Skip to content

DCA93MA033

1993-03-31 · ANCHORAGE, Alaska, United States · None · 1 aircraft · Status: Completed

Airport ANC

Aircraft involved

Probable cause & findings

THE LATERAL SEPARATION OF THE NO. 2 ENGINE PYLON DUE TO AN ENCOUNTER WITH SEVERE OR POSSIBLY EXTREME TURBULENCE THAT RESULTED IN DYNAMIC MULTI-AXIS LATERAL LOADINGS THAT EXCEEDED THE ULTIMATE LATERAL LOAD-CARRYING CAPABILITY OF THE PYLON, WHICH WAS ALREADY REDUCED BY THE PRESENCE OF THE FATIGUE CRACK NEAR THE FORWARD END OF THE PYLON'S FORWARD FIREWALL WEB.

Factual narrative

SEE NTSB BLUE COVER AVIATION ACCIDENT REPORT AAR-93-06 FOR FURTHER INFORMATION. SHORTLY AFTER TAKEOFF FROM ANCHORAGE, THE AIRPLANE FLEW INTO AN AREA OF SEVERE TURBULENCE, WHILE CLIMBING THROUGH AN ALTITUDE OF ABOUT 2000 FEET. THE NUMBER 2 ENGINE AND ENGINE PYLON SEPARATED FROM THE AIRPLANE. THE FLIGHTCREW DECLARED AN EMERGENCY AND THE FLIGHT RETURN TO ANCHORAGE, WHERE AN UNEVENTFUL LANDING WAS ACCOMPLISHED. THE INVESTIGATION REVEALED THAT A STRONG EASTERLY WIND INTERACTED WITH MOUNTAINS EAST OF ANCHORAGE, WHICH PRODUCED MOUNTAIN WAVE ACTIVITY. THE AIRCRAFT ENCOUNTERED SEVERE OR POSSIBLY EXTREME TURBULENCE. THERE WAS EVIDENCE THAT THIS RESULTED IN DYNAMIC MULTI-AXIS LATERAL LOADINGS THAT EXCEEDED THE ULTIMATE LATERAL LOAD-CARRYING CAPABILITY OF THE NUMBER 2 ENGINE PYLON, WHICH HAD ALREADY BEEN REDUCED BY THE PRESENCE OF A FATIGUE CRACK NEAR THE FORWARD END OF THE PYLON'S FORWARD FIREWALL WEB. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1993_DCA93MA033.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Search this event elsewhere

External sources are reported, not agency: signal that something happened, not fact about what happened.

Related research

Matched on aircraft type or causal vocabulary (turbulence). All research papers