Incident Overview
On May 18, 2013, about 0104 eastern daylight time, a Piedmont Airlines Bombardier DHC-8-102, registration N934HA, operating as US Airways Express flight 4560, landed with all landing gear retracted on runway 4L at Newark Liberty International Airport (EWR), Newark, New Jersey. The flight had originated from Philadelphia International Airport (PHL) and was operating under Title 14 Code of Federal Regulations Part 121. The aircraft carried 2 pilots, 1 flight attendant, and 31 passengers; no injuries were reported. The airplane sustained substantial damage.
Landing Gear Failure and Troubleshooting
During the initial approach to runway 4R, the left main landing gear (MLG) failed to lower and lock. The flight crew's attempts to lower the left MLG were unsuccessful. After a fly-by, the tower confirmed the left MLG appeared partially extended. The crew executed the alternate landing gear extension checklist, but pulling the main gear release handle did not extend the gear. The first officer (FO) had not read notes at the bottom of the checklist regarding a hydraulic pump handle. In consultation with a maintenance control supervisor, the crew attempted to use a hand pump to extend the MLG, without success. The captain inspected the MLG from the cabin and observed that the gear doors were open but the left MLG was not extended.
Further attempts included reconfiguring the alternate gear system to normal, raising and re-extending the gear, and applying positive G forces, all unsuccessful. The crew then retracted the gear and left it retracted.
Emergency Landing
When fuel remaining was 900 lbs, the captain decided to make an emergency landing with all gear retracted, with agreement from maintenance personnel. The crew briefed passengers and performed the emergency landing checklist. The captain flew an ILS approach to runway 4L, maintaining speed above 130 knots to silence the landing gear warning horn until close to the runway. The airplane landed about 3,000 feet down the runway and slid about 2,000 feet, stopping on the centerline in a wings-level attitude. After landing, the captain observed smoke on the right side and ordered an evacuation via the left main cabin door. All occupants evacuated without injury.
Postaccident Examination
Examination of the left MLG uplock roller revealed it was seized and would not rotate by hand; the right MLG uplock roller rotated freely. A worn groove was found on both uplock latches, with the left latch groove at or beyond wear limits. Testing of the alternate gear extension system showed that the left MLG required more than 240 pounds of force to release, while the right MLG released with normal force. After swapping the left and right uplock rollers, both MLG extended normally. The removed left uplock roller had rust on internal bearings, flat spots, and corrosion, and lacked lubricant.
Personnel and Maintenance Information
The captain and first officer had no prior accidents or incidents. The captain had been with Piedmont since 1988; the FO was hired in 2011. Both reported being well-rested and not affected by fatigue. Piedmont's maintenance procedures included visual inspection of the MLG uplock actuator latch every 440 flight hours and inspection of the uplock roller every 220 flight hours. The last B check was on March 21, 2013. The latch groove had last been measured in 2003 and was within tolerance. After the accident, Piedmont implemented changes including fleet-wide inspection and lubrication of roller assemblies, revised work cards, and enhanced checklists.
Flight Recorder Data
The cockpit voice recorder and flight data recorder were recovered and provided good audio and data. The FDR contained about 27 hours of data.