Mitsubishi MU-2B-40 N9052Y

Summary

On 30 November 2001 at about 15:28 local time, a Mitsubishi MU-2B-40 registered N9052Y was involved in an accident near St Paul, Minnesota, 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

30 November 2001 at 15:28

Classification

Accident

Location

St Paul, Minnesota, United States

Nearest airport

St Paul Downtown Holman Fld (STP)

Coordinates

44.9307, -93.0793

Aircraft

Mitsubishi MU-2B-40

Registration

N9052Y

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Business

Phase of flight

Not recorded

Route

Benton Harbor → Saint Paul

Aircraft damage

Substantial

Weather

IMC

Light

Day

NTSB number

CHI02LA044

Nobody was injured.

The autopilot's computer connections arcing and reported disconnection during the localizer approach and the pilot not performing a go around prior to the hard landing. A factor was the pilots lack of total experience in the accident airplane's make and model.

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

Read the full NTSB narrative

The airplane sustained substantial damage on impact with the runway during a hard landing following a coupled autopilot approach. The pilot and three passengers were uninjured. Instrument meteorological conditions prevailed. The pilot reported, "I was using the autopilot to fly the ILS localized timed approach. I was looking for the runway and watching the time. The autopilot inadvertently disengaged, turning the airplane to the left. I righted the airplane just before touchdown. It landed on the mains with the nose slightly high. It came down, and the front wheel and strut broke." During the next flight, a ferry flight for repairs, the accident pilot reported that he engaged the autopilot at 2,500 feet. The pilot reported that when the autopilot was engaged, the airplane pitched down and turned sharply to the right. The pilot reported using opposing control inputs and differential engine power to maintain airplane control. The pilot performed a no flap landing at an en route airport with a 2,497-foot long runway. An examination of the airplane revealed that when the autopilot computer was moved in its shock mount the yoke moved "violently right in roll axis and forward in pitch axis." The MU-2 airplane flight manual's emergency procedures stated, "In case of emergency, the autopilot can be overpowered manually to correct the attitude, but the autopilot must immediately be disengaged. If the autopilot remains engaged, the autopilot will trim the airplane to oppose the pilot's actions. This could result in a severely out of trim condition." The manual stated, "The autopilot can also be disengaged by any of the following methods, "1. Operate trim switch UP or DOWN, 2. Position inverter switch to OFF momentarily and then return, to original position, 3. Turn off the ELECTRIC MASTER SWITCH." The pilot reported 11 hour hours of pilot in command time in the accident airplane make and model.

Quoted verbatim from the NTSB record.