EOLs

[DennisK]

Hi guys & gal,

We all know that if you ask three pilots for the best sequence of control handling for a standard engine-off landing, you're likely to get four answers. So can we have some tips please.

My standard teach is. After the standard pre-exercise checks ... Establish what I call a 'steady state' descent in autorotation, (rrpm & airspeed steady, slip ball centred, wings level) ... at say 50 to 65 knots & 75% to 90% max auto rrpm for most piston types adding circa 10 knots for the smaller turbines. Depending on type, weight, air density and w/v - commence a 'progressive' cyclic flare at around 30 to 50 feet AGL. In the latter stages of the flare, progressively introduce 50% of available collective lever to reduce ROD and increase rrpm so that for a second or two both cyclic and collective are pulled to minimum achievable groundspeed and positioning for the desired landing point. As airframe approaches say 10 to 20 feet skid height - still in the tail down attitude ... forward cyclic to level the skids. Allow airframe to sink to the 'skids on' position progressively raising collective lever, co-ordinated, but 'in arrears' to the observed sink rate. As skids make contact, no further collective or cyclic movement but using yaw pedals to maintain direction if a 'run-on' landing is made. With aircraft stationary, cyclic and yaw pedals are centralised and collective lever lowered gently to minimum position.

So guys ... that's me ... lets have the options please. Dennis K.

[Epiphany]

Not sure what Elf and Safety would have to say about that Dennis. Surely far too risky? Do engines actually fail these days? Does anyone teach EOL's outside of the mil? Last real one I did was at MW in the 1980's.

[Sven Sixtoo]

Whether they fail or not, I would want to know what to do. The thought of it all going quiet and the Nr going through the floor at a couple of thousand feet with no idea what to do next would keep me on the ground.

And it's not only engine failure that results in an EOL. Gearbox malfunctions
and tail rotor failures both may lead you to EOL.

Sven

[puntosaurus]

I don't think many people I know would teach the use of the collective before the flare is over and the ship levelled, unless for control of rrpm.

[the coyote]

puntosaurus, I disagree.

I was taught a basic auto (ie first lessons) in a small piston like this:

1. Lower lever fully - rapidly and smoothly, ensure its fully down.
2. Maintain the attitude - dont let the nose drop, don't let it roll, keep it in balance.
3. Check the RRPM is restoring
4. Set the attitude for the desired speed - we used 55KT in R22 and H300 nil wind
5. Turn into wind
6. Control RRPM as required with collective, middle of the green
7. Hold your speed until the groundspeed seemed excessive
8. Flare smoothly but positively as required to lose the groundspeed you need to lose (ie back to a safe run on speed, or zero speed, depending upon terrain)
9. Hold the flare until you had lost the speed, or were concerned about a tail strike and it sinking out
10. A short pitch pull on the collective (only a couple of inches or so), at the end of the flare, to further reduce groundspeed and prevent it sinking out
11. Immediately level the ship and cushion it onto the ground with collective as required, ensuring its straight.

[Whirlygig]

Does anyone teach EOL's outside of the mil?Oh yes.

Just tried to armchair fly the maneouvre after a glass of Rioja ... but I don't think I was taught to raise the collective during the flare ... Flare, Level, Check.

Cheers

Whirls

[Epiphany]

Flare check level cushion - 3 Riojas.

[Whirlygig]

The debate could run and run ...

http://www.pprune.org/rotorheads/19323-f-c-l-f-l-c.html

3no. Riojas now consumed but still .. Flare, Level, Check :)

Cheers

Whirls

[212man]

introduce 50% of available collective lever to reduce ROD and increase rrpm

I presume you mean "decrease rpm"?

[topendtorque]

I presume you mean "decrease rpm"?


increase, momentarily, Monsieur Coriolis will explain.

whirls
i'm with epiphany, but I make it four riojas (FCLC) or seeing as how its only three particpants in the riojas then we should even it at the next logical common demoninator and consume four each.

usually only in a big wind can you get away without an initial, "check."

[GoodGrief]

The aircraft levels with application of collective, not cyclic.
Give an inch or two on the lever at the end of the flare and it hangs in the air and noses over. Works nicely. Thanks to Shawn and Gordy for getting me there...

[Arm out the window]

Depends what aircraft you're flying.

Not saying it's the only way, but I like and cast my vote for:

1. Establish in auto at desired speed with collective fully down.

2. At the right height (type, DA, wind etc dependent, use your good judgement...), flare.

3. When you've washed off enough speed, or the tail's getting too close to the ground, whichever comes first (ideally both at once), do a little pitch pull - short, sharp movement on the collective, maybe an inch or so.

4. Cyclic forward to adopt the landing attitude - skids level.

5. Freeze collective, keep straight with pedal, let it settle.

6. As skids reach a bee's dick above the ground (technical measurement term there), cushion on with remaining collective.

7. When the ground slide stops, lower the collective.

8. Congratulate yourself on a job well done.

[[email protected]]

To check or not to check........I think it depends on the inertia of your rotor system - the flare, check, level, cushion worked well on the Gazelle in the mil for many years and the same technique is taught on the squirrel.

However, something like an R22 is a different kettle of fish and applying 50% of the lever before you have the skids level and are cushioning will decay the Nr very rapidly (TET would love you to explain how Mr coriolis manages a slight rise - the coning effect and CAV will be massively opposed by rotor drag)

On larger mil helos the approved technique is not to check but use flare, level and cushion with the level and cushion being a coordinated movement.

Personally, on the Gazelle, I used to encourage a small amount of lever application during the initial stages of the flare to utilise the extra Nr generated to increase rotor thrust, especially on the heavy Army ones. The teaching for the check was to wait until the flare started to lose its effect and anticipate the 'sink'.

The crucial element is always to get the skids level and land straight, most EOLs are survivable if you do that - this requires forward cyclic - helicopters generally are not self-levelling:)

Ultimately everything is variable in a variable flare EOL, the flare, the check the level, and the cushion all depend on the conditions of the day and the aircraft mass and C of G, not to mention the landing area.

[rotorfan]

I'm with crab on this, specifically regarding the R22. However, I took the previous posts to suggest a slight tug on the pole, not 50%. Regardless of the amount, the R22 RRPM decays so quickly, I don't want to pull the pole any sooner than the "cushion", because there just isn't a whole lot of cushion there.:eek:

[Peter-RB]

My lady Instructor at EGNH, impressed her tight control on EOLs right from the word go, at first the butterflys alway hit me with that dumping of power to simulate the problem but after a few more lessons it becames almost second nature and held no fears for me, Like wise a really good man then showed me in the 206 which amazed me as to the total lack of hurry that big rotor (cmpared with the R22/44) induced almost a calmness that the Robbies didnt, I was fortunate to have been taught to complete run ons on both C/crete and grass, and they way DK suggests is exactly as I have been shown and indeed done., being at EGNH I nearly aways had the help of the wind, still conditions made things just a tad faster until head started to control the hands.

On a check ride I ws shown by Geoff Day some additional moves but I think they were only for bigger and heavier craft not the range I fly.

But on the whole EOL do not worry me, but ask me after I have landed.!!

Peter R-B
Vfrpilotpb

[puntosaurus]

I should have mentioned that the majority of my own experience teaching EOLs and those I work with has been in R22s. There's a neat part of the Robinson Safety Course presentation which shows the energy of the R22 in HP seconds, so you can see how long the height, the speed and the rotor inertia will keep you up. From memory the latter is less than 5% of the total from 2000ft and 70kt, so not much to play with. I'm sure it's a different story in other machines.

However I've never come across anyone in any machine on my profile who teaches use of collective prior to the levelling the ship, unless to control rrpm. Even rrpm control during the flare is a little moot in a real world (as opposed to training) situation. I've always thought that was a sensible rule because real world EOLs are not marked for artistic impression, only survivability. By keeping the rotational inertia till the very end you give yourself the best shot at the landing.

Now there are plenty of machines I've not flown (including the Gazelle which has a very long tail) so I can only speak from my own experience. But given that caveat, I would say that once you start teaching people to fiddle around with the collective during what is already a busy time, you're opening the door to (more) mistakes.

[topendtorque]

(TET would love you to explain how Mr coriolis manages a slight rise - the coning effect and CAV will be massively opposed by rotor drag)


easy, get a piece of string with a weight on the end of it. swing it around in a circle at a constant speed, then shorten the string a little and see how it speeds up.

same as the diameter of a coning set of blades reduces.

Mr C talks about all those fangled things like - cetrifugal forces - and - sum total of masses and energy -, but really the bit of string is easy to demonstrate and happens well before any extra drag shows up.

one more red please.
tet.

[drop lead]

TET
Your string and weight example is a demonstration of the conservation of angular momentum...not Coriolis Effect ! (or possibly the Red effect) :)

[Fareastdriver]

E O Ls as I was taught.
Close the throttle, full flare and lever to the bottom.
Establish 65 knots, raise the lever 2 notches on the collective indicator and establish 1,500 rpm on the engine.
Trim the flying controls. (For/aft lateral wheels in the cockpit.)
With luck the Rrpm will be at about 2 o’clock on the gauge, adjust if necessary and turn into wind and your landing point is straight ahead; if it is OK carry on. (It’s a practice.)
Pull the slow running cut out to stop the engine. (This is so the engine control cam does not open the throttle when the collective lever is pulled on landing.)
At 100ft AGL flare the aircraft to kill off most of the groundspeed.
When the ground starts to swallow you up pull full collective and slight forward cyclic to ensure the aircraft is rolling forward when it lands. (This is to stop the undercarriage splaying in a zero speed condition that would cause the tyres to roll in off their rims.)
After landing ensure the blades do not hit the cockpit roof as your lower the lever and RESTART THE ENGINE. (This is important, the droop stops were not very reliable and there was a good chance of the blades chopping into the boom.)
When everything is stabilised rotors running on the ground you realise that as your instructor was following through with both hands he actually did it all for you.
That was how I was taught on the Bristol Sycamore in 1965. Supercharged radial engine, wooden blades, trim wheels, they have it easy now.

[EN48]

The implication so far in this thread is that EOL technique needs to vary with type. What do the pro's suggest for the B407?

[waragee]

I believe this is a Sycamore, pic take in 1989 near Kununurara. I think story goes, Engine failure, succesfull auto but blade strike. Company base in Adelaide and new engine + blades trucked up, road so rough that new blades damaged in transit, Airframe abandoned.


http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs631.snc4/59087_436608632866_736382866_4990643_8309162_n.jpg

[Helinut]

Dennis,

I would say your run through was about right. How much check lever at the end of the flare is going to be type specific depending on inertia: the best comparison is between the R22 and the B206. AS is also more critical with the low inertia machines IMO, because you are using the KE to power the flare and cushion. Too little AS provides not enough KE, too much AS is hard to get rid of in the flare.

Someone (ex mil, I guess) was saying how the non military world did not seem to do EOLs. I suspect that would be your experience if you only were exposed to twin engine training/operations. Most ME heles have full training EOLs banned in their AFMs. EOLs are a requirement of all S/E skill tests in the UK. I guess there is a risk assessment in there that EOL for ME is less likely and the potential repair bill for practice EOLs correspondingly greater.

For many years I flew just MEs and EOLs got remote. I have recently started flying S/E again and feel reassured to have that extra tool back in practice.

[handbag]

Sounds picture perfect for light singles Dennis. The same overlay technique should be used for teaching power recoveries and touchdowns - but of course I respect that you've been flying longer than I've been walking :cool:

[mikelimapapa]

I used to teach an opposite approach. Higher A/S around 70kts, RRPM bottom of the green, just above the horn. During the flare, LOWER collective fully, hold until you are about to fall thru, level, settle then pull.

This accomplishes several things; first you can flare more aggressively without ballooning up ie quickstop, which reduces your ground run. Most of the time you will be practicing this on a paved surface, but real world slower touchdown speed will keep you from rolling over. Second you are guarenteed to see a large increase of RRPM so you have more to cushion with at the bottom. Thirdly and most important for low inertia systems is that with zero pitch you reduce your rotor decay between leveling settling and pulling.

I've taught this technique to 20+ students(including DPE/FAA examiners) and it works like a charm in the 22/44/300. Only difference is the 44 requires less aggressive flare and in the 300 you don't have to play with the lever as much. The only other variable is how high you can level and still get away with a smooth touchdown. 22 being the lowest <8ft, in the 300 you can get away with 10 maybe 12ft and the 44 15-20ft as long as you wait to cushion.



DISCLAIMER: This technique only works with 2 people in the aircraft. The reduced weight of solo ops requires you to maintain higher RRPM throughout the manuver, because RRPM will not significantly increase during flare.

[perfrej]

OK, I've read all the posts. I have one question that bothers me a bit.

Higher RRPM gives a greater rate of descent. So, in the flare, wouldn't the best practice be to not build up too much of it? That gives a better arrest rate of forward speed, which, in turn, reduces the risk of rolling over.

Some of my instructors have practiced this and made the autorotations at very low RRPM - in a 206 90% and 90kts - which takes you a really long way past your expectations, followed by a long flare with a fairly high amount of collective pitch and a really smooth touchdown with zero forward speed. Just before touchdown, the RRPM has been a bit below 100% indicating a slight buildup for good margins in the actual cushioned ground contact.

I understand that this is not possible to the same extent in helicopters with low inertia rotor systems, but at least not build up RRPM to the red line or above.

[topendtorque]

TET
Your string and weight example is a demonstration of the conservation of angular momentum...not Coriolis Effect ! (or possibly the Red effect) http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif


Hmm here we go again, the old bookshelf, rummage rummage, oh yes here we are, dust an all. Not the first one I owned someone stole that, this is a 1979 model but still word for word the original.
FAA Basic Helicopter Handbook p 14/15, a couple of excerpts.

“Coriolis Effect, when the blade of a three bladed rotor system flaps upward, the centre of mass of that blade moves closer to the axis of rotation and blade acceleration takes place and conversely.....To a lesser extent in a two bladed system when it is underslung....
The tendency of a rotor system to increase or decrease its velocity in its plane of rotation due to mass movement is known as Coriolis Effect, named for the mathematician who made studies of forces generated by radial movements of mass on a rotating plane...”
Of course formulae for the conservation of angular momentum follows.
More red please.
tet

[[email protected]]

TET - raise the lever to get the lift, the flapping and the conservation of angular momentum and you increase drag as well as lift so the blades slow down because the engine isn't driving them any more.

Lever up in auto = Nr down.

[parabellum]

rotor pedals to line the skids up in the direction of the ground run.


Assuming you have the luxury of a ground run. My only EOL for real was in an AB206A and the terrain did not allow for any run-on.

Flare>rapid check>level>cushion on with remaining collective.

[Fareastdriver]

waragee

It's a Sycamore all right. It wasn't there when I was flying out of Kununuara in 1999.

Kununuarar--Truscott--rig--Truscott--Kununuara

[topendtorque]

TET - raise the lever to get the lift, the flapping and the conservation of angular momentum and you increase drag as well as lift so the blades slow down because the engine isn't driving them any more.

Lever up in auto = Nr down.


every one here talks about RRPM increase in the flare, so do I. the flare and sometimes a quick click on the collective will convert the ROD and airspeed into RRPM -and - slow the aircraft down in both directions.

Now, here we are sitting fat dumb and happy with a decaying nr, (admittedly with a higher drag configuration on the M/R than during flat pitch and descent mode) settling and awaiting the cushioning pull of the remaining collective. No arguments from me at all.

Each action, the flare and the quick click on the lever, has the reaction of coning the blades and thus moving their mass inwards, that is why they increase in RPM. the trick is to make sure that the static auto RRPM setting is right, not too high or that increase may be over the redline.

my shout or yours?

[spinwing]

Mmm ...

That Sycamore has been there for at least 40+ years that I know of .... can't for the life of me remember the details ... lost way too many of those memory cell thingys...


:hmm:

[Shawn Coyle]

The sequence of flare / level / collective check is very much type dependent, and also has a lot to do with the CG position relative to the mast. A forward CG will allow use of the collective check to level the helicopter, as the CG and thrust vector (small as it is ) want to align.
For teetering rotor machines, trying to level with the cyclic is not as effective as it is in fully articulated types, as the small change in tilt of the thrust vector produces very little effect. For that reason, using collective to assist in leveling is most effective in those machine. But a Bell 206 or R-44 will normally have much more effect in leveling using collective than an R-22 because the CG is further from the mast. A 206 loaded with an aft CG (lots of stuff in the baggage compartment and a single pilot, for example) may not level using collective only, so Beware!
The only other things I'd like to add to this discussion is that the purpose of the flare is to stop the rate of descent - anything else that happens is a beneficial side effect.

[[email protected]]

TET - the flare increases the Nr - the pull, check or click on the collective does the opposite.

If you check whilst flaring, the flare effect may well overcome the extra drag from the check but raising the lever does not increase Nr no matter how quickly you do it.

It is feasible, with an aft C of G, that raising the lever will bring the nose up slightly effectively giving an increase in the flare effect but it is still flare effect that is raising the Nr.

[waragee]

Fareast
It was well off your track,I put the Sycamore roughly at 70nms at 218degrees from Kununurra from memory
Amazing fabric covered blades like the wing of a fabric covered airplane. How was the auto re inertia and so on? I bet the hot radial could take a bit of starting sometimes post auto.

spinwing
In another pic I have you can see the trunk of the tree he collected, still standing there cut off at blade height, also some of the engine.

[Nigel Osborn]

I think that sick.a.more is the one Jim Ferguson of Rotorwork put down in the 60s.:(

[Savoia]

.
Ciao Dennisimo!

I wonder if you can even count the number of engine offs you have performed - it must be in the multiple thousands by now - and I am sure you're procedure has brought you down safe and sound every time!

Great thread Maestro!


My only EOL for real was in an AB206A and the terrain did not allow for any run-on.


Mine was also in a 206A (converted to a B) which was eventually bought by Dennis Kenyon, G-AYTF. According to PPRuNer TRC it was caused by a failure in the turbine's P2 line.

We were at approx. 700ft agl and with no place to go except straight ahead where, mercifully, there was an open field. The field had fairly large furrows running roughly east-west and we were southbound out of the Team Lotus headquarters at Hetel and therefore set up to land across the furrows.

Sincerely, I can't recall whether Bob introduced a touch of collective prior to levelling but, given the brevity of our descent and the available time, I don't think so.

There was no possibility of permitting any forward speed, with forward momentum the furrows would have tipped the little Ranger on its back! For this reason the flare was extreme, it seemed as if we were almost vertical at one point but, we levelled and cushioned with zero forward speed, a gentle touchdown and the 'Dancer' (G-AYTF) was intact. It was the Colonel at his best!

This incident is recalled on another thread and one thing I learnt from it is that in a genuine scenario, unless this procedure runs through your veins, well - scrambled eggs come to mind!

http://www.tc.gc.ca/media/images/ca-publications/exercise13a.jpg

At Point 4. the 206's nose-high attitude was pronouned just prior to a 'smart' (rapid) level leading into a zero-forward-speed cushion.

With Dennis' one time chief flying instructor 'Antonio' (Tony 'Nobby' Clarke) I was taught the 'collective-in-flare' technique but as an option to increase/decrease Nr according to the intended landing profile, zero-stop, run on, etc.

In the days when I used to fly commercially I regularly attended refresher courses in the US and have to voice my admiration for the various instructors I encountered there. They were among some of the most professional and well disciplined aviators I have come across, with heaps of proficiency in power-off landings, and which familiarity was conveyed with confidence during their training exercises.

Here for your perusal, the Alabama State Troopers practicing autos in one of their Kiowas.

E2a9H8Xw8Mo

S.

[Davey Emcee]

"half a crown sixpence" springs to mind !! :)

[[email protected]]

EOLs in a 206 are hardly challenging, watch an R22 doing them with a couple of fatties inside and you will see "half a crown sixpence" :)

[rotorfossil]

I remember the Sycamore as well. Quite the most specialised EOL technique compared to any other helicopter I've ever flown.
Best technique for the R22 is level the skids and apply collective at the same time so that the skids achieve the level attitude at the moment of touchdown. Works for most other types as well if you fly multiple types, although they all have their own ideal techniques that may work better depending on blade inertia.

[Earl of Rochester]

Not sure if anyone is interested in seeing a 'perfectly' executed auto but .. in case you are .. here you go:

A8CgMEnoyVo&feature=related

Pretty much how I seem to remember my base checks. ;)

I went through the clip using the pause button intermittently in an effort to discover evidence of collective application in the flare and decided that I couldn't decide! But I think not.

Re: 'checking in the flare' would that procedure not be ideally suited to something like the Hughes 500 where rrpm can deplete (from what I am told) quite rapidly?

Earl

[Hughes500]

Have to check in the flare in a 500 otherwise you will exceed max rrpm, espically if you " stand it on its tail" The technique for a 500 is the same as for a 300, she comes in a bit faster with slightly higher rate of descent but no problem really. Obviously not the same as a 206 but still quite easy

[parabellum]

EOLs in a 206 are hardly challenging, watch an R22 doing them with a couple of fatties inside and you will see "half a crown sixpence"


Is that so!!!:)

I had four up, it was Indonesia, (+33, 85%), the engine failed when we were at 700' and I only had a small clear area to go, didn't fancy the trees! (Aircraft flew again as soon as spares arrived).

[DennisK]

Thanks for the note Savoia and I'm so glad you produced a good EOL to preserve my old friend, G-AYTF. I do have a piccy of her taken at Leeds Castle parked inside the moat when she was in the JPS all black & gold JPS colours, but having just moved home, it is in storage. But no doubt it was dear old 'Nobby Clarke's specialised EOL technique you learned that saved that particular day. And yes ... I do actually log every practice 'full stop to the ground' engine-off landing and having been instructing now since 1974, my log book has recorded 3,868 events as at 30 November. Oddly in my 14,250 hours, I am still waiting for the real thing ... and I bet it gets me when I least want it. But being three quarters retired, I may just get to beat the odds.

Back to the many EOL techniques discussed here. Naturally the use of any amount of 'up' collective drops the RRPM, but that doesn't take into account the advantage of combining the early use of collective with cyclic flare. Used by itself, a firm aft cyclic can ... as noted here ... take Nr beyond the max PFM limit, especially so at high a/c weights, but using the combined flare/collective method allows the pilot to use a firmer flare where the rrpm is held at the max Nr figure using collective. With good co-ordination of the two controls, a zero speed touch down can usually be obtained if there is any sort of breeze. At lower a/c weight, no breeze is necessary.

Like many of the 'old uns,' I've been lucky enough to take the old Fort Worth pilot course where the Bell aces showed me the Jetranger technique from 175 feet AGL and a zero ASI reading. Firm lever down gets the airflow under the horizontal stabilisor which pitches the nose down sharply without any cyclic control change by the pilot. Zero speed becomes 60 knots by 75 feet AGL allowing the standard flare recovery for a zero speed skids-on landing.

Bell also demo'd the EOL from a 40 foot AGL hover ... lever rapidly fully down and back up again at around 10 feet. Useful for the air photo pilots who get asked to manoeuvre low level.

'Elf n Safety ... Don't try this at home without a type experienced instructor. AND avoid a high speed run-on landing on the 206. Them pesky transmission lamiflex links attached to the M/R transmission are around $2,500 at the last count. The standard pre-flight check on the tell-tale 'spigot' will reveal all.

Keep the ideas coming please, Dennis Kenyon.

[topendtorque]

oK crab, i'll go quietly i knew I had bombed that last post when I was trying to go to sleep, but been a bit busy to get back and correct it. lifting the collective will reduce nr.

however please bear with me, momentarily that is not the case, when recovering from an overspeed and you jerk the collective up, there is an agonising half second where the nr does not follow the rule book at all. in fact speaking from the experience of every mustering pilot which might happen to them hundreds of times in a the one or two very windy and choppy days in the year at low level with gusts to 30 35 knots if stationary in the hover the nett effect is more collective - more wind over the sails-, the nr increases, because the blades are being flapped up, the governor reacts by reducing MAP by up to 3.5" then of course increases to counter the then resultant effect of reducing rpm. this is a 2 to 3 second sequence somedays this occurs every twenty seconds or so.
In my case i usually turn the governor off as I can't stand the feeling of tearing the guts out of engine, drive belts and xmon every twenty seconds.

back to EOL's. the most important thing Dennis is to make sure before you start teaching them that the student understands the best range airspeed from the AFM, and will acquire it immmediately; where the wind is coming from (even when he is asleep) is going to continually acquire suitable EOL sites as his flights unfold, and can deomonstrate going into them in an into wind final appoach; how to get the collective fully down sharply and will check his RRPM when done; and will tell someone about it.
put that together, many don't, then they may get close to the ground in a safe manner.

Then, further previous reference to the AFM will tell them the best A/S to be at before the termination stage, flare etc.

their capacity to accomplish that last bit will be predicted by the amount of time their ab-initio instructor spent with his hands off the controls rather than on them. it is very irksome at the operational level to have to allow and encourage people to find their own way when it should have been done right at the beginning.

very few also understand the full down bit on the collective, that is because they were taught in aircraft which had the auto RPM set too high and had to constantly adjust to keep it within the green arc. I nearly always have to go through the whiteboard bit about weight between minimum and max auw varies equally the different RRPM all the way through the engine off allowable range; and how the correct as per the Maintenance manual setting will give the lowest ROD and also allow the use of the full collective lever at the bottom.

[charlesp]

Hey Dennis
can't believe you are talking about that old dog - had to go and find one of the old log books - last flew TF in 1980 with Colin Chapman (Lotus boss, for those that don't know!) from Hethel to Liege for Belgian GP on 30 April and then shuttling between Villers and Zolden on 1st May.

Within months was back on S61, S 76 and Bell 214ST's - EOL's on all very different - but I like your recipe for the 206, worked well for me with BCal at Shoreham - and you should know after so many years telling the tale!

[Savoia]

.
Found this almost zero-flare auto-touchdown mildly interesting. The approach seems to utilise the lower extremity of the Nr limit.

CJGvm1IOgwk&feature=related

S.

[Brilliant Stuff]

I thought you couldn't have pax on board during training EOL?

[DennisK]

Well ... remember how I opened this thread .... three pilots - at least four answers! I haven't actually counted the variation of engine-out handling procedures offered, but I think I qualify for a QED.

Thanks S for the 206 video, but I'd estimate the ASI was showing 50 knots most of the way down and was not what I would describe as a constant attitude/no flare technique. Using the ubiquitous Enstrom as my example, and for the right student pilot, I occasionally teach the 'constant attitude technique to achieve a pin-point touch down.' The exercise is ... 20-30 knots maximum ASI reading while holding a 'steady state,' near vertical autorotational descent (w/v dependent) ... wings level, stable lever position (mostly fully down) when, in the Enstrom, the cyclic can be trimmed to a 'hands-off' position.

Looking through the chin windows, the target needs to be held in a constant position relative to the yaw pedals. (at this point I often mention to the handling pilot ... that if he does nothing else - he will at least hit the target with his feet! Holding this attitude ... 'til around 20-30 feet, firm collective lever only is introduced to arrest the ROD and bring the skids to a short duration hover say 4 - 6 feet above the surface. Note absolute nil use of cyclic to this point. The helicopter is allowed to sink the final few feet using the remaining rrpm to cushion the final skids touch-down. The required judgment at the point of the first lever movement is quite critical and to get the timing right, that wonderful old CAA war horse, Ken Reid used to teach me to say to myself .... " Not now .... pause ... NOW!" I call this method 'the flopper' and is what I would use for real to make a landing in one of London's back garden sites or at night since there is absolutely no 'run-on.' With a few practices, a slight refinement becomes available since the first raising of lever results in the airframe picking up a couple of knots forward speed which can be corrected by combining the smallest amount of aft cyclic as the lever is first raised.

When that lovable guy John ZZ was instructing, between us and using the constant attitude technique, we'd lay a £5 bet on who could get the nearest to a nominated target in the training area. The target was the said note pinned under a brick BUT the winner had to collect his winnings without getting out of the seat!

The usual side note ... please don't try this at home without a type experienced instructor and a few knots of breeze always assists practice dramatically. Bye for now to all ppruners.

Dennis K.

[rotorfossil]

Because of the steep angle of descent in a Constant Attitude autorotation, the ASI can have very large pressure/position errors, dependent on the position of the pitot and static.
In some helicopters including the R22, holding 20-30kt will almost certainly result in bent skids as the ASI over reads a lot and about 40 kt IAS is about the minimum. The same was true of the Bell 47 G4A, but not the G2 model which had differently a positioned static port.

[DennisK]

Yup .... totally agree & should have added the ASI error note. Thanks fossil.

Dennis Kenyon.

[Savoia]

Two examples of autos with run-ons:

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The 206 certainly manages run-ons more effectively on 'shorts' (low skids).

nutnbgy_-Ow

H500 run-on .. make sure the ground is smooth!

Note: The second half of the video digresses somewhat.

[Hughes500]

Savioa

Not a very good eol there i am afraid unless it is very hot ( doesnt look like it) or very high , dont know ? The guy hardly flares at all, shouldnt need to run on more than anout 2 to 3 ac lengths not half an airfield !

[Savoia]

I did wonder at one stage whether our sheep-loving brethren on the far-away isle were perhaps practicing a t/r control failure but, given the auto-intro, one supposes not .. unless of course such failure was additionally simulating an over-speed .. and which I suppose is perfectly possible!

In reality most engine failures in singles require zero (or near zero) forward speed touch-downs and these, in my view, are where one should hone one's skills.

The 500 is 'nippy' (read descends quickly) during autos but I remember too that her main rotors were remarkably responsive with just slight manipulations of pitch required to enliven or tame Nr.

The 500 remains the best 'fun' I've ever had in a rotorcraft. Oh, except for this time I flew a Singaporean model in a 206 but that, as they say, is another story. ;)

[Savoia]

More Hughes autos:

5-V_NO7YIbE&feature=endscreen

I have to say that I never did practise high speed run-ons in the 500 so I don't know if this is how they are usually performed. I also do not recall the 'snap' style flare .. but, there we are, there are so many different techniques.

[hillberg]

Too much speed at the bottom end, Slow it down to best climb speed and reduce the need for a hard flare, Never had it slide over 6 ft, the hard part is making up for high DA at low gross weight,

[Hughes500]

Sav

Both of those EOL's not great the instructor is levelling the machine out too early hence the long run on. If he held the flare for another 20 to 30 ft before levelling off the result would be a lot kinder to the skids !

[SASless]

Anything over two skid lengths ground run is a failure in my book.

More helicopters are destroyed due to getting tripped up in soft ground or hitting obstacles that catch a skid than are ever hurt by too short a ground run and too much vertical speed.

[Gordy]

I'm with SAS on this one......

[Thomas coupling]

Definitely aircraft specific, but the raw ingredients remain the same:
Pick your descent speed to get into the LZ! Everyone talks about EOL's as if they will always have a football pitch in front of them:oh:
Turn as much into wind as possible.
Switch the engine/fuel/igniters OFF.
Flare to reduce your g/s such that you will make your LZ.
Check before you level on some helos and level and then check on other a/c.
Finally raise the remainder of collective to minimise ROD and cushion the landing.
Ideally always train to do a zero zero.

PS: Raising the lever during the flare will never pitch the helo fwd - where did you get that from? The cyclic is in your crotch by then anyway??

NOTHING is more satisfying than an EOL. I had the privilige of teaching every conceivable type of EOL in both the sports car of the helo world (Gazelle) and the SeaKing before the hierachy decided the latter was too risky.

Best ones were doing Staff SCT PFL's to an engine off to a letter on the airfield. The skids had to land on the chalk to qualify.

The best "commercial" EOL I have ever seen is Mike MS's on the Treasur Hunt programme when he landed on top of some balloons in a 206. Beautiful.

You Bet | Castle Air Helicopter Challenge (Treasure Hunt / Interceptor) - YouTube

[Ready2Fly]

Stunning :ok:

[Vertical Freedom]

:ok:;) WoW :eek::ok: Awesome precision :cool::O:)

[Hughes500]

I thought you werent supposed to do EOL's to the ground with floats on in a 206, mind you 10 years since I have flown one ?

[Savoia]

H500: You may well be right when it comes to fixed floats for (as you probably know) the 206 doesn't have a skid under the floats (unlike the 500) but .. as far as I remember there was no prohibition on performing autos with the emergency 'pop-outs' fitted.

However, in the 80's many insurance companies were wary of providing cover for power-off autos in 206's fitted with high gear (into which category the pop-outs fitted).

I imagine that with fixed floats (and unless one was landing on water or ice or performing a zero-forward-speed touch down) one might just end up on one's nose!

[Thomas coupling]

Hi Hughesy: I can't remember when he did this, but at a guess perhaps 20yrs ago??? Anyone?

Ironically - Mike MS lost an engine in his 206 crossing the channel a while after making this programme - and by all accounts did a superb EOL. No-one hurt.

[Dennis Kenyon]

Sure agree ... a great piece of 'theater flying' by Mike and an absolute joy to see his precision handling. Just a pity the finished product as broadcast included too many clips where Mike was NOT in autorotation, but that is the film business as we all know.

I would still take the view that where a precision target landing is necessary, especially when surrounded by obstructions, the 'constant attitude' method is more likely to be successful.

Going back to the MD 500 EOL demonstrations. I agree with 500 that neither approached anything like what can be achieved by a type experienced handler. I teach and expect my pilots to make a zero ground speed touch down at anything other than max AUW or L & V wind conditions.

Some pruners might know of the 2005 WHC event, where I attempted to touch down 'skids on' to coincide exactly with Ravel's famous 'last bar slide into A Major' finish to his Bolero. The manoeuvre occupied precisely 13 seconds from 400 feet to skids on the ground. Don't ask me why I keep such useless facts in my head!

And lovely to see dear old G-SHCC floating around, the second of Starline Helicopters SH series Jetrangers which was sold to that affable Welshman Gwyn Humphries circa 1988 ... and as we all love original registrations here, the others 206s in the series being, SHBB, SHJJ, SHRR, SHVV and the Mark Thatcher SHZZ. Take care all and a really, merry and happy Christmas. God bless us ... everyone!

Dennis K.