Mitsubishi MU-2B-30 N618BB

Summary

On 28 September 1996 at about 12:35 local time, a Mitsubishi MU-2B-30 registered N618BB was involved in an accident near Chillicothe, Ohio, United States. 4 people were 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

28 September 1996 at 12:35

Classification

Accident

Location

Chillicothe, Ohio, United States

Nearest airport

Ross County (RZT)

Coordinates

39.3294, -82.9809

Aircraft

Mitsubishi MU-2B-30

Registration

N618BB

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 135: Air Taxi & Commuter

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Columbus

Aircraft damage

Substantial

Weather

IMC

Light

Day

NTSB number

NYC96LA188

Nobody was injured.

failure of the pilot to follow the published emergency procedures after loss of power in the left engine. Factors relating to the accident were: fatigue failure of the left torque sensor and gear assembly, which resulted in the loss of engine power, failure of the manufacturer to comply with the respective service bulletin, and the pilot's improper use of the flaps and reverse (single-engine) thrust.

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

Read the full NTSB narrative

The Pilot (plt) said that after climbing about 500' after takeoff, at 120 kts with the gear retracted, the left engine lost power. He feathered the propeller, lowered the nose to the horizon, & began a shallow left turn back to the airport. He left the flaps at 20 deg & noted a descent of 200' to 300' per min in the turn. After clearing trees, the plt extended the landing gear, banked the aircraft (acft) to the right to align it with the runway (rwy), & lowered flaps to 40 deg. After touchdown, he applied single engine reversing. Acft went off right side of rwy & into a ditch, collapsing the right main & nose gear. Exam of the engine revealed the torque sensor housing had failed, resulting in loss of drive to the fuel pump. Metallurgical exam of the housing arm of the torque sensor revealed it had failed from fatigue. On 9/14/79, a service bulletin (SB) was issued for replacement of the torque sensor housing with an improved housing. The manufacturer overhauled the engine on 12/1179, but SB was not complied with. SB indicated a history of resonant vibration causing cracks in the housing arm of original torque sensor & gear assemblies, & that the housing should be replaced, no later than during next part exposure. Investigation revealed pilot did not comply with engine failure procedures & airspeeds. Flight manual cautioned not to use 40 deg of flaps during single engine landings.

Quoted verbatim from the NTSB record.