- Effective
- January 17, 1983
- Superseded by
- AD96-12-07
- Model
- Magnetos
- Product
- Appliance
- Amendment
- 39-4538
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed August 7, 2025.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 24 KB | db07090a…4e05101 | FAA DRS (API key needed) |
On this page
Registered aircraft
No registered aircraft matched this AD’s modelsForeign aircraft aren’t included, and ADs on propellers and appliances aren’t matched by model.
NTSB investigations that cite this AD · 11
Their narratives or probable cause name AD 78-09-07, often to say whether the aircraft complied with it.
NTSB ERA10LA475Accident · Serious injuriesLimited investigationFinal reportCessna 150 · Fayetteville, WVA loss of engine power due to the failure of the left magneto system’s distributor gear as a result of the improper maintenance of the magnetos by maintenance personnel.NTSB FTW99LA027Accident · Minor injuriesLimited investigationFinal reportMooney M20J · San Angelo, TXThe total loss of engine power due to the magneto failure resulting from oil contamination when the bearing plate retainer screw fractured due to improper manufacturing. Factors were the lack of suitable terrain for the forced landing, and the dark night…NTSB CHI94LA121Accident · No injuriesLimited investigationFinal reportPiper PA-32-300 · Ellsworth, NEthe jammed impulse coupling on the left magneto which caused the crankshaft drive gear to shear from the crankshaft.NTSB FTW90FA119Accident · 2 fatalField investigationFinal reportPiper PA-28-140 · Bossier City, LALoss of engine power for an unknown reason.NTSB LAX89FA014Accident · 5 fatalField investigationFinal reportPiper PA-32-300 · Sedona, AZTotal failure of the magneto's impulse coupling which resulted in a shearing of the crankshaft's idler gear teeth and the crankshaft dowel pin.NTSB ATL88FA055Accident · 4 fatalField investigationFinal reportPiper PA-32-260 · Lagrange, GAPlt lost power in cruise, in day, VMC. Made apch to interstate hwy I85. Hit overpass support column at 15 feet AGL. Engine overhauled 51 hours before accident. Overhaul records indicated magneto repair. Annual insp records indicated compliance with AD…NTSB ATL85LA024Accident · No injuriesLimited investigationFinal reportPiper PA-25-235 · Lincoln, TNThe acft was making a swath run spraying crops when the engine suddenly lost power with 200 yards of level field remaining for an emergency landing. After touchdown the plt turned the acft to avoid a collision with trees. During the turn the nose of the acft…NTSB MKC80FCG31Accident · Minor injuriesClosedAero Comdr A-9B · Cameron, MONTSB FTW80FA020Accident · Serious injuriesClosedPiper PA-32 · Harrah, OKNTSB MIA80FKT17Accident · Serious injuriesClosedPiper PA-32 · Miami, FLNTSB MIA79FLA14Accident · Minor injuriesClosedPiper PA-32 · Cross City, FL