Hiller FH-1100 N5068F

Summary

On 6 September 1986 at about 23:30 local time, a Hiller FH-1100 registered N5068F was involved in an accident near Abilene, Texas, United States. 6 people were on board and nobody was injured. The aircraft was substantially damaged. No probable cause statement is available for this record.

Date

6 September 1986 at 23:30

Classification

Accident

Location

Abilene, Texas, United States

Nearest airport

Abilene (ABI)

Coordinates

Not recorded

Aircraft

Hiller FH-1100

Registration

N5068F

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Unknown

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

FTW86LA164

Nobody was injured.

The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.

Nothing about the cause is stated here that is not in the source record.

Read the full NTSB narrative

THE PLT WAS CONDUCTING SIGHT-SEEING FLTS FROM A RODEO/FAIRGROUND AREA. DURING A CRITICAL PART OF A TAKEOFF, A TAIL ROTOR BLADE SEPARATED & THE PLT LOST DIRECTIONAL CONTROL. HE ATTEMPTED AN AUTOROTATIVE LANDING. AFTER SPINNING AROUND ABOUT 3 TIMES, THE PLT PULLED FULL COLLECTIVE, JUST BEFORE THE HELICOPTER CRASHED, BUT IT WAS STILL BADLY DAMAGED. AN INVESTIGATION REVEALED THAT A TAIL ROTOR TENSION-TORSION (T-T) BAR ASSEMBLY, PN 24-55106, HAD FAILED WHERE THE ATTACHMENT BOLT GOES THRU THE T-T STRAPS. A METALLURGICAL EXAM REVEALED CHLORINE RICH DEPOSITS IN THE FRACTURE AREA. THE GREASE FROM THE T-T BAR CAVITY HAD DARKENED & THE CAVITY FOR THE OTHER SET OF T-T STRAPS CONTAINED A SMALL AMOUNT OF FLUID WITH AN UNPLEASANT ODOR. AN ANALYSIS OF THE GREASE REVEALED EXCESSIVE AMOUNTS OF CHLORINE. THERE WAS EVIDENCE THAT WATER & CHLORINE CONTAMINATION HAD RESULTED IN STRESS CORROSION & EVENTUAL FAILURE OF THE T-T BAR ASSEMBLY.

Quoted verbatim from the NTSB record.