Goodlett SAFARI N912TT

Summary

On 3 September 2005 at about 15:30 local time, a Goodlett SAFARI registered N912TT was involved in an accident near Trona, California, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 September 2005 at 15:30

Classification

Accident

Location

Trona, California, United States

Coordinates

35.6667, -117.3333

Aircraft

Goodlett SAFARI

Registration

N912TT

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Ridgecrest → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX05LA288

1 person had minor injuries.

the in-flight fatigue failure of a control system connecting rod, which resulted in a loss of helicopter control.

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

Read the full NTSB narrative

The experimental helicopter impacted terrain after experiencing a failure of a flight control connecting rod. According to the pilot, he was maneuvering the helicopter about 50 feet above the ground when he heard a loud bang followed by a whirring or buzzing noise. The helicopter rolled to the left, which the pilot was unable to counter with control inputs, and impacted terrain on the left side. A post-accident examination of the helicopter by the pilot/builder revealed that a 27.875-inch aluminum control rod was fractured near the middle of the rod. The control rod was connected between the collective-cyclic mixing assembly and a walking beam that connected to the stationary swash plate of the left side (pilot side) of the helicopter. The break in the control rod was perpendicular to the longitudinal axis of the rod. Examination of the control rod by a metallurgical laboratory revealed the failure was a result of a fatigue crack that had propagated through nearly 75 percent of the control rod. A portion of the break was polished indicating that the crack had been present for quite some time. The pre-existing crack in the control rod reduced its strength to a point that allowed the flight control forces to fail the remaining material. According to the pilot/builder, a break in the control rod would result in flight characteristics consistent with that experienced by the pilot during the accident flight. The control system has been redesigned by the kit manufacturer as a result of this accident and now incorporates steel control rods as opposed to aluminum ones.

Quoted verbatim from the NTSB record.