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MIA92LA189

1992-09-21 · ORLANDO, Florida, United States · None · 1 aircraft · Status: Completed

Airport ORL

Aircraft involved

Probable cause & findings

UNDETECTED CHAFFING AND GROUNDING OF A WIRE TO THE NOSE LANDING GEAR SQUAT SWITCH WHICH RESULTED IN THE LANDING GEAR BEING SIGNALLED AT ALL TIMES FOR GEAR UP WHEN ELECTRICAL POWER WAS APPLIED TO THE SYSTEM. CONTRIBUTING TO THE ACCIDENT WAS THE OVERHEATING OF THE GEAR DOWN SOLENOID WHICH CAUSED IT TO STICK IN THE GEAR UP POSITION AND PREVENTED THE GEAR FROM BEING MANUALLY EXTENDED.

Factual narrative

PILOT STATED THAT WHILE ATTEMPTING TO EXTEND THE LANDING GEAR THE GEAR HYDRAULIC MOTOR OPERATED BUT THE GEAR DID NOT EXTEND. AFTER SEVERAL SECONDS OF GEAR MOTOR OPERATION THE CIRCUIT BREAKER FOR THE GEAR MOTOR POPPED. FURTHER ATTEMPTS TO EXTEND THE GEAR BY NORMAL AND EMERGENCY PROCEDURES WERE UNSUCCESSFUL. A GEAR UP LANDING WAS MADE. AFTER THE ACCIDENT THE AIRCRAFT WAS RAISED AND THE LANDING GEAR WAS EXTENDED BY USE OF THE MANUAL GEAR EXTENSION EMERGENCY HYDRAULIC PUMP. ACCORDING TO MAINTENANCE PERSONNEL A WIRE TO THE NOSE LANDING GEAR SQUAT SWITCH WAS CHAFFED AND GROUNDED WHICH CAUSED THE SYSTEM TO BE SIGNALLED FOR GEAR UP AT ALL TIMES. THEY FURTHER STATED THE PILOT COULD NOT EXTEND THE GEAR BY USE OF THE BACKUP HYDRAULIC PUMP BECAUSE THE GEAR DOWN SOLENOID HAD OVERHEATED DURING ATTEMPTS TO LOWER THE GEAR AND FROZE IN THE GEAR UP POSITION. AFTER THE SOLENOID COOLED AFTER LANDING THEY WERE ABLE TO MANUALLY LOWER THE GEAR. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1992_MIA92LA189.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

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