Investigation brief · generated 2026-10-09 · source: NTSB public docket and accident database
BOMBARDIER DHC8 — Newark, NJ, USA, 2013-05-18
NTSB number
DCA13FA094
Operator
Piedmont Airlines
Registration
N934HA
Highest injury
No injury
Regulation
Part 121
Damage
Substantial
Cohort
Part 121 airline
Recorder data
Tier 1 — decoded recorder tables
Every sentence below is taken directly from NTSB records — the accident database, the docket's recorder reports and the Board's findings — with its source noted. Nothing is paraphrased or inferred.
NTSB summary
While on an instrument approach to the airport, when the flight crew attempted to lower the landing gear, they received an unsafe indication on the left main landing gear (MLG). They conducted a fly by of the airport control tower, and the controller verified that the left MLG was only partially extended. The flight crew performed the alternate landing gear extension procedure and worked with company maintenance to troubleshoot the failure, however, the left MLG would not extend after multiple attempts. Although the first officer indicated that he became confused after the sixth step of the alternate landing gear extension procedure, post accident testing determined that this did not have any effect on the outcome Because the left MLG would not extend, the captain elected to conduct the landing with all gear retracted to minimize the likelihood of a loss of directional control after touchdown. All passengers and crew successfully evacuated after the airplane came to a rest on the runway.
Postaccident testing confirmed that the left MLG would not deploy using the normal or alternate gear extension systems. Examination of the landing gear components found that the left MLG uplock roller was seized and the groove on the left uplock latch was out of tolerance. The seized uplock roller and worn latch caused the forces to exceed the crews capability to release the landing gear by use of the alternate gear extension system.
Examination of the operators maintenance records indicated that the uplock rollers were to be inspected every 220 flight hours and that they were to be lubricated only on condition. The accident airplanes left MLG uplock was inspected 11 times in year prior to the accident. In all instances, the inspection paperwork indicated that the roller rotated freely and did not require lubrication for the last. Further, the uplock latches were to be visually inspected every 440 flight hours. The latches were not required to be measured and were replaced only on condition. The last measurement of the left MLG latch on the accident airplane occurred 10 years prior to the accident. After the accident, the operator modified the maintenance procedures to include regular lubrication of the rollers and to measure the wear of the uplock latch.
the frozen left main landing gear (MLG) uplock roller due to lack of lubrication and the uplock 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.
Verbatim, NTSB determination.
Flight data recorder
— 7,871 samples, 9 parameters, 22:51:01.0 to 25:02:12.0.
Parameter
Max
at
Min
at
Final
at
Pressure altitude ft
6,784.0
23:12:52.0
-288.0
25:01:50.0
-256.0
25:02:12.0
Pitch attitude deg
15.6
24:32:57.0
-3.0
25:01:36.0
10.0
25:02:12.0
Roll attitude deg
24.4
23:48:05.0
-24.3
24:07:16.0
19.9
25:02:12.0
Vertical acceleration g
1.6
24:32:20.0
0.7
24:33:01.0
1.0
25:02:12.0
Computed from the docket's tabular attachment; times as recorded (local or SRN as published).
Sequence of events (FDR factual report)
Time
Event
Page
23:05:22 EDT (May 17)
Takeoff
3
23:12:38 EDT
Aircraft leveled at an average pressure altitude of 6,800 ft
3
23:27:42 EDT
Descent to land began
3
23:30:52 EDT
Go-around on final approach, pitching to 9 degrees and climbing to a pressure altitude of 2,800 ft
3
00:04:42 EDT (May 18)
After holding about 2,800 ft, the aircraft began descending for another approach
3
00:12:21 EDT
Second go-around: pitched up to 11 degrees and climbed back to about 2,800 ft
3
00:32:20 EDT
First vertical g maneuver reaching 1.6 g (attempt to lower the left main gear)
3
00:32:52 EDT
Second vertical g maneuver reaching 1.4 g
3
00:57:58 EDT
Aircraft began the landing descent from 2,600 ft
3
01:01:51 EDT
During the gear-up landing, high excitations in the accelerations began to build; airspeed dropped from about 81 knots to a final value of 58 knots
3
01:02:03 EDT
Power removed from the FDR
3
Extracted by claude-fable-5-1 (in-session); 2 of 11 stated events verified against the raw recorder data.