What happened
Shortly after takeoff, the crew of a Boeing 737 (registration not provided) heard a loud bang, which was immediately followed by a loss of cabin pressurization. During the event, the pilots observed an unsafe nose gear indication on the instrument panel.
In response to the indication, the pilots moved the landing gear handle to the down position and subsequently received three green lights, confirming the gear was locked. To verify the status of the aircraft, the control tower monitored a low pass, which confirmed that the landing gear remained in the down position. The flight eventually completed an uneventful landing at Denver.
The investigation
Post-accident examination conducted by maintenance personnel identified a hole in the forward pressure bulkhead and a broken nose gear actuator. Specifically, investigators found that the piston rod of the nose landing gear actuator had worn threads. Additionally, a key locking washer within the gear assembly was found to have sheared. The airline reported that these components were part of the original equipment.