High-speed fighter formation took evasive action during close encounter with light trainer near Lelystad.
See-and-avoid rules are a weak safety barrier for collision avoidance in cases where high-speed military fighters are flying in the same airspace as slower general aviation aircraft, Dutch investigators are warning.
The Dutch Safety Board says see-and-avoid has “limitations” in such circumstances, following its probe into an air proximity event involving two Lockheed Martin F-16s and a Tecnam P-Mentor near Lelystad airport on 16 November 2023.
Both F-16s were returning to Volkel air base after an exercise, while the Tecnam had departed Lelystad for a commercial pilot training sortie covering climbing and descending turns.
The F-16s had been instructed to fly at 3,000ft and were following a roughly southern heading when the Tecnam entered a climbing turn to 3,000ft and rolled out onto a northern track.
This meant the pilots of the fighter formation and the training aircraft “found themselves on more or less opposite courses at the same altitude” — but were more than 10km apart and did not notice one another visually.
Within Class E airspace air traffic control does not provide separation between instrument and visual flights, and the safety board adds that the F-16s and Tecnam were on different military air traffic centre frequencies.
“Consequently, the air traffic services personnel as well as the flight crews could not hear each other’s radio transmissions,” it states.
An air traffic controller who had newly come on duty informed the formation of traffic about 2nm ahead of the lead F-16, whose pilot observed an aircraft on the fighter’s interrogator but not the radar.
The pilot sought to identify the traffic visually and, after seeing the light aircraft, took immediate evasive action.
Radar data indicates that the F-16, travelling at 420kt, passed the Tecnam at a horizontal distance of 240m and with 125ft vertical separation.
The inquiry says the limitations of see-and-avoid, particularly with high-speed fighters, is a “recurring” observation.
“Pilots of slow-flying aircraft have minimal chances to detect a potential conflict and…make an evasive manoeuvre due to the high closing speed,” it states.
“Crews of high-speed military fighter aircraft are in a better position to do so, due to their training, skills and on-board equipment.”
Although the F-16 is no longer part of the Royal Netherlands Air and Space Force — having been replaced by the F-35, which has more advanced sensors — the investigation says a mid-air collision remains a “realistic scenario”.
It has recommended that the Dutch ministry of defence should assess the operational risk of high-speed aircraft in relation to safe separation between military and civil traffic, and implement mitigation measures, while also improving radio communication co-ordination at military air traffic centres.
The post Dutch inquiry faults ‘weak’ see-and-avoid rules after F-16 airprox first appeared on FlightGlobal.