L2018-03 Serious incident at Kokkola-Pietarsaari Airport on 22 March 2018

On 22 March 2018 at 08.02 (UTC + 2h) Jonair Affärsflyg AB’s flight JON01 from Skellefteå landed at Kokkola-Pietarsaari Airport (EFKK) on a runway which was occupied by runway maintenance vehicles.

At 07:49 EFKK air traffic control (ATC) permitted runway maintenance vehicles to enter Runway 19. Almost simultaneously JON01 contacted the ATC, which then issued an approach clearance and said that runway maintenance was in progress and that it might cause some delay. JON01 replied that a narrow, cleaned section of the runway would be sufficient for landing. At that point the pilots were witnessing light icing. At the time of the occurrence it was snowing heavily, visibility was approximately 1000 m and the cloud base was at approximately 200–500 ft (60–150 m).

At 07:54 JON01 requested a short approach. At 07:56 the ATC replied that it would take approximately 10 more minutes for runway maintenance to be completed. JON01 replied that they could not wait that long because there was icing at every layer. At the same time the air traffic controller permitted the runway friction measuring vehicle to enter the runway. The air traffic controller told JON01 that there was very much snow on the runway to which JON01 replied that they would like to attempt an approach or, otherwise, be forced to make a missed approach owing to the icing conditions. The pilots also considered returning to Skellefteå, from where they had departed.

At 07:57 the ATC issued an approach clearance and, a moment later, requested that JON01 report passing the final approach fix. At 08:00 JON01 requested the ATC to confirm that the high-intensity runway approach lights were on full intensity. There was no reply and the pilots repeated the request twice. The person measuring the runway surface friction was speaking at the same time on the loudspeaker, making it difficult for the air traffic controller to hear anything else. Transmissions were simultaneously coming in on the ground frequency and the aviation frequency. As the ATC’s and JON01’s transmissions were partly overlapping, the air traffic controller could not make out what JON01 was saying. The air traffic controller assumed that they had reported passing the final approach fix, at which time the controller told JON01 to go around.

The co-pilot of JON01 consulted the captain about going around. The captain replied that it was necessary for them to land because of the icing and that, according to his account, he believed that they were cleared to land. The ATC asked whether JON01 had received the order to go around. JON01 replied that they would land if the runway was free. Rather than issuing a landing clearance the air traffic controller again ordered JON01 to go around because there were three maintenance vehicles on the runway.

When the airplane broke through the cloud the pilots made visual contact with the runway, at which time they also spotted the vehicles on the runway. JON01 immediately told the ATC that they had to land in front of (i.e. before reaching) the vehicles. At 08:02 JON01 flew over the friction measuring vehicle which was in the centre of the runway at the location of the precision approach lights. Then they landed on the left side of Runway 19 on a section which had not been cleared of snow, passing the runway maintenance vehicles from the left. The air traffic controller warned the vehicles of the aircraft when it was already in the landing phase. The snow plume raised by the maintenance vehicles degraded runway visibility. The incident did not result in any injuries to persons or damage to material.

The investigation revealed that the radio phraseology used by the parties did not entirely comply with regulations, nor was it sufficiently clear-cut. The radio equipment used by the ATC made it possible for the airport ground frequency transmission on ATC speakers to be overheard on the aviation frequency, which interfered with the radiocommunication between the flight crew and the air traffic controller. Moreover, the ATC’s and JON01’s transmissions partially coincided with each other. The pilots did not report passing the final approach fix, nor could the air traffic controller, with their existing system, monitor the position of the aircraft during the final stages of the approach. Neither did the flight crew sufficiently clearly describe the effects of the icing on the airplane’s performance and so the air traffic controller was unaware of the severity of the icing.

The air traffic controller had little experience in coordinating runway winter maintenance and air traffic. The co-pilot’s ability to evaluate the situation and support the captain was limited. This was the co-pilot’s first flight in the company; it was carried out as a line training flight for him. The co-pilot had no prior experience of flying in icing conditions.

Safety Investigation Authority Finland recommends that:

• Air Navigation Services Finland ensure sufficient scope and content of local recurrent training at each aerodrome regarding special situations.

• Air Navigation Services Finland and Finavia also update the communication and air traffic services/management systems of airports where there is little traffic to meet modern requirements.

• The Swedish Transport Agency ensure that crew resource management and radiocommunication at the operators they supervise as well as the operators’ training comply with the training programmes the Agency has approved.

L2018-03 Investigation report (in Finnish) (pdf, 1.35 Mt)

Published 21.1.2019