L2019-04 Serious incidents in the vicinity of the Jyväskylä airport in the morning of 5 April 2019

The serious hazards occurred in the vicinity of the Jyväskylä airport on Friday 5 April 2019 at 10.47. Two wings of the Finnish Air Force (callsigns Spade 1 and Spade 5) were returning from the Final 2019 flight operations exercise to the Jyväskylä airport. First of the serious incidents occurred when the Spade 1 wing (comprising four Hawk jet trainer aircraft) flew into an airfield traffic pattern to runway 30 in order to split the wing for a landing pattern above the runway. The Spade 1 wing had to take evasive action due to Patria Pilot Training Ltd’s general aviation aircraft OH-TPI (type Tecnam P-2002 JF) that was in an airfield traffic pattern for runway 30 at the same time; the Spade 1 wing did not gain a visual of the aircraft at any point. The second incident occurred immediately afterwards when, as a result of the evasive action, the Spade 1 wing dispersed and flew through Spade 5 wing (two Hawk jet trainer aircraft and one F-18 Hornet multi purpose fighter) as individual aircraft, when Spade 5 was about to join the right-hand tailwind section for runway 30.

The occurrence of the incidents was contributed by the wings receiving a VFR clearance, but the air traffic control workstations being manned for IFR returns. The fixed-period meteorological airport report (METAR) at 10.20 was valid for a while longer, but in practice, the weather in the vicinity had changed with respect to the cloud ceiling so that it would have required special VFR or IFR clearance. The air traffic control’s desire to serve exceeded the procedure suitable for the situation. Based on the investigation, it can be said that the air traffic control should have followed the pre-planned procedure. Desire to serve must not supersede safety.

The Finnish Air Force considered the return from the exercise area to be a routine flight operation. Although the vicinity of an airport is a safety-critical environment, the risks of the departures and returns were not take into consideration in the ORM risk analysis prepared for the exercise. Based on the investigation, it can be said that the risks related to military aviation departures and returns should be critically reviewed, particularly in joint-use airports also involving civilian traffic.

In the situation, the wings were coming in at the same time from opposite directions to the same point. Regardless, the air traffic control did not limit the speeds of the wings or take any other measures, although the development of the situation was evident in the ATC systems. The air traffic control does not have a single, clear procedure for VFR returns; instead, the returns require adaptation. Additionally, the features of the TopSky system used by the air traffic control were used in such a manner that the air traffic control no longer had an up-to-date situational awareness of the incoming wings or whose responsibility they were in the air traffic control. Based on the incidents it is clear that the air traffic control must, if necessary, take action early enough in order to also organise VFR traffic. The co-operation of COR, ARR and TWR workstations related to controlling VFR flights must follow a clear and unambiguous procedure, because the features of the TopSky system do not sufficiently support VFR operations.

Instructions and orders enable verbal coordination between adjacent air traffic control workstations. The verbal coordination should implement the closed-loop communication principles, ensuring that the information was correctly received and understood. In the incidents that occurred, a mix-up of the numbers of the similar callsigns of the aircraft affected the escalation of the situation. This stems from the Finnish Air Force using similar aircraft callsigns in its exercises, easily confused in radio traffic. Indeed, the aircraft callsigns should be sufficiently different in order to avoid confusion.

The Jyväskylä approach air traffic control has not ensured the optimal positioning of the workstations with respect to their co-operation. There is no uniform template or standardisation for the positioning of the workstations. Based on the investigation, the ATC workstations should be positioned uniformly in different units, if the premises allow, so that verbal communication between the workstations is functional and effective. Additionally, the established practices of the Jyväskylä air traffic control allowed the deficient application of the instructions. As things currently stand, the competence assessment of the air traffic controllers is carried out unit-internally at three-year intervals. Based on the investigation, it can be said that the intervals between the competence assessment and them being implemented unit-internally have enabled the development and adoption of deviant, even incorrect and incomplete practices at the individual level and within the unit. This could be impacted with competence assessment done every 12 months or with continuous competence assessment.

The Safety Investigation Authority recommends that:

• The Finnish Transport and Communications Agency reassess the purposefulness and effectivity of the competence assessment process of Air Navigation Services Finland Ltd.

• The Finnish Air Force take into account in the ORM risk analysis for its exercises the air navigation risks related to the departures and returns of wings, and update the flight operation instructions for its exercises to conform with this risk management.

• The Finnish Air Force develop clearly distinguishable aircraft callsigns for its exercises.

• Air Navigation Services Finland Ltd. prepare uniform instructions for the placement, hardware and workstation ergonomics for joint-operation airports.

Investigation report (in Finnish) L2019-04 (pdf, 2.88 Mt)

Published 25.3.2020