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FTW89FA134

1989-07-11 · FORT WORTH, Texas, United States · Serious · 1 aircraft · Status: Completed

Airport FTW

Aircraft involved

Probable cause & findings

A LOSS OF CONTROL OF THE AIRPLANE DUE TO THE PILOT'S INABILITY TO RAISE THE FLAPS WHICH RESULTED IN A STALL. THE FLAP FAILURE AND SUBSEQUENT FULL FLAP TAKEOFF WERE THE RESULT OF THE OPERATOR'S IMPROPER MAINTENANCE OF THE AIRPLANE AND THE OPERATOR'S USE OF A CUSTOM CHECKLIST THAT DEVIATED SIGNIFICANTLY FROM THE MANUFACTURER'S APPROVED CHECKLIST. CONTRIBUTING TO THE ACCIDENT WERE THE PILOT'S FAILURE TO ENSURE THAT THE FLAPS WERE FULLY RETRACTED PRIOR TO TAKEOFF, AND THE OPERATOR'S INADEQUATE INITIAL TRAINING OF THE PILOT.

Factual narrative

IMMEDIATELY AFTER LIFTOFF THE NEWLY-CERTIFICATED PILOT BECAME AWARE THAT THE FLAPS WERE FULL DOWN. HE WAS UNABLE TO RAISE THEM AND THE AIRCRAFT STALLED WHILE IN A CLOSED TRAFFIC PATTERN. AN AGS-15 NON-SLOBLO FUSE WAS FOUND TO BE BLOWN. THE FLAP DOWN LIMIT SWITCH WAS OUT OF ADJUSTMENT RESULTING IN THE JACKSCREW TRAVELING TO THE MECHANICAL LIMIT & EVENTUALLY CAUSING AN ELECTRICAL OVERLOAD. THE FUSE WAS REPLACED TWICE WITHIN THE PREVIOUS 45 DAYS. FOUR OTHER AIRCRAFT OF THE OPERATOR'S FLEET ALSO HAD INCORRECT FUSES INSTALLED. THE PILOT HAD LOWERED THE FLAPS FOR HIS WALK-AROUND. THE OPERATOR (SCHOOL) HAD DEVELOPED THEIR OWN CHECKLIST DIFFERENT FROM THAT CONTAINED IN THE APPROVED OWNER'S MANUAL. THIS CHECKLIST CALLED FOR LOWERING OF FLAPS DURING PRE-START INSPECTION AND RAISING OF FLAPS DURING AFTER-START. THE CHECKLIST DID NOT CONTAIN A SPECIFIC ENTRY TO CHECK THAT THE FLAPS WERE UP PRIOR TO TAKEOFF. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1989_FTW89FA134.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

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Related research

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