Accident with an aircraft of the model SOCATA MS 893 A

During a private flight from Goleniów in Poland, a smaller aircraft with the registration number HA-BNS crashed into the sea at Gränsö outside Arkösund. The two pilots onboard were fatally injured in the accident. The aircraft was found at a depth of 10 metres.

Summary

On the evening of June 18, 2023, an aircraft of the model Socata MS 893 A crashed in the water north of Arkösund. The two pilots on board were fatally injured on impact. The flight was a private flight from Hungary, via Poland with a planned final destination in Dala Järna. The flight was planned to be conducted under visual flight rules (VFR). The aircraft was equipped for VFR flight.

The general weather conditions for the route across Sweden showed unsettled weather with a low-pressure centre over northern Öland. Although the forecasts for the planned flight path overall indicated that it was possible to fly according to VFR, the weather situation was complex.

The pilots started on Sunday morning at 07:39 from Budaörs Airfield (LHBS) in Hungary and stopped at Szczecin Airport (EPSC) in Poland to refuel before they continued towards Dala Järna.

At Jönköping Airport, they encountered adverse weather and decided to fly to Växjö/-Kronoberg Airport. After the pilots independently obtained weather information for Stockholm/Skavsta Airport, that reported VFR conditions, they changed the destination there. However, the weather at the airport deteriorated rapidly, probably without their knowledge.

On their way to Stockholm/Skavsta Airport, they changed the destination airport back to Dala Järna when the weather probably improved. When the weather deteriorated again in the northern part of Lake Vättern, the destination airport was again changed back to Stockholm/Skavsta Airport. At that time there were no good alternative airports in the area. Most likely the pilots decided to fly to Stockholm/Skavsta Airport to see what the weather was like in the area around and at the airport. With this, they were flying against the worst weather in the area.

Everything points to the fact that the aircraft ended up in clouds. Thus, the visual references were lost and as a result the pilots lost control of the aircraft. The impact in the water was heavy and probably inverted at a steep angle to the surface of the water.

Witnesses in the area alerted SOS who in turn activated the rescue services. The rescue measures are deemed relevant and reasonable.

The technical investigations carried out did not identify any technical faults or deficiencies that could have contributed to the accident.

During the investigation, safety deficiencies have been identified for how airport operators describe an airport's availability in the AIP[1] (PPR[2]) and how the Air Traffic Control expresses themselves when the Air Traffic Services (ATS) is open or closed at an airport. Overall, there is therefore a risk of misunderstanding and that it can be difficult to know whether an air-port is accessible or not.

There is no organisation with a clear overall responsibility that can be addressed with the issue of PPR unlike phraseology, which is handled by the Swedish Transport Agency's regu­lations on radiotelephony and phraseology. However, the Swedish Transport Agency is deemed to be best to deal with the problem as a whole.

The SHK therefore considers that the Swedish Transport Agency, together with Air Traffic Control providers and airport operators, should review the system to increase clarity and prevent misunderstandings.

Causes

The accident was caused by several circumstances and decisions that together reduced the possibility of conducting the flight safely. As a result, the pilots flew into the worst weather in the area and lost visual references, which in turn caused them to lose control of the aircraft.

Safety recommendations

The Swedish Transport Agency is recommended to:

• Within the framework of the oversight of airports, promote the use of a common standard for how PPR is described in the AIP.
• Analyse how airports accessibility is limited by PPR and how it affects aviation safety.
• Clarify the ATC phraseology regarding the availability of an aerodrome when the ATS is open or closed.

[1] AIP – Aeronautical Information Publication.

[2] PPR – Prior Permission Required.