What happened
On Saturday, July 16, 1983, at approximately 17:10 local time, a Piper PA-38-112 Tomahawk bearing registration D-EAZJ departed from Samedan Airport in Switzerland. The pilot, accompanied by his son as a passenger, intended to conduct a Visual Flight Rules (VFR) flight to Neubiberg, Germany. After taking off from runway 21, the aircraft climbed straight ahead for roughly 1,800 meters along the runway axis. Witnesses observed the plane passing to the right of the San Gian hill before initiating a left turn toward the Staz railway station area.
During this initial left turn, the aircraft flew at a low altitude over a high-voltage power line before crashing into the Stazerwald forest near Chastlatsch. The impact caused the fuel tank to rupture and ignite, resulting in a complete destruction of the airframe by fire. Both occupants sustained fatal injuries instantly. The crash also caused damage to the surrounding forest.
The investigation
The Swiss Transportation Safety Investigation Board (STSB) examined the technical condition of the aircraft, the pilot's qualifications, and the environmental factors present at the time of the accident. Technical inspection of the wreckage revealed no evidence of pre-existing mechanical failures that could have contributed to the crash. The propeller deformation indicated the engine was producing power at the moment of impact.
The investigation focused on flight performance data and navigation compliance. Reports confirmed that the aircraft was fully fueled before departure, likely reaching its maximum takeoff weight of 1,670 lbs. Weather conditions included a temperature of 22°C, resulting in a high density altitude of 7,600 feet, along with winds from 230 degrees at 15 knots with gusts up to 20 knots.
Findings
The primary cause of the accident was the pilot's failure to follow the prescribed departure route published in the AIP Switzerland. By continuing straight ahead instead of following the designated path, the pilot entered a topographically constrained area that required a sharper turn than standard procedures allowed.
Contributing factors included:
- High Density Altitude: The combination of high temperature and elevation significantly reduced engine performance and climb capability.
- Heavy Weight: The aircraft was loaded near its maximum takeoff weight, further degrading acceleration and climb rates.
- Wind Conditions: During the turn, the aircraft encountered turbulent downslope winds and a transition from headwind to tailwind, reducing airspeed rapidly.
- Insufficient Flight Preparation: The pilot did adequately account for the reduced performance margins caused by the high density altitude and heavy load.
The aircraft lost airspeed below the minimum safe speed during the tight turn over rising terrain. This loss of lift led to a stall and subsequent collision with trees at an approximate bank angle of 90 degrees.
Safety action
This report highlights the critical importance of adhering to published departure procedures, particularly in mountainous terrain where topographic constraints limit maneuvering room. It also underscores the necessity of accurate weight-and-balance calculations and performance planning under high-density-altitude conditions.