What happened
As the flight approached its destination, the nose landing gear failed to fully extend. After verifying the unsafe gear configuration via an inspection window, the crew executed emergency checklist procedures and prepared the passenger cabin for an emergency landing. The aircraft returned to its departure airport for the landing.
During the subsequent emergency landing, the nose gear collapsed, causing the aircraft to come to a stop on the runway on its nose. An evacuation of the cabin was initiated in two stages: a partial evacuation was first conducted using the tailcone slide, after which it was determined safe for the remaining passengers and crew to exit through the forward cabin doors. There were no injuries reported.
The investigation
Post-accident inspection revealed that an improperly secured flexible hydraulic hose had interfered with the nose wheel downlock mechanism. This interference prevented the gear from locking over center. The investigation determined that this flexible hose had been installed as a temporary measure to replace a leaking rigid line.