Why Is a Plane Circling? Common Reasons and How to Check

A plane usually circles because it is waiting to land, practising, or working over one spot. Airliners that circle high above a city are almost always in a holding pattern. Small planes circling low near an airfield are often on training flights. Aircraft that orbit for an hour over a field or a neighbourhood may be doing survey, photography or police work.

You don't have to guess. If the aircraft broadcasts ADS-B, a live flight map shows its callsign, type, height and track, and that usually tells you which of those it is. Here is how to read the signs.

Check planes over your city

The quick way to find out why a plane is circling

1. Open What's overhead and share your location, or open the planes over cities page and pick your city.
2. On a city page, look at the Circling or loitering count and the section called Is a plane circling over your city.
3. Note the type and height of the aircraft listed. That alone answers most cases: an Airbus at 9,000 ft and a Cessna at 1,200 ft are circling for very different reasons.
4. Tap the flight to see its route, origin and destination on the live map.

Reason 1: a holding pattern while waiting to land

When an airport has more arrivals than it can land, controllers park the extra aircraft in holds. A hold is a racetrack: two turns and two straight legs around a fixed point. The aircraft flies laps until a controller clears it onward.

The FAA spells out how holds are flown in the Aeronautical Information Manual (AIM 5-3-8):

That last line is useful when you see a plane in a hold on a map. The crew has been given an "expect further clearance" time, so the hold has a planned end. And because each straight leg lasts only a minute or so, a holding plane keeps passing over the same houses, lap after lap.

Busy airports use the same holds every day, often stacked one above another. Heathrow has four: Bovingdon, Lambourne, Ockham and Biggin. Heathrow says the levels in each stack are 1,000 ft apart and the bottom is around 7,000 ft, and that aircraft "fly in an oval pattern to wait for a landing slot" (Heathrow). If you live under one of those stacks, circling jets are part of daily life.

Anything that slows landings, such as bad weather or a closed runway, means more aircraft waiting in the holds at once.

Reason 2: training circuits near an airfield

Flight schools teach take-offs and landings by flying the same loop around the airport over and over: take off, turn, fly parallel to the runway, turn, land or touch and go, repeat. From the ground this looks exactly like circling.

The FAA's rules for this loop, the traffic pattern, are in AIM 4-3. Propeller aircraft enter the pattern at 1,000 ft above ground level, and "unless otherwise indicated, all turns in the traffic pattern must be made to the left", except for helicopters. Airports with right-hand patterns mark them on the charts.

The Chandler screenshot above is a good example. The circling section lists fixed-wing aircraft with the type codes C172, C72R and BE23, all small single-engine planes, at 1,200 to 1,300 ft, each staying within a few kilometres of one spot for 12 to 16 minutes. Small planes going round at circuit height look a lot like training traffic. GodsView can't tell you that they are training, and the registration on each flight page is the way to check who operates them.

Reason 3: survey, photography and inspection

Aircraft that map the ground fly lawnmower lines or tight orbits over one area for hours. So do planes taking aerial photos, checking pipelines and power lines, or counting traffic. These are usually small planes or helicopters at a few thousand feet or lower, often with a private registration rather than an airline callsign.

On a flight page, the registration is the clue. Look it up and you'll often find a survey or photography company as the operator.

Reason 4: police, news and emergency aircraft

Police aircraft circle to keep a camera on a scene. News helicopters do the same over a fire or a traffic accident. Air ambulances sometimes orbit while waiting for a landing site to be cleared. Most of these are helicopters, and some don't appear on public maps at all.

There is a separate guide for that: why is a helicopter circling my house.

Reason 5: dumping fuel or sorting out a problem

Occasionally an airliner circles because it needs to land early. Some aircraft can jettison fuel. When a crew needs to, the AIM says they should tell ATC, and controllers then broadcast a warning "immediately and every 3 minutes thereafter" giving the location, altitude and type (AIM 6-3-5). The controllers' own manual sets the separation: in cloud, the dumping aircraft is kept at least 2,000 ft above the highest obstacle within 5 miles (FAA JO 7110.65, 9-4).

A crew working through a technical problem may also hold for a while before landing, to run checklists. If that is the case, the aircraft may be squawking 7700. The squawk 7700 guide explains the codes, and the emergency squawks page lists aircraft on an emergency code right now.

Reason 6: going around and trying again

A plane that comes down toward the runway, climbs away and comes round again has done a go-around. Pilots do this when the runway isn't clear, the approach isn't stable or the wind is wrong. It is a normal, trained manoeuvre. On a map, it looks like a loop back to the start of the approach, then a second landing a few minutes later.

The AIM also describes practice approaches, where a pilot flies the approach and then goes around on purpose, often several times in a row (AIM 4-3-12). Training jets and turboprops do this at regional airports.

How GodsView decides a plane is circling

Every planes over city page watches the low aircraft near that city once a minute. An aircraft is flagged as circling when, over the last 20 minutes of positions, it has turned through a full 360 degrees, or it has stayed within 4 km of one spot across at least four positions spanning six minutes or more. The page then tells you how long it has been there and how tightly it is circling.

That catches holds, training circuits, survey orbits and helicopters hovering over a scene. It doesn't catch aircraft that don't broadcast. Many military flights, some police aircraft and most drones never appear on public maps. And a city page that has only just started watching may need a few minutes before it can call a turn a circle.

What's flying over me?

Circling at night

Planes circling at night are usually doing the same things as by day: holding, training (flight schools fly at night too) or police work. You can't see the aircraft type in the dark, so the map matters more. Check the height first. Airliners in a hold sit at several thousand feet and you hear a steady jet roar. A light aircraft or helicopter at under 2,000 ft sounds closer and changes pitch as it turns.

If the aircraft on the map is a helicopter over a residential area at night, the helicopter guide covers who to ask.

When to worry, and who to call

Circling on its own is almost never a sign of danger. A few things are worth noticing:

• An emergency squawk. 7700 on the map means the crew has asked for priority.
• A very low aircraft over houses. FAA rules set minimum heights over congested areas for planes (14 CFR 91.119). Noise from low-flying aircraft is not treated as a safety issue, but if an aircraft looks like it is flying unsafely, the FAA asks you to report it to your local Flight Standards District Office (FAA).
• Noise. For noise from your local airport, the FAA says it is best to contact the airport manager or staff first, since airports are chiefly responsible for noise around their facilities (FAA).

For everything else, the map is enough. If you want to keep an eye on your own area over time, add it to My places, and read what's flying over my house for how to match a plane in the sky to the one on screen.