What aircraft was involved and where did it happen?

The accident on 2018-02-12 involved a SAAB, 340A, registration SP-MRB, at Szwecja, PL.

SkyTaxi Saab 340 Avoids Collision in Swedish FIR After TCAS RA (SP-MRB)

On February 12, 2018, a SAAB, 340A (registration SP-MRB) was involved in an aviation accident near Szwecja, PL. Investigators recorded the probable cause as: The failure of another aircraft's crew to maintain their assigned flight level in the vicinity of the EKRON reporting point, which necessitated a TCAS-induced descent by the SP-MRB to avoid collision. This summary draws on records from the Polish State Commission on Aircraft Accidents Investigation (PKBWL).

Sourcesthe Polish State Commission on Aircraft Accidents Investigation (PKBWL)Primary reportUpdated 1785092869Data API Editorial standards

Aircraft registered SP-MRB. Photo: Björn Strey / CC BY-SA 2.0, via Wikimedia Commons

A SkyTaxi Saab 340 avoided a mid-air collision in Swedish airspace when another aircraft failed to maintain flight level, triggering a TCAS descent advisory.

What happened

On February 12, 2018, a SkyTaxi Saab 340A with registration SP-MRB was conducting a ferry flight from Vilnius International Airport (ESGG) to Warsaw Chopin Airport (EPWR). The aircraft carried three crew members: the captain acting as pilot monitoring, the first officer as pilot flying, and a TRIU/TRE instructor/examiner. Approximately 46 minutes after departure, while cruising at flight level 190 with a true airspeed of 205 knots, the crew observed traffic on a reciprocal heading. The conflict was visualized on the TCAS display, showing a horizontal separation of 6 nautical miles and a vertical separation of 900 feet decreasing to 800 feet.

The flight crew received a "TRAFFIC TRAFFIC" advisory followed by a TCAS Resolution Advisory (RA) commanding a descent. The first officer disconnected the autopilot and initiated a descent in accordance with the RA instructions. The aircraft descended 600 feet, establishing safe separation from the conflicting traffic. After passing the other aircraft, the captain reported the TCAS RA to Sweden Control on frequency 124.85 kHz and requested to resume flight level 190. Shortly thereafter, the crew of the other aircraft contacted control, stating they likely caused the RA but had encountered turbulence and failed to maintain their assigned altitude. The SP-MRB continued its flight to EPWR without further incident.

The investigation

The PKBWL investigated the incident under case number 291/18. The inquiry focused on the sequence of events leading to the near mid-air collision and the crew's response to the TCAS RA. Meteorological conditions were reviewed and determined to have no impact on the occurrence, although the conflicting aircraft reported encountering turbulence.

Findings

The investigation established that the primary cause of the incident was the failure of the crew of the other aircraft to maintain their assigned flight level in the vicinity of the EKRON reporting point. The SP-MRB crew correctly followed TCAS procedures by executing the descent advisory, which successfully prevented a collision.

Safety action

No safety recommendations were issued by the PKBWL for this incident. SkyTaxi did not implement specific preventive actions related to this event.

Probable cause

The failure of another aircraft's crew to maintain their assigned flight level in the vicinity of the EKRON reporting point, which necessitated a TCAS-induced descent by the SP-MRB to avoid collision.

2018-02-12: SAAB, 340A (SP-MRB) — Szwecja, PL