Bell UH-1L N4964N

Summary

On 31 May 1986 at about 14:10 local time, a Bell UH-1L registered N4964N was involved in an accident near Wenatchee, Washington, United States. One person was on board and one died. The aircraft was destroyed. No probable cause statement is available for this record.

Date

31 May 1986 at 14:10

Classification

Accident

Location

Wenatchee, Washington, United States

Coordinates

47.3696, -120.3504

Aircraft

Bell UH-1L

Registration

N4964N

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

Unknown

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

SEA86FA137

1 person died.

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

N4964N, A BELL UH-1L, WAS BEING OPERATED IN LOGGING OPS BY AN EXPERIENCED, MILITARY TRAINED PLT WHO POSSESSED 6000 HRS OF FLT EXPERIENCE IN MODEL. WHILE LIFTING A SLING LOAD GND CREW RPTD SMOKE FROM THE TAIL ROTOR AREA. PLT RELEASED SLING LOAD & ACKNOWLEDGED THE WARNING RADIOING HIS INTENTIONS TO LAND NEARBY. THE SUBSEQUENT LOSS OF TAIL ROTOR/DIRECTNL CNTRL PLACED ROTORCRAFT IN A CONDITION WHEREBY AN AUTOROTATION WAS NOT POSSBL & A RUN ON LNDG WAS NECESSARY. UNSUITABLE TERRAIN LEFT THE PLT WITH ONLY TWO FORCED LNDG OPTIONS, ONE ON CURVING, HILLY HWY WITH POTENTIAL FOR A COLLISION WITH AUTO TRAFFIC, OR THE OTHER INTO HEAVILY TREED TERRAIN. THE PLT APPEARS TO HAVE CHOSEN THE LATTER. IT IS NOT APPARENT WHY HE CHOSE THIS OPTION RATHER THAN DIVERTING TO A NEARBY AIRSTRIP OR SOME OTHER LEVEL FORCED LNDG AREA. THE 42 DEGREE GEARBOX, WHICH HAD BEEN OVERHAULED AND INSTALLED 195 HRS PREVIOUSLY IN ACFT, WAS FOUND TO HAVE FAILED WHEN THE INPUT PINION GEAR FRACTURED IN FATIGUE ORIGINATING FROM CORROSION.

Quoted verbatim from the NTSB record.