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SEA88IA074

1988-04-13 · PORTLAND, Oregon, United States · None · 1 aircraft · Status: Completed

Airport PDX

N291AS has since been reassigned. It is now registered to a different aircraft (BEECH B300, built 2001), which was not involved in this event.

Aircraft involved

Factual narrative

THE BOEING 727 WAS PUSHED BACK FM THE GATE COUNTERCLOCKWISE THROUGH AN ARC OF 90 DEGREES RESULTING IN MISPOSITIONING THE ACFT RELATIVE TO THE INTENDED TAXI DIRECTION. THE GROUND CREW (TUG AND SAFETY OPERATORS) ATTEMPTED TO RESOLVE THE OUT OF POSITION CONDITION BY CONTINUING THE PUSH BACK THROUGH A SECOND 90 DEGREE (COUNTERCLOCKWISE) ARC. THIS REQUIRED PUSHING THE AIRCRAFT UPSLOPE ACROSS THE RAMP. DURING THE SECOND 90 DEGREE ARC THE TUG BECAME POSITIONED APPROXIMATELY 90 DEGREES TO THE TOWBAR/AIRCRAFT LONGITUDINAL AXIS. THE DOWNSLOPE AND IDLE POWER CONDITIONS OVERPOWERED THE TUG'S BRAKING CAPACITY AND THE TOW BAR BROKE UNDER A BENDING LOAD ALLOWING THE AIRCRAFT TO ROLL FORWARD IMPACTING THE TUG. ALL THREE B-727 ENGINES WERE OPERATING AT IDLE THRUST. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1988_SEA88IA074.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.