There are two main scenarios you may have seen a helicopter circling: either it was a police helicopter or a helicopter was circling before landing.
Police helicopters circle for a variety of reasons, including to search an area for a fugitive, to use less power compared to hovering, to not be a sitting target and minimize the chances of getting shot, and to avoid settling in their own downwash, which can be dangerous.
Helicopters circle before landing because it is the best way to view an area from all sides and determine the best direction for approach to ensure a safe landing.
4 Reasons Police Helicopters Circle
1. To Survey an Area
One of the main reasons police helicopters circle is to survey an area when there is a fugitive on the run.
From at an altitude of 1,000 feet, a police helicopter has an excellent vantage point and can easily survey a wide area
As police helicopters are equipped with thermal imaging equipment and spotlights, tracking the movement of suspects when circling becomes much easier.
2. To Use Less Power & Fuel
Everyone is aware of a helicopter’s unique ability to hover. But not as many people know that hovering uses a very large amount of power and fuel compared to forward flight – i.e. circling.
So when you see a police helicopter or any other helicopter circle, this has the added benefit of reducing the engine load and conserving fuel, though it may not necessarily be the main reason why a helicopter is circling at the time.
3. To Avoid Being a Sitting Target
It may not happen often, but police helicopters have been shot down.
If a helicopter is just hovering in place, then it becomes a sitting target and is much easier to shoot down compared to if it is circling.
4. To Avoid a Downwash
Every time a helicopter hovers for a long period of time close to the ground, it can result in settling in its own downwash.
This can cause significant damage to nearby vehicles and objects, as well as people.
While climbing to a higher altitude can help avoid this, this option isn’t always available to police helicopters, considering they need to operate lower than most other helicopters.
It’s therefore better for a police helicopter to fly in circles to avoid this.
Why Helicopters Circle Before Landing
Helicopters circle before landing to give the pilot the best possible view of an area from all sides to ensure a safe landing.
When circling, a pilot can also determine the best direction for approach to ensure a safe landing.
When circling, a pilot may assess the following:
- Wind: Landing into a headwind requires less power, which makes for a safer landing
- Objects: Trees, buildings, debris, people, and other objects may affect how and whether a helicopter can land
- Wires: Wires can often be hard to spot without actively looking for them, and can pose a serious danger to helicopters
- Slope: Landing on a slope greater than 5-10 degrees can be dangerous
- Sun: The glare of the sun can obscure vision when attempting to land