Pilot Debrief

PIPER PA-32R-300 near Guntersville, AL — 2013-09-08

Final reportERA13LA407
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Date
2013-09-08
Location
Guntersville, AL, USA
Airport
8A1
Aircraft
PIPER PA-32R-300
Registration
N8362C
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Cruise

Probable cause

The improper installation of the engine magneto by unknown maintenance personnel, which resulted in the magneto separating from the engine and a subsequent total loss of engine power. Contributing to the accident was the pilot's delay in proceeding directly to the nearest airport and his failure to prevent the automatic extension of the landing gear following the total loss of engine power, which resulted in a landing undershoot.

Contributing factors

Contributing to the accident was the pilot's delay in proceeding directly to the nearest airport and his failure to prevent the automatic extension of the landing gear following the total loss of engine power, which resulted in a landing undershoot.

NTSB narrative

The pilot reported that, about 3 to 4 nautical miles east-northeast of the nearest airport, the engine suddenly quit. GPS data indicate that the airplane was about 4,300 ft about that time. The pilot's attempts to restore power were unsuccessful. The pilot stated that he turned the airplane right toward the airport, and that, as he neared it, he announced his intention to land. While on approach, about 1/2 to 3/4 mile from the intended runway and with the flaps retracted, he allowed the airplane to slow to the point that the landing gear autoextend system caused the landing gear to extend, which he had not planned to do. He continued toward the runway, and the airplane touched down in water about 100 yards from the approach end of the intended runway. The pilot stated that, if the landing gear had not extended automatically, he believed that he could have reached land. Although the pilot reported that he turned toward the airport after the power loss, GPS data indicated that he actually flew west of the extended runway centerline and then maneuvered toward the airport. Based on data from the best glide chart in the Pilot's Operating Handbook, if the pilot had proceeded on a more direct course to the airport after the engine power loss or had not allowed the landing gear to automatically extend while on short final, the airplane likely would have been able to reach the intended runway. Postrecovery examination of the engine revealed that the single-drive dual magneto was separated from the accessory case because the lower attachment hardware had lost its clamping force and that the upper flange of the magneto had fractured due to fatigue cracking. Examination also revealed that the magneto was not installed in accordance with an engine manufacturer's service instruction—an incorrect gasket, washer, and clamp were used—all of which contributed to the separation of the magneto. Although compliance with service instructions is not mandatory for Part 91 operators, if the instructions had been complied with the last time the magneto was serviced, it is likely that it would not have separated despite the fact that the airplane had not undergone an annual inspection in over 2 1/2 years and, therefore, was unairworthy at the time of the accident.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have ensured proper magneto attachment before flight.

NTSB coding

Evidence available

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  • 15 docket documents
View NTSB final reportView NTSB docket

Docket documents15

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