McDonnell Douglas 369E N371EE

Summary

On 18 June 2021 at about 12:45 local time, a McDonnell Douglas 369E registered N371EE, operated by Haverfield International, was involved in an accident near Swan Lake, New York, United States. 2 people were on board and 2 were seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

18 June 2021 at 12:45

Classification

Accident

Location

Swan Lake, New York, United States

Coordinates

41.7345, -74.7594

Aircraft

McDonnell Douglas 369E

Registration

N371EE

Category

Helicopter

Year built

1989

Engines

1

Operator

Haverfield International

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

External Load

Phase of flight

Not recorded

Route

Monticello → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA21LA262

2 people were seriously injured.

The pilot's failure to maintain adequate clearance from the power transmission tower structure during powerline maintenance work, which resulted in the helicopter's main rotor striking the lifeline support bracket for the tower catwalk and the subsequent loss of control and collision with terrain.

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

Read the full NTSB narrative

The pilot positioned the helicopter near one of the power transmission tower structures as the lineman, seated on a platform that was attached externally on the skids, began the maintenance. The pilot and the lineman both reported that they then heard a bang, and the helicopter began to shake violently. The pilot maneuvered the helicopter away from the tower and descended through the tree branches. The helicopter came to rest upright in a heavily wooded area. A microscopic postaccident examination of one main rotor blade tip revealed witness marks consistent with metal impact, and a support bracket for the tower catwalk displayed impact damage. A postaccident examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation of the helicopter. A postaccident examination of the tower revealed that, unlike the majority of the towers being maintained, it was equipped with a catwalk which had a lifeline support bracket protruding from the top of it for the tower catwalk. Given this information, it is likely that the pilot did not note this hazard and that main rotor blade tip impacted the tower structure and resulted in the subsequent loss of control.

Quoted verbatim from the NTSB record.