DAVID LEARMOUNT / LONDON
The Italian investigators' interim report on the Milan Linate runway incursion accident shows that both the Cessna Citation CJ2 pilot and the ground controller missed several clues in their radio exchanges indicating that the CJ2 was taking the wrong taxiway in fog (Flight International, 16-22 October 2001).
In the 8 October 2001 accident, a Scandinavian Airlines (SAS) Boeing MD-87 taking off on runway 36 and a private CJ2 that entered the runway collided, killing all 114 people on both aircraft and four on the ground.
The CJ2 pilot was ordered: "D-VX [the CJ2] taxi north via R5, QNH 1013. Call me back at the stop bar of the main runway extension." The CJ2 pilot read back: "Roger, via R5 and 1013, call you back before reaching main runway." The CJ2 pilot then taxied south on R6 but reported throughout that he was on R5.
The factual report notes that the controller did not challenge the omission of the words north, stop bars, and extension from the CJ2's readback, or note that he referred to reaching main runway. R5 does not intersect with the runway - it goes north from the general aviation apron, then turns east and passes clear of the north end of runway 18/36 and joins the main apron. The visibility was 100m in fog, and in the absence of surface movement radar, the controller had to rely upon the pilot carrying out instructions precisely.
As the CJ2 continued taxiing along R6, which leads to runway 36 just north of its centre, the pilot should have realised that what he was seeing did not tally with what the controller told him. Similarly, when the controller asked for the CJ2's position the pilot replied "approaching the runway", which the controller did not challenge.
Meanwhile the SAS aircraft had been told to change from ground to tower frequency, so the CJ2 pilot, as he approached the runway and received clearance to "continue your taxi on the main apron", did not hear the MD-87 accept take-off clearance.
The two aircraft collided just as the MD-87 lifted off the runway. The SAS aircraft had its right main gear wiped off and starboard wing leading edge damaged. The gear damaged the right flap, then knocked the No 2 engine off its pylon, and the aircraft crashed.
Source: Flight International
