carburetor icing. Applying carburetor heat at nearly 21°C and enriching the mixture unnecessarily reduced power. The erratic throttle movements failed to stabilize power at 2100 RPM. Convinced of fuel starvation, he kept the throttle at idle during the emergency landing attempt.
Stress increased as obstacles appeared. The pilot believed he cleared the floodlight mast only by using full flaps, which initially caused a climb but then reduced glide performance. After the stall warning, he lowered the nose to regain speed, avoided a fence, and made a hard landing in a field with gliders. The unstable approach left little chance for a successful emergency landing.
Causes
The accident was due to: inadequate pre-flight preparation; stress induced by an erroneous analysis of the situation (the pilot thought there was a lack of fuel); a loss of self-control during an emergency landing attempt; insufficient flight training, respectively too long a flight interruption.