Hiller UH-12A N8180H

Summary

On 24 February 2007 at about 20:08 local time, a Hiller UH-12A registered N8180H was involved in an accident near Bethlehem, Georgia, United States. 2 people were on board and 2 died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 February 2007 at 20:08

Classification

Accident

Location

Bethlehem, Georgia, United States

Coordinates

33.7569, -83.6517

Aircraft

Hiller UH-12A

Registration

N8180H

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Bethlehem → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ATL07LA045

2 people died.

The pilot's failure to maintain adequate rotor rpm, which resulted in an attempted autorotation and in-flight collision with trees. Contributing to the severity of the accident was the pilot exceeding the helicopters takeoff capability.

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

Read the full NTSB narrative

The commercial pilot attempted a downwind departure at or about maximum gross weight in a very tight landing zone with high obstacles, forcing the pilot to use rotor energy to gain altitude which would have slowed rotor RPM below safe operating limits. With a tailwind the engine had insufficient power for the helicopter to reach transitional lift. Once the pilot determined that he could not regain rotor speed, he would have selected an area in the woods to try and descend. Rotor RPM would have continued to decay and the pilot would have initiated an Auto-Rotation. The pilot closed the throttle as noted by the crushed throttle linkage. The tail-rotor descended into the trees as evidenced by impact marks to the leading edge of the tail-rotor blades. The engine was still developing power to the rotor system as observed in the twisting of the tail-rotor drive shaft aft of the tail-rotor universal joint. The helicopter descended through the trees vertically and nosed down when the main rotor blades exited the helicopter. The metal strip on the main rotor blades contacted the tail boom at the rear universal joint of the tail rotor drive shaft. The helicopter impacted the ground. The transmission and rotor system crushed the flight deck. Examination of the helicopter found no preimpact mechanical failure or malfunctions that would have prevented the helicopter from operating properly.

Quoted verbatim from the NTSB record.