Serious incident to the Embraer ERJ175 registered PH-EXH operated by KLM and the Boeing 737 registered 7T-VKR operated by Air Algérie on 05/09/2022 at Lyon Saint-Exupéry

Lyon-Saint-Exupéry airport was operated in a single-runway configuration on 17L, under VMC conditions. The TWR controller asked the Embraer 175 crew if they were ready for immediate take-off. The crew replied that they were ready and the controller asked them to line up, wait and be ready, without mentioning any immediate take-off. The Embraer crew were surprised by this request and the absence of an immediate take-off clearance. As for the crew of the Boeing, on final, about 4.3 NM from threshold 17L, they indicated that they considered the take-off clearance given to the Embraer as being for an immediate take-off. Without the volume of traffic requiring it, the LOC controller, based on her experience, inserted an aeroplane for take-off between two landing aeroplanes, probably focused on optimisation and efficiency. She did not adjust the Boeing’s approach speed and then belatedly informed the crew of the Boeing (located 0.7 NM from the threshold and at a height of 250 ft in relation to the threshold) that the landing clearance would be given late.

The strategy applied offered no margins and did not take into account any unexpected events (such as the time necessary for the preceding aeroplane to vacate the runway, for the aeroplane taking-off to start the take-off run, or even for the aeroplane on final to go around).

Moreover, the controller’s strategy was based on an obsolete minimum separation value, as the operating procedures had been altered one month earlier pursuant to a change in regulations.

The LOC controller and her assistant, whose attention was focused on the warnings from the A SMGCS ground radar, realised at a late stage that the reduced separation distance (which they thought was applicable) between the Embraer that was taking-off and the Boeing that was landing would potentially not be observed when the Boeing 737 crossed the runway threshold
on landing.

The controller gave the landing clearance to the crew of this aeroplane when they were at a height of approximately 60 ft and about 200 m from the threshold, after seeing the wheels of the Embraer ERJ 145 lift off the ground. When the Boeing crossed the runway threshold, the Embraer was still 700 m from the opposite threshold. This represented a loss of separation in relation to the operating procedures in force at the time of the event, which require the aeroplane to have crossed the opposite threshold.

To prevent any conflict from arising between the Boeing making a go-around and the Embraer taking-off, the controller decided to let the landing and take-off continue.