Narrative:

I was flying a metropolitan III (SA227) type aircraft for a small scheduled commuter airline. This particular type aircraft is known for problems with uncommanded nosewheel steering. The particular aircraft in this instance was written up by the previous captain for abnormal nosewheel steering indications on the aircraft annunciator panel (flashing nosewheel steering green light) which indicates a difference of 3 degrees or more between the rudder pedals and the nose gear. Maintenance had worked on the aircraft all day and signed off the aircraft along with 2 other unrelated write-ups. They also did a ground operations check of the nosewheel steering system, which was normal. I accepted the aircraft with discrepancies resolved by maintenance and also accomplished first flight of the day checks, including a nosewheel steering test. All tests had normal indications. We taxied the aircraft for takeoff at billings, mt, for a trip to lewistown, mt, and then scheduled to proceed on to havre, mt. The taxi and takeoff at billings was normal and uneventful. The landing and taxi in and out at lewistown was also normal. It had been snowing significantly at lewistown and there were taxiway closures which required a back taxi and a 180 degree turn at the end of runway 25. The runway was plowed and snow covered with 3 - 3 1/2 inches in ht hard packed snow berms on both sides of the runway 8-10 ft inside of the runway edge lights. As I began the takeoff, I held the brakes through 25-30% torque to insure the aircraft was off the start locks. I released the brakes after sufficient torque rise and began the takeoff roll. The aircraft initially began to drift to the right slowly and then at an increased rate. I opposed the turning tendency with left rudder which had no affect on directional control. I then immediately put the engines in full reverse to abort the takeoff, but was unable to stop the aircraft before impacting the snow berm on the right side of the runway with the #2 engine. The impact caused extensive damage to the propeller and engine. My first officer reported to me that he last saw both engines torque climbing through 40% with no rise in the airspeed indicator shortly before the aborted takeoff was initiated. In my opinion this, by all indications -- ie, tests normal, 180 degree turn, normal taxi, torque rise, past 20% on both engines, demonstrates a poorly designed steering system. There are very few aircraft that require a hydraulic nosewheel steering system for the initiation and commencement of a takeoff roll. This aircraft system requires several inputs to activate normally and with its reputation as an aircraft that can easily run off the runway, I believe this system needs to be seriously scrutinized. This is the third incident within a yr that the company has had an aircraft divert off the runway. My first officer had 350 hours in type and has witnessed several similar close calls. Unfortunately for us both, this was not a close call but an incident. Callback conversation with reporter revealed the following information: pilot stated that his air carrier has had 3 off runway incidents in the past yr, and another air carrier has had 27 incidents due to steering problems. The pilot thinks the nosewheel steering system is overly complex. He thinks it would make rube goldberg proud. The system has an on/off switch, 2 warning lights, a power lever cutout switch, and a power lever cutout switch override. Needless to say it is complex and doesn't work very well. The captain stated that his aircraft had a previous discrepancy reported. After the aircraft was returned to service there were 3 more incidents on this same aircraft. All steering components were replaced and the aircraft has had no further problems.

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Original NASA ASRS Text

Title: SA227 CREW HAD RWY EXCURSION ON TKOF ROLL.

Narrative: I WAS FLYING A METRO III (SA227) TYPE ACFT FOR A SMALL SCHEDULED COMMUTER AIRLINE. THIS PARTICULAR TYPE ACFT IS KNOWN FOR PROBS WITH UNCOMMANDED NOSEWHEEL STEERING. THE PARTICULAR ACFT IN THIS INSTANCE WAS WRITTEN UP BY THE PREVIOUS CAPT FOR ABNORMAL NOSEWHEEL STEERING INDICATIONS ON THE ACFT ANNUNCIATOR PANEL (FLASHING NOSEWHEEL STEERING GREEN LIGHT) WHICH INDICATES A DIFFERENCE OF 3 DEGS OR MORE BTWN THE RUDDER PEDALS AND THE NOSE GEAR. MAINT HAD WORKED ON THE ACFT ALL DAY AND SIGNED OFF THE ACFT ALONG WITH 2 OTHER UNRELATED WRITE-UPS. THEY ALSO DID A GND OPS CHK OF THE NOSEWHEEL STEERING SYS, WHICH WAS NORMAL. I ACCEPTED THE ACFT WITH DISCREPANCIES RESOLVED BY MAINT AND ALSO ACCOMPLISHED FIRST FLT OF THE DAY CHKS, INCLUDING A NOSEWHEEL STEERING TEST. ALL TESTS HAD NORMAL INDICATIONS. WE TAXIED THE ACFT FOR TKOF AT BILLINGS, MT, FOR A TRIP TO LEWISTOWN, MT, AND THEN SCHEDULED TO PROCEED ON TO HAVRE, MT. THE TAXI AND TKOF AT BILLINGS WAS NORMAL AND UNEVENTFUL. THE LNDG AND TAXI IN AND OUT AT LEWISTOWN WAS ALSO NORMAL. IT HAD BEEN SNOWING SIGNIFICANTLY AT LEWISTOWN AND THERE WERE TXWY CLOSURES WHICH REQUIRED A BACK TAXI AND A 180 DEG TURN AT THE END OF RWY 25. THE RWY WAS PLOWED AND SNOW COVERED WITH 3 - 3 1/2 INCHES IN HT HARD PACKED SNOW BERMS ON BOTH SIDES OF THE RWY 8-10 FT INSIDE OF THE RWY EDGE LIGHTS. AS I BEGAN THE TKOF, I HELD THE BRAKES THROUGH 25-30% TORQUE TO INSURE THE ACFT WAS OFF THE START LOCKS. I RELEASED THE BRAKES AFTER SUFFICIENT TORQUE RISE AND BEGAN THE TKOF ROLL. THE ACFT INITIALLY BEGAN TO DRIFT TO THE R SLOWLY AND THEN AT AN INCREASED RATE. I OPPOSED THE TURNING TENDENCY WITH L RUDDER WHICH HAD NO AFFECT ON DIRECTIONAL CTL. I THEN IMMEDIATELY PUT THE ENGS IN FULL REVERSE TO ABORT THE TKOF, BUT WAS UNABLE TO STOP THE ACFT BEFORE IMPACTING THE SNOW BERM ON THE R SIDE OF THE RWY WITH THE #2 ENG. THE IMPACT CAUSED EXTENSIVE DAMAGE TO THE PROP AND ENG. MY FO RPTED TO ME THAT HE LAST SAW BOTH ENGS TORQUE CLBING THROUGH 40% WITH NO RISE IN THE AIRSPD INDICATOR SHORTLY BEFORE THE ABORTED TKOF WAS INITIATED. IN MY OPINION THIS, BY ALL INDICATIONS -- IE, TESTS NORMAL, 180 DEG TURN, NORMAL TAXI, TORQUE RISE, PAST 20% ON BOTH ENGS, DEMONSTRATES A POORLY DESIGNED STEERING SYS. THERE ARE VERY FEW ACFT THAT REQUIRE A HYD NOSEWHEEL STEERING SYS FOR THE INITIATION AND COMMENCEMENT OF A TKOF ROLL. THIS ACFT SYS REQUIRES SEVERAL INPUTS TO ACTIVATE NORMALLY AND WITH ITS REPUTATION AS AN ACFT THAT CAN EASILY RUN OFF THE RWY, I BELIEVE THIS SYS NEEDS TO BE SERIOUSLY SCRUTINIZED. THIS IS THE THIRD INCIDENT WITHIN A YR THAT THE COMPANY HAS HAD AN ACFT DIVERT OFF THE RWY. MY FO HAD 350 HRS IN TYPE AND HAS WITNESSED SEVERAL SIMILAR CLOSE CALLS. UNFORTUNATELY FOR US BOTH, THIS WAS NOT A CLOSE CALL BUT AN INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: PLT STATED THAT HIS ACR HAS HAD 3 OFF RWY INCIDENTS IN THE PAST YR, AND ANOTHER ACR HAS HAD 27 INCIDENTS DUE TO STEERING PROBS. THE PLT THINKS THE NOSEWHEEL STEERING SYS IS OVERLY COMPLEX. HE THINKS IT WOULD MAKE RUBE GOLDBERG PROUD. THE SYS HAS AN ON/OFF SWITCH, 2 WARNING LIGHTS, A PWR LEVER CUTOUT SWITCH, AND A PWR LEVER CUTOUT SWITCH OVERRIDE. NEEDLESS TO SAY IT IS COMPLEX AND DOESN'T WORK VERY WELL. THE CAPT STATED THAT HIS ACFT HAD A PREVIOUS DISCREPANCY RPTED. AFTER THE ACFT WAS RETURNED TO SVC THERE WERE 3 MORE INCIDENTS ON THIS SAME ACFT. ALL STEERING COMPONENTS WERE REPLACED AND THE ACFT HAS HAD NO FURTHER PROBS.

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.