What happened
On July 18, 2002, at 08:56 UTC, a serious airprox event occurred in the airspace near Milan Linate airport involving two aircraft. The first aircraft, a SIAI Marchetti SF 2 260 with registration I-ISAI, was conducting a training flight from Vergiate toward Parma. The second aircraft, a British Aerospace HB-25B with registration I-ALHO, had departed from runway 36R at Milan Linate bound for Nice.
During the flight, the I-ISAI entered the Milan Linate control zone (CTR). The two aircraft eventually converged at the same altitude with a minimum separation of only 925 meters (approximately 0.5 nautical miles). At the moment of crossing, there was a vertical separation of 213.36 meters (700 feet). The event was classified as a "Safety not assured" airprox by ICAO standards.
The investigation
The ANSV investigation examined radio communications, radar tracks, and the coordination between various air traffic control (ATC) units, including Milan Information (FIC), Saronno radar, Parma radar, and Linate Tower.
The investigation established that the pilot of the I-ISAI had provided an incomplete read-back during communications with Milan Information. Furthermore, the controller at Milan Information failed to notice the incomplete read-back and did not warn the pilot that they were entering the Linate control zone without specific authorization. The investigation also noted a lack of effective coordination between the Milan Information, Radar, and Linate Tower controllers. Additionally, the TCAS on the I-ALHO only issued a resolution advisory when the aircraft reached 1,000 feet, as the system is inhibited below that altitude.
Findings
- The pilot of the I-ISAI miscalculated the timing of their overflight of Saronno.
- The instructor on board the I-ISAI maintained an overly confident mental attitude, which reduced the necessary critical analysis of flight maneuvers and communications.
- The Milan Information controller provided instructions to proceed under VFR toward Parma, which coincided with the planned IFR destination.
- Inadequate coordination between Milan Information, Milan Radar, and Linate Tower was a primary contributing factor.
Safety action
- The ANSV recommended that pilots be sensitized to the fact that VFR flight conduct remains the pilot's responsibility and that information from Flight Information Centers (FIC) is purely informative; entry into controlled airspace must only occur with specific ATC authorization.
- A recommendation was made to ensure that coordination between ATC entities is precise and timely to prevent uncertainty regarding which authority holds control of a specific aircraft.