Hovering out of ground effect...

[cdb]

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

[[email protected]]

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.

[Brian Abraham]

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".

[Flying Bull]

Hi,
it all depends - on the helicopter, the load and the pilot.
It´s 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 you´re not trained or don´t have appropiate power available.

[Farmer 1]

It's when ATC ask you to hover OGE while in IMC that you realise their knowledge is somewhat lacking.

[NickLappos]

The lesson is a good one:

Only the Pilot in Command is responsible for the conduct of the flight.

[fluffy5]

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

[fluffy5]

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.

[remote hook]

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

[cdb]

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.

[fluffy5]

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.

[mickjoebill]

So which helicopters are safe to hover out of ground effect?


Mickjoebill

[JimBall]

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.

[[email protected]]

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.

[Twiddle]

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.

[remote hook]

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.:ugh:


RH

[Bronx]

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. :ok:

http://www.websophist.com/Laughing_RoflSmileyLJ.gif

[clifftop]

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?

[petop]

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!!!

[Twiddle]

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.

[Overt Auk]

More to the point is the penalty for getting it wrong. Sink a little in a low hover, the ground cushion increases, descent stops, end of story.

Start sinking in a true free air hover, apply power to stop the sink, re-circulate your downwash and end up in a vortex ring state, requiring determined inputs and possibly thousands of feet to recover. Not funny if you only start at hundreds.
OA

[Bertie Thruster]

Someone mentioned Belfast.

Reminded me of “Number 32 of 101 things to do in a helicopter”

…. At 1500ft over the City it was important to keep your morale up when sent up for the umpteenth time that week on surveillance work. There was nothing to do but hover.

In one spot.

For a long time.

After flying to collect an "observer" you would fly over the City and stop where you were told by that person sitting beside you.

The civilian clad but heavily armed, operative sitting beside you would then start eyeballing something through high-powered gyro-stabilised binos. They had their own comms that the pilot could not monitor. You had no idea what they were looking for. All the pilot had to do was maintain position.

If you were lucky the operative was female.

So now the added challenge was to fly the helicopter without using your left hand!

The Gazelle you were flying was quite basic; no stabilisation, no stick trim.

The trick was to gently position the helicopter so that the observer ended up twisted hard to the left in order to observe. That way she was facing completely away from you.

After a bit of practice it became possible to almost “balance” the Gazelle using the tiniest movements on the cyclic to instantly correct for any immediate movement up or down showing on the VSI. A little headwind wind helped and the heading control had to be held nailed.

This meant that your left hand became “available”. The collective friction was set just enough to hold the lever where it was. It was possible then to move your hand away from the collective and towards……..the right thigh of the female observer!

The tension was great. First, the helicopter was at very low speed and at high power; an engine failure meant instantaneous recovery of your left hand to the collective (or die). The engine failure also meant an always very exciting auto entry from the hover and finally it would ultimately result in a sporty landing into somewhere quite tight in the City where people (then) weren’t all friendly.

Secondly though and perhaps even more seriously, what would happen if you didn’t just hover your hand an inch over the female operators thigh but accidentally touched it? What would the reaction be?

She had a Heckler-Koch and 300 rounds.

Just how long could you hold your hand an inch above her leg and hold the machine steady at the same time? Oh, the tension!

Sad days a long time ago.:hmm:

[Chukkablade]

'She had a Heckler-Koch and 300 rounds'

:ok: Absolutely loving your work B.T., loving your work:D :D

[Whirlygig]

Careful Bertie, she might have been a cousin of mine!

http://clarityandresolve.com/idfGirlM4.jpg

Cheers

Whirls

[ShyTorque]

10,000 feet (or more, depending on the windspeed) is an interesting altitude for an OGE hover, especially at night, lights out and transponder off, of course. We did have the luxury of cross hairs on the AI showing the along and across Doppler motion but it had to be flown by hand. The best / quietest way to get there was a climbing quickstop; less blade slap to alert those on the ground. Mind you, it was interesting when you ran out of power and the aircraft just fell out of the sky. In this case we gained some airspeed before vortex ring set in, flew away and came back a thousand feet lower and tried again. Once established, we used to set max. continuous power and accept the altitude it gave us and stay there for an hour or more. We couldn't tell ATC exactly where we were and we faded from radar once we slowed right down. We once watched a set of nav lights, travelling at speed, which turned directly towards us. We eventually chickened out and descended rapidly, only to see a B737 pass directly over us, exactly where we had been hovering. We discovered later that the military charts didn't yet show the new airway; we had been hovering right in the middle of it. I might have finished my days as a radiator mascot on one of the first scheduled aircraft to fly in it. :hmm:

[[email protected]]

Yes Shy but whose thigh were you trying to touch at the time - I know what you 230 boys were like:)

[ShyTorque]

Crab, good try - but it was 33 Sqn :p

[[email protected]]

They come over to Ireland, once in a while...etc..etc

The ending of the song is the same - you just add 230 or 33 but the mists of time have dulled my memory - I forgot that 230 was still in RAFG then:)

[ShyTorque]

When I was first on 230, they were at Odiham, yer cheeky young sprog! ;)

[[email protected]]

Was that on Blenheims or Beaufighters?:)

[ShyTorque]

Well, I'm not quite that old (even though, as I'm sure you know, 230 never flew either of those types)!

It was Pumas (those plastic helicopters that folk said "will never last" - ever since 1971). They were getting a bit tired in 1979 when I first flew them but seem to have "settled in nicely" since their "end of life update".

36 years ain't bad for a plastic cab!

P.S. Bill Parry, one of the crewman I went through the OCU with, started life as a flight engineer on Lancasters!

[[email protected]]

No but they did have one or other type at Odiham during the war.

Yep the Puma keeps on going....it's a testament to how toothless our Flight Safety system is; how many BOIs have recommended the addition of anticipators? The same crashes keep on happening!

As for your crewman - I think we've still got some Masters in the SAR force who are nearly that old:)

[Whirlygig]

Jeez, Crab and ShyT, sounds like you two need to get a room! :} :D :E

Cheers

Whirls