Date: 201605
Local time of day: 1801-2400
Location: SDF.Airport, KY
Weather elements / visibility: Thunderstorm
Aircraft: Citation Excel (C560XL)
Flight phase: Taxi
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Training / Qualification
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: Aircraft parked with many others on a 'closed' taxiway; i.e.; remote. Thunderstorm was in progress with moderate to heavy precipitation. Lighting was 'dim to nil'. As per SOP; [First Officer (FO)] first to arrive at aircraft to perform pre-flight inside and out. I arrived +45 later concurrent with the arrival of our 8 passengers. I performed normal outside check and boarded aircraft. We were given clearance to taxi from parked position to 'Spot Yellow' making normal turns for about 1 mile. Given taxi clearance to RW 17L and soon felt nose wheel shimmy. Requested and given clearance to stop and pulled aside (no other aircraft near us). I shut-down left engine and went outside while [FO] remained at his station. I found the nose wheel steering pin not properly installed. I re-connected the assembly and considered the condition 'corrected' and with the concurrence of my flying partner decided the flight could continue as planned. Received ATC clearance to continue taxiing and completed the flight. Post flight inspection found the steering pin installed but the safety pin was NOT locked; i. e.; Safety Pin not perfectly functional. I completed a Maintenance Log Book Entry and notified maintenance as per SOP.[Suggest] Standardization of Excel fleet to re-fit all nose wheel steering with 'permanent' steering pins.


Second narrative: The aircraft was parked at a remote ramp without any lighting. It was raining and lightning strongly. I did the required walk around and pre-flight duties. After the captain had taxied approximately 1.5 miles; making a 90 degrees right turn out of the parking position; and 3 left turns; the nose gear began to shake. We thought; we might have a flat tire; or ran over something in the dark; while taxiing. The Captain brought the aircraft to a stop. We notified ATC that the aircraft was disabled on the taxiway. The Captain set the brakes; shut down the engine; and proceeded to inspect the nose gear; while I remained in the cockpit. The Captain found that the scissors on the nose gear had become loose. He attached the scissors back together; started the left engine; notified ATC; and we continued to taxi. I will conduct a more through pre-flight regardless of the weather conditions. I understand that this event has occurred previously on our property. I was told that Cessna has a service bulletin on this issue. I would suggest that the aircraft with the correct serial number be modified in agreement with the service bulletin.


Synopsis: CE560XL flight crew reported they taxied out with the nose wheel steering pin not properly secured.