LANCASTER, CA, USA
N4376P
PIPER PA-23-180
AFTER COMPLETION OF AN ANNUAL INSPECTION, THE AIRCRAFT OWNER ELECTED TO CONDUCT A MAINTENANCE TEST FLIGHT. WHILE AIRBORNE, HE SHUT DOWN THE RIGHT ENGINE, THEN FEATHERED AND UNFEATHERED THE PROPELLER, AND RESTARTED THE ENGINE BY LETTING THE PROPELLER WINDMILL. WHEN HE FOLLOWED THE SAME PROCEDURE WITH THE LEFT ENGINE AND PROPELLER, THE PROPELLER FAILED TO UNFEATHER AND HE COULD NOT RESTART THE ENGINE. THE PILOT RETURNED TO THE AIRPORT WITH ONE ENGINE OPERATING AND ATTEMPTED TO EXTEND THE LANDING GEAR DURING PATTERN ENTRY. THE LANDING GEAR DID NOT EXTEND AND THE PILOT INITIATED A GO-AROUND. THE AIRCRAFT DID NOT CLIMB AND BEGAN TO LOOSE ALTITUDE. EVENTUALLY, IT COLLIDED WITH THE GROUND OFF AIRPORT DURING AN UNARRESTED DESCENT. THE LANDING GEAR EXTENSION AND RETRACTION SYSTEM WAS HYDRAULIC AND POWERED BY A PUMP ON THE LEFT ENGINE. THE FLIGHT MANUAL PROVIDED TWO ALTERNATE MEANS OF EMERGENCY GEAR EXTENSION, NEITHER OF WHICH THE PILOT ATTEMPTED ON THE FIRST LANDING APPROACH.
THE PILOT'S FAILURE TO FOLLOW ESTABLISHED PROCEDURES IN RESTARTING THE ENGINE THAT DRIVES THE HYDRUALIC PUMP AND HIS FAILURE TO FOLLOW PUBLISHED EMERGENCY LANDING GEAR EXTENSION PROCEDURES. THE PILOT'S DECISION TO SHUT DOWN AN ENGINE AND FEATHER THE PROPELLER BEFORE ASSURING HIMSELF THAT THE PROPELLER WOULD UNFEATHER AND HIS INADEQUATE TRAINING IN EMERGENCY PROCEDURES WERE FACTORS IN THE ACCIDENT.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
