History
On Tuesday, 1 February 2000 at 14:19 UTC, flight KLM1931, a Boeing 737-400 on a regular commercial flight from Amsterdam to Geneva, was on final approach to runway 23 and was authorised to land by airport control. At the same time, a Piper PA28 light aircraft (registration HB-OQS) was holding at Yankee intersection. The airport control authorised HB-OQS to line up behind aircraft KLM1931, while a Speedbird flight (BAW728) was leaving the runway in front of it. However, HB-OQS immediately aligned itself on runway 23 during the landing phase of the Boeing 737. The airport controller did not notice this event and consequently took no measures to eliminate the danger. KLM1931 touched down at the beginning of runway 23, braked, and left the runway at Charlie intersection, behind the aligned Cherokee. The pilot of KLM1931 notified the controller that the runway was occupied during landing and advised that he was submitting an incident report.
Findings
- The runway in operation was runway 23.
- At 14:20:10, Speedbird (BAW) 728, a Boeing 757 from London, landed on runway 23 and was instructed to vacate via the next left intersection, which was Charlie taxiway.
- At 14:20:25, KLM1931 was authorised to land when 2.5 nm from the touchdown zone.
- The runway distance from touchdown 23 to Charlie intersection is 1400 metres; to Yankee intersection, 1500 metres.
- At 14:20:33, BAW728 was transferred to Traffic frequency and was on Charlie taxiway opposite HB-OQS.
- At 14:20:40, HB-OQS was authorised to line up on runway 23 behind the incoming traffic. KLM1931 was then 2 nm or less than 60 seconds from touchdown.
- The pilot of HB-OQS acknowledged and asked about the route after take-off.
- At 14:21:55, HB-OQS signaled that it was lined up on runway 23 and ready for departure. The controller did not notice and did not react.
- At 14:21:59, KLM1931 was instructed to vacate left via Charlie taxiway.
- The pilot of KLM1931 reported another aircraft on the runway and stated he would submit an incident report.
Analysis
The incident occurred on the ground at the intersection of runway 23 and Yankee taxiway. About one minute and 30 seconds elapsed between KLM1931 receiving landing clearance and being on the runway behind HB-OQS. About one minute elapsed from when HB-OQS lined up and signaled readiness. During that minute, 11 radio contacts took place, possibly distracting the controller. The controller stated he was surprised by the speed of events and that it was too late for intervention when he realised the situation. The phraseology used for the line-up clearance was standard but not sufficiently accurate for a conditional authorisation. The pilot of HB-OQS likely misinterpreted the meaning of "incoming traffic."
Cause
The incident was due to the premature alignment of a light aircraft on the runway in operation, in front of a commercial aircraft in landing phase. The pilot of the light aircraft misunderstood the aircraft indicated at the time of the line-up clearance issued by the Control Tower, which did not notice his intrusion onto the runway. A contributing factor was lack of precision in the line-up clearance.