News provided by Simple Flying – link to story. A hint from PH.
by Joanna Bailey, March 19, 2020
Two Air Canada aircraft were in a near-miss earlier this month, as both accelerated down the same runway at the same time. The aircraft involved were a Boeing 777-300 and an Embraer E190 trying to take off from Toronto Airport on the 7th March. Both aircraft aborted takeoff and successfully avoided collision; all passengers are reported to be safe.
On the 7th March this year, as reported in the Aviation Herald, two Air Canada aircraft experienced a hair raising near miss on the runway at Toronto’s Pearson airport. The two aircraft involved were a behemoth Boeing 777 and a much smaller Embraer ERJ-190.
The Embraer, registration C-FMZW, was performing flight number AC-1037, traveling from Toronto to Denver. It had 87 passengers and crew members on board, and had been cleared for takeoff using Toronto’s runway 06L. Visual departure procedures were in place, indicating that weather conditions and visibility was good on the day.Advertisement
The E190 began its takeoff roll. Immediately, air traffic control signaled the Boeing 777-300 following behind that it could taxi to position and hold at the entrance to runway 06L. The 777, registered C-FJZS, was headed for Halifax under flight number AC-606.Advertisement
The E190 was still performing its takeoff roll, when the tower gave the instruction to the crew of the 777 that they were cleared for takeoff.
In the moments following, a few incidents of serendipity caused the near-miss to occur on runway 06L. First, the E190 suffered a bird strike. Bird strikes are relatively common, but can be disastrous. Had the Embraer already begun to climb out of the airport at this point, it would likely have continued to climb and then requested to land again after.Advertisement
However, at this point the Embraer’s wheels were still on the runway. As such, the crew took the decision to reject takeoff. The AvHerald reports that the aircraft was traveling at 135 Knots-Indicated Air Speed (KIAS) at this time.
As is normal, the E190 crew radioed the tower to advise of the problem and to inform that they had rejected the takeoff. However, at precisely the same moment, the crew of the 777 radioed the tower too, to acknowledge their takeoff clearance prior to beginning their takeoff roll.
Whether this caused the two messages to the tower to block each other out is not yet known, but seems likely as the 777 then began its takeoff roll with no warning from the tower about the slowing E190 ahead. The 777 accelerated past 100 KIAS, and a collision appeared imminent.
As the Boeing reached around 110 KIAS, the crew noticed that the Embraer was still ahead of them on the runway. The crew reacted fast, rejecting takeoff and managing to stop just clear of the E190.
Both aircraft managed to clear the runway under their own steam, with no damage to either aircraft. The Boeing had to hold on a taxiway to cool its brakes for around 45 minutes. The E190 returned to the apron to have the bird strike damage inspected, and the 777 also returned to the apron, likely with a couple of pilots requiring a strong cup of tea!
How could this happen?
According to FAA rules on separation, takeoff clearance need not be withheld until separation is achieved if the controller anticipates the separation will exist when the following aircraft begins its takeoff roll. In fact, aircraft are allowed to begin their takeoff rolls when the forward plane is at least 6,000 feet down the runway (TOTH to captainzak for this info).
However, in this situation, it seems something went very wrong. Whether it was down to radio transmissions blocking each other out or some other form of communication breakdown, incidents like this just shouldn’t be able to happen.
The AvHerald reports that the Canadian Transport Safety Bureau (TSB) has opened a Class 3 investigation into the incident, to get to the bottom of how this could be allowed to happen. According to the TSB website, a Class 3 occurrence is one which,
“…may have significant consequences that attract a high level of public interest. It may involve multiple fatalities and/or serious injuries … It is quite likely that new safety lessons will be identified and that transportation safety will be advanced by reducing risks to persons, property, or the environment. A detailed investigation is required.”
Clearly, the Canadian TSB is taking the incident very seriously by classifying it as a Class 3 occurrence. We can expect to see a detailed investigation into the moments that led up to the near miss, and new protocols established at Toronto to protect future passengers and aircraft from encountering a similar problem.