Why do police helicopters always fly in circles while news helicopter hover in one spot? Is it to avoid criminals opening fire at them, or is it because there is a difference between the two types of helicopters?
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4Same question: Why do police helicopters fly in circles instead of hovering?. However, I agree with others that police helicopters can just hover. I have seen them just floating above a point during street protests. – Robert Werner Nov 01 '15 at 19:04
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1@Energizer777 It's amazing how many people who don't know what they are talking about comment with authority. One of the answers in that question includes "auto-rotate were the rotors spin in the other directions". – Simon Nov 01 '15 at 20:17
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3This is just a comment because I have no references, but it seems to me like there's a strong advantage to being on the move because it is harder to dodge the helecopter's lights if they are constantly changing angles. – Cort Ammon Nov 02 '15 at 05:48
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4News copters want to deliver a stationary image whenever possible as it's what they want to show viewers. The police don't care about that. – GdD Nov 02 '15 at 10:09
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1I've never seen news helicopters hovering... @GdD I don't think stationary images has any relevance, as all news choppers I have seen have a stabilized camera which produces very steady images under most conditions. – Michael Nov 03 '15 at 02:06
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In Boston where I live the police helicopters and the news helicopters all circle and rarely hover stationary. I have seen a police helicopter stationary over the harbor, but never over the city. Sometimes the helicopters over a newsworthy event look like a Lufbery circle, and I assume they circle because stationary craft could easily drift into collision. – A. I. Breveleri Dec 16 '16 at 16:09
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Police helicopters don't always fly in circles. I've often seen my local police helicopter hovering. There are a few reasons you might have seen police helicopters flying in circles:-
- Not all types of helicopter can hover out of ground effect. It might be that the police helicopters in your area can't hover at the heights they work at, with the weight of their usual equipment.
- Helicopters are safer if they're moving forwards than hovering. In the event of an engine failure, they can autorotate to land safely, but they need to have some airspeed to be able to do this. The required airspeed depends on height (see the chart in the linked question), so if your news helicopters are usually operated higher up than police helicopters, they may be able to hover safely. (This is quite likely, as police aircraft are exempt from the 500 ft rule and the 1000 ft rule, while news helicopters are not.)
- Police helicopters often circle to search an area for a fugitive or casualty using thermal imaging cameras. News helicopters tend to either follow a vehicle or hover to get a steady camera shot of a news event.
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I also believe there is a risk of vortex effect that makes one lose all lift suddenly when hovering (in no wind situation). – v.oddou Jun 21 '16 at 01:53
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5@v.oddou Vortex ring state doesn't just happen randomly in a hover. It can be caused by descending too fast with too little horizontal velocity, or by extreme downdrafts. See http://aviation.stackexchange.com/questions/16108/how-do-modern-helicopters-tackle-vortex-ring-state – Dan Hulme Jun 21 '16 at 07:41
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@bogl Could you ask that as a new question? That way anyone can answer and you'll probably get some illustrated examples. – Dan Hulme Jul 09 '17 at 17:48
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@DanHulme Helicopters are not subject to the 500 ft rule, please see FAR 91.119. News helicopters can circle or hover just as low as an LE helicopter. – Richard May 03 '18 at 16:22
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There is little difference between the helicopters used by news crews and police. It is their operation that differs.
Flying instead of hovering helps minimize the chance of getting shot. There has been incidents when law enforcement helicopters have been shot down.
Forward flight (at low speed) uses less power compared to hover. This reduces the engine load and increases the time spent over target.
Police helicopters fly pretty low compared to the news helicopters. Hovering for long periods can result in one settling in their own downwash. In this case, the altitude can help news helicopters to gain forward momentum to get out of this. As this option is not available to police helicopters, it is better for them to fly in circles.
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3Would another possible issue be a desire to avoid making viewers dizzy? – supercat Nov 02 '15 at 02:52
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8@supercat: I suspect that is the actual answer. The question is backwards: flying forward is safer and more fuel-efficient than hovering out of ground effect, so the question should rather be: why would a news helicopter not do that? BTW: I don't know how feasible it is to use a helicopter as a sniper platform (outside of Hollywood, that is), but in that case, they'd probably be hovering, too. – Jörg W Mittag Nov 02 '15 at 07:09
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From what i know USCG use helicopter as firing platform (not to accuracy of sniper though). – vasin1987 Nov 02 '15 at 08:59
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Helicopters have been used in combination with snipers, but it's less precise than firing from a stable non-vibrating object like a building or elevated terrain – Chris V Mar 05 '16 at 22:37
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As far as I'm aware you can only have settling with power (vortex ring state) in a descent of more than 300-500 feet per minute with significant power applied. Not being in a hover – Chris V Mar 05 '16 at 22:41
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Hovering for long periods can result in one settling in their own downwash- no it can't. In order to settle with power, you must be descending and if you're descending, you are not hovering. You can hover until the fuel runs out, you get cramp or the next person needing the helicopter starts waving their arms in strange patterns. – Simon Apr 11 '16 at 17:46
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Often the police helicopter is out looking for the target. A circle is a search pattern. News typically has a known target they just need a shot of.
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