Why do police helicopters fly in circles instead of hovering?
When police helicopters are using their spotlight at night, they always seem to fly in circles around a stationary point. Why not just hover in one spot? Would that not be easier and less fuel consuming?
- 1 decade agoBest Answer
There can could be many reasons why a Police helicopter circles a crime scene rather than hover. Here are a few reasons why this could be.
1. If hovering and a vehicle runs from the scene the pilot then has to go from hover to forward flight possibly losing time. Also if there is another call more important than the current scene the helicopter just veers away if circling.
2. Presents a less easy target to shoot at. You say people shoot at Police Helicopters? Yes they do and where I live in Albuquerque, New Mexico a Sheriffs Helicopter was shot down in 2004 while over a possible crime scene seriously injuring the pilot and observer. During the 1992 Los Angles Riots people were shooting at Police Helicopters and because of this pilots sat on bullet proof vests for protection. And just 2 months ago a Police Helicopter in Rio, Brazil was shoot down by rival gangs. If hovering you present an easier target to hit than circling though a good shooter could shot even a circle helicopter.
3. Hovering takes concentration and leaves the pilot less able to observe the scene he is flying over.
4. As others stated the height need to hover at is to high to be effective in observing the crime scene.
5. If hovering you want high altitude so if there is engine failure you can auto-rotate were the rotors spin in the other directions to reduce the sink rate of the helicopter.
Hope this helps.
- JoyceLv 44 years ago
How does a helicopter fly? A helicopter can take off and land vertically (straight up and down). It can fly in any direction, even sideways and backwards. It can also hover or hang in the air above a given place. A helicopter gets its power from rotors or blades. When its rotors are spinning, a helicopter doesn't look much like an airplane. But the rotor blades have an airfoil shape like the wings of an airplane. So as the rotors turn, air flows more quickly over the tops of the blades than it does below. This creates enough lift for flight.
- Anonymous1 decade ago
Every helicopter has a "Height-Velocity" or H-V diagram that shows the safe operating zones. In order to hover safely, the height would likely have to be too high for useful surveillance, and as mentioned, hovering is less efficient than forward flight.
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- Anonymous1 decade ago
the helicopter in forward flight is more stable than in hover.
it has lower fuel consupmtion as well.
moreover, hovering at night in higher heights above terrain is difficult and to some extent angerous. you cannot refference your position to the terrain like you do during day. Obviously there are missions that require that.. like night time hoist or slingload operations, rapelling deployment of rescuemen, however if you can avoid hovering high in the night, you avoid it.
finally, like the other answerer said, if the helicopter hovers in certain height and engine fails, transition to autorotation may be beyond the capabilities of common pilot. because of that, the helicopter maintains certain speed to be out of the dangerous height-velocity combination. the dangerous combination starts at about 25 feet above terrain and ends at about 230 ft. above that, the pilot has plenty of time to commence autorotation and gain forward speed (since vertical autorotation requires more vertical speed than the forward flight autorotation, so you avoid the vertical one if practicable)
summed up, the way they do it, is the more efficient, less consuming and more convenient way.Source(s): flying SAR and HEMS.
- 1 decade ago
The pilot of a Helicopter will try to maintain forward airspeed so that in the case of an engine failure he has adequate airspeed to successfully perform an autorotation. In addition to enhanceing the autorotation ability of the aircraft it reduces the amount of power required to operate because the aircraft is operating in translational lift. Below that speed the helicopter is, in essence, hovering which requires large amounts of power.
CM24Source(s): 40 years of flying helicopters
- 1 decade ago
Could they be concerned that the helicopter could become a target?
Watch out for the ghetto bird!!