ATL92LA038 · Beech J-35
Beech J-35 · Accident: total loss of engine power (mechanical failure) en route
From an unrecorded airport to Cobb County International Airport-McCollum Field (RYY)
Event
- NTSB case
- ATL92LA038
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Beech J-35
- Aircraft type
- Beechcraft J-35
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N185Y
- Operator
- Webster, Gordon · private individual
- Onboard fatalities
- Unknown
- Route
- From not recordedTo Cobb County International Airport-McCollum Field (RYY), Marietta, GA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Total loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Engine assembly, cylinder › Undertorqued
- Manufacturer › Maintenance, overhaul, inadequate
- Manufacturer › Procedure inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
SHORTLY AFTER TAKEOFF, THE PILOT REPORTED A SEVERE VIBRATION IN THE AIRPLANE, FOLLOWED BY A COMPLETE LOSS OF ENGINE POWER. AN EMERGENCY LANDING WAS ATTEMPTED TO RUNWAY 24R AT MCGHEE TYSON AIRPORT, BUT THE AIRPLANE CRASHED A MILE SHORT OF THE RUNWAY. EXAMINATION OF THE ENGINE ASSEMBLY REVEALED THAT NUMBER 1 & 2 CYLINDERS HAD SEPARATED FROM THE ENGINE CASE. THE EXAMINATION ALSO DISCLOSED THAT THE CYLINDER HOLD DOWN STUDS WERE DAMAGED AND THE THREADS WERE BATTERED. THERE WAS AN ACCUMULATION OF METALLIC DUST ASSOCIATED WITH FRETTING ADJACENT TO THE CYLINDER FLANGE AND ENGINE CASE. SEVERAL HOLD DOWN NUTS WERE NOT RECOVERED FOR EXAMINATION. THE ENGINE MAINTENANCE LOG SHOWED THAT THE NUMBER 1 CYLINDER WAS REMOVED AND INSTALLED IN ACCORDANCE WITH CURRENT SERVICE INSTRUCTIONS 314 HOURS PRIOR TO THIS ACCIDENT. SUBSEQUENT TO THIS ACCIDENT CONTINENTAL MOTORS ISSUED A SERVICE BULLETIN INCREASING THE HOLD DOWN TORQUE NUT VALUES FROM 710 INCH POUND TO 810 INCH POUNDS, AND CHANGED EXISTING SIX POINT HOLD DOWN NUTS TO TWELVE POINT NUTS.
Probable cause
THE MANUFACTURER'S FAILURE TO PROVIDE ADEQUATE TORQUE INFORMATION WHICH RESULTED IN THE LOSS OF TORQUE ON THE CYLINDER HOLD DOWN NUTS AND THE COMPLETE LOSS OF ENGINE POWER.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL92LA038
- Event ID
- 20001211X13937
- Case number
- ATL92LA038
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: e3262b0d92108c084416518e2ae9be00deb33d1bd7e80dbdd8da85aacd8ad1c0; retrieved 2026-09-23T03:26:20.155Z.