PA-31 Navajo/Chieftan/Mojave/T1040
Air Traffic Control Fully Certified; Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Air Traffic Control Military 22; Air Traffic Control Supervisory 16; Flight Crew Last 90 Days 80; Flight Crew Total 1425; Flight Crew Type 75
Other / Unknown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Aircraft Damaged; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft; Human Factors; Procedure
The aircraft was towed from the hangar to the line by unknown personnel. Prior to the tow; the pin in the Nose Wheel Scissors was removed and stowed above the scissors. This allows the nose wheel to turn freely beyond the stops during towing. Upon completion of the tow; the lower half of the scissors was returned to the connecting position with the top half of the scissors. However; the Pin was not replaced to hold the scissors together. (It is placarded to: Install Nose wheel Pin prior to removing Tow Bar.) During the pre-flight inspection; I removed the nose wheel chock from the nose wheel; and gave a cursory look at the nose wheel scissors. At that time; the scissors was together and appeared to be linked; however it was later determined that the top and bottom scissors were connected; but the pin was not installed to hold them together. As I taxied out I made a right turn out of parking and two left turns onto the runway without noticing a lack of nose wheel steering; since the scissors was connected. As I departed; and began to remove weight from the nose of the aircraft; the scissors separated and came apart due to the pin not being installed. I then began to get a severe shudder from the nose wheel area. Upon departing; I raised the gear. I got a RED 'Gear not stowed safely' light. I then put the gear down; and got three Green lights. I then attempted to raise the gear again; with the same RED light results. The gear handle also did not return to the center position. I manually centered the lever after a few minutes. As I approached 20 NM from the destination airport; I attempted to lower the gear; and got two main Green lights; and no Nose Gear light. After advising ATC; and considering my options; I opted to declare an emergency; and return to the departure airport. As I was returning; I used the Manual Gear Lever to manually pump the gear down into a 3 Green indication. As I approached; I used full flaps and touched down lightly with the mains. I eased the nose down until it touched down. It shuddered a bit as the rubber was worn away; and then the wheel began to slide on the runway surface. I immediately pulled the power to idle; the props to 'Feather'; and the Mixture to cut off. I also shut off the Mags and Master. I came to a stop slightly left of centerline; and exited the aircraft. It was determined that the nose wheel was 90 degrees to the right upon landing; and that the scissors pin had not been installed. The aircraft was then towed to the ramp area without further incident. There was minor damage to the aircraft; i.e. the nose wheel tire/rim. There were no injuries. When the Scissors Pin is removed; the lower half of the scissors typically swings downward and rests on the nose wheel; which makes it very obvious during the pre-flight inspection that it is not connected. It also prevents nose wheel steering; making it obvious that there is a problem. This scissors was stiffer; and had enough resistance to stay 'in place' with the top half of the scissors; even without the pin being installed; therefore still allowing nose wheel steering while taxiing; and giving no indication that there was a problem until it was too late. The maintenance chief is checking to see if the STC allows for the Pin Cable (which attaches the pin to the upper half of the scissors) to be shortened. This would raise the upper half of the scissors enough that the lower half of the scissors is not able to touch or connect with the upper half; without the pin being installed. Other options are also being discussed.
PA31 pilot reports that the nose wheel scissors pin is removed for towing and the scissors reconnected afterwards but the pin is not reinstalled. This is not detected during preflight and the aircraft is taxied out for departure. As the weight comes of the nose wheel during takeoff a shudder develops and the nose gear does not retract. The gear is cycled with the same result. Upon returning to the departure airport the nose gear will not extend and is pumped down. A successful landing ensues with both engines shut down during the roll out.