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It's not uncommon for GA aircraft to circle in the pattern for separation purposes. Does that ever happen to big commercial jets?

Imagine an airliner were cleared for a visual yet forced to execute a go-around and instructed by ATC to take a pattern. When there's another traffic on final, is it a viable option for ATC to instruct the jet to make a left or right 360 for the traffic on final? Does it actually happen in the real world?

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Yes, it can happen, but it's pretty uncommon.

Airliners arrive at the destination airport having been sequenced by ARTCC ("Center") and Approach so that they are showing up in an orderly sequence, spaced out so that there is adequate room between them. They may be set up for an ILS, or they may see the field and accept a visual approach, but either way the flow is generally quite predictable and orderly. VFR traffic, by its nature, is less controlled and ordered, so it's more likely in that sort of an operation that you'd have two aircraft in positions to arrive at the runway at about the same time, so a solution like a 360 on downwind or on final becomes necessary. With a flow of airliners (and other IFR traffic) spaced out at 3-5 miles apart, that solution would create as much trouble as it would solve, because now the conflict is with the aircraft behind the one that circled, rather than with the one in front of it.

What does happen more frequently, is the 360 happens much farther out from the airport, and that's called "going into holding" due to traffic saturation. Maybe the airport is over-loaded with arrivals, or it had to suspend operations while the active runway was changed from 18 to 36 (or whatever they are at a particular field), or there is weather affecting the approaches which slows down the rate at which it can accept arrivals. The Approach and Center controllers will work to keep the flow of traffic coming into the airport neat & orderly, which means delaying aircraft before they get to Tower's airspace (i.e. the "traffic pattern"). Ideally, they will do this with speed adjustments to get the desired interval, but sometimes the delay needed is more than speed adjustments alone can accomplish. Then they'll put the arrivals into holding for however long it takes until they can start sending them in again.

That's the more common airline version of a "360 on final"... doing 360's with 10 mile legs on a really, really extended final -- 100+ miles out!

In the case of a go-around that turns downwind, rather than a 360 on final, the typical solution would be to extend turning final out until there is adequate space. Staying on downwind past a 5 or 10 mile base & final is highly undesirable for a VFR pattern, but for airliners where everybody has an ILS and doesn't really have to maintain sight of the runway, it's no big deal. For big airports, extending the traffic pattern out to longer finals is highly preferred over having jets circling on final.

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    $\begingroup$ I was speaking to a controller about this just recently, who said they much prefer to give a plane long slow S-turns to increase their spacing rather than a 360. You can fine-tune spacing with an S-turn, but once you start a full-circle turn, you have to finish it, and if it takes too long, then you have more spacing than necessary. $\endgroup$
    – abelenky
    Commented Jul 15, 2017 at 15:25
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    $\begingroup$ As a passenger, I've seen it twice. Once, landing at JFK on an MD-11, it was already in final, full flaps, landing gear down, when the pilot applied full power, landing gear up, flaps up, completed the 360, flaps down, gear down, and then re-entered the final and landed. An, another time, on a CRJ700 at a small airport. $\endgroup$
    – Martin Argerami
    Commented Jul 15, 2017 at 22:04
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It can happen in China. I've heard of cases where ATC ordered a widebody to do a 360 to stay clear of other traffic at cruise level. Didn't get another flight level but had to fly a 5 minute 360 instead.

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  • $\begingroup$ Actually a standard 360 degree turn will take exactly 2 minutes, not 5. A standard rate one turn is 3 degrees per second. $\endgroup$
    – 60levelchange
    Commented Jul 16, 2017 at 10:00
  • $\begingroup$ @J.Hougaard Talking about "at cruise level" I suspect he means a 5 minute holding pattern. Not what you & I think of as "a 360" but the distinction between a racetrack vs a continuous turn may often be lost on pseesengers. $\endgroup$
    – Ralph J ♦
    Commented Jul 16, 2017 at 13:43
  • $\begingroup$ @RalphJ I agree, but I thought it was worth clarifying regardless $\endgroup$
    – 60levelchange
    Commented Jul 16, 2017 at 14:03
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    $\begingroup$ @j.hougaard Jet aircraft at cruise levels will typically be bank limited and incapable of performing standard rate turns. Even if not incapable, half standard rate is more typical at cruise, at least for my operation. $\endgroup$
    – J W
    Commented Jul 16, 2017 at 14:09
  • $\begingroup$ @JWalters Exactly, for those looking for more info, see: What is the standard rate of turn for heavy aircraft? $\endgroup$
    – Lnafziger
    Commented Nov 16, 2018 at 17:33

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