What happened
During a night flight in instrument meteorological conditions, a twin-engine airplane was conducting a cross-country flight and approaching its destination airport. The weather at the time featured fog, light rain, and an overcast ceiling of only 200 feet. While the aircraft was cleared via radar vectors for an ILS approach to runway 20, the flight path failed to properly intercept the glideslope or the localizer.
Data recovered from the aircraft's electronic horizontal situation indicator (EHSI) and radar simulations revealed that the aircraft crossed the final approach fix significantly below the glideslope. The aircraft maintained a descent below the glideslope and drifted east of the localizer centerline. Approximately one nautical mile from the runway threshold, the pilot initiated a 90-degree left turn that did not follow the published missed approach instructions. During this deviation, the aircraft experienced several pitch excursions. The flight path and ground speeds recorded during the simulation indicated that both engines were functioning. However, calculations regarding the angle of attack suggest the aircraft likely encountered an aerulent stall during its eastward deviation. The aircraft eventually struck the ground in a nose-low, upright position about 2.2 miles east-northeast of the runway threshold.
Findings
Investigations into the accident identified several contributing factors:
- The glideslope antenna cable was improperly secured, which prevented the cockpit avionics from receiving a valid glideslope signal. This forced the pilot to fly a localizer-only approach that had not been anticipated.
- The aircraft's center of gravity was located aft of the allowable limit. This improper weight and balance caused adverse handling characteristics, specifically making it difficult for the pilot to maintain pitch control during the flight.
- The pilot had been awake for approximately 18 hours, and the timing of the accident occurred during a period of low circadian alertness. This likely resulted in fatigue.
- The combination of low visibility, the unexpected loss of glideslope guidance, and the difficulty in managing the aircraft's pitch due to the aft center of gravity significantly increased the pilot's workload and degraded performance during the approach.