What happened
On November 22, 1999, at approximately 12:30 PM, a two-seat Pilatus PC-9/B departed from Kiel-Holtenau to perform a target simulation exercise for the German Navy in the Lübecker Bulf. The aircraft was acting as a target for a Navy tender, performing several approaches from various directions.
During the final approach, the aircraft flew at a very low altitude over the water. Shortly before reaching the vessel, the pilot executed an abrupt, steep climb followed by a tight right-hand turn. This maneuver placed the aircraft in an extreme knife-edge attitude. As the aircraft maintained this lateral orientation, its altitude steadily decreased until the right wing made contact with the water. The impact caused the aircraft to break apart and sink immediately. The pilot was killed in the accident.
The investigation
The BFU investigation, conducted alongside local police, recovered the wreckage from the seabed, approximately 1 km south of Grömitz. Technical examination of the wreckage revealed that the engine and propeller were largely intact, though the propeller blades showed significant deformation consistent with the impact. Notably, the ejection seat had been ripped from the airframe rather than being deployed.
Radar data from the Deutsche Flugsicherung GmbH (DFS) confirmed the aircraft's flight path, showing a descent from 3,700 ft to 1,900 ft during the approach. An accelerometer recovered from the wreckage indicated that the aircraft had experienced high G-loads, with a reading stuck at +7g.
Medical examinations of the pilot revealed a history of cardiac arrhythmia and conduction disturbances dating back to 1992. While the autopsy found no evidence of alcohol or drugs, it did note traces of caffeine and aspirin. The investigation also examined the pilot's medical certification process, noting that the pilot's known heart condition should have triggered more rigorous medical evaluations by the aviation medical authority.
Findings
- The aircraft was flying significantly below the required minimum altitude of 100 ft due to the lack of a radar altimeter, which made precise low-level altitude maintenance difficult.
- The flight profile used during the exercise—characterized by very low approaches to remain undetected—deviated from the official Flight Operations Manual (FOM) and relied on unwritten practices established by previous instructors.
- The extreme maneuver (steep climb and tight turn) subjected the pilot to high positive G-loads, which likely impaired perception and reaction capabilities.
- The pilot's pre-existing cardiac condition and the physiological stress of the high G-load maneuver may have caused a loss of consciousness or an inability to timely control the aircraft's flight surfaces and engine power.