Incident Overview
Witnesses at the airport observed an airplane entering the traffic pattern for touch-and-go landings on runway 28. They reported that the airplane landed hard, porpoised three or four times, and then departed the right side of the runway.
Pilot Reports
According to the pilot-in-command (PIC), the pilot-rated passenger in the right seat, who was reported to hold an airline transport rating, applied full power after announcing "let's go around." The PIC stated that the power in the right engine "was slow to develop, which instantly skewed the airplane off the runway."
As the airplane reached about 5 feet above the ground, the PIC said he "reduced the power to the good engine." The airspeed was at or near VMC, and the PIC added that "the airplane started to roll and directional control was not possible." He then reported that he "pulled both engines back and flared."
Recommendation
In the recommendation block of a Pilot/Operator Report, the PIC recommended "not attempting [a] full throttle go-around until both engines are confirmed operational, or far above VMC."
Analysis
The event involved a hard landing followed by a go-around attempt where differential engine thrust led to a loss of control and a runway excursion. No further details were provided in the source.