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Hovering out of ground effect...

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Old 6th May 2007, 09:39
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cdb
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Hovering out of ground effect...

Anyone want to join this topic, I realise most eggbeater pilots seem to think ATC are put on the planet to make life as difficult as possible for you...
FWIW I handle 100 helicopter movements on a busy day, personally I'd normally have asked the heli to go behind, using extending downwind or slowing as required.
http://www.pprune.org/forums/showthread.php?t=274033
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Old 6th May 2007, 12:23
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cdb, I think shytorque has given a good idea of the pilot's view on this - high hovering is hard work, especially for a low time pilot in an underpowered machine like an R22. Coming to the hover also makes you all but invisible to other traffic as it is the movement of an aircraft that usually attracts your eyes to it.
The short answer is that pilots and ATCos should have a working knowledge of each other's jobs and limitations - usually a visit to the tower or a famil flight is all it takes - everone enjoys it and all go away with more knowledge and understanding than they started with.
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Old 6th May 2007, 12:44
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Hovering out of ground effect at altitude is just asking for trouble - read accident. Too many people have died trying this one on already. Should ATC ask for this the pilot should just reply "unable".
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Old 6th May 2007, 15:58
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Hi,
it all depends - on the helicopter, the load and the pilot.
Itīs often my daily/nightly job hovering outside ground effect - sometimes from refuelstop to refuelstop - but thats another story.
My boss gives me an appropiate helicopter and normaly I avoid hovering with tailwind.
Doing some freelancing with smaler helicopters, I easily reach the limits of the helicopter - because outside ground effect helicopters need normaly lots of power.
So its really best to reply "unable" to ATC, if youīre not trained or donīt have appropiate power available.
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Old 6th May 2007, 16:03
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It's when ATC ask you to hover OGE while in IMC that you realise their knowledge is somewhat lacking.
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Old 6th May 2007, 16:06
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The lesson is a good one:

Only the Pilot in Command is responsible for the conduct of the flight.
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Old 6th May 2007, 17:17
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I have just read the post, a student pilot recently at the airport I am currently at was on a solo circuit, the atc told him to hold downwind, yet not to orbit but to hold and hover. This is not atc procedure to ask an aircraft to hold and hover at 700ft. As the student pilot did so, and did not realise the situation he was putting himself in held the hover, pointed it into wind and then lost pedal authority in the little R22, spiraled twice while descending to 200ft agl before recovering positive airspeed with power.
Complete ignorance / lack of knowledge by atc with an instruction that is not standard to circuit traffic. This was the students 2nd solo, with the atc not understanding on the day of the near fatality that their instruction could have caused.
now I call the student lucky
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Old 6th May 2007, 17:32
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I have now properly read this thread, and it is the same incident. An mor has been filed. This was a student pilot flying, a non standard hold and hover is of fault on both parties the atc and the pilot. The only reason this has come to pass at this airport is because of some occasion, some instructors have been to hold and orbit, and they have deliberatly held a hover to show that their a helicopter " look at me ". The radar controller comes back and asks that are you holding because they can see you stationary, or tower can physically see you in the circuit. through these actions the controllers have naturally assumed that any pilot of any experience can perform any of these manoevres. Now I call that pilot LUCKY, because that student almost lost his life. Through the report that will come in the future, no doubt it will be a benefit to atc and also to the training school in making things a little more specific.
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Old 6th May 2007, 21:40
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Fluffy5 Wrote:
"As the student pilot did so, and did not realise the situation he was putting himself in held the hover, pointed it into wind and then lost pedal authority in the little R22,"


Bet you $20 he started flying backwards....unintentionally.
RH
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Old 7th May 2007, 08:04
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Fair enough guys, already mentioned I wouldn't hold a heli out of ground effect... just think your thoughts might also be appreciated on the ATC thread - I don't normally venture in here and will post a cross link.
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Old 7th May 2007, 08:22
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I thank you for posting cdb, this has brought awarness on both parties.
That instructing side at busy airports on light helicopters for students and a glimmer of light for atc. Unlike fixed wing, helicopter types have vast differences in operation, and the capacity of a student pilot learning is limited. Atc would not know differences of type of aircraft, and to say different would be completely unfair. Both parties can walk away with something to learn from.
As always keep everything pink and fluffy.
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Old 7th May 2007, 11:47
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So which helicopters are safe to hover out of ground effect?


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Old 7th May 2007, 13:57
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Yes mickjoe. I'm finding some of the points here a bit astounding. To make a generalisation about "I wouldn't hover out of ground effect" is mad.

All helicopters have to be able to hover OGE - look at the POH and you'll see the graph that proves this point.

And, as with all things flying, it's all to do with weight, power and wind. Plainly, any heli at MTOW is going to be borderline if there's nil wind or a tailwind.

The best heli for OGE hovering is the the one that's not on its limits for weight and power. And that could be a 22 with an hour of fuel and just a pilot.

And any heli with its nose stuffed into a headwind > 15 kts will be very happy.

High/OGE hovers are of course a part of training - and they are used to demonstrate incipient vortex ring.

Last edited by JimBall; 7th May 2007 at 17:07.
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Old 7th May 2007, 14:29
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It's not that one helicopter is safer than another to hover OGE - it's that hovering at 50 -100' is not the same as hovering at 500 -1000' - all the hover references are much further away making precise control more difficult.

Because the hover references are further away it is much easier to end up flying backwards or sideways without realising it and whilst an R22 may have enough power to hover OGE, there isn't much left for manoeuvering and an inadvertant descent usually follows. A normal hover scan doesn't usually include the VSI (RCDI) but this is vital in high hovering.

We do a lot of high hovering (500 to 1500') for FLIR searches and having an aircraft with a dopplermeter (hovermeter), a decent stab and a bar alt/rad alt hold makes it much easier. Doing the same thing in an R22 without any of the above is more difficult, especially if you haven't practised it before.
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Old 7th May 2007, 16:43
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As with all things aviation, currency rules, I regularly hover a 22 at altitude, its no great shakes and a scan of the vsi does become part of the routine.We were holding oge at stansted the other day 2 up trying to look for one on finals and we just didn't have the power, but you then just try into wind and if you can't hold that then tight orbits.Hovering OGE was covered during training as far as I recall.
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Old 7th May 2007, 17:04
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It's really interesting/frightening reading some of the things posted on this site from time to time....

Where do some of you people fly/work anyway? Many of you make the simple act of flying a circuit or taking a machine from A to B sound like some sort of newsworthy feat.

Hovering a helicopter OGE is safe, as long as the pilot is aware of what's happening. Is it something you want a 30hr student doing? Probably not, but as far as blanket statements saying it's unsafe... well that's just ignorant.


RH
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Old 7th May 2007, 23:40
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Where do some of you people fly/work anyway? Many of you make the simple act of flying a circuit or taking a machine from A to B sound like some sort of newsworthy feat.
Aint that the truth.


Last edited by Bronx; 8th May 2007 at 15:17.
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Old 8th May 2007, 11:31
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Could someone kindly explain:

If, as suggested, a heli can't hover and remain stable without some forward speed, how do the pilots of, for example, police and rescue heli's seem to manage it?
 
Old 8th May 2007, 11:51
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I used to remember, and they probably still do, Army Lynx's hovering with the HeliTele thing high up above Belfast, especially during the marching seasons. Any experts care to say if it was easy with the Lynx or not? I expect with all the weight etc it probably needed skilled pilot to do it or am i wrong?

And by the way im not saying mil pilots are not skilled!!!
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Old 8th May 2007, 14:35
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They're stable, it's just that some of the visual cues in a low hover are missing.

If you sit at 1000ft and just look out, you'll find it hard to tell if you're descending or not so you have to include a scan of the VSI as part of your instrument check.

Likewise as you slow from forward speed to nil

(a) you lose translational lift so you need more power
(b) the need for large pedal inputs can sometimes catch you out the first few times and the machine suddenly swings on them as they counter (a) and find that they suddenly get affected by weather-cocking.

And the wind direction and velocity at altitude isn't the same as it is on the deck either.
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