Incident Overview
On 31 January 1998, a Piper PA-28R-200, registration G-BOJH, was operating a private flight from Glasgow Airport, Scotland. After a normal takeoff, the landing gear was selected up but the in-transit light remained illuminated. When the pilot selected the gear down, the two mainwheel green lights illuminated but the nose gear light did not. The pilot attempted the flight manual emergency lowering procedures without success.
Diversion to Perth
The pilot decided to divert to Perth (Scone) Airport, being aware of its grass runway and engineering facilities. Upon arrival, a low fly-past was conducted and an engineer confirmed that the nose landing gear had only partially extended from its bay. The pilot circled the airfield while emergency services arrived, then performed six practice approaches and go-arounds before deciding to land on the main wheels only.
Landing and Evacuation
The pilot briefed the three passengers on emergency and evacuation procedures. During the final approach, the engine was lean-cut, magnetoes and master switch were turned off. After touchdown, the pilot held the nose up until the elevators became ineffective and the nose dropped. Following a short ground slide, the pilot and passengers evacuated without difficulty. No injuries were reported.
Post-Incident Examination
Examination revealed that the nose landing gear leg had been prevented from extending due to a 'hang-up' involving the steering centring mechanism. The nosewheel was found canted to one side. As the nose gear retracts, a roller mounted from the support structure enters a channel-section guide fixed to the steering arm. The guide is flared to engage the roller at any steering angle, then narrows to centre the nosewheel. In this case, the roller had become displaced from the guide and ran down the outside of the channel during gear extension until the flare prevented further movement. Forcing the leg down during recovery distorted the guide and roller mount.
In the retracted position, engagement of the roller in the guide appeared only partial. The maintenance organisation reported that even in a correctly rigged system, the roller is partially visible beyond the end of the guide; further movement towards the 'up' position could cause disengagement. However, this would not explain the initial failure to retract. It remained a possibility that the roller failed to correctly engage during retraction at Glasgow. Recovery damage and repair prevented confirmation of pre-accident rigging, but no component failure or excessive wear was found.
The pilot had reported stiffness in nosewheel steering when turning right shortly before the incident. Maintenance found hardened grease and a dry steering system, which was lubricated. Whether this stiffness was related to the subsequent nose gear jamming is not known.