Robinson R44 N441TB

Summary

On 4 February 2011 at about 00:20 local time, a Robinson R44 registered N441TB, operated by Whirlybird Helicopters LLC, was involved in an accident near Ogden, Utah, United States. 2 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 February 2011 at 00:20

Classification

Accident

Location

Ogden, Utah, United States

Coordinates

41.3522, -112.1942

Aircraft

Robinson R44

Registration

N441TB

Category

Helicopter

Engines

1

Operator

Whirlybird Helicopters LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Ogden → Ogden

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR11CA121

Nobody was injured.

The certified flight instructor’s failure to maintain adequate main rotor blade rpm during a practice autorotation, resulting in a hard landing and rollover.

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

Read the full NTSB narrative

After completing several practice landings and autorotations at the airport, the certified flight instructor (CFI) and student pilot departed for the practice area. The CFI demonstrated straight-in and 180-degree autorotations; the first 180-degree attempt began at 6,000 feet mean sea level and at 55-60 knots. During the second 180-degree attempt, he started about 200 feet lower. The airspeed bled off to about 50 knots during the turn, and the main rotor blades’ rpms began decaying rapidly. About 200 feet above ground level the CFI attempted a power recovery, but the rpms did not increase with an increase in throttle. He unsuccessfully attempted to flair to bring the rpms back before attempting a full down autorotation. He put the helicopter in a level attitude prior to contact with the ground and the helicopter bounced upon initial contact; on the second contact, the right skid dug into the muddy ground and the helicopter rolled onto its right side. The helicopter sustained substantial damage to the airframe and rotor blades. The pilots stated that the helicopter had no mechanical failures or malfunctions prior to the accident.

Quoted verbatim from the NTSB record.