Super King Air 350
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 110; Flight Crew Total 2750; Flight Crew Type 205
Situational Awareness
Conflict Ground Conflict; Critical; Conflict NMAC
Flight Crew Executed Go Around / Missed Approach; Flight Crew Took Evasive Action
Human Factors
We were cleared for a visual approach to 31. Entered left downwind to 31; on left base we were cleared to land. At 500 feet on final; I as the pilot monitoring; noticed a Cessna Skyhawk taxi onto the intersecting Runway 5. My first thought was maybe they were given a line up and wait Runway 5 but I never recalled hearing that instruction given from ATC. I advised the pilot flying of the Skyhawk on Runway 5. The Skyhawk entered Runway 5 and proceeded to add takeoff power and started rolling down the runway. At that point I queried ATC about the Skyhawk on the intersecting Runway and that we were short final 31; less than 200 feet. We started to execute a go-around when the tower also instructed us to go around. We passed above the Skyhawk. The Skyhawk did indeed takeoff from Runway 5. Luckily we caught glimpse of the Skyhawk entering the runway initially because from our viewpoint of final on 31 most of Runway 5 was blocked by tall trees. The Skyhawk disappeared during its takeoff roll and that's when I called for the go around. We didn't see the airplane again until we were executing a go around and the airplane was airborne and directly below us. This absolutely would have been a very close call had we landed on 31. A classic clear; VFR day.
BE350 FO reported executing a low altitude go-around at MMU when a light aircraft began takeoff roll on an intersecting runway.