Bell 407 N11HX

Summary

On 12 November 2001 at about 19:20 local time, a Bell 407 registered N11HX was involved in an accident near Whitley City, Kentucky, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

12 November 2001 at 19:20

Classification

Accident

Location

Whitley City, Kentucky, United States

Coordinates

36.7192, -84.4707

Aircraft

Bell 407

Registration

N11HX

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Public Use

Purpose of flight

Public Use

Phase of flight

Not recorded

Route

Whitley City → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

NYC02TA026

1 person was seriously injured.

The pilots decision to operate the helicopter at an airspeed in excess of the maximum demonstrated stable airspeed for the water bucket. A factor in the accident was the pilot did not follow the published emergency procedure.

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

Read the full NTSB narrative

The pilot was conducting a fire suppression flight. While indicating approximately 100 knots of airspeed, with an empty water bucket that was occasionally unstable during the flight, the pilot heard a "bang." The helicopter yawed to the right, and the tail rotor quit spinning. The pilot jettisoned the bucket, and because there was no place to land, he continued to the dip-point. At the dip-point, the pilot selected an open area. The area was sloped, but the pilot was uncertain of the airworthiness of the helicopter and did not want to look for another area. He entered a "needles joined autorotation." As the helicopter slowed, it started to spin to the right. The spin stopped, the helicopter impacted the ground, and then rolled onto its right side with little or no power applied to the main rotor. Examination of the wreckage revealed that the bucket had entered the arc of the tail rotor, and that the tail-rotor driveshaft was severed consistent with overload. The operating manual for the bucket stated that the bucket had been proven stable up to an airspeed of approximately 96 knots, and that a bucket with a overall length greater than the distance from the cargo hook to the front arc of the tail rotor could result in a tail rotor strike. The emergency procedure for a complete loss of tail rotor thrust in-flight was reduce throttle to idle, and immediately enter autorotation. If a suitable landing site was not available, the vertical fin may permit controlled flight to a suitable area.

Quoted verbatim from the NTSB record.