Citation X (C750)
Maintenance Airframe; Maintenance Powerplant
Troubleshooting; Communication Breakdown; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance; Ground Event / Encounter Object; Inflight Event / Encounter Object
Aircraft Aircraft Damaged; Flight Crew Took Evasive Action
Human Factors; Procedure
The aircraft was not on [the FBO] ramp but we saw it on the customs ramp. We got to the aircraft and started a walk around. I plugged in the batteries and pulled the main chock. The other technician hooked up the torque links. I got in the aircraft in the pilot seat and looked over the CB panel and the various switches in the cockpit. I turned the batteries on. I turned the aux hydraulic switch on the buildup press and set the brakes. With brakes set the nose chock was pulled. I started the APU and got the generator on line. I turned on the inverters and turned on the AHRS [attitude and heading reference system] and power supply. With avionics up I started the right hand engine. With the engine running and amps at a good level; I started the left engine. I checked the oil pressures and hydraulic pressures. I called ground [control] for clearance to taxi to [FBO ramp]. With clearance I pushed the brake off and started rolling. I went to turn and had no nose wheel steering. I applied the brakes and had no brakes. I pulled the parking brake handle and had no results. I was closing in on the hangar in front of me and shut down the engines to avoid damage to the engines. I impacted the hangar right after that. I shut down the APU and shut down the power. I then got out of the aircraft and unplugged the batteries. After a bit of time talking to the [airport personnel] I then thought of squat switches as a possible problem and found the squat switches were manually placed in air mode.Suggestions1) Documentation of tooling installed on aircraft2) Flags on all maintenance lockout/pins etc3) Inspection Buy Back of ground lock devices being removed
A Maintenance Technician reported impacting a hangar during taxi when the nosewheel steering system and brake system were disabled by the unreported activation of the landing gear squat switch.