Rotorcraft Development UH-1B N843M

Summary

On 13 May 2009 at about 16:08 local time, a Rotorcraft Development UH-1B registered N843M, operated by Avag Inc, was involved in an accident near Richvale, California, 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

13 May 2009 at 16:08

Classification

Accident

Location

Richvale, California, United States

Nearest airport

Richvale Airport (07CL)

Coordinates

39.4975, -121.7711

Aircraft

Rotorcraft Development UH-1B

Registration

N843M

Category

Helicopter

Engines

1

Operator

Avag Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Richvale → Richvale

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR09LA241

1 person was seriously injured.

The pilot's failure to maintain control of the helicopter during takeoff for undetermined reasons.

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

Read the full NTSB narrative

The helicopter had undergone a 100-hour inspection the day prior to the accident, which included a flushing of the hydraulic system. The pilot reported that as he lifted the helicopter into a hover, he initiated forward movement. The pilot stated that the controls felt "ratchety" and stiff, as if the helicopter had the hydraulic system turned off. He was not able to land the helicopter by lowering the collective, nor was he able to control direction with the cyclic. The helicopter had climbed about 15 feet above the ground and subsequently collided with a hangar about 160 feet away. The fuselage section remained embedded in the building, while the tail section came to rest on the ground below. A post accident examination revealed no mechanical malfunctions or failures that would have precluded normal flight. A representative for Bell stated that it is common during the "initial start up of all of these aircraft after assembly and/or reassembly or after first servicing," to cycle all of the controls for as long as 2 minutes to attain smooth and uninterrupted control motion. He further stated that during these initial run up exercises it would not be unusual to feel "ratcheting or binding in the cyclic that is generally accompanied by a howling noise" as the hydraulics purge air from the lines, pumps, and actuators. It is unknown if the pilot adequately cycled the controls through their full travel prior to flight.

Quoted verbatim from the NTSB record.