Gulfstream 100 Runway Excursion at Hamilton Airport

Flight Overview and Approach Details On the day of the occurrence, a Gulfstream 100, registration C-FHRL and serial number 150, operated by Jetport Inc., was conducting an instrument flight rules (IFR) charter flight from West Palm Beach, Florida, to Hamilton, Ontario. The aircraft was crewed by two pilots, with the co-pilot seated in the left seat acting as the pilot flying (PF). The flight was the final leg of a charter operation that included a stop at Toronto/Lester B. Pearson International Airport to pick up two passengers. As the aircraft approached Hamilton Airport, the crew received radar vectors from the Toronto Area Control Centre and was cleared for the instrument landing system (ILS) approach to Runway 12. The approach was conducted at night in instrument meteorological conditions, with the aircraft encountering heavy precipitation and turbulence. The crew added 10 knots to the calculated landing reference speed (Vref) of 125 knots, conducting the approach at 135 knots indicated airspeed. The runway environment was acquired visually before reaching the decision height, and the PF disengaged the autopilot to continue the approach. ## Runway Excursion and Damage The aircraft touched down on the wet runway at approximately 1902 eastern standard time with about 3,000 feet of runway remaining. The flight crew utilized all available braking systems, including aircraft brakes, spoilers, and thrust reversers, to slow the aircraft. However, the aircraft ran off the end of the runway and traveled 122 feet downslope before coming to an abrupt stop when the nosewheel sheared off. The aircraft sustained substantial damage, including the sheared nose landing gear, the right main landing gear striking two steel survey stakes, and the right wing striking an aerodrome lighting standard and terrain. Neither flight crew member was injured during the incident. The emergency locator transmitter activated, and aircraft rescue and firefighting teams responded to the scene. ## Contributing Factors and Investigation Findings The investigation identified several factors that likely contributed to the runway excursion and subsequent hydroplaning. These included a touchdown speed higher than Vref, slow deployment of the thrust reversers, standing water at the intersection of the runways, friction values at the runway ends at or below the Transport Canada runway maintenance planning level, and limited tire tread depth. Radar data indicated that the aircraft's speed did not decrease below 130 knots until it was entering the intersection of the runways. Tire marks on the runway surface showed that the aircraft crossed the centerline from left to right and yawed to the left as it exited the paved surface. Investigators observed reverted rubber on both left main gear tires, indicating hydroplaning. ## Aircraft and Personnel Information The aircraft was certified, equipped, and maintained in accordance with existing regulations, with no indication of airframe failure or system malfunction. The landing weight was 18,250 pounds, and the unfactored landing distance on a wet runway was determined to be about 3,200 feet. The aircraft was equipped with a cockpit voice recorder but not a flight data recorder, which was not required by regulation. The pilot-in-command had 3,600 flying hours, including 600 hours on the aircraft type, and was seated in the right seat as the pilot not flying (PNF). The co-pilot had 5,600 flying hours, including 14 hours on type, and was acting as the PF for the first time on this aircraft type. Both pilots were certified and qualified for the flight in accordance with existing regulations.