Why the Plane Circles Before Landing

A Queue in the Sky

A runway can only take a certain number of landings each hour. When more planes arrive than it can handle, air traffic control asks some of them to wait. Planes can't stop in mid-air, so they fly a gentle loop instead. This is called holding.

What a Hold Looks Like

A hold is shaped like a racetrack. The plane flies a straight leg, makes a gentle turn, flies back and turns again. Each lap takes about four minutes.

At very busy airports, several planes hold over the same spot, stacked 1,000 feet apart in height. As the lowest plane leaves to land, the others step down in turn. London Heathrow, for example, has four of these "stacks".

Why It Happens

• A busy hour — lots of planes arriving at once.
• Weather — strong winds or fog mean fewer landings per hour.
• A runway change — sometimes a runway is briefly closed for an inspection.
• Spacing — controllers keep a safe gap between every arrival.

Is There Enough Fuel?

Yes. Before take-off, the pilots check the delays expected at your destination and add fuel for them. Every flight also carries fuel for a backup airport, plus a final reserve. Read how much fuel a plane carries.

Controllers also give the pilots an expected time to leave the hold. If the wait ever grew longer than planned, the pilots would simply fly to the backup airport — well before the spare fuel ran low.

What You'll Notice

• The plane levels off and the engines get quieter.
• Gentle turns every couple of minutes.
• An announcement such as "We've been asked to hold for about ten minutes."
• Then the descent continues as normal.

If You're Feeling Nervous

• Think of it as waiting at traffic lights. Nothing is wrong — it's just busy.
• Air traffic control can see every plane in the stack and keeps them all apart.
• Use the extra minutes for a breathing exercise, music or a podcast.

Sources

• FAA, Aeronautical Information Manual, Chapter 5, Section 3 — holding procedures and leg timing: https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap5_section_3.html
• SKYbrary, Holding Pattern: https://skybrary.aero/articles/holding-pattern
• Gatwick Airport, Airspace: Holding Stacks — aircraft in a stack are separated vertically by 1,000 ft: https://aircraftnoise.gatwickairport.com/wp-content/uploads/2025/02/Airspace_Holding_Stacks_2024_v6.pdf
• Wikipedia, Heathrow arrival stacks — the four Heathrow holding stacks: https://en.wikipedia.org/wiki/Heathrow_arrival_stacks