Incident Overview
On 3 April 2000 at 0955 UTC, an Airprox (air proximity) incident occurred near PINIK on approach to Lugano Airport. The aircraft involved were LEA010R, a Falcon 10 (registration F-GDLR) operated by Leadair-Unijet, and CRX44UT, a Saab 2000 (registration HB-IZT) operated by Crossair. Both aircraft were operating under Instrument Flight Rules (IFR) in Class E controlled airspace. The weather at the time was Instrument Meteorological Conditions (IMC) with rain, and the visibility was 6 km. The pilots of LEA010R reported unreliable instrumentation, including the GPS and altitude selector.
Sequence of Events
LEA010R initially contacted Lugano Tower descending to 6000 ft on a heading to CALDO Intersection. The controller cleared it for an IGS approach to Runway 01 and instructed it to report inbound at PINIK. About 4.5 minutes later, LEA010R reported initiating a go-around and requested diversion to Milano Malpensa. The controller instructed LEA010R to follow the missed approach procedure, climb to 6000 ft, and return to the PINIK holding point. Shortly after, the controller learned from Milano Control that CRX44UT had switched frequency and was also inbound to Lugano. CRX44UT then contacted Lugano Tower and was cleared to descend to 7000 ft in the PINIK holding area.
Seconds later, LEA010R called again, reporting stable at 8000 ft on a heading to PINIK. The controller immediately recognized the conflict potential with CRX44UT, which was cleared to 7000 ft. Assuming CRX44UT had already left 8000 ft and that LEA010R would continue climbing, the controller cleared LEA010R to 9000 ft to establish vertical separation. The controller then asked CRX44UT for its altitude and received a vague "descending to 7000 ft," accompanied by a report that LEA010R was directly below them on TCAS. Further queries confirmed that CRX44UT was at 8500 ft and LEA010R at 8000 ft. The controller instructed CRX44UT to maintain 8500 ft and later to climb to 9000 ft to achieve standard separation, while coordinating with Milano Control to resolve the conflict with radar guidance.
Contributing Factors
The investigation identified several factors that influenced the incident:
- The pilots of LEA010R had inadequate task distribution and teamwork.
- The pilot-in-command of LEA010R lacked the required qualification for IFR operations at Lugano and had not prepared the flight sufficiently.
- The controller did not request a full readback from LEA010R when it acknowledged the missed approach clearance incompletely, omitting the altitude restriction.
The approach controller did not correct the erroneous readback of "ILS approach" instead of "IGS approach" by LEA010R, though this did not contribute to the incident.
Cause
The incident was caused by the pilot of LEA010R not respecting the altitude limitation of 6000 ft after a go-around and continuing the climb to 8000 ft without clearance.