Narrative:

After deplaning the passenger and their baggage, the door was closed and the right engine was restarted to taxi the aircraft to another location on the ramp. The ramp is part of the cessna factory and is not under control by ict ground. My intent was to park the aircraft with the left wingtip about 15-20 ft from the hangar door in order to facilitate unloading the rest of the baggage. As I approached my turn point, I applied right brake to pivot the aircraft the brake pedal was stiff and the aircraft did not turn. Confused initially, I incorrectly assumed the pedal was jammed and the steering was inoperative. At that point I applied the brakes but realized that both brake pedals were 'hard.' when I realized that the aircraft would not stop I was only a few ft from the hangar. The aircraft's left wing struck a small tree and then the left wing hit the corner of the hangar while the nose struck the hangar door. I shut down the right engine as the aircraft impacted the hangar and the crew egressed the aircraft. Factors contributing to this incident included the decision to park adjacent to the hangar, the relative lack of turning capability of this type without differential braking, my initial confusion regarding the nature of the malfunction, my inability to react and use the emergency pneumatic brake in a timely manner. My performance was degraded by my incorrect assessment of the malfunction and the lack of available time to sort things out. Callback conversation with reporter revealed the following information: cessna engineering investigated the problem. Nothing definite was found to positively point to the failure mode. There was a squat switch miscompare message in the maintenance computer, however, that alone should not have caused the problem. Each main gear strut has a squat switch, and when they disagree the miscompare message is generated. The cessna flight manual calls for the antiskid to be left on all the time. Locked wheel protection will not allow aircraft brake application when the aircraft thinks it is in-flight. Somehow the antiskid system locked out the brakes on the ground. The pilot reports that this has happened to another pilot in his company's operations. Also the same system is installed on several other models of cessna aircraft. There have been other problems with these models. The pilot is concerned that cessna is not taking this problem seriously enough. They appear to have a very low level effort to find the problem.

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Original NASA ASRS Text

Title: C550 CREW HIT A HANGAR WHEN THEIR ANTISKID SYS LOCKED OUT THE BRAKES ON THE GND.

Narrative: AFTER DEPLANING THE PAX AND THEIR BAGGAGE, THE DOOR WAS CLOSED AND THE R ENG WAS RESTARTED TO TAXI THE ACFT TO ANOTHER LOCATION ON THE RAMP. THE RAMP IS PART OF THE CESSNA FACTORY AND IS NOT UNDER CTL BY ICT GND. MY INTENT WAS TO PARK THE ACFT WITH THE L WINGTIP ABOUT 15-20 FT FROM THE HANGAR DOOR IN ORDER TO FACILITATE UNLOADING THE REST OF THE BAGGAGE. AS I APCHED MY TURN POINT, I APPLIED R BRAKE TO PIVOT THE ACFT THE BRAKE PEDAL WAS STIFF AND THE ACFT DID NOT TURN. CONFUSED INITIALLY, I INCORRECTLY ASSUMED THE PEDAL WAS JAMMED AND THE STEERING WAS INOP. AT THAT POINT I APPLIED THE BRAKES BUT REALIZED THAT BOTH BRAKE PEDALS WERE 'HARD.' WHEN I REALIZED THAT THE ACFT WOULD NOT STOP I WAS ONLY A FEW FT FROM THE HANGAR. THE ACFT'S L WING STRUCK A SMALL TREE AND THEN THE L WING HIT THE CORNER OF THE HANGAR WHILE THE NOSE STRUCK THE HANGAR DOOR. I SHUT DOWN THE R ENG AS THE ACFT IMPACTED THE HANGAR AND THE CREW EGRESSED THE ACFT. FACTORS CONTRIBUTING TO THIS INCIDENT INCLUDED THE DECISION TO PARK ADJACENT TO THE HANGAR, THE RELATIVE LACK OF TURNING CAPABILITY OF THIS TYPE WITHOUT DIFFERENTIAL BRAKING, MY INITIAL CONFUSION REGARDING THE NATURE OF THE MALFUNCTION, MY INABILITY TO REACT AND USE THE EMER PNEUMATIC BRAKE IN A TIMELY MANNER. MY PERFORMANCE WAS DEGRADED BY MY INCORRECT ASSESSMENT OF THE MALFUNCTION AND THE LACK OF AVAILABLE TIME TO SORT THINGS OUT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CESSNA ENGINEERING INVESTIGATED THE PROB. NOTHING DEFINITE WAS FOUND TO POSITIVELY POINT TO THE FAILURE MODE. THERE WAS A SQUAT SWITCH MISCOMPARE MESSAGE IN THE MAINT COMPUTER, HOWEVER, THAT ALONE SHOULD NOT HAVE CAUSED THE PROB. EACH MAIN GEAR STRUT HAS A SQUAT SWITCH, AND WHEN THEY DISAGREE THE MISCOMPARE MESSAGE IS GENERATED. THE CESSNA FLT MANUAL CALLS FOR THE ANTISKID TO BE LEFT ON ALL THE TIME. LOCKED WHEEL PROTECTION WILL NOT ALLOW ACFT BRAKE APPLICATION WHEN THE ACFT THINKS IT IS INFLT. SOMEHOW THE ANTISKID SYS LOCKED OUT THE BRAKES ON THE GND. THE PLT RPTS THAT THIS HAS HAPPENED TO ANOTHER PLT IN HIS COMPANY'S OPS. ALSO THE SAME SYS IS INSTALLED ON SEVERAL OTHER MODELS OF CESSNA ACFT. THERE HAVE BEEN OTHER PROBS WITH THESE MODELS. THE PLT IS CONCERNED THAT CESSNA IS NOT TAKING THIS PROB SERIOUSLY ENOUGH. THEY APPEAR TO HAVE A VERY LOW LEVEL EFFORT TO FIND THE PROB.

Data retrieved from NASA's ASRS site as of July 2007 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.