The crew left parking area 10B at 19:17, more than an hour late on the scheduled time, with a west-facing push-back proposed by the controller for taxiway T, for a flight bound for Lisbon.
The ground controller cleared the crew to taxi via taxiways T and A, and to hold at holding point A1 in order to take off from runway 04L. The crew read back the route but not the instruction to hold at the holding point. One minute later, at the crew’s request, the ground controller confirmed the taxi route. The crew then started up the second engine. A few seconds later, the first officer carried out the flight control tests while the aeroplane was taxiing.
When the aeroplane was in the middle of the bend from taxiway T to taxiway A, the crew contacted the tower controller and indicated that they were at holding point A1 for runway 04L, ready for departure. The tower controller cleared them to line up on runway 04L.
Forty seconds later, the tower controller cleared the crew to line up and take off from runway 04L. The aeroplane was at this point on taxiway U. The controller repeated the clearance ten seconds later and specified that they were to make a quick take-off. The crew requested to “stand by please.” The tower controller then asked them to hold at holding point A1. The crew replied that they were on the runway without using the word “negative” as specified by the standard phraseology. The controller replied “OK” and asked them to contact him when they were ready.
When the crew indicated that they were ready, the tower controller cleared them to line up and make a quick take-off from runway 04L. The crew read back the take-off clearance and started the take-off. Around 20 s later, the tower controller asked them to immediately cancel the take-off as they were on the taxiway. The aeroplane had travelled around 550 m from the application of thrust and the aeroplane speed was then more than 85 kt. The crew rejected the take-off. The crew then again asked for clearance to take-off which occurred at 19:33. The flight to Lisbon took place without any particular event.
The west-facing push-back from the aeroplane’s stand led the ground controller to choose, from habit, the route via taxiway T. As for the crew, they were used to using taxiway U to get to the runway 04 thresholds. They thus found themselves in an unusual situation without probably realizing it and even though they correctly read back the ground controller’s messages about taxiing.
The crew taxied without sufficiently looking outside for visual references (lighting, signs, indications) and without using and checking the charts at their disposal. The number of actions to be carried out, in particular due to the starting up of the second engine while taxiing, and the short taxiing time from push-back from the stand probably contributed to limiting the crew’s availability to monitor, check and confirm the position of the aeroplane while taxiing.
On arriving at the end of taxiway T, the captain mistook the taxiway A sign for the mandatory sign at holding point A1. He then thought that the runway in service, 04L, was the first route on his left as was usually the case when taking the route via taxiway U.
Focused on other tasks, neither the ground controller nor the tower controller checked the position of the aeroplane. Hence, they did not identify the positioning error of the crew.
The tower controller wanted to insert the take-off before two approaches due a few minutes later in order to gain time and avoid the aeroplane being even temporarily at a standstill at holding point A1. He gave the line-up and take-off clearance before the aeroplane had reached holding point A1. The aeroplane had not yet passed taxiway U. This practice, even if it is authorized in the operations manual, leaves room for the crew to make a route error which is difficult to detect by the controllers.
The change in lighting when making the turn, from blue edge lighting to green centreline lighting may have misled the crew and make them think that they had entered the runway. While lining up, they did not identify the difference between the colour of the taxiway lighting and runway lighting. Lastly, they were not alerted by the dimensions of the taxiway as this was as wide as a runway and there was no sign at the beginning of taxiway U to indicate their error.
The captain did, however, have a doubt, and asked the first officer to confirm where they were. The latter confirmed that they were on the runway. The crew did not call the controller for clarification as stipulated in the operator’s procedures.
The various alignment and take-off clearances from the tower controller to keep the traffic flowing probably increased the time pressure linked to the aeroplane running late which led the crew to accelerate the before take-off actions to the detriment of asking the controller for confirmation of the aeroplane’s position.
Lastly, the before take-off actions include a warning to check that the aeroplane is on the correct runway. The crew were aware of this warning but did not check that the 04L indication was actually present on the runway. It was not an item of the check-list.
Thanks to a ground radar, the ground controller detected the take-off run on the taxiway and the take-off was cancelled.
The BEA has issued two safety recommendations to the DSNA.
Download the report(s) by clicking on the link(s) below: