Hughes 369HS N8315F

Summary

On 5 June 1990 at about 13:15 local time, a Hughes 369HS registered N8315F, operated by Helicopter Minit MEN, Inc., was involved in an accident near Brookville, Pennsylvania, United States. 3 people were on board and one was seriously injured, 2 had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

5 June 1990 at 13:15

Classification

Accident

Location

Brookville, Pennsylvania, United States

Coordinates

41.1595, -79.0803

Aircraft

Hughes 369HS

Registration

N8315F

Category

Helicopter

Engines

1

Operator

Helicopter Minit MEN, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Dubois → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

NYC90LA125

1 person was seriously injured.

WORN TAIL ROTOR PITCH CONTROL ASSEMBLY, DUE TO IMPROPER MAINTENANCE/INSTALLATION, AND SUBSEQUENT FATIGUE FAILURE OF THE TAIL ROTOR SWASHPLATE.

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

Read the full NTSB narrative

DURING A POWER LINE PATROL FLT OVER WOODED TERRIAN, AT ABOUT 60 TO 85 FT AGL, TAILROTOR CONTROL OF THE HELICOPTER WAS LOST. THE HELICOPTER BEGAN TO SPIN TO THE RIGHT AND THE PLT ATTEMPTED A HOVERING AUTOROTATION. THE HELICOPTER BEGAN SPINNING FASTER. SUBSEQUENTLY, IT SETTLED ONTO THE POWER LINE, THEN CRASHED TO THE GROUND. AN EXAM REVEALED THAT THE TAIL ROTOR SWASHPLATE HAD FAILED FROM FATIGUE. THE SWASHPLATE OUTER DIAMETER WAS WORN WITH EVIDENCE OF SPALLING, THE BEARING INNER DIAMETER WAS LIGHTLY SCORED, THE SWASHPLATE THREADS WERE SEVERELY WORN WITH EVIDENCE OF SPALLING DUE TO RELATIVE MOTION WITH THE MATING THREADS OF THE LOCKNUT, AND THE LOCKWASHER TANG HAD WORN A SIGNIFICANT PATTERN IN THE SWASHPLATE KEYWAY.

Quoted verbatim from the NTSB record.