Short Brothers SC7 N20086

Summary

On 13 July 1992 at about 20:30 local time, a Short Brothers SC7 registered N20086, operated by Arctic Circle Air Service Inc., was involved in an accident near Bethel, Alaska, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

13 July 1992 at 20:30

Classification

Accident

Location

Bethel, Alaska, United States

Nearest airport

Bethel (BET)

Coordinates

60.8093, -161.8495

Aircraft

Short Brothers SC7

Registration

N20086

Category

Airplane

Engines

2

Operator

Arctic Circle Air Service Inc.

Operating rule

Part 135: Air Taxi & Commuter

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Chevak

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

ANC92FA106

1 person died.

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.

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

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.