20200530014451I

Pilot stated the aircraft was at Brown field for maintenance and he was there for after maintenance checks. After a brief external walk around the aircraft the pilot removed the chock that was around the left landing gear. Berfore starting the engines all systems including hadraulics where operating properly. Starting the right engine everything appeared to be normal except the oil pressure indication light was flickering. The gage was indicating movement between 40 and 55 PSI during the start sequence. As the start sequence continued the oil pressure stabilized and the engine showed normal operating parameters. He then let the right engine run for approximately one minute. Increasing throttle ¼? To an estimated 60% he turned on the overhead generator reset/on switch. He confirmed the load presence on the right amp meter and waited approximately one additional minute for the load on the battery to reduce before attempting a start on the left engine. He then began the process of starting the left engine. When the left engine was at 50% he noticed the aircraft was in motion and turning left. He pushed hard on the brake petals and simultaneously attepted to move the tiller lever. The pilot reported the aircraft steering and brakes where not effective. He also stated the pedals went to the floor and he could not move the tiller lever. At this time the right engine was making considerable more noise than the left engine and he pulled the engine controls to idle. The aircraft had traveled more than 80 feet turning 95 degrees to the left before impacting the left side of a parked V-22 osprey. Immediately after impact the pilot egressed the aircraft. The fire was extinguished by pilots and mechanics working in a nearby hangar.