Porter Airlines says it suspects it was a drone flying at the altitude of aircraft — 9,000 — that imperiled one of its flights arriving at Billy Bishop Airport on Monday morning. The Transportation Safety Board is on the job with an account from the pilots that their flight was on a collision course with the object before they went into a dive to avoid it. This occurred about 7:30 a.m “A Porter aircraft was on its initial approach to Billy Bishop airport for landing. It was at an altitude of approximately 9,000 feet over Lake Ontario near Pickering when the pilots noticed an object in the distance,” Porter spokesman Brad Cicero said. “As they approached the object, they realized it was very close to their flight path and decided to take appropriate evasive action. There was no contact between the aircraft and object.” Cicero said the pilots initially thought the object was a balloon, but the airline says it could have been a drone. Two flight attendants received minor injuries as the aircraft performed evasive manoeuvres, but none of the 54 passengers were hurt.