What happened
On October 3, 1964, a Piper Aztec aircraft with registration AP-ATN, operated by the Karachi Aeroclub of Pakistan, crashed on Pico Alto hill on Santa Maria Island in the Azores. The aircraft was engaged in a ferry flight from Santa Maria to Lisbon. The two crew members were killed in the accident.
The aircraft departed Santa Maria Airport at 15:00 local time (13:00 UTC) after receiving clearance for runway 05 and an IFR route via Lisbon, maintaining flight level 90. Shortly after takeoff, the pilot executed a right turn. The aircraft flew over the northern and eastern coasts, passing the village of Almagreira around 13:15 UTC. It then began another right turn toward Pico Alto, entering cloud cover at approximately 300 meters altitude. The aircraft collided with the eastern slope of the hill, roughly five meters below the summit, while in a nose-up attitude with engines at full throttle. The impact caused a fire, and the wreckage slid down the steep western slope before coming to rest.
The investigation
A commission appointed by the Portuguese Department of Civil Aviation investigated the accident. The aircraft was new, having accumulated less than 24 hours of flight time. Both pilots were qualified, with valid licenses and medical certificates. Post-mortem examinations revealed no evidence of physical or mental incapacitation.
Technical examination of the wreckage indicated that the control surfaces and cables were operative up to the moment of impact. The engines were at full throttle, and the propellers were in operation. No structural defects were found prior to the crash. An HF transceiver crystal mismatch was noted but determined not to have affected the flight plan execution.
Findings
The investigation established that weather conditions required Instrument Flight Rules (IFR) operations due to overcast skies. The primary cause of the accident was the failure to observe IFR departure procedures. The change from visual meteorological conditions to instrument meteorological conditions below minimum safe altitudes led unavoidably to controlled flight into terrain.
Safety action
The GPIAAF report does not record specific safety recommendations or actions taken following this incident.