Beechcraft 58P N6688D

Summary

On 2 September 2002 at about 15:00 local time, a Beechcraft 58P registered N6688D was involved in an accident near Swanzey, New Hampshire, United States. 7 people were on board and 7 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

2 September 2002 at 15:00

Classification

Accident

Location

Swanzey, New Hampshire, United States

Nearest airport

Dillant Hopkins Airport (EEN)

Coordinates

42.8667, -72.2422

Aircraft

Beechcraft 58P

Registration

N6688D

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Unknown → Charleston

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

NYC02FA178

7 people died.

**This report was modified on 2/24/2016. Refer to the public docket for this accident for additional information.** the pilot's improper preflight planning and his decision to depart with known landing gear system mechanical deficiencies, which resulted in a forced landing during a partial loss of power on one engine. Factors related to the accident were the fatigue failure of an engine cylinder barrel, the inadequate manufacturing process of the cylinder barrel, and the pilot's inability to retract the landing gear.

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

Read the full NTSB narrative

The six-passenger airplane arrived at the departure airport with a malfunctioning landing gear system. Due to lack of maintenance personnel, the pilot elected to conduct the accident flight with the landing gear extended. The airplane departed with seven occupants, near the certified gross weight. Witnesses observed the airplane flying about 200-300 feet above the ground, with its engines "sputtering and backfiring." The airplane made a left turn towards the airport, descended, and came to rest in a wooded area about 2 miles southeast of the airport. Examination of the right engine revealed the propeller was not feathered, and the number 5 cylinder head was fractured about 3/4 inch from the bottom of the upper portion of the head. A fatigue fracture initiated in the root radius of the cylinder head thread that engaged with the top thread on the cylinder barrel. Indentations and displaced material on the upper and lower flanks of the cylinder head threads matched with the locations of protruding material observed on the cylinder barrel threads. The protruding material was located on the flank/crown radius of the threads, and was consistent with the folding over of a burr into the thread, originating during the manufacturing process. The number 5 cylinder assembly consisted of a new cylinder head that had been installed on a remanufactured barrel. The right engine was remanufactured in 2001, and had accumulated about 140 total hours of operation since. According to 14 CFR Part 91.7, "No person may operate a civil aircraft unless it is in an airworthy condition. The pilot in command of a civil aircraft is responsible for determining whether that aircraft is in condition for safe flight. The pilot in command shall discontinue the flight when unairworthy mechanical, electrical, or structural conditions occur." According to 14 CFR Part 91.107, "...each person on board a U.S.-registered civil aircraft must occupy an approved seat or berth with a safety belt...during movement on the surface, takeoff, and landing." According to the Airplane Flying Handbook (FAA-H-8083-3), Transition to a Multiengine Airplanes, "When one engine fails on a multiengine airplane, performance is not halved, but is reduced by approximately 80 percent."

Quoted verbatim from the NTSB record.