Sikorsky S-64E N6959R

Summary

On 27 June 1991 at about 21:05 local time, a Sikorsky S-64E registered N6959R, operated by Erickson Air Crane Co., was involved in an accident near Index, Washington, United States. 5 people were on board and 2 were seriously injured. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

27 June 1991 at 21:05

Classification

Accident

Location

Index, Washington, United States

Coordinates

47.8405, -121.4299

Aircraft

Sikorsky S-64E

Registration

N6959R

Category

Helicopter

Engines

2

Operator

Erickson Air Crane Co.

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Route

Index → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

SEA91FA143

2 people were seriously injured.

THE CONTROL INTERFERENCE BY THE MECHANIC WHEN HE INADVERTENTLY RAISED THE COLLECTIVE PITCH AND THE COPILOT'S FAILURE TO ATTEND THE FLIGHT CONTROLS. FACTORS RELATING TO THE ACCIDENT WERE THE MOTION SICKNESS OF THE MECHANIC, INADEQUATE COLLECTIVE PITCH CONTROL LOCKING MECHANISM UTILIZED BY THE COMPANY, AND ADMINISTRATIVE TASKS THAT DIVERTED THE CO-PILOT'S ATTENTION FROM ATTENDING THE FLIGHT CONTROLS.

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

Read the full NTSB narrative

THE ACFT WAS ON AN EXTERNAL LOAD LOGGING OPN AND THE PIC HAD LANDED AT A FIELD SITE TO REFUEL. THE PIC EXITED, WITH THE ACFT RUNNING AT FULL RPM WHILE IT WAS BEING REFUELED, AND THE COPILOT REMAINED IN THE RIGHT SEAT COMPLETING LOAD REPORTS. THE ACFT CONTROLS WERE UNATTENDED. THE CREW CHIEF WAS SEATED IN THE AFT FACING HOIST OPR STATION, WHICH HAD THE COLLECTIVE PITCH STICK INSTALLED BESIDE THE SEAT. HE HAD BECOME AIR SICK DURING THE FLT, AND REMAINED SEATED AFTER THE PIC EXITED. WHEN HE ATTEMPTED TO EXIT, WHICH REQUIRED THAT HE STAND, TURN AROUND AND STEP UP OUT OF THE SEAT WELL, THE ACFT TOOK OFF TO A HOVER AND ROTATED TO THE LEFT. THE TAIL ROTOR STRUCK A ROTOR BLADE BOX ON TOP OF A SUPPORT TRAILER PARKED BY THE REFUELING SITE, FRACTURING THE AFT TAIL BOOM, PYLON AND TAIL ROTOR FROM THE ACFT. THE ACFT PITCHED NOSE DOWN, ROLLED OVER AND IMPACTED THE GROUND.

Quoted verbatim from the NTSB record.