NTSB Identification: CHI93IA078.
The docket is stored on NTSB microfiche number 52814.
Scheduled 14 CFR operation of USAIR (D.B.A. operation of USAIR )
Incident occurred Tuesday, January 26, 1993 in DETROIT, MI
Probable Cause Approval Date: 08/26/1994
Aircraft: FOKKER F-28 MK 1000, registration: N452US
Injuries: 42 Uninjured.
NTSB investigators used data provided by various sources and may not have traveled in support of this investigation to prepare this aircraft incident report.THE CAPTAIN OBTAINED NO RESPONSE TO NOSE-UP STABILIZER TRIM DURING DESCENT. NORMAL NOSE-DOWN TRIM REMAINED OPERABLE; ALTERNATE TRIM WAS NOT ATTEMPTED. THE CREW REPORTED A JAMMED STABILIZER AND LANDED WITH NOSE-DOWN TRIM. DISASSEMBLY OF THE HORIZONTAL STABILIZER CONTROL UNIT SHOWED INADEQUATE LUBRICANT AND EXTENSIVE CORROSION IN A GEARBOX. THE AIRFRAME MANUFACTURER'S PROCEDURE FOR REPLENISHING THE GEARBOX LUBRICANT COULD RESULT IN UNDERSERVICING. THE OPERATOR OBSERVED A GEARBOX SERVICE INTERVAL WHICH WAS 250% OF THE MANUFACTURER'S RECOMMENDATION.
The National Transportation Safety Board determines the probable cause(s) of this incident to be:
IMPROPER LUBRICATION OF THE HORIZONTAL STABILIZER GEARBOX BY COMPANY MAINTENANCE PERSONNEL. A FACTOR WAS THE MANUFACTURER'S INADEQUATE SERVICE PROCEDURE. Index for Jan1993 | Index of months