No fatalities

1985-02-06: Douglas DC-9 (N926AX) — Airborne Express — Philadelphia, United States of America

Philadelphia, United States of AmericaTakeoff (climb)

On February 6, 1985, a Douglas DC-9 (registration N926AX) operated by Airborne Express was involved in an aviation accident near Philadelphia, United States of America during takeoff. No fatalities were reported. Investigators recorded the probable cause as: Occurrence #1: loss of control - in flight, Phase of operation: takeoff - initial climb. Findings: (f) weather condition - rain; (f) weather condition - snow; (f) weather condition - icing conditions; (f) light condition - dark night; (c) wing - ice; (c)… This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 4 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781218718Data APIEditorial standards

After parking in freezing drizzle, a DC-9-15 crew declined de-icing. On takeoff, the aircraft rolled left, both engines compressor stalled, and the crew aborted. Investigation found a thin ice layer on wings raised stall speed.

Incident Overview

After landing, the aircraft was parked on the ramp for approximately 39 minutes to load cargo. During that time, light freezing drizzle was falling, intermittently mixed with ice pellets and snow. The crew checked the aircraft surfaces from the cockpit and entry door, but observed no ice or snow adhering to the tops of the wings, nose section, windshield, or above the door. The captain declined an offer to de-ice, while two other aircraft were being de-iced.

Takeoff and Loss of Control

The takeoff was normal, with an 18° nose-up attitude, until just after lift-off. The aircraft then entered an uncommanded left roll, and both engines experienced compressor stalls. The captain corrected with left aileron and rudder, then began aborting the takeoff.

Abort and Final Positions

The aircraft touched down left of the runway on the tail skid and right wing tip, approximately 5,600 feet from the threshold and on a 070° heading. It then traveled another 2,025 feet in a sweeping right arc, hitting two runway signs, and came to rest heading west with the right pylon bent down.

Investigation Findings

Investigations revealed that a thin layer of ice, estimated at 0.15 inch thick, would have been on the wings, raising the aircraft's stall speed. The aircraft involved was a DC-9-15, and the source notes that when such aircraft stall, engines are susceptible to compressor stalls.

Probable Cause

The official findings list multiple occurrences: Loss of control in flight during takeoff initial climb, with findings including weather conditions (rain, snow, icing), dark night light condition, wing ice, ice/frost removal not performed by the pilot in command, visual/aural detection by the pilot in command, and inadvertent stall by the pilot in command. A second occurrence involved loss of engine power (total, nonmechanical) during takeoff initial climb, with the aborted takeoff initiated by the pilot in command. A third occurrence was an in-flight collision with terrain/water during takeoff. A fourth occurrence was an on-ground/water collision with an object during other phase.