Bell OH-58A N153SA

Summary

On 20 May 2020 at about 13:33 local time, a Bell OH-58A registered N153SA was involved in an accident near West Branch, Michigan, 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

20 May 2020 at 13:33

Classification

Accident

Location

West Branch, Michigan, United States

Coordinates

44.2156, -84.1881

Aircraft

Bell OH-58A

Registration

N153SA

Category

Helicopter

Year built

1968

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

West Branch → West Branch

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN20LA187

Nobody was injured.

The pilot's failure to maintain rotor rpm during a precautionary autorotation, which resulted in a hard landing. Contributing to the accident was the airframe vibration for reasons that could not be determined because examination of the helicopter revealed no anomalies.

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

Read the full NTSB narrative

While cruising about 500 feet above ground level, the pilot of the helicopter felt a vibration and entered a precautionary autorotation, though he did not observe any caution or warning lights or horns associated with the vibration. The pilot turned toward an open field for landing and, after clearing some trees, the low rotor rpm horn activated. He reduced collective and made a hard run-on landing, during which the helicopter slid about 20 to 30 ft on its skids before coming to rest upright. The main rotor drooped and one blade struck the tail boom, severing the tail rotor drive shaft and resulting in substantial damage. There was also crush damage to the underside of the tail boom caused by impact forces. The pilot could not describe the location or frequency of the vibration, and the passenger reported that he felt no vibration. Postaccident and follow-up inspections of the helicopter by revealed no anomalies that would have resulted in the vibration. Although the source of the vibration could not be determined, it is likely that the hard landing was the result of the pilot's failure to maintain rotor rpm during the precautionary autorotation.

Quoted verbatim from the NTSB record.