What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On March 16, 2025, at 1425 MDT, a Beech C90A, suffered a left main landing gear collapse during the landing rollout at Helena Regional Airport, Helena, Montana, while on an evaluation flight (check-ride) for the PIC. The investigation found that both main landing gear wiring harnesses were routed and clamped incorrectly per the king air 90 series maintenance manual (rev D3). This caused the clamps to contact the gear up-position switch bracket each time the gear was retracted. It appears that on March 16, 2025, the left main gear up-position switch bracket broke at the mounting surface. This allowed the wiring harness to tangle in the landing gear. When the gear extended multiple wires in the harness were broken causing electric shorts leading to tripped circuit breakers and incorrect operation of the landing gear system. Both pilots stated that they cycled the gear three times and did not receive a nose gear down indication once and left main down twice. On the third gear down cycle there was no gear down and locked indication for the left main. They did not receive an unsafe landing gear warning horn or the landing gear handle unlocked/in-transit lights. The PIC requested a low pass of the Helena Montana tower and air traffic control personnel reported that the gear appeared to be down. Both pilots stated that they did not execute the manual extension checklist as they believed it was an indicating system problem. They proceeded to land with a left main unsafe gear condition. While turning left onto a taxiway at the end of the landing rollout the left main collapsed. The aircraft was substantially damaged, and the check airman and examinee pilot were not injured. The aircraft was blocking runway 27 so it was moved to a hangar on the south end of the airport. During recovery operations a mechanic performed the manual extension procedure and received a cockpit annunciator down and locked gear indication for the nose and both main landing gear. The flight originated at Helena, Montana, on March 16, 2025, at 1231 MDT.
As the FAA filed it
ON MARCH 16, 2025, AT 1425 MDT, A BEECH C90A, SUFFERED A LEFT MAIN LANDING GEAR COLLAPSE DURING THE LANDING ROLLOUT AT HELENA REGIONAL AIRPORT, HELENA, MONTANA, WHILE ON AN EVALUATION FLIGHT (CHECK-RIDE) FOR THE PIC. THE INVESTIGATION FOUND THAT BOTH MAIN LANDING GEAR WIRING HARNESSES WERE ROUTED AND CLAMPED INCORRECTLY PER THE KING AIR 90 SERIES MAINTENANCE MANUAL (REV D3). THIS CAUSED THE CLAMPS TO CONTACT THE GEAR UP-POSITION SWITCH BRACKET EACH TIME THE GEAR WAS RETRACTED. IT APPEARS THAT ON MARCH 16, 2025, THE LEFT MAIN GEAR UP-POSITION SWITCH BRACKET BROKE AT THE MOUNTING SURFACE. THIS ALLOWED THE WIRING HARNESS TO TANGLE IN THE LANDING GEAR. WHEN THE GEAR EXTENDED MULTIPLE WIRES IN THE HARNESS WERE BROKEN CAUSING ELECTRIC SHORTS LEADING TO TRIPPED CIRCUIT BREAKERS AND INCORRECT OPERATION OF THE LANDING GEAR SYSTEM. BOTH PILOTS STATED THAT THEY CYCLED THE GEAR THREE TIMES AND DID NOT RECEIVE A NOSE GEAR DOWN INDICATION ONCE AND LEFT MAIN DOWN TWICE. ON THE THIRD GEAR DOWN CYCLE THERE WAS NO GEAR DOWN AND LOCKED INDICATION FOR THE LEFT MAIN. THEY DID NOT RECEIVE AN UNSAFE LANDING GEAR WARNING HORN OR THE LANDING GEAR HANDLE UNLOCKED/IN-TRANSIT LIGHTS. THE PIC REQUESTED A LOW PASS OF THE HELENA MONTANA TOWER AND AIR TRAFFIC CONTROL PERSONNEL REPORTED THAT THE GEAR APPEARED TO BE DOWN. BOTH PILOTS STATED THAT THEY DID NOT EXECUTE THE MANUAL EXTENSION CHECKLIST AS THEY BELIEVED IT WAS AN INDICATING SYSTEM PROBLEM. THEY PROCEEDED TO LAND WITH A LEFT MAIN UNSAFE GEAR CONDITION. WHILE TURNING LEFT ONTO A TAXIWAY AT THE END OF THE LANDING ROLLOUT THE LEFT MAIN COLLAPSED. THE AIRCRAFT WAS SUBSTANTIALLY DAMAGED, AND THE CHECK AIRMAN AND EXAMINEE PILOT WERE NOT INJURED. THE AIRCRAFT WAS BLOCKING RUNWAY 27 SO IT WAS MOVED TO A HANGAR ON THE SOUTH END OF THE AIRPORT. DURING RECOVERY OPERATIONS A MECHANIC PERFORMED THE MANUAL EXTENSION PROCEDURE AND RECEIVED A COCKPIT ANNUNCIATOR DOWN AND LOCKED GEAR INDICATION FOR THE NOSE AND BOTH MAIN LANDING GEAR. THE FLIGHT ORIGINATED AT HELENA, MONTANA, ON MARCH 16, 2025, AT 1231 MDT.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.