Training pilot ‘was unable to reach the fuel flow control lever’
The Transportation Safety Board of Canada (TSB) has concluded that a fatal helicopter training accident near Whitehorse, Yukon, resulted from a power recovery from autorotation that led to vortex ring state (VRS) at low altitude in a confined valley where wind direction could not be reliably observed, compounded by rapidly changing mountain winds and delayed emergency access.
In its air transportation safety investigation report A25W0045 – released on March 10, 2026 – the TSB found that a Horizon Helicopters Ltd. Aérospatiale AS350B (C‑GHZN) entered a fully developed VRS during a power recovery, likely in unrecognised tailwind conditions, and struck the ground before there was sufficient height to recover.
VRS occurs when a helicopter’s flight path, airspeed, and rate of descent (ROD) coincide with the helicopter’s downwash.
The training was being carried out in a remote dried lakebed valley east of Grey Mountain, about 5.5 nautical miles east‑southeast of Whitehorse/Erik Nielsen International Airport, where “there was little indication of wind direction, and the closest emergency services were at CYXY,” the report states.
The Board emphasises that the investigation was conducted “for the purpose of advancing transportation safety” and that “it is not the function of the Board to assign fault or determine civil or criminal liability.”
Training context and location
The accident occurred on May 2, 2025 during a company training flight in support of the operator’s Subpart 703 operation. On board were a contract training pilot, who was a Transport Canada‑approved check pilot, and a pilot candidate recently hired to become chief pilot. The candidate was fatally injured; the training pilot survived. The helicopter was destroyed.
The valley – a dried lakebed clear of trees and obstacles – was commonly used for training to avoid conflicts with other air traffic. However, the TSB notes that aircraft operating in mountainous regions can be exposed to “mechanical turbulence, and channelling, funnelling, converging, or diverging winds,” creating complex and shifting local wind patterns. In this case, the lack of clear wind indicators in the valley increased the risk that pilots would misjudge wind direction during critical low‑altitude manoeuvres.
According to the report, the flight departed Whitehorse at about 1400 local time. For roughly the first hour, the crew conducted normal approaches, confined‑area work, hydraulic and tail rotor emergency procedures, steep turns, hover exercises and autorotation training.
The final phase of the flight involved straight‑in and 180‑degree autorotations with power recoveries, flown in a southerly direction to align with what the pilots assessed as the prevailing wind.
The fifth and last autorotation, flown by the candidate, began from about 1500 feet above ground level. The helicopter was established in autorotation at roughly 60 knots indicated airspeed, with a rate of descent of about 1400 feet per minute. At around 100 feet AGL and 65 knots, the candidate initiated a flare to reduce airspeed and descent rate.
The TSB determined that as the helicopter reached approximately 70 feet AGL and 20 knots, “the ROD increased and the airspeed decreased further, to 0 KIAS, with no reduction in ground speed.” Neither pilot realised the wind had shifted by roughly 180 degrees, effectively placing the helicopter in a tailwind during the power recovery.
The helicopter then descended into its own downwash and entered a fully developed VRS. The training pilot took control and attempted to gain forward airspeed, but with the aircraft already close to the ground there was insufficient altitude to recover. At about 1510, the helicopter collided with the terrain.
Impact sequence and safety response
On initial impact, the skid gear spread and the tail rotor struck the ground, rendering it ineffective. The helicopter bounced and became briefly airborne before beginning to descend again. As collective pitch was increased to arrest the descent, the helicopter began rotating to the left because of the loss of tail rotor authority.
The TSB report notes that the training pilot “was unable to reach the fuel flow control lever located on the floor between the front seats due to centrifugal forces,” limiting his ability to shut off fuel and reduce rotor energy while the helicopter was spinning.
The helicopter struck the ground a second time while still rotating, then skidded until the left cross tube caught and broke, causing the aircraft to roll onto its left side. As it rolled, “at least one of the main rotor blades entered the cabin over the front seats and struck the candidate,” resulting in fatal injuries. The training pilot survived, shut down the engine with the power lever once rotation stopped and exited the helicopter.
The emergency locator transmitter activated automatically, and the Joint Rescue Coordination Centre in Victoria, British Columbia, received the signal at 1516. The first emergency response helicopter arrived at 1541.
In its safety messages, the TSB warns that “when conducting power recoveries after an autorotation, pilots should be aware that there is a risk of the helicopter entering VRS, which increases in tailwind conditions.”
It states that autorotation training should be conducted where wind direction and velocity “are easily observed, such as an airport.”
On May 9, 2025, Horizon Helicopters adopted a policy that emergency training “will be conducted at an airport with suitable facilities to report or indicate wind direction and speed.”
