The Toronto runway flip is one of those accidents that forces pilots to look hard at the intersection of energy management and structure. The Transportation Safety Board’s preliminary data show a classic chain: a gust-influenced approach, an increasing sink rate with an EGPWS sink-rate alert, a high energy touchdown well above the landing gear’s intended absorption capacity, structural failure of the right main gear attachment, and then rapid breakup and fire when the right wing separated. Those facts matter because they let us trace cause and effect in technical and operational terms rather than speculation.

What the record shows about the approach. The crew set the speed bug and approach speeds consistent with company procedures for gusty conditions, but data capture shows considerable variation in energy in the last 5 seconds. At about 50 feet AGL the airplane was near 145 kt and descending at roughly 1,100 feet per minute. Two and a half seconds before touchdown the enhanced ground proximity warning system issued a “sink rate” alert and that sink rate remained in excess of 1,000 fpm until impact. The aircraft contacted the runway in a slight right bank with vertical acceleration recorded at about 3 g and a touchdown vertical velocity around 18.3 ft/s, roughly 1,100 fpm. Those are hard numbers you do not want at touchdown.

Why that profile stresses the landing gear. Landing gear and supporting structure are designed to absorb a defined impact energy. Reports summarized by investigators point out that the design absorption capability for the gear was about 12 ft/s. When the airplane touched down at roughly 18.3 ft/s, the vertical energy exceeded the design absorption by a significant margin. The result was the fracture of the side-stay on the right main landing gear, the gear folding, and the right wing fracturing at its root. In plain terms, the gear was asked to absorb more energy than it was built to handle and the load path failed.

How asymmetric loading becomes an inversion hazard. With the right wing and its MLG compromised and the left wing still producing lift, the aircraft developed a strong roll moment. The detached right wing also released fuel and allowed a rapid progression to fire and structural breakup. The intact left wing continued to produce lift as the fuselage tumbled, which explains the violent rolling and eventual inversion seen on video. Those dynamics are textbook physics applied to a damaged, asymmetric airframe.

Operational signals pilots should take away. The final seconds in this flight show a sequence we practice against: unstable energy, an aural sink-rate alert, and a crosswind/gust environment. If the approach is not stabilized by a defined gate, or if an immediate recovery action is required to arrest a significant sink rate, go around. A few practical reminders:

  • Stabilized approach criteria matter. If airspeed, rate of descent, or bank are outside limits inside the gate, execute a go-around early. You have far more options above the runway than at the moment the wheels touch.
  • Respect the EGPWS sink-rate alert. It is a short fuse. If you get the alert low on final, increase power and pitch to arrest the descent or go around. Delays of two to three seconds are what separate a recoverable bounce from an overload.
  • In gusty conditions monitor your gust-corrected Vref and consider an extra margin of speed. The crew had increased the bug in line with procedure, but energy can still change rapidly when a gust ends and you reduce power. Anticipate gust dynamics rather than react after the fact.
  • When flying regional types with relatively light structure and limited wing-fuselage margins, be conservative on touchdown energy. Design limits for shock absorption are not generous compared to larger narrowbodies.

What investigators and operators will look at next. The TSB has emphasized that fractography and lab examination are needed to determine why the side-stay fractured and whether there were any pre-existing defects, maintenance issues, or design margins that contributed. Those forensic steps are non-trivial and necessary before assigning root cause beyond the energetic sequence captured by the FDR. Meanwhile, operators will be focused on training, stabilized approach enforcement, simulator scenarios that replicate gust-induced sink near the runway, and procedural emphasis on prompt go-arounds.

Crew resource management and decision bias. From a pilot perspective the human factors are as important as the physics. An approach flown to remain precisely on the centreline in gusty wind can bias a crew against going around when the airplane starts to sink. Reinforcing callouts, threshold gate discipline, and an unambiguous command hierarchy for the go-around call will reduce the chance that desire to land overrides objective energy criteria. Simulated practice of recovering from sudden airspeed loss at 150 to 60 feet will build the reflexes needed to restore energy or abandon the landing. Lessons here are procedural, not proprietary.

Final note on survivability. Despite the dramatic airframe breakup and inversion, all 80 occupants evacuated and the injury count, while significant, was far lower than the worst-case outcome. Seat belts and evacuation procedures work when crews and passengers can apply them and act quickly. The accident is painful evidence that prevention of overloads on touchdown is both a structural safety issue and a human factors problem. The technical details now in the hands of the TSB will inform whether this is primarily an operational failure, a maintenance or structural issue, or a complex mix of causes. Until the final report is published we should treat the sequence described by the preliminary data as a sober operational lesson about energy control, go-around discipline, and respect for structural limits.