A Pilatus PC-12 and Hawker 1000 bizjet were involved in a bizarre ground incident at Long Island MacArthur Airport back in the first week of February, and now we know a little more about what happened, courtesy of the NTSB. While the Agency’s final report is probably still 10 months away and data from the PC-12’s “lightweight combination voice and flight data recorder” must still be analyzed for any conclusions about probable cause, this week’s report sheds light on the pilot’s perspective as things got out of hand.
Video clearly showed the eight-year-old Pilatus, with PIC and pilot-rated passenger aboard, lurch from its parking spot at the northernmost end of the airport ramp and strike a parked Hawker jet with enough force to shear the right wing from the Pilatus, not to mention about half of the jet’s right wing. Thankfully, there were no fire or injuries.
The preliminary report states, in part, “While pushing on the toe brakes [the pilot] pushed the starter switch and verified that the oil pressure was rising, and the compressor turbine (Ng) had increased to 13%. At 13%, he noted the temperature of the engine oil, and moved the condition lever to flight idle per the checklist. He observed the Ng increase to 40% and felt the airplane ’lurching forward.’ He pressed harder on the toe brakes, but the airplane continued forward, while the engine spooled up.”
It’s common to see Ng speed exceed 50% during PT6 engine start procedures, so the 40% figure in the pilot’s statement doesn’t give us a clue as to why the airplane ran away. Investigators obviously will consider multiple possibilities including the mechanical state of the propeller governor and power controls, recent maintenance history, and weather conditions including potential snow and ice contamination of the parking surface. We’ll keep you posted in future updates.
