Downwind Autorotations?

[HCU]

We all know should you suffer an engine failure downwind you would perform a 180 degree auto to finish flaring into wind.

However there are apparently 4 defined reasons why it's bad to auto downwind - any ideas?

- Fast ground run on speed?
- Larger glide distance?
- poor IAS in relation to ground speed?
- ?

[Arm out the window]

If going for zero ground speed, you'll experience zero and then a little bit of negative airspeed in the latter stages of the flare, therefore crunching on harder than normal (eg. into a 10 kt breeze).
Directional control in the last stages would also be harder with the wind up the choof.

[SASless]

I am confused....what does "a slight bit of negative airspeed" have to do with "crunching down harder"?

[griffothefog]

Nowt, if you drive a chinook :E

[Arm out the window]

Maybe I didn't put that quite right - if a 'normal' auto had 10 kts on the nose when you got zero ground speed, you'd have a decent amount of cushioning power.
If there's some tailwind, somewhere in the latter part of the flare you'll have zero airspeed - if that's the time you're levelling and cushioning on, it'll be like doing a zero speeder in nil wind, so not so much spare collective for the cushion.
Going through that point and getting some negative airspeed might help you out from the cushioning point of view, I suppose, but the weathercocking effect would probably be a pain for directional control.

[DennisK]

My two pennorth.

Inadvisable ... final flare has reduced cyclic responsiveness and quite likely to result in a higher speed 'run on' with increased risk of roll over.

However, when teaching advanced emergency handling, there is a school of thought that says 'providing there is a reserve of height ... and particularly where the surface offers minimum landing site options ... following the failure, it can be preferable to initially 'Turn downwind.'

The procedure allows the heli to cover more of the surface and provides greater selection of suitable landing sites. Always providing the heli is returned to an 'into wind' position for the actaul touch down.

I teach the method when offering mutual advanced continuation training to interested pilots.

Happy and safe flying out there.

DRK

[A.Agincourt]

HCU (http://www.pprune.org/forums/member.php?u=202647)
http://www.pprune.org/forums/images/infopop/icons/icon5.gif Downwind Autorotations?
We all know should you suffer an engine failure downwind you would perform a 180 degree auto to finish flaring into wind.

Really? To be honest I cannot think of a single set of circumstances other than as a demonstration why not, when I would even contemplate such a manoeuvre.

Best Wishes

[Bertie Thruster]

Really? To be honest I cannot think Mr Agincourt has flown a military Gazelle low level.

[A.Agincourt]

So please explain the technique Bertie - in a Gazelle. Lets say 100 knots downwind at 50' over a set of ploughed fields. W/V - say 270/20 heading on entry 090.

Curiosity here

Best Wishes

[3top]

Hi all,

a short while ago I had a discussion about a similar subject with a "Safety Counselor".

The subject was "Downwind take off - loss of engine"

a) I do not generally promote downwind take offs.

b) In this case though it is (in my opinion...) preferable to a take-off into the general wind direction.

The hangar to take off from is at the up-wind end of the runway. Directly after the runway there is a village/town.

Downwind is all open fields, mostly level.

Downwind take off can be done over a blacktop runway or a hard grass area beside the runway.

So far I was always able to creep slightly into the wind (quartering tailwind),
obtain recommended climbout speed (60-65 IAS) before leaving the boundaries of the airport. In case of an engine failure, my selection would be in this case to run it on straight ahead (AS350B3, other aircraft may be less forgiving when putting them down at 30-40 kts....).

c) It was suggested and asked, why I would not hover downwind and then take off into the wind.

To hover downwind in the usual conditions, seems (to me...) no less dangerous than "let the bird run". Especially if it behaves well - no overly itchy tail, good power, good acceleration....

Further, even if I hover all the way to end of the runway (keep in mind downwind...) I still would have to do at least a 120 degree turn (quartering tailwind again) to avoid going over the town at less than 500 ft, although this would be at an altitude of around 500 ft.
Never the less, an engine failure at 500 ft at 70 kts IAS and I still have to go downwind before I can turn into the wind again, is not my choice if can avoid it!
The town is arranged in such a manner, that even from a 1000 ft it would be hard to find a place to go if an auto should become necessary.....

Back to the downwind hover: Obviously it would be a rather high torque, low speed situation. If a power failure occurs in this situation I would not consider it any less challenging than a run-on at 30-40 kts Groundspeed.

I had a sudden engine stoppage in a R-22 in a hover (my fault/stupidity) and was not prepared for the violent fast turn to the left!! It is quite a difference from practising a soft (or even snappy) engine failure in a hover (you are prepared for it and counting on it!), to the real thing. This "occurance" happened into the wind. Don't want to know what it looks like downwind!

My preference would be with the downwind run-on in my specific case.


d) Again! I do not promote downwind autos as a general maneuver!

Off course one has to take into account all factors in a specific case:

1 - Straight downwind versus slightly quartering downwind
2 - Engine power available for take-off (useless when the engine is gone, but struggling to stay in the air while trying to run for take-off is not good enough...)
3 - Aircraft - familiarity, tendency to run well on the ground, roll-over tendency, weight/power
4 - Terrain in case of emergency
5 - Above all, pilot proficieny


In this specific case I prefer the down wind take-off, because:

1 - Enough Power to get going fast
2 - Aircraft is very well behaved on the ground (running on situation)
3 - Aircraft has a very strong landing gear
4 - Complete avoidance of over flight of the town
5 - Fraction of time spent in adverse (tailwind) situation versus prolonged downwind hover (see my rational about hover power failures above)
6 - Terrain favorable for run-on landing


My personal choice in this specific case is to limit the exposed time as much as possible.


Of course before going towards "advanced maneuvers", one has to analyze the specific situation and if possible, practice simulated situations with a proficient instructor.
Remember, there is no old heroes!

If you are "working" with your helicopter, a lot of times you would have no choice but downwind (or any wind), because it is the only option.
No matter what, keep flying the aircraft until everything has stopped moving.
If the engine fails you really just care to be able to walk away, no matter if the airframe ever flies again - if it does, it is a bonus...


Back to lurking!

Fire away!:)

3top :cool:

[Fly_For_Fun]

A.Agincourt

So please explain the technique Bertie - in a Gazelle. Lets say 100 knots downwind at 50' over a set of ploughed fields. W/V - say 270/20 heading on entry 090.


What are you doing at 50ft agl. Another reason for the 500ft rule perhaps.

Bertie you are my hero.:D

[Bertie Thruster]

500ft? Our mil auths often used to read "transit not above 150ft agl."


A. Agincourt.....I don't think I'd be happy cruising downwind (or even into wind) at 100kt/50ft, so lets say Intermediate Pitch Setting with a 125 kt IAS approx (some cabs would give you 130kt)

1.Dowwind you had always just flown over and observed and had just behind you the terrain you would have for a forced landing if the donk stopped.

2. If the terrain just behind was ok when the donk stops;you're laughing;

3. Bang!..... Coordinated zoom climb to what height you can get at 60-70 kt (up to 300ft, if you got it going pronto,)

4. 180' turn or a/r into w/v.

5.Land, aiming for min fwd ground speed.

If, due to the nature of the terrain just passed you elected to continue and land downwind then a flare to height was still required to get the airspeed off before hitting the ground.

All this needed practice. We were given plenty. (one of our QHI's would initiate this exercise at max chat, 20-30ft downwind by chopping the throttle!! That was on a large grass airfield however and you knew it was coming......good fun though!)

I only had 1 engine failure in a Gazelle. Luckily it was into wind. (and conveniently at a 5 ft hover!)


Chuteless; spot on! I presume "GOG" is some reference to grey hair? (very little actually) Abbreviation search gave me;

"GOG: Gift of God"

[HELOFAN]

So avoiding settling with power is an answer then?

but wait there is more.

HF

[Rotorbee]

So avoiding settling with power is an answer then?

You can't get into settling with power in an autorotation. No power, no settling with it. And as we are on the subject, no ring state vortex either.

[Bertie Thruster]

PS oh to be working an aircraft that could gain 300 feet from engine failure

It made Gazelle 'quickstops' a really good coordination exercise; a twitch too much on the cyclic and you went up like a rocket.

[HELOFAN]

Oh I thought we were PRACTICING auto's downwind meant recovering with power, not sitting it down as not everyone likes to teach full downs to al students at every stage.


Course now I dont see the word practice in the ORIGINAL post so that would make me assuming and we all know what that makes us.

So then I guess I would rather the into wind auto over the with wind auto so that I still have some lift available for the nice cusioned flare rather than the crunching, heavy run on landing with wind auto.

A little more lift is better than a little less isnt it.
Doesnt VRS = SWP?

:cool:

HF

[A.Agincourt]

Fly_For_Fun (http://www.pprune.org/forums/member.php?u=209864)
A.Agincourt

Quote:
So please explain the technique Bertie - in a Gazelle. Lets say 100 knots downwind at 50' over a set of ploughed fields. W/V - say 270/20 heading on entry 090.
What are you doing at 50ft agl. Another reason for the 500ft rule perhaps.

Bertie you are my hero.:D


You might have missed Bertie's point - "military" Gazelle was specified. Military aircrew frequently fly at 50 feet AGL or to be more precise 50' above obstacles en-route when engaged on tactical operations or practising for such.

The 500' rule is not always mandatory, under certain circumstances.

You nominate hero's rather to soon methinks.

Best Wishes

[[email protected]]

We use flare effect to stop the aircraft during a normal EoL - the airflow is presented to the underside of the disc by selecting a nose up attitude which increases rotor thrust, reduces RoD and forward speed. Now try this with a 20 kt tailwind - as you pass zero airspeed you still have 20 kts groundspeed to get rid of so you pull the nose up further but nothing happens. Why? because the air is approaching the disc from behind so all the nose up in the world won't generate any flare effect. You will still hit the ground at 20 kts but with the tail striking first because you have so much nose up attitude. Or worse - you will start to raise the lever when the nose up doesn't work and hit even harder with rapidly decaying Nr.

Try a downwind approach to the hover in 20 kts of wind if you don't believe me - it takes more nose up to slow the aircraft down and more power which is the reason we teach slow walking pace for downwind approaches - flaring hard at the end because you are coming in hot will lead to embarassment.

[A.Agincourt]

Bertie:
I don't think I'd be happy cruising downwind (or even into wind) at 100kt/50ft,

Hell's teeth old boy, neither would I but I never specified that it was in a cruise profile. You'll agree I am sure, that these things always seem to occur at the least opportune moment. I have no doubt's that you have indeed carried out the above profile - at some point in time. Tell me clearly that you have not please.

so lets say Intermediate Pitch Setting with a 125 kt IAS approx (some cabs would give you 130kt)

Ok....

1.Dowwind you had always just flown over and observed and had just behind you the terrain you would have for a forced landing if the donk stopped.

As always.......

2. If the terrain just behind was ok when the donk stops;you're laughing;
3. Bang!..... Coordinated zoom climb to what height you can get at 60-70 kt (up to 300ft, if you got it going pronto,)
4. 180' turn or a/r into w/v.
5.Land, aiming for min fwd ground speed.

Agreed.........but you left off the end the following techniques available following the zoom and 180. You also are aware of course, that the manoeuvre you describe whilst usable, does have a very clear danger in terms of cyclic control and the old issue of cyclic against gut, nose down and no airspeed. Which is why a full 180 in this event is not completely without danger. But it does depend upon the W/V value. The lower the velocity the less of a problem and vice versa.

All this needed practice. We were given plenty. (one of our QHI's would initiate this exercise at max chat, 20-30ft downwind by chopping the throttle!! That was on a large grass airfield however and you knew it was coming......good fun though!)

Indeed.

I only had 1 engine failure in a Gazelle. Luckily it was into wind. (and conveniently at a 5 ft hover!)

In the scenario you proposition above, I'd recommend that following the zoom to 300 feet [or whatever is achievable] you ensure you have 20 knots plus the wind speed indicated and do not turn more than 100 degrees until you have positively identified and selected the point to go to. The turn should be a low angle [less than 15 degrees of bank] without attitude correction. Once into wind you can then adjust accordingly and as you mention, minimum TD velocity in both directions is preferable.

Best Wishes

[A.Agincourt]

chuteless (http://www.pprune.org/forums/member.php?u=78395) : A.Agincourt must own a huge amount of teddies

when he throws one away it seems to get replaced awful quick:E

I am not too sure to what you are referring. If you could post a reference or something.

Best Wishes

[muffin]

Thanks Crab - that is the best explanation of the lot.

[jab]

From downwind, 50 feet and 130 knots its going to take a very talented and wide awake driver to turn into wind from an unexpected engine failure. From experience I know that it takes a second or two to even have the brain admit that the engine has failed, despite the evidence in front of you, and only then will the reflexes take over. I would not even try to turn around, at 50 feet and 130 buttons you will not make it to an open spot you just flew over even if you are expecting it. It all sounds good in theory, reality bites.

[Bertie Thruster]

Quote:
I only had 1 engine failure in a Gazelle. Luckily it was into wind. (and conveniently at a 5 ft hover!)

In the scenario you proposition above, I'd recommend that following the zoom to 300 feet [or whatever is achievable] you ensure you have 20 knots plus the wind speed indicated and do not turn more than 100 degrees until you have positively identified and selected the point to go to. The turn should be a low angle [less than 15 degrees of bank] without attitude correction. Once into wind you can then adjust accordingly and as you mention, minimum TD velocity in both directions is preferable.


Don't know about any of that. I just pulled the lever.

[ShyTorque]

One great big reason for not landing downwind unless there's no other option is "the gatepost".

Downwind 10 kts is 20 kts ground speed worse than 10 kts into wind.

Assuming, despite the odds, that you manage, somehow, to make a smooth but downwind run-on landing in Farmer Giles' field. Then you have to contend with "the gatepost".

You first see the gatepost some tens of yards away, just as you lose directional control of the aircraft on the wet grass. The gatepost comes rapidly towards the aircraft and you suddenly realise you are going to have to stop it between your legs.... :ooh:

Turning 90 degrees to a crosswind position is better than stuffing up Nr by trying to turn a full 180 degrees.

[XV666]

Quote:
: A.Agincourt must own a huge amount of teddies

when he throws one away it seems to get replaced awful quick
I am not too sure to what you are referring. If you could post a reference or something.

Reference = 31 deleted posts in Rotorheads this month by A.Agincourt. :ooh:

New pram on order?



Back OT, not only Mil spend lots of time below 500ft. A lot of my ops are in the 50 - 250' area, filming, sling loads, etc. I make sure that my refresher training includes low level autos, with 50ft/60kts as a normal entry.

The concept of continuing on for a downwind touchdown is one that I've not considered before this discussion: I'll certainly give it some thought, but I'm not sure that I'd be happy to risk an aircraft on a training sortie :=

[helicfii]

I don't want to completely hijack this thread, but I have a question that is somewhat related:

I am an EMS helicopter based at an airport. Depending on the wind speed & direction, for departure I will either hover over to a nearby parallel taxiway for take-off, or simply pedal turn into wind and perform a max performance take-off from my helipad, directly over the power lines. Unless the wind is a very stiff crosswind or tailwind, I always prefer to use the taxiway for departure, willing to accept that I am not into wind in exchange for a more suitable area to perform an emergency landing, if need be...

My question is: Assuming the wind is about ~12 knots or less, would you prefer to accept a crosswind, tailwind/quartering tailwind in order to be able to utilize the paved taxiway for departure, or would you rather take off into wind, going right through the shaded portion of the H/V diagram?

[Overdrive]

I am an EMS helicopter based at an airport.



Wow! You can talk... and type! You EMS helicopters are much more advanced than I thought... :ok:

[Whirlybird]

Turning 90 degrees to a crosswind position is better than stuffing up Nr by trying to turn a full 180 degrees.

I wondered about that. Particularly in an R22, don't think I'd fancy a downwind auto at all!!!:( But turning through 180 degrees could be near to impossible at times. Is there anything against a crosswind auto other than the fact you now have nil wind conditions?

[ShyTorque]

As long as you can deal with the lateral drift, no.

[Bertie Thruster]

Is there anything against a crosswind auto other than the fact you now have nil wind conditions?

not being prepared for the unusual feeling of being cross controlled in order to ensure the skids/wheels land straight. (unless rolling over is preferable to hitting what is ahead of you on the ground)

[[email protected]]

Whirly - depending on which side the wind is coming from and which way your rotor turns it could have a serious impact on directional control, especially as Nr decreases during the cushion and the TR loses effectiveness.

The Gazelle (clockwise rotation when viewed from above) would run out of left pedal during the run on with any significant crosswind from the right. Because you are slowing the rotor down during the application of collective, the torque reaction works in the opposite way to normal and tries to yaw the fuselage right (in the case of the Gazelle) - this effect is exacerbated by the weathercock effect of the crosswind which is also trying to yaw the fuselage right into wind.

In my experience, the zoom climb from low level, 180 EoLs in the Gazelle were only ever achieveable as a pre-briefed exercise and in the real case would be very unlikely to work given a normal delay for recognition of the failure and the subsequent reaction.

[A.Agincourt]

helicfii: (http://www.pprune.org/forums/member.php?u=220585) Depending on the wind speed & direction, for departure I will either hover over to a nearby parallel taxiway for take-off, or simply pedal turn into wind and perform a max performance take-off from my helipad, directly over the power lines. Unless the wind is a very stiff crosswind or tailwind, I always prefer to use the taxiway for departure, willing to accept that I am not into wind in exchange for a more suitable area to perform an emergency landing, if need be...

In any event, the answer in my book is that you select that which you are the most comfortable with at that time. Some might take the view that the percentage chance of you needing the 'nicer' area for EOL is so much less than the requirement for 'alternatives' ..........always your call.

In some cases, for most of the time, there is often a greater danger from mishandling the aircraft due to adverse weight, wind, obstacles or other and or a combination. Clearly, for the most part, the chances of having everything just so are so small you can count on one hand. [If EMS can count that is] The secret for any pilot is to determine the plan of action that has the least potential unwanted consequence.

My question is: Assuming the wind is about ~12 knots or less, would you prefer to accept a crosswind, tailwind/quartering tailwind in order to be able to utilize the paved taxiway for departure, or would you rather take off into wind, going right through the shaded portion of the H/V diagram?

To my mind the best solution is usually the one where the following are true:

The value of power/pitch/Tq is the absolute minimum you can achieve, below translational lift speed, the fuselage is pointing into wind. But it all depends upon specific aircraft type characteristics.

Best Wishes

[A.Agincourt]

Whirlybird (http://www.pprune.org/forums/member.php?u=24436)
Quote:
Turning 90 degrees to a crosswind position is better than stuffing up Nr by trying to turn a full 180 degrees.
I wondered about that. Particularly in an R22, don't think I'd fancy a downwind auto at all!!!:( But turning through 180 degrees could be near to impossible at times.
Oh yes indeed

Is there anything against a crosswind auto other than the fact you now have nil wind conditions?Once established in auto, a useful technique is to reduce to minimum ROD speed and deliberately turn cross wind or anything between 45 degrees and 90 degrees [90 being the limit after which you gain a down wind component] and sit with the intended area of TD out the door on your side. Its a useful technique used to loose excessive height if the selected area is too close to you and avoiding high angles of bank and dizzying turns all of which increase RRPM requiring collective correction - dependant upon rate - which often does reduce available energy for cushioning. Your eyes are also diverted from the TD point.

If you are really too close, and dependant upon height of entry, you can go past 90 degrees and allow the wind to blow you down wind of the TD point. However, I'd never do a manouvre like this unless I had a comfortable speed and that value is pretty much dependant upon type and the strength of the wind from the surface up to about 500 feet ish.

Auto's cross wind are not a problem so long as you plan to land into wind at the bottom. Otherwise, you could be in trouble.

Best Wishes

[A.Agincourt]

Heli: "as a junior sub on 826". My pram has a current MOT and offers verrrry verrry good MPG. Does that answer your question old boy?:}

Best wishes

[A.Agincourt]

chuteless (http://www.pprune.org/forums/member.php?u=78395)
not quite a teddy but the best I could do at short notice

(don't try this downwind your glide ratio will be reduced:ok:)
http://www.freegamesonline.dk/funnyg...nnon/index.php (http://www.freegamesonline.dk/funnygames/arcadegames/kittencannon/index.php)

Thank you dear chap, excellent fun and appealed to my sense of humour. 1815 I got.

Best wishes

[XV666]

"as a junior sub on 826". My pram has a current MOT and offers verrrry verrry good MPG. Does that answer your question old boy?

Rather raises more questions, old boy. I do hope we weren't junior subs on 826 at the same time :ooh:

[[email protected]]

A.A - just exactly how do high angles of bank and 'dizzying turns' reduce the RRPM then?

The original question was not about how you position for an EoL but whether or not the EoL itself could be carried out downwind.



Ahhh - nice try AA I see you have edited your post to remove the bull;)

[Bertie Thruster]

Crab is 100% correct:

In my experience, the zoom climb from low level, 180 EoLs in the Gazelle were only ever achieveable as a pre-briefed exercise and in the real case would be very unlikely to work given a normal delay for recognition of the failure and the subsequent reaction.

In reality we weren't often exactly 180' downwind when blatting about max chat at 50ft.
So the zoom climb auto, even if a bit delayed by reaction, would give you the slim chance of a. getting the speed off and b. turning 40 or 50 degrees and landing into wind.

If possible choice of fast low level transit in Germany was over trees, at tree top height, about 100-200m inside the tree line. (There were a lot of forests in our area of interest. ) A zoom auto (in theory) would get you to the surrounding countryside!

[Evalu8ter]

I found throttle initiated LL EOLs on the Gazelle bad enough in-to wind!!!

My solution was to cheat and fly the Chinook! What wind? and great single engine hover performance (even if downwind). Hats off to those that flew heavier Gazelles operationally where this must have been a genuine concern.

I've just had a mental thought of doing a 180 EOL at LL and it brought me out in a chill - still, like FW turnbacks, if all you've got is behind you then needs must. I agree with the Trimmers on this thread, if you're confident you can cope with a X-Wind run on then any turn towards wind will reduce the space you require..but I think, like FW, it's important to have a point above the ground where you go wings level and concentrate on the tricky bit. Too many people have got fixated on the turn and not made the landing...

[Bertie Thruster]

The Army Gazelles we were operating at the time were actually even lighter than the RAF training machines;

No stab. Not one piece of Nav equipment, (not even minitans) No observer sight. Often no observer!

Like the Chinook, the Gazelle had great single engine performance..even downwind!!!

[A.Agincourt]

Evalu8ter: Too many people have got fixated on the turn and not made the landing...

A very good point, I can see no reason to enter anything other than a gentle turn through no more than 90 degrees following an engine failure.

Best Wishes

[3top]

quote:
" The concept of continuing on for a downwind touchdown is one that I've not considered before this discussion: I'll certainly give it some thought, but I'm not sure that I'd be happy to risk an aircraft on a training sortie..."


Heli, I assume you refer to my post about practising advanced maneuvers...

Certainly you would not practise (and risk the aircraft) with a actual downwind run-on auto!
BUT you can practise with a faster than usual (look for about 30 kts IAS, just before you touch - you will be slower actually touching, ....in the aircraft I have at this time - AS350B3) into the wind running on auto.
It is not so much the actual speed on touch down, but the correct attitude - IF you can manage: slightest hint of nose (skid front) low, plenty of RRPM (keeps you in control of the tail), I would not worry to much about the actual speed, but on keeping it straight after touch down....

AGAIN: I am not promoting general take-offs or autos downwind!!

In very isolated cases though the situation may prefer a downwind take-off.

There is absolutely no question, that you will turn into the wind in an auto - if you can!!

helicfii:

We may face a similar decision making dilemma.
I am having a hard time getting my point understood. I wish I could demo the case in reality, on site, with the prevailing conditions.
NOT the downwind auto, but the minimum exposed time, weighing off - into the wind versus downwind...

Your case may be somewhat easier as I assume you have a twin and fly it accordingly.
In your case it would also depend on, what is immediately after the powerlines (....for me). If you have any failure on top of or before the powerlines - what are you options?
Loosing a donk downwind on the taxiway, what are your options? Are you still flying away on the other engine?

You loose your one engine (in a single) before the lines or on top ? Where'd you go?
You think you can run the aircraft on as a gyroplane downwind?

As I said, if one even considers a downwind operation, it will always depend on the specific situation - I would not ever dream of generalizing anything downwind!!

Fly safe!

3top:cool:


PS: Volunteering for one of those all-out 50 ft/130kts sorties in a Gazelle!:O .....any direction!:O

[Bertie Thruster]

PS: Volunteering for one of those all-out 50 ft/130kts sorties in a Gazelle! .....any direction!


A sort of autorotation:

The large high tension cables were often taken at the cruise...sometimes even in pairs.

Roadside telephone and electricity wires were scraped under at a hover taxi!


On one exercise, as I moved forward to a likely FAC observation position, I hover taxied along the right hand side of a small (500m sq) wood.
My oppo, the flight commander, was moving forward to cover me on the left hand side of the wood.

3x 30,000V wires came into view to my front about 20ft high, simply slung out in front of me,running out of the trees from a pole inside the wood, at right angles to me, stretching to an unseen pole out on the right somewhere.

A quick warning radio call to the Flt Cdr. "Wires from wood... my side.. low"

"I know. Iv'e just hit them"

He had just dumped the lever and landed.

One of his pitch rods was completely burnt through.

We had no wire cutters in those days.


The Gazelle was recovered that afternoon.

He got another machine and on went the exercise.

[SASless]

Evalu8tr,

Toss in 33 or 44 field ready infantry with a 130 pounds of kit each, full fuel, hot and high takeoff as done in Afghanistan daily......and tell me about that great wonderful single engine hover capability.

Empty Chinook....well hells bells...lots of oomph in that rotor system.

[Evalu8ter]

SASLess,
Quite so chap, and I have run out of power in a Chinook a few times. The trick for a wokka driver is to remember your mortality in Afg and treat her like a "real" helo, not just in terms of power but also control authority, and plan your approaches and departures accordingly.

However, in the UK, at ISA, OEI hover IGE at full fuel (3000Kg) and about 2500Kg of troops / cargo is a happy place to be compared to most helos, you don't have any TR / MR torque considerations on the roll out and the aircaft is designed, and the crews trained, to land at up to 60kts IAS.

Best place to practise 180 EOLs? The simulator!! Though a competition to do EOLs to the Carrier in the Sim was quite interesting.....

[Floater AAC]

I think the main point here is:

1. Know you're aircraft and how it can handle. Some are good in auto, some are a real *itch.
2. It depends on how high you are and point 1. In Iraq we tried not to be much above 50ft, in which case what you see in front is what you get regardless of the wind. Or Uber high in which case you have options.
3. How competant you are. If you have a good option infront which is downwind and you are not confident of a 180 due to height etc then go for it and accept a bumpy one that you can walk away from.

When low level on my type and the others that I have been on the most you will get is 30 degrees either way. That is what has been taught for a while and that is what I have been taught to teach.

[helicfii]

I'm in the US, where pretty much everybody is flying single engine EMS. No second engine to enjoy when I suck a frog into the compressor. :uhoh:

[topendtorque]

helicfii (http://www.pprune.org/forums/member.php?u=220585)
I sincerely hope that you don't get to fly in france, engine failure for you may become commone.

Back to original question, which needs to be applauded for a probationary.

not all people have the gumption to ask, or think, what if.

May I respond by saying that I hope for you that you have an instructor who teaches you EOL's to the ground, both as a zero zero excercise and as a deliberate run on.

Never practice downwind EOL's (onto the ground I mean)

hopefully you are also taught and encouraged to practice the different flight profiles of hot, heavy all the way to light, cool, no wind, and or big mobs of wind.
Then you will deveolp a "PICTURE" that you will automatically "SEE" as to where you will get to.

You should have also been taught to always "LOOK" for where you will land "IF" the unforeseen happens.

It is fair to say that in a downwinmd situation that it is much easier to fall out of the bottom of the EOL. The answer to that is simple, you will probably have presented the aircraft in a situation where it is suddenly descending at only 300 to 500 feet per minute, with pitch pulled and the airflow is presenting ( by virtue of the downwind configuration) downward and forward of your position.

This can also happen in light winds (less than five knots headwind) where you have flared and pitch pulled and propelled your rotorwash into where you will descend.

It will never happen in a crosswind as your spent and distrubed air will be blown sideways away from you. (just get in a stationary hover at about thirty feet, in a dusty place whilst pedal turning and see what happens to your rotorwash in any sort of a wind.)

Falling out of the bottom of the EOL is not something to worry unduly about, you may touch down slightly heavy at worst.

if you had a genereous instructor to take you through all of that, then you will have the tools to decide whether at any time you "NEED" to turn to the downwiund cleared area or go into wind into the unfriendly jungle.

it's just like a tumbling excercise, if you know how to fall, do you tuck your head and roll, in the split of a second, or fall flat on your face?
good luck tet