18th of May 2013, Seized Uplock, Blog #704
- V2Aviation
- 5 days ago
- 3 min read
After an uneventful flight from Philadelphia International Airport (PHL/KPHL) a Bombardier DHC-8-102 was on approach to Newark-Liberty International Airport (EWR/KEWR) on this day in aviation history, the 19th of May 2013.
With the first officer as pilot flying (PF), the flight was cleared for an instrument landing system (ILS) approach to runway 4R. While configuring the aircraft for landing, the left MLG showed a red unsafe indication in the cockpit. The captain requested a fly-by of the field so ATC could check the configuration. This was approved by ATC after the fly-by by the tower controller confirmed that the left MLG appeared to be partially extended. Subsequently, ATC issued vectors and cleared the flight to maintain 3,000 ft mean sea level to troubleshoot the issue. The crew changed roles, with the captain taking over the role of pilot flying and the first officer becoming the pilot monitoring. The alternate landing gear extension checklist was performed, and the main gear release handle was pulled, but the gear did not extend.
A call was made to the company operations department and the situation was discussed with the maintenance control supervisor, who advised using the hand pump to extend the MLG. After attempting to lower the gear using the handpump the gear still indicated unsafe. The captain then left the cockpit to inspect the MLG from the cabin and observed that the gear doors were open but that the left MLG was not extended. A second fly-by of the tower confirmed the crews' observations. The alternate gear extension system was reconfigured to the normal gear operation and a normal retraction and extension were performed, again the left MLG showed a red unsafe indication. Subsequently, the landing gear was retracted again. The same sequence was repeated while applying a positive G force to the airplane. This maneuver was not successful. The landing gear was retracted again and remained retracted for the remainder of the flight.
It was then decided that an emergency landing with all landing gear retracted. The relevant checklist was performed and at 01:04 local time, the aircraft touched down on its belly 3000 feet down the runway and slid about 2,000 ft, stopping on the runway
centerline in a wings-level attitude. An evacuation of the aircraft was initiated and all occupants exited the aircraft without injuries. The accident was investigated by the National Transportation Safety Board (NTSB). On the 22nd of September, the NTSB published their report on the accident. They concluded that the probable cause of the accident was;
A frozen left main landing gear (MLG) up-lock roller due to lack of lubrication and the up-lock latch that had worn beyond acceptable tolerances, which prevented the flight crew from extending the left MLG using the alternate extension system. Contributing to the accident were the operator's improper maintenance practices, which did not detect the lubrication issue with the roller and the wear of the latch.
The NTSB report (which served as the source for this blog) can be accessed by clicking on the .pdf file below;
The NTSB Docket with the investigation details can be accessed on the NTSB website by clicking on the following link; https://data.ntsb.gov/Docket?ProjectID=86939
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