Almost immediately after take-off, the plane stops climbing at around 5,000ft and then circles a few times before continuing on with the journey?
I'm referring to this in particular:
The crew might have gotten a nuisance warning. Since the A350 is a brand new airplane it is still getting a few bugs worked out. Nuisance alarms are common during introduction of a new type into service. A consultation between the crew and the engineers on the ground, most likely involving Airbus engineers in France as well, followed during which the crew didn't want to venture too far away from its home base in case they had to return.
After 10 minutes (2.5 loops, 4 minutes each, standard hold pattern) they must have decided that the issue wasn't a big deal and it was OK to proceed.
I can think of a few possible reasons.
1. Air traffic control put them in a "Holding pattern" This can happen if air traffic control gets too busy. (although it is unusual to enter a holding pattern right after take off. it is more common to happen closer to landing)
2 the pilot had a concern over some possible issue. maybe a waring light came on.. so the pilot went into a holding pattern near the airport while they were troubleshooting the problem.. this way if necessary they could turn back to the airport quickly and land again if necessary.
It looks like air traffic control had them enter a holding pattern, The most likely explanation is normally for traffic separation, but a low altitude hold shortly after take off is a bit unusual. An fully loaded airliner burns a lot of fuel at 5000 ft.
My guess is that there was some reason that someone thought there was a chance the flight may have had to return to the airport. Perhaps the crew got a warning light or detected a possible problem and had to check it out before continuing – the hold would have provided time to talk to dispatch and maintenance. Perhaps one of the passengers name was on a watch list. All you can get from this forum is conjecture.
They were directed to hold by air traffic control.
His route wasn't clear.
hold waiting for clearance or traffic.
probably the pilot would know best.
Hi He had instructions from sound control to go into a holding pattern as other aircraft where too close. so the circling is a technique used a lot above commercial airfields. these circling ideas have stacks of aircraft one above the other at londons heathrow they have as many as six stacks at any one time. usually aircraft wanting to land.