ANC92FA106

NTSB accident investigation · Short Brothers SC7 · Bethel, AK · July 13, 1992

Accident · FatalField investigationFinal report
Date
July 13, 1992, 12:30 local (20:30 UTC)
Place
Bethel, AK
Injuries
1 fatal
Damage
Destroyed
Phase of flight
Initial climb
Aircraft
N20086Short Brothers SC7
Weather
Visual (VMC) · Day
Status
Completed · report December 9, 1993
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19920713025039A
Case key
5645

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

Inadequate security of the cargo which shifted rearward during the takeoff roll. Factors which contributed to the accident were: the over gross weight condition, and the improper alteration of the tie down rings by the overhauling maintenance facility.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - in flightTakeoff - initial climb
Security of cargo - inadequatePilot in commandCause
Aircraft weight and balance - exceededPilot in commandFactor
Maintenance,major alteration - improperOther maintenance personnelFactor
In flight collision with terrain/waterTakeoff - initial climb

Analysis

The airplane rolled 200-300 ft before becoming airborne in a very nose high attitude. It maintained this attitude, made a right, then a left bank, and fell to the ground in a nose high attitude. The cargo consisted of eight 55-GAL drums of fuel, laid on their side and secured by one cargo strap running fore and aft and another cargo strap running diagonally across the barrels. The tie down ring ultimate strength rating was 1600 pounds. The weight of the cargo was 2863 pounds. Three of the cargo hooks associated with the cargo straps were found still attached to the tie down rings, and one hook and tie down ring were not located. Post-impact fire destroyed the cargo straps, and the barrels were strewn randomly through the cabin/cargo area. According to the manufacturer, the davis tie down ring installation is not approved by the manufacturer. The modification should have been accomplished under a supplemental type certificate. The logbooks showed only an entry. The certificated max gross weight was calculated to have been exceeded by 324.8 lbs.

Aircraft

Registration
N20086
Reported as
Short Brothers SC7
Category
Airplane
Serial number
SH-1918
Airframe hours
6,390
Engine
Garrett TPE331-2-201A, 715 horsepower, turbo prop
Damage
Destroyed
Fire
On-Ground
Flight
Part 135
Operator
Arctic Circle Air Service Inc., doing business as Arctic Circle Air Service Inc.
Registered owner
Scope Leasing Inc.
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · May 14, 1992 · 94 hours before
Departed
BET
Destination
VAK · Chevak, AK
Flight plan
Company VFR
Airport
BET · Bethel, runway 18, 6,398 × 150 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
31
Certificates
Airline transport, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Toxicology
Performed
Flight hours
5,000 total · 2,000 in this make and model · 4,800 as pilot in command · 150 in the last 90 days · 80 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
28° at 11 knots
Visibility
25 statute miles
Lowest ceiling
1,500 ft overcast
Temperature
52 °F, dew point 45 °F
Altimeter
29.00 inHg
Observed at
BET, 1 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.