Near mid-air collision of planes over Sudbury sparks probe
Porter, Jazz aircraft within 1,200 metres of each other
OTTAWA— Federal investigators have launched a formal probe after a “risk of collision” between two commuter aircraft at a Sudbury, Ont., airport.
The close call between the Porter Airlines and Jazz Aviation aircraft, both Q400 turboprops, triggered alerts by collision avoidance equipment in each plane, showing the pilots how best to take evasive action.
Now the Transportation Safety Board of Canada (TSB) has launched an investigation into the Oct. 14 incident that saw the aircraft pass less than a kilometre from each other, both at an altitude of about 1,200 metres.
It’s too soon to say whether there was a true risk of a collision, said Ken Webster, a senior regional investigator with the safety board.
But, Webster said, that distance “is certainly closer than anyone would like to be at with those two types of aircraft.”
Webster said they were notified about the “risk of collision” by Nav Canada, the independent agency that provides air traffic control services.
The Porter flight was inbound to Sudbury from Toronto’s Billy Bishop airport and the Jazz Aviation Q400 had just departed for Toronto’s Pearson International Airport.
As the two aircraft approached, the traffic alert and collision avoidance system in each plane sounded cockpit warnings.
Their proximity then triggered “resolution advisories,” guidance to each flight crew whether to climb, descend or remain level to avoid the other plane.
Sudbury airport does not have a control tower; it’s served instead by a flight service station which provides an advisory service to aircraft in the area.
However, that type of service can restrict arrivals and departures by aircraft flying under what is known as instrument flight rules, as commercial aircraft typically do.
To help avoid delays, in good weather an aircraft can depart under visual flight rules (VFR) and pick up a clearance once airborne. That’s what happened in this case.
The normal separation standards for aircraft operating under instrument flight rules are 300 metres vertically and at least 5.5 kilometres horizontally, said Michelle Bishop, a spokesperson for Nav Canada.
However, because the Jazz aircraft had departed under visual rules, separation was based on “see and avoid” rather than set distances, she said.
“When one aircraft is VFR, our role is to provide traffic advisory service to aid pilot situational awareness of other aircraft in their vicinity and conflict resolution where required,” Bishop said.
The cloud layer was at about 1,500 metres at the time with good visibility below that. Webster could not say whether the planes were in visual contact.
In several accident reports — most recently in its investigation of a fatal mid-air collision in 2015 — the safety board has warned of the “inherent limitations” in trying to visually spot and avoid other aircraft.
As a result, it has underscored the need for technology, such as the collision avoidance equipment that may have helped in this incident, which it says can “significantly reduce the risk of mid-air collisions.”
Investigators are still gathering information gleaned from pilot interviews, flight data recorders and communications with air traffic control to get a better understanding of the event and determine exactly how close the two aircraft came, Webster said.
Investigators will also be looking at the warnings provided by the collision avoidance systems and how the pilots reacted.
Porter spokesperson Brad Cicero said the incident was a “loss of separation . . . There was not a ‘near collision’.
“Our pilots responded according to standard procedures given the circumstances,” he said
A spokesperson for Jazz Aviation declined to comment, citing the ongoing TSB investigation.