Associated links (A16A0032)
Kathy Fox, TSB Chair
Montreal, Quebec
10 January 2018
Check against delivery.
Kathy Fox
Good morning. On March 29, 2016, a Mitsubishi MU-2 twin-engine turboprop aircraft crashed on approach to les Îles-de-la-Madeleine, Quebec, killing all seven people on board.
Following every accident, TSB investigators seek to answer the basic questions—what happened, and why. To do that, we need information. But too often we run into an old problem: there are no cockpit flight or data recorders—no "black boxes"—required on board. Information contained in these recording devices is especially important when there are no witnesses or survivors and wreckage is too damaged to be of assistance.
In this occurrence, the pilot had not only developed a lightweight recorder of sorts, but installed it on board the aircraft, even though it was not required by regulation. It was an initiative that proved invaluable, providing TSB investigators with cockpit audio along with acceleration and GPS data—in short, allowing us to piece together a detailed history of the flight.
Thanks to the onboard recording, we learned early in the investigation that a number of aircraft parameters during the approach were higher than recommended, which is indicative of an unstable approach that, in this occurrence, led to an aircraft upset.
Now, we will show you a brief animation of what happened. Although we've made the ground visible for viewer comprehension, the aircraft was in clouds during the approach.
Now you know what happened—the pilot continued an unstable approach and experienced an aircraft upset at an altitude too low to prevent impact with the ground.
The question is why?
The MU-2 is a high-performance aircraft, challenging to fly, especially at low speed, and particularly during sudden applications of engine power. This adds to the complexity of approach and landings—already a critical phase of flight due to the aircraft's proximity to the ground, the pilot's increased workload, and the need to manage an aircraft's speed, altitude and rate of descent during the approach.
Several key performance criteria were not stabilized throughout the approach. The pilot's workload was very high as he attempted to reduce his speed, altitude and rate of descent, complete the necessary checklists, and configure the aircraft for landing.
Throughout the approach, the pilot was juggling multiple tasks, reacting to the situation instead of controlling events in a more deliberate, measured manner. One option in such a circumstance is to conduct a "go-around"—abandoning the approach and climbing to a safe altitude to determine the next course of action.
However, with his situational awareness reduced by the high workload, the pilot would have been less likely to recognize the deteriorating circumstances and the need for a go-around. As a result, he continued with the unstable approach.
We want to make two points.
The first is about stable approaches. Regulators, operators, and aircraft manufacturers have defined stable-approach criteria, which pilots are trained to follow. Stable approaches make landings more consistent and predictable—giving pilots time to monitor key elements such as speed, altitude, rate of descent, and to complete checklists—thereby improving the likelihood of a safe landing. That's why it's so important for pilots to consider a go-around when an approach is unstable.
The second point we would like to make is about the recording device that the pilot had installed on board. Without it, we might never have learned what happened. Just as important, we wouldn't have been able to rule out other hypotheses that were considered during the course of the investigation—such as, for instance, an aircraft malfunction or possible icing on the wings.
And although the TSB does not endorse any single product, it would be fair to say that the lightweight recorder on this aircraft can be viewed as an indication of the way forward. However, under current regulations, even a high-performance, challenging aircraft like the MU-2 is not required to have an onboard flight data or cockpit voice recorder.
The benefits of lightweight recorders are obvious: knowing what happened is the first step to understanding why. With this information, the TSB was better able to determine why this accident happened. Furthermore, we can point out deficiencies and risks, and communicate them to industry, the regulator, and all Canadians.
As for unstable approaches, we've seen too many of these in the past lead to tragic accidents. That's why unstable approaches are on our Watchlist which identifies the key safety issues that need to be addressed to make Canada's transportation system even safer. And why we'll keep highlighting the risks when pilots continue an unstable approach to a landing.
Thank you.