Accident: LOT B763 at Warsaw on Nov 1st 2011, forced gear up landing
By Simon Hradecky, created Thursday, Dec 1st 2011 11:44Z, last updated Thursday, Dec 1st 2011 11:54Z
The Polish Panstwowa Komisja Badania Wypadkow Lotniczych (Polish State Commission for Aircraft Accident Investigation, PKBWL) released theirpreliminary report reporting that the aircraft suffered a hydraulic leak shortly after takeoff from Newark’s runway 04L, when the gear and flaps were retracted. The center hydraulic system’s (System “C”) pressure dropped as a result. Just after the flaps had fully retracted the crew received a low pressure message on the Engine Indication and Crew Alerting System (EICAS), the hydraulic quantity indication reduced from 105.1% to 10.6% in 2 minutes, the aircraft was climbing through 3850 feet MSL at that point. The crew actioned the relevant checklists and consulted with the airline’s operations center resulting in the decision to continue the flight.
While on approach to Warsaw the crew performed the alternate gear extension procedure however the gear did not extend. While in a holding military aircraft were dispatched to visually check the aircraft and reported the gear was still in the up position. The crew attempted another gravity extension which still did not extend the gear.
About 72 minutes after aborting the first approach to Warsaw, in view of the failed attempts to lower the gear and the fuel reserves depleting the crew decided to commence a belly landing. After the aircraft came to a stop an evacuation commenced through all doors except for the right hand overwing exits, the evacuation was completed in about 90 seconds.
About 15-20 minutes after the end of the evacuation the first members of PKBWL arrived at the scene and found the “C829 BAT BUS DISTR” circuit breaker on the P6 panel was in the popped position, the “C4248 LANDING GEAR - ALTN EXT MOTOR” circuit breaker was in the closed position. The recordings of cockpit voice recorder and flight data recorder were secured.
Circuit breaker C829 protects a number of systems including the alternate landing gear extension system. It’s position was not recorded or indicated by any aircraft system.
After the aircraft was lifted off the runway, the circuit breaker C829 was closed, then the alternate landing gear extension was activated and successfully extended the landing gear, so that the aircraft could be towed to the airline’s maintenance hangar.
On Nov 2nd the location of the hydraulic leak was identified in a damaged hose belonging to the center hydraulic system. The hose was disassembled and sent to the NTSB for further analysis.
The captain held an ATPL and accumulated 15,980 hours total flying time (thereof 14,007 hours in command) and 13,307 hours on type. The first officer (ATPL) accumulated 9,431 hours total flying time, thereof 1,981 hours on type.