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Why would this airliner be doing a 90° course change at cruising altitude? I saw this while waiting for a traffic light to change.

9 Jan 2020 1:42 pm (18:42 UTC) at Virginia Beach, VA, coordinates: 36°46'38.070"N 76°05'18.03"W, my heading: 237 deg.

enter image description here

And from Flightradar24, flying at 37,000 feet:

enter image description here

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    $\begingroup$ Related: What aircraft can make these sharp 90-degree turns? $\endgroup$
    – fooot
    Commented Jan 10, 2020 at 20:54
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    $\begingroup$ For review purposes: These questions are not duplicate - the linked one refers to technical capability to make sharp turns, this one to the purpose, and it uses tracking data on the map. $\endgroup$
    – Therac
    Commented Jan 11, 2020 at 3:35

2 Answers 2

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This answer assumes the manouevring was related to the Military training activities going on off-shore. While plausible, there is another plausible explanition in ymb1's answer.

That was a British Airways Boeing 747 on its way from London to Miami.

Just off the coast there is a military exercise going on (see the LJ35 doing circles in the screenshot from flightradar24.com below; probably a military contractor like the one in this question).

Therefore all flights that would normally fly in that area end up flying over the coast. It seems that when the peak traffic from Europe towards Miami was passing, ATC decided to put everybody onto their original route as soon as they passed the bottleneck in order to reduce the traffic density. The result is quite a few sharp turns.

Screenshot from FR24

A few hours later there were at least 4 Learjets playing around off the coast. Note that most military traffic is not shown on FR24, so it may have been quite a bit busier.

enter image description here

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  • $\begingroup$ Perhaps unrelated, but what are a bunch of Lears doing near a military exercise? Are those C21-A (Learjet 35A in military service) for observation purposes? $\endgroup$
    – Mast
    Commented Jan 13, 2020 at 8:37
  • $\begingroup$ @Mast did you follow the link provided in this answer? It is explaned there. $\endgroup$
    – DeltaLima ♦
    Commented Jan 13, 2020 at 8:48
  • $\begingroup$ Ah, of-course. They're towing the targets. Thank you. $\endgroup$
    – Mast
    Commented Jan 13, 2020 at 10:10
  • $\begingroup$ @DeltaLima, may I ask how do you show multiple aircraft track on Flighradar24 in the first screenshot please? $\endgroup$
    – JuanLoveJesus
    Commented Jan 15, 2020 at 0:43
  • $\begingroup$ When you open fr24 in the browser on a desktop, there is a combobox in the top right corner where you can choose "Multi Select". I think the number of aircraft you can select depends on the type of subscription you have. $\endgroup$
    – DeltaLima ♦
    Commented Jan 15, 2020 at 7:35
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I'd like to add to @DL's answer:

enter image description here

Skipping further ahead in time, it wasn't a reroute out of a bottleneck, rather an introduced time delay. Either TBFM (Time Based Flow Management), or sector capacity constraints (though it also happened for northbound traffic).

The FAA website confirms Miami (MIA) as one of the airports with TBFM deployed.

The military activity off the coast is unrelated, as that area is a warning area almost year-round, with no commercial activity going through.

The following day during rush hour there was this:

enter image description here

The way it's always happening near Virginia Beach, hints at the metering location for the TBFM being there.

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  • $\begingroup$ Nice find ymb1! This should be the accepted answer. $\endgroup$
    – DeltaLima ♦
    Commented Jan 13, 2020 at 8:44
  • $\begingroup$ However, I checked approximately 15 days randomly from the first half of last year, and I could find any examples during those days. That would hint at this is a recent change to the procedure for KMIA. I am not 100% convinced yet. $\endgroup$
    – DeltaLima ♦
    Commented Jan 13, 2020 at 9:08
  • $\begingroup$ @DeltaLima: It's possible it's new indeed, since it's being rolled out in stages. Also remember the wrong turn screenshot? So it's not just KMIA, but can also apply to KJFK (also TBFM enabled) with the same metering location. It is interesting. $\endgroup$
    – user14897
    Commented Jan 13, 2020 at 11:54
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    $\begingroup$ Thanks everyone. You folks are awesome !! $\endgroup$
    – TIM FESSLER
    Commented Jan 14, 2020 at 21:23

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