TCAS Resolution Advisory triggered by unauthorized airspace penetration near Toulouse

Casualties unknown • :, FR

An Airbus A320 and a Cessna 150 experienced a near-collision after a flight training aircraft entered a class D control zone without radio contact.

What happened

On January 29, 2005, at 15:44, an Airbus A3 320-100, operated by Air France, was performing a commercial passenger flight from Paris Orly to Toulouse Blagnac. While maneuvering near the TOE radio beacon within the Toulouse class D control zone, the crew received a TCAS Resolution Advisory (RA) instructing them to "adjust vertical speed."

At the same time, a Cessna 150, operated by a flight club for instruction purposes, was flying under Visual Flight Rules (VFR) between 2,500 and 2,800 feet. The instructor and student pilot had departed from Castelnaudary for Toulouse Lasbordes. The Cessna 150 entered the class D airspace without establishing radio contact with the controller. The two aircraft crossed paths with a vertical separation of only 200 to 400 feet. The crew of the Airbus reported that they did not visually identify the Cessna during the encounter.

The investigation

The investigation focused on why the flight training aircraft entered the controlled airspace and why the air traffic controller did not identify the presence of the VFR aircraft sooner. The instructor stated that they had intended to bypass the controlled zone by flying east of the TOE beacon. However, the instructor was providing instruction to the student and had momentarily lost focus on navigational tracking.

Radar records showed no technical malfunctions regarding aircraft detection or visualization. The controller noted that while VFR plots can be manually hidden, an aircraft entering the zone without authorization should trigger an automatic orange label on the radar screen. In this instance, the controller did not detect the aircraft until the Airbus crew alerted them to the TCAS RA.

Findings

  • The primary cause of the incident was the triggering of a TCAS Resolution Advisory due to a loss of vertical separation.
  • The instructor's attention was focused on teaching the student, which led to imprecise navigation and the unintended penetration of the class D airspace.
  • The air traffic controller's detection of the training aircraft was delayed because the aircraft was not in radio contact.

Probable cause

The incident was caused by the flight training aircraft entering controlled airspace without authorization, driven by the instructor's loss of navigational focus during instruction, which resulted in a TCAS Resolution Advisory for the commercial airliner.

Frequently asked questions

What happened in the 2005-01-29 aircraft accident near :, FR?

An Airbus A320 and a Cessna 150 experienced a near-collision after a flight training aircraft entered a class D control zone without radio contact.

What aircraft was involved and where did it happen?

The accident on 2005-01-29 involved a aircraft, at :, FR.

What was the probable cause of the accident?

The incident was caused by the flight training aircraft entering controlled airspace without authorization, driven by the instructor's loss of navigational focus during instruction, which resulted in a TCAS Resolution Advisory for the commercial airliner.

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