Hughes 369HS N9154F

Summary

On 25 November 2008 at about 19:45 local time, a Hughes 369HS registered N9154F, operated by Skyhawk Helicopter Service, Inc., was involved in an accident near Fillmore, Utah, United States. One person was 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

25 November 2008 at 19:45

Classification

Accident

Location

Fillmore, Utah, United States

Coordinates

38.9581, -112.3631

Aircraft

Hughes 369HS

Registration

N9154F

Category

Helicopter

Engines

1

Operator

Skyhawk Helicopter Service, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Business

Phase of flight

Not recorded

Route

Richfield → Spanish Fork

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR09LA048

Nobody was injured.

The loss of engine power due to fuel starvation as a result of a loose fuel filter upper drain cap, which was not properly secured by maintenance personnel.

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

Read the full NTSB narrative

According to the pilot, during cruise flight the helicopter's engine lost power and it entered an autorotation. The helicopter was over mountainous/hilly terrain and there was no open place to land. The pilot selected a spot on a steep hill covered with 20- to 30-foot-tall oak trees. Upon touchdown, the helicopter began to roll, but was stopped by the vegetation. The tailboom incurred structural damage during the landing. Postaccident examination of the helicopter revealed that the fuel pump filter bowl's upper drain plug had been replaced with a non-standard threaded nipple fitting and cap. This cap was found with zero torque (loose) and partially backed off of its seat. Less than two threads retained the cap on its fitting. In standard configuration, the upper and lower drain plugs are lock-wired to each other, thus ensuring both fittings remain properly torqued. On the accident engine, the lower drain plug was lock-wired to the upper drain's threaded nipple fitting. However, the cap was not lockwired. The fuel spray nozzle's fuel supply line was found to be devoid of any residual fuel. (This line would typically have about 1 to 1.5 teaspoons of fuel following a normal engine shutdown.) The engine was removed from the airframe and shipped to the facilities of the engine manufacturer for a test run. The suspect loose cap was gently tightened with a wrench. The engine was then run and met all test cell parameters for new engine production. Since the fuel pump filter bowl operates at a negative pressure during operation, a compromise at this point in the fuel system would not result in a fuel leak, but would rather result in an air induction into the fuel system, interrupting the supply of fuel to the fuel spray nozzle.

Quoted verbatim from the NTSB record.