Robinson R44 N44EK

Summary

On 24 February 2017 at about 23:23 local time, a Robinson R44 registered N44EK was involved in an accident near Chatham, New Jersey, United States. 2 people were on board and one was seriously injured, one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 February 2017 at 23:23

Classification

Accident

Location

Chatham, New Jersey, United States

Coordinates

40.7394, -74.3883

Aircraft

Robinson R44

Registration

N44EK

Category

Helicopter

Year built

1999

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Millville → Lincoln Park

Aircraft damage

Substantial

Weather

VMC

Light

Night

NTSB number

ERA17LA116

1 person was seriously injured.

Maintenance personnel's improper installation and inspection of the crankshaft gear bolt during major overhaul, which resulted in the crankshaft gear disengaging from the accessory gears of the engine and a subsequent loss of power.

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

Read the full NTSB narrative

The private pilot was on the second leg of a cross-country flight in the helicopter. After about 45 minutes and while in cruise flight at 1,800 ft mean sea level, the engine lost total power; the low rpm warning sounded, and the pilot initiated an autorotation in the congested area during nighttime conditions. During the autorotation, the helicopter struck a building, which resulted in substantial damage to the fuselage. Postaccident examination of the engine revealed that the crankshaft gear bolt was about 3/16 inch from the seated position. The safety lockplate washer was worn, the back of the bolt head displayed rotational scoring, the bottom threads of the bolt were damaged, and the alignment dowel had sheared. The engine had accumulated 5.9 hours total time since undergoing major overhaul about 1 year before the accident. It is likely that, when the engine was overhauled, the crankshaft gear bolt was not properly seated against the gear, which resulted in the crankshaft gear disengaging from the accessory gears and a subsequent total loss of engine power.

Quoted verbatim from the NTSB record.