Event Sequence
The accident occurred when a Piper Apache, during a single-engine approach, veered off the runway and collided with a taxiway light, causing the landing gear to collapse. Earlier, the left engine could not be restarted after a practice shutdown and feather. The certified flight instructor (CFI) was aware that the hydraulic pump, located on the left engine, would be inoperative, requiring manual landing gear extension. The private pilot under instruction flew an instrument landing system approach while the CFI attempted to extend the landing gear.
The private pilot positioned the landing gear lever in the down position and pulled out the gear pump. The CFI did not verify the lever's position and pumped the handle about 10 to 20 times but did not achieve a down-and-locked indication nor a neutral return of the selector handle. The CFI continued troubleshooting, but no landing gear down-and-locked lights illuminated.
The air traffic control tower (ATCT) instructed the airplane to perform a 360-degree right turn at 500 feet above ground level. Before the turn, the CFI considered using the Emergency Gear Extender but was focused on airplane control during the turn. After rolling out, the CFI asked the controller to confirm the landing gear appeared down; the controller replied affirmatively. The CFI then took complete control. Just prior to the flare, a blind transmission indicated the nose gear did not appear down. The CFI applied power, but the airplane rolled left and impacted the ground.
Aircraft Systems Details
According to the Piper Apache owner's handbook, the hydraulic pump is driven by the left engine; a left engine failure renders the pump unusable. To obtain hydraulic pressure manually, the emergency pump handle must be extended and pumped 30 to 40 times to raise or lower the landing gear. Upon full extension or retraction, the handle returns to neutral. The Emergency Gear Extender, which uses carbon dioxide from a cylinder under the floorboards, can be used if a hydraulic system failure occurs due to line breakage or selector valve malfunction. Its control is located beneath a cover plate under the left pilot's seat.
Post-Accident Examination
Post-accident examination of the airplane and landing gear system revealed that the landing gear lever was positioned close to the neutral position, rather than in the down position. The emergency landing gear system was actuated through the hand pump and extended into the down-and-locked position with no operational anomalies noted.