Mechanical & Engine Failure · NTSB ANC11FA065
PIPER PA-12 — Delta, AK
| Date | July 17, 2011 |
| Location | Delta, AK |
| Aircraft | PIPER PA-12 |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Emergency descent Loss of control in flight |
| Pilot age | 28 |
| Pilot total time | 230 hrs · Low time |
| Time in type | Unknown |
| Fatalities | 1 |
Probable cause
NTSB findings
- Aircraft-Aircraft power plant-Engine (reciprocating)-(general)-Inoperative - C
- Not determined-Not determined-(general)-(general)-Unknown/Not determined
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained - C
- Environmental issues-Conditions/weather/phenomena-Temp/humidity/pressure-Conducive to carburetor icing-Not specified
- Aircraft-Aircraft structures-Fuselage-Seat/cargo attach fitting-Failure - F
- Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot - C
What happened
Witnesses reported that the airplane was departing a private airstrip. It reached an altitude of about 200-300 feet above the ground when the engine lost all power, and the airplane began a left turn. During the turn, the airplane's nose pitched down abruptly, and the airplane collided with the ground in a steep, nose-down attitude. Two of the witnesses, both of whom are pilots, noted that before the loss of power, the engine made some popping noises and sounded unusual.
A postaccident examination of the airframe and engine disclosed no mechanical malfunctions. A carburetor icing probability chart indicated that the relative humidity and temperature at a nearby airport about the time of the accident was conducive to serious icing at glide power. Although carburetor icing was possible, absent any mechanical malfunctions or fuel contamination, it could not be determined why the engine lost power.
The accident site was adjacent to a road and about 300 yards from a clear field. Despite these potential landing areas, the pilot decided to attempt to return to the airstrip by initiating a turn at low altitude and low airspeed following the loss of engine power, which resulted in an aerodynamic stall and a loss of control with insufficient altitude to recover.
During the impact, the pilot's seat separated from the airframe and moved forward about 6 inches, which allowed the pilot to impact the instrument panel and subsequently contributed to the severity of the pilot's injuries.