The Flight
A Transport Canada Beechcraft King Air A100, serial number B-112, departed from Ottawa/McDonald-Cartier International Airport on a visual flight rules training flight. The two pilots proceeded to Ottawa/Gatineau Airport to conduct practice visual approaches and landings. At approximately 1430 eastern standard time, a visual circuit and approach to runway 27 was flown with the left engine at low power, simulating an engine failure. The landing gear was not lowered before landing, and the aft fuselage and both propellers contacted the runway surface. The captain initiated a go-around, declared an emergency, and subsequently landed at Ottawa/McDonald-Cartier International Airport. No injuries were reported. The aircraft was substantially damaged.
Circumstances
The flight was intended for recurrent training for the co-pilot, occupying the left seat as pilot flying, who was not current. The pilot-in-command, a Transport Canada training pilot, occupied the right seat. Following a touch-and-go landing on runway 27, the aircraft climbed through approximately 500 feet above ground level when the left throttle was retarded to simulate an engine failure. The landing gear warning horn sounded and was immediately silenced. Silencing the horn during flapless configurations with throttles retarded is normal to avoid distraction. The emergency checklist for engine failure (simulated) was completed. The PIC directed a flapless touch-and-go landing with simulated left engine failure; both engines were to be used for take-off. Neither pilot called for the Before Landing checklist, and neither noticed the gear was not lowered. Upon contact, the PIC advanced throttles and commanded a go-around. The aircraft traveled about 1400 feet along the runway before becoming airborne. Moderate airframe vibrations were apparent but controllable.
System Description
The King Air A100 is equipped with a landing gear warning system comprising a horn and a light in the gear handle. The horn sounds when either power lever is retarded below flight settings with gear not down and locked. It can be silenced by pressing the HORN SILENCE button when flaps are up, but the light remains on. The horn will reactivate if flaps are lowered or if the triggering power lever is advanced and then retarded again. The Pilot's Operating Manual does not clearly describe the system's behavior when power levers are sequentially retarded. Inspection after the event showed the gear system operated as designed. In daylight, the gear warning light may not attract a pilot's attention unless directly viewed.
Findings
The investigation identified that a simulated single-engine, flapless landing was conducted with the landing gear warning horn silenced. The standard operating procedures do not require a redundant check of landing gear status during single-engine approach and landing exercises. The crew forgot to complete the Before Landing check and did not lower the gear. With the horn disabled, no aural warning was present, though the gear warning light was likely illuminated.
Additional findings noted that the SOPs provide no specific guidance on when to complete the Single-Engine Approach and Landing checklist. The PIC had worked significant overtime in preceding months and had expressed concern about workload and fatigue, though the work schedule complied with regulatory limits. Fatigue analysis was inconclusive regarding chronic fatigue.