Narrative:

Another technician and myself were dispatched to work a nosewheel steering problem on aircraft X. While I was debriefing pilots on malfunction; the shift supervisor had arrived at aircraft and was attempting to retrieve fault codes from nosewheel steering computer. Pilots also stated that the aircraft was scheduled as a quick turn. After finishing with pilot's debrief; I started checking nosewheel steering switch position and resetting of circuit breakers in hopes of getting the nosewheel steering computer to show any faults it had logged. At this time the supervisor had left the aircraft and the other technician went to get the amm and flight information manuals to help troubleshoot. Once he arrived back to aircraft; we had successfully downloaded several faults and were checking them out in the flight information manual. Somewhere in this time period; the lead had come out to aircraft. We decided to perform an operations check of nosewheel steering. Another technician and myself tried to use the nosewheel jack to place the skid plate under the tires but the jack placement prevented clearance. The other technician then called for ramp personnel to clear aircraft of baggage loader and baggage carts and to tow aircraft onto skid plates. It was decided to use the #2 engine as hydraulic power source to perform operations check. Ramp had come out and moved baggage carts and loader as requested; but then left with no signs of tow team. I called the supervisor thinking he was working maintenance control that day; to find out when tow team would be available to move aircraft for us. The supervisor stated to hold on and came out to aircraft. He stated to me it would be faster to just roll aircraft onto skid plates once I had the #2 engine started; then to wait for tow team. I already had the aircraft ready to start and had performed my pre-engine run situational awareness mental checklist prior to this change in plans. I followed the run/taxi checklist and started the #2 engine for gain #2 hydraulic pressure of operations check. Not re-accomplishing my pre-engine run situational awareness mental checklist again after it was decided to roll aircraft onto skid plates; I failed to recognize the need to have #1 hydraulic system pressure for normal brakes or the need to have a second person in cockpit as required for all aircraft taxies. The thought that this was an aircraft taxi movement did not occur to anyone at this time. At the time of engine start; I had another technician; the lead; and the supervisor at nose of the aircraft. I verified I had good #2 system hydraulic pressure but overlooked ensuring my standby hydraulic and ptu switches were on. The other technician marshaled me forward when I then brought the #2 condition lever to minimum and released parking brakes. The aircraft failed to move forward under this power setting; so I momentarily moved #2 power lever to flight minimum until aircraft started to move. The nose immediately started sliding to the left once it hit the grease plates. I brought the #2 power lever back to disc and applied toe brakes. Ground crew were signaling me to stop; but normal braking did not operate. I took the #2 power lever momentarily to reserve; which stopped forward movement and then it started rolling forward again. The only thing I could think to do was to shut down the #2 engine; which I did. I was still applying toe brakes without success before I finally realized to use the parking brake lever. At this time I was unaware that the aircraft had came into contact with anything until I deplaned. By the time I stopped the aircraft I had rolled 33 ft; wedged #1 propeller blade against maintenance van; and struck a maintenance stand with the spooling down #2 engine propeller. I performed post engine run shutdown procedures and ensured aircraft was chocked. I then went to the office to start reporting procedures.

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Original NASA ASRS Text

Title: A DHC8-400 DURING TROUBLESHOOTING OF A NOSE GEAR STEERING PROB THE ACFT WAS TAXIED WITH #2 ENG PWR. LOSS OF ACFT CTL INCURRED DAMAGE TO ACFT AND GND EQUIP.

Narrative: ANOTHER TECHNICIAN AND MYSELF WERE DISPATCHED TO WORK A NOSEWHEEL STEERING PROB ON ACFT X. WHILE I WAS DEBRIEFING PLTS ON MALFUNCTION; THE SHIFT SUPVR HAD ARRIVED AT ACFT AND WAS ATTEMPTING TO RETRIEVE FAULT CODES FROM NOSEWHEEL STEERING COMPUTER. PLTS ALSO STATED THAT THE ACFT WAS SCHEDULED AS A QUICK TURN. AFTER FINISHING WITH PLT'S DEBRIEF; I STARTED CHKING NOSEWHEEL STEERING SWITCH POS AND RESETTING OF CIRCUIT BREAKERS IN HOPES OF GETTING THE NOSEWHEEL STEERING COMPUTER TO SHOW ANY FAULTS IT HAD LOGGED. AT THIS TIME THE SUPVR HAD LEFT THE ACFT AND THE OTHER TECHNICIAN WENT TO GET THE AMM AND FLT INFO MANUALS TO HELP TROUBLESHOOT. ONCE HE ARRIVED BACK TO ACFT; WE HAD SUCCESSFULLY DOWNLOADED SEVERAL FAULTS AND WERE CHKING THEM OUT IN THE FLT INFO MANUAL. SOMEWHERE IN THIS TIME PERIOD; THE LEAD HAD COME OUT TO ACFT. WE DECIDED TO PERFORM AN OPS CHK OF NOSEWHEEL STEERING. ANOTHER TECHNICIAN AND MYSELF TRIED TO USE THE NOSEWHEEL JACK TO PLACE THE SKID PLATE UNDER THE TIRES BUT THE JACK PLACEMENT PREVENTED CLRNC. THE OTHER TECHNICIAN THEN CALLED FOR RAMP PERSONNEL TO CLR ACFT OF BAGGAGE LOADER AND BAGGAGE CARTS AND TO TOW ACFT ONTO SKID PLATES. IT WAS DECIDED TO USE THE #2 ENG AS HYD PWR SOURCE TO PERFORM OPS CHK. RAMP HAD COME OUT AND MOVED BAGGAGE CARTS AND LOADER AS REQUESTED; BUT THEN LEFT WITH NO SIGNS OF TOW TEAM. I CALLED THE SUPVR THINKING HE WAS WORKING MAINT CTL THAT DAY; TO FIND OUT WHEN TOW TEAM WOULD BE AVAILABLE TO MOVE ACFT FOR US. THE SUPVR STATED TO HOLD ON AND CAME OUT TO ACFT. HE STATED TO ME IT WOULD BE FASTER TO JUST ROLL ACFT ONTO SKID PLATES ONCE I HAD THE #2 ENG STARTED; THEN TO WAIT FOR TOW TEAM. I ALREADY HAD THE ACFT READY TO START AND HAD PERFORMED MY PRE-ENG RUN SITUATIONAL AWARENESS MENTAL CHKLIST PRIOR TO THIS CHANGE IN PLANS. I FOLLOWED THE RUN/TAXI CHKLIST AND STARTED THE #2 ENG FOR GAIN #2 HYD PRESSURE OF OPS CHK. NOT RE-ACCOMPLISHING MY PRE-ENG RUN SITUATIONAL AWARENESS MENTAL CHKLIST AGAIN AFTER IT WAS DECIDED TO ROLL ACFT ONTO SKID PLATES; I FAILED TO RECOGNIZE THE NEED TO HAVE #1 HYD SYS PRESSURE FOR NORMAL BRAKES OR THE NEED TO HAVE A SECOND PERSON IN COCKPIT AS REQUIRED FOR ALL ACFT TAXIES. THE THOUGHT THAT THIS WAS AN ACFT TAXI MOVEMENT DID NOT OCCUR TO ANYONE AT THIS TIME. AT THE TIME OF ENG START; I HAD ANOTHER TECHNICIAN; THE LEAD; AND THE SUPVR AT NOSE OF THE ACFT. I VERIFIED I HAD GOOD #2 SYS HYD PRESSURE BUT OVERLOOKED ENSURING MY STANDBY HYD AND PTU SWITCHES WERE ON. THE OTHER TECHNICIAN MARSHALED ME FORWARD WHEN I THEN BROUGHT THE #2 CONDITION LEVER TO MINIMUM AND RELEASED PARKING BRAKES. THE ACFT FAILED TO MOVE FORWARD UNDER THIS PWR SETTING; SO I MOMENTARILY MOVED #2 PWR LEVER TO FLT MINIMUM UNTIL ACFT STARTED TO MOVE. THE NOSE IMMEDIATELY STARTED SLIDING TO THE L ONCE IT HIT THE GREASE PLATES. I BROUGHT THE #2 PWR LEVER BACK TO DISC AND APPLIED TOE BRAKES. GND CREW WERE SIGNALING ME TO STOP; BUT NORMAL BRAKING DID NOT OPERATE. I TOOK THE #2 PWR LEVER MOMENTARILY TO RESERVE; WHICH STOPPED FORWARD MOVEMENT AND THEN IT STARTED ROLLING FORWARD AGAIN. THE ONLY THING I COULD THINK TO DO WAS TO SHUT DOWN THE #2 ENG; WHICH I DID. I WAS STILL APPLYING TOE BRAKES WITHOUT SUCCESS BEFORE I FINALLY REALIZED TO USE THE PARKING BRAKE LEVER. AT THIS TIME I WAS UNAWARE THAT THE ACFT HAD CAME INTO CONTACT WITH ANYTHING UNTIL I DEPLANED. BY THE TIME I STOPPED THE ACFT I HAD ROLLED 33 FT; WEDGED #1 PROP BLADE AGAINST MAINT VAN; AND STRUCK A MAINT STAND WITH THE SPOOLING DOWN #2 ENG PROP. I PERFORMED POST ENG RUN SHUTDOWN PROCS AND ENSURED ACFT WAS CHOCKED. I THEN WENT TO THE OFFICE TO START RPTING PROCS.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.