Near-miss pilot said collision with aircraft ‘almost certain’

The pilot of a passenger plane said a collision with a light aircraft over Orkney would have been “almost certain” if they had not taken avoiding action.

An official probe was told that the pilot of the light aircraft had wrongly assumed that the other plane was a less powerful Islander that would level off below them.

To their surprise they then realised the aircraft – a Saab 340 (SF340) – was faster and climbing higher than anticipated.

They observed the SF340 passing underneath and behind their aircraft.

The incident happened two-and-a-half miles west of Kirkwall on June 26.

The pilot of the Saab said that they heard several light aircraft on Kirkwall control’s frequency.

They were cleared for take-off and climbing away to the west, could see the light aircraft on its traffic alert and collision avoidance system (TCAS).

The pilot mentioned to the flight officer that it “looked like the other aircraft was coming their way”, flying towards Kirkwall. They could then see the aircraft and they levelled off at 1,500ft as the other aircraft was at 2,500ft and flying through the extended centreline of the runway.

“Their projected flight paths looked like they would certainly have had a collision if they didn’t have visual contact and the help of their TCAS,” said the report to the UK Airprox Board, which investigates near misses.

“They informed the controller once it was quieter. The pilot assessed the risk of collision as ‘high’.”

The Cessna 172 (C172) pilot had not heard the route clearance for the Saab but “probably subconsciously assumed this was an inter-island flight as they could see the aircraft in the distance”.

“Due to radio chatter, they were unable to alert Kirkwall of their position and routing despite trying to.

“This lasted for a significant period of time (at least until their priority shifted to observing the SF340). They noted the aircraft starting its take-off roll as they were routing around the Kirkwall air zone and asked their frontright seat passenger to keep an eye on it while they divided their duties.

“Their projected flight paths looked like they would certainly have had a collision

“At about the time the SF340 reached 1,000ft they realised for the first time that the aircraft was definitely not an Islander due to its size, speed and climb rate. There was possibly a brief element of ‘paralysis by analysis’ at this point as there was no clear safe course of action due to their being quite close to crossing the runway extended centreline.

“Certainly, by the end of these few seconds of consideration they believed their best course was now to maintain their current track due north to maximise separation. While they didn’t believe an actual collision was imminent due to the SF340 starting to move down and rearwards in the passenger window, they still felt the relative speeds and distance were far from ideal and were not surprised when the SF340 pilot reported the incident and opted to file an Airprox even though it was incipient rather than actual.

“The SF340 pilot stated a collision was almost certain if they hadn’t taken avoiding action, however, if the flight radar trace is to be believed, they would have passed quite some distance behind them.”

The board said the actions of the SF340 pilot ensured at least 1,000ft of vertical separation was maintained and determined that there was no risk of collision.

An official probe into an air incident near Kirkwall Airport has been published.