Beechcraft J-35 N185Y

Summary

On 12 January 1992 at about 19:02 local time, a Beechcraft J-35 registered N185Y, operated by Webster, Gordon, was involved in an accident near Knoxville, Tennessee, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

12 January 1992 at 19:02

Classification

Accident

Location

Knoxville, Tennessee, United States

Coordinates

35.7895, -83.9703

Aircraft

Beechcraft J-35

Registration

N185Y

Category

Airplane

Engines

1

Operator

Webster, Gordon

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Unknown → Marietta

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ATL92LA038

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.