Beech 1900
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Aircraft Equipment Problem Less Severe; Ground Event / Encounter Loss Of Aircraft Control
Aircraft Aircraft Damaged; General Maintenance Action
Aircraft
On landing rollout on Runway XX in ZZZ; the aircraft began to hop and chirp and became directionally unstable; with an increasing deceleration rate. I was instructing a Captain student; who performed a decent landing with no potential for aircraft damage in normal circumstances. I told the student to get off the brakes thinking he was locking them up; to which he replied that he was not applying any brake. I verified this and realized there was a problem. The aircraft remained on centerline and came to a stop. We could not move the aircraft even with application of large amounts of power to clear the runway. I exited the aircraft after informing ATC of the situation and obtaining permission to do so. Once outside I found that the scissor link on the right main had come apart; but with no pieces broken. The gear was inspected in preflight and between legs with no damage found. When the scissor link came apart; one half of it lodged in the main tire; causing it to lock up and turn completely sideways. Thorough inspection of nose gear on preflight.
Beech 1900 Captain reported right main landing gear locked up on landing.