C5/2006L An incident between military and civilian aircraft formations southwest of Uusikaarlepyy on 29 June 2006

An incident involving a Hawk (HW) jet trainer formation from the Finnish Air Force Training Air Wing and two Cessna 152s from the Finnish Aviation Academy occurred southwest of Uusikaarlepyy on Thursday 29 June 2006 at 13:31 Finnish time. The three-ship HW formation and the Cessna 152 pair had to carry out an evasive manoeuvre. This happened in a training area within the Kauhava military control area (MILCTA). The Hawks were on a combat training sortie and the Cessnas on a cross-country flight, enroute to Pori. On 3 July 2005 Accident Investigation Board Finland (AIB) appointed investigation commission C5/2006 L to this incident. Investigator Ari Huhtala was named investigator-in-charge and Captain Janne Hotta, representing the Training Air Wing, member of the commission.

Air traffic control (ATC) cleared the HW formation for MILCTA training areas Kilo Alfa (KA) and Kilo Bravo (KB) under VFR (visual flight rules). As they arrived in their training area, the leader of the formation set 1700 ft as the minimum altitude and 3200 ft as the lowest limit for unrestricted manoeuvring. The “hostile”, or target, aircraft in the formation was flown by a solo pilot and the crews of the “friendly” fighters comprised a student and an instructor pilot each. A little later the radar controller cleared the C152 pair, flying from Kokkola to Pori via Vaasa, to climb to 2000 ft or below in the MILCTA under VFR. The route of the Cessnas passed through the training area which had been reserved for the HW formation. The radar controller issued traffic advisories to both formations, but did not separate the formation and the pair from each other. This was done in compliance with existing regulations. Soon afterward the crew of the lead Hawk saw a white silhouette flash below them in their front right quadrant. Simultaneously they spotted the second Cessna a little farther ahead on the right. Their wingman, too, saw the Cessnas whereas the pilot of the “hostile” HW, farther away, did not notice them at all. The lead pilot of the C152 section observed that one of the Hawks was closing in from close above and left and so pushed his nose down. He estimated that the Hawk passed approximately 100 m above him. His C152 wingman, following in line formation, did not spot the Hawks at all. Visual meteorological conditions (VMC) prevailed in the area.

The cause of the incident was the inadequate instructions and the established ATC practice by which VFR traffic is possible to be cleared through an active training area within the MILCTA only based on traffic advisories. Since no instructions about paying attention to traffic advisories have been issued, flight control operations have evolved according to the demands of practice. Furthermore, each of the crews involved had low situational awareness regarding the traffic. This was because the radar controller did not update traffic information, nor did the crews actively request any updates. What’s more, the radar controller was not aware of the HW formation’s mission-specific minimum altitude in the training area because said altitude had not been recorded in his Flight Progress Strip.

The investigation commission recommends that Civil Aviation Administration Finavia, together with the Finnish Air Force Headquarters (FIAF HQ), review the procedures for Kauhava MILCTA, that the FIAF HQ determine whether regulations should be issued so that military pilots-in-command would automatically establish and maintain sufficient separation from their traffic; that the FIAF HQ standardize the practice of how formation leaders ensure that all pilots in the formation are aware of relevant flight safety factors; and that the Training Air Wing, together with Kauhava Air Traffic Control, improve their local flight reporting system, making all ATC units sufficiently aware of the altitude limits of sorties flown in training areas.

C5/2006L Report (pdf, 1.06 Mt)