Title: Helicopters Flying In Circles – Why Do They Do That? – Pilot Teacher
Headings: Helicopters Flying In Circles – Why Do They Do That?
Helicopters Flying In Circles – Why Do They Do That?
Why Do Helicopters Circle Overhead?
Why Does A Helicopter Circle Before Landing?
Circling Vs Hovering
Hovering
Circling
H/V Diagram
To Finish
Further Reading:
Rick James
Aircraft Cockpits: Why Are There So Many Buttons!!?
What Do Pilots Use iPads For? More Thank You Think!

Content: As the helicopter begins to accelerate the main rotor system begins get a hand from aerodynamics and the power required to keep the helicopter flying reduces. At 6o knots this is when the power required to fly is at its lowest. Once the helicopter goes past this speed, drag on the aircraft begins to require more power to overcome it and push the helicopter through the air. By flying orbits at 60 knots it allows the helicopter to use the least amount of power, which means the least amount of fuel burn, thus the pilot is able to remain on scene much longer than just sitting there in a hover. H/V Diagram
The H/V or Height Velocity Diagram is a diagram issued by the helicopter manufacturer that tells the pilot when a helicopter could be landed safely if their engine were to stop. This diagram is based on height above the ground and airspeed. Height and airspeed are the two best friends to a pilot in an engine failure situation and having both are great but what if you only have one…
If I have lost you, just hang in there and I will explain: If the aircraft is low and slow when then engine fails then the chances of the helicopter making a safe autorotation landing are slim. If the helicopter is low and fast and the engine quits the pilot may be unable to slow the helicopter down in time before it sinks and contacts the ground. In the diagram above, to avoid these scenarios, the pilot will accelerate to around 50 knots while staying 5-10ft above the ground then begin to climb away.