Messerschmitt-Bolkow-Blohm BK 117 N504TJ

Summary

On 4 May 2014 at about 21:40 local time, a Messerschmitt-Bolkow-Blohm BK 117 registered N504TJ, operated by Mercy Flight Inc, was involved in an accident near Hamburg, New York, United States. 3 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

4 May 2014 at 21:40

Classification

Accident

Location

Hamburg, New York, United States

Coordinates

42.6947, -78.7736

Aircraft

Messerschmitt-Bolkow-Blohm BK 117

Registration

N504TJ

Category

Helicopter

Year built

1971

Engines

2

Operator

Mercy Flight Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Buffalo → Olean

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA14LA223

Nobody was injured.

Wear in the left cabin door assembly parts, which resulted in the door partially opening in flight, dislodging from the lower door track assembly, and then separating from the helicopter.

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

Read the full NTSB narrative

The pilot reported that, during a repositioning flight of the emergency medical services helicopter and while at cruise altitude, the flight nurse notified him and the paramedic that the left cabin door had partially opened. As the flight nurse and paramedic were attempting to close the door, it dislodged from the lower track assembly, pivoted up, and struck the main rotor system; the door subsequently separated from the helicopter. The pilot then initiated a forced landing to a field. Examination of the door assembly revealed that both of the lower door's bracket guides and the aft lower catcher and guide assemblies were worn and that the door's upper sliders were worn down to their minimum tolerances. The Airplane Maintenance Manual states that, if one of the two sliders does not meet the minimum tolerance, "both sliders must be replaced with new ones." A review of the maintenance logbook revealed that the door assembly had been inspected 127 hours before the accident in accordance with an alert service bulletin but that no anomalies with the door assembly were noted at that time.

Quoted verbatim from the NTSB record.