Practice Autos from 100FT / Hover

[BlenderPilot]

Back in 1999 I went to PHI-Petroleum Helicopters Inc. just for the training (the airline I worked for sent me there), Bell 206 recurrent ground and flight training, PHI said since we had never been there before it was going to be treated as an Initial Pilot Course, and this included autos to the water in a float equipped 206 from several areas of the shaded area of the HV diagram, 80FT/Hover, 100FT/Hover, up to about 200FT/Hover, and as I understand it was the way they did it for all their pilots.

After the training and doing this type of manuver I realized it is a basic manuver that could easily save your life in many instances.

Many pilots never practice or learn to do, autos from the the shaded area of the HV diagram, and from reading posts in this forum some pilots consider it almost impossible.

So I would like to know if any of you have practiced this manuvers, what aircraft, and what you think of this manuver? Do you think all companies should have their single engine pilots practice this manuvers?

A large number of pilots due to the nature of their work have to spend a lot of time flying within the shaded area of the HV diagram, out there helicopters can't be flown like airplanes all the time and I think its interesting that some pilots who routinely due to the nature of their job (or just for fun) fly in this conditions and don't even know how to do this type of auto.

[Bladestrike]

I've only had two instructors over the years that took me for an auto from a 100 foot hover (thats going on 20 years this year). I don't think its the standard but for anyone spending time at the top of a 100 or 200 foot longline........it should be

[low height bug]

BlenderPilot

I remember an instructor at NTPS telling me that the shaded area on a HV chart should not be called the avoid curve but the “area of increased vigilance” as helicopters are designed to work there (but not fail very well from there).

Not being a helicopter pilot (or pilot of any sort) could you elaborate on the technique used for this particular flight case. Presumably you are talking about engine failure in a single engined aircraft. How valid is the technique when starting with a rotor speed that is likely to be below the datum speed (as I am assuming it was when you were training) due to the IDT (intervention delay time) resulting from the time taken to recognise and react to such a failure?

lhb

[[email protected]]

Blenderpilot, were there any wind limits set on these failures, especially minimum ones? In a 206 you can make a survivable auto from many configurations that would kill you in an R22 or similar low rotor inertia helicopter.

I know you are referring to my comments on the 'cap thrown at helicopter' thread but many people fly low inertia rotor systems and if they think they can get away with EOLS from deep inside the HV curve they are wrong.

Bear in mind 2 things - 1. you were practising these hover EOLs ina controlled environment, you knew the failure was coming and therefore there would be no delay between throttle chop and lowering the lever (not a realistic representation of the real world or the HV curve data) and 2. you were doing them to water with big cushioning floats on, not with skids to a hard surface (again not representative of the real world).

You mentioned in your post on the other thread that when you did this the lever had to go down and up again lightning fast and the resulting landings put "crayfish on the windshield" so if the student made any error at all how was the instructor going to rectify the situation?

I am sure it was great training but at what potential cost? how many pilots have had to auto to the water following an engine failure in a single from a high hover? very few I guess.

[tecpilot]

Have tested auto's on such conditions many times and an auto from a 100ft or 200ft hover isn't a funny thing and it should not be recommended to train! Dead mans area on the hv-chart is the purpose of many chrashes.

The discussion shows lacks of aerodynamic background.

After initiating an auto (after engine failure) it needs 2-10 seconds to establish the autorotive airflow on the blades and the rpm is decreasing meanwhile. During the stabilized auto the rpm is ok, but the sinking rate is very high especially on low airspeeds. To high for a safe touchdown with only the rotor inertia! Therefore you need some speed for a flare.
Additionally to the "normal" problems- hold or increase RPM and get some speed for a flare- on the "two bladers" like 206 or other Bell helicopters it's easy to see mast bumping. Dropping down the pitch for RPM and pushing forward the stick to get some speed ends in negative g's! Pushing the stick forward drops down the rpm more than you think and without speed it's not possible to reestablish a good RPM. On a real engine failure in hover you could see a very strong a/c reaction and the ship turns to the left or right side (depends on rotor turning directions) while going down.
It's easy to impress a student with that kind of "flights" and the engine is running and you are prepared to react. But in the real business it's better to try to stay out of shaded hv area or only to stay there for a limited time.

It's not absolutely impossible to auto from shaded area, but it's very dangerous and the shortest way to bend the ship. I'm shure your insurance company is very lucky to pay for a ship bended by training flights in the shaded area! :ok:

[Ascend Charlie]

So we are not supposed to operate inside the shaded area??

So why do people fit winches?

Any hoisting op is going to be in the shaded area, as is any longline job. All it means is that if the engine quits, the aircraft is likely to be damaged, and possibly the people too. The risks of demostrating it (rather than regularly practising it) were balanced by the "Wow, i didn't know you could do that!" revelation.

In the RAAF in the 70s we carried out "engine failures in the hover" (because as explained above, you are not truly in autorotation) from heights of 60 and 100 feet. Remember that the Huey has a 275-ft hoist cable - you can be in a 250-ft hover over some of these big ghost gums.

The technique - and we were ready for it - was to dump the lever, hold attitude, and when you see the ground coming and you think "Oh, 5h1t!!" you take a sharp pull on the lever (makes a loud wok-wok sound) and then assess the cushioning pull in the normal manner. The first sharp pull also seemed to make the machine move forward at a fast walking pace - we didn't consciously lower the noes attitude.

One instructor advocated the "broomstick auto" - cut a circular hole through the floor under the collective, and poke a broomstick through it. Engine fails, put the lever to the floor and relax. When the chopper gets close to the ground, the broomstick pushes the collective up and the landing is smooth. or so he said...:sad:

[GLSNightPilot]

I just have to get a few words in here. The technique is to get the pitch down (not in a huge hurry, certainly not as fast as you can) and lower the nose a few degrees. In 2 or 3 seconds, the RPM in a 206 won't decay all that much. There is no negative G load, unless you screw it up. If you get the entry even close to right, you end up in a normal auto, with just enough airspeed on the bottom. The point of doing this is to simulate an engine failure on takeoff from a platform - most offshore platforms are in the general neighborhood of 100', & while it isn't all that common, an engine failure here is probably slightly more likely than most other times, since you're applying a lot of power, often 100% torque, from flat pitch. Granted, the practice auto here isn't completely realistic, but it's better than nothing, when that Roll-Royce decides to come apart in little pieces just as you clear the fence on the edge. And a Roll-Royce (nee Allison) will do that to you now & then.

I've done this in the 206, & do it annually in the 412 and the S76. In these aircraft, it's just one engine, & it's not that big a deal, but in the sim, try having both engines fail at the same time. It gets your attention, but the repairs are quick & cheap.

[BlenderPilot]

Bladestrike,
I don't think its the standard but for anyone spending time at the top of a 100 or 200 foot longline........it should be
Just my point!




low height bug

Not being a helicopter pilot (or pilot of any sort) could you elaborate on the technique used for this particular flight case. Presumably you are talking about engine failure in a single engined aircraft. How valid is the technique when starting with a rotor speed that is likely to be below the datum speed (as I am assuming it was when you were training) due to the IDT (intervention delay time) resulting from the time taken to recognise and react to such a failure?
Technique used? Lower collective ASAP, hold attitude or keep slightly nose down, and when close to the ground, level (don't flare) and pull on the collective VERY SHARPLY, and whatever you do, DON'T try to nose down to gain airspeed and then flare, there is no time for this.
I never really thought about IDT or Datum Speed, I'm sure in reality it could be a lot worse, but survivable if you know what to do, which is my point.




crab©SAAvn.co.uk
Blenderpilot, were there any wind limits set on these failures, especially minimum ones? In a 206 you can make a survivable auto from many configurations that would kill you in an R22 or similar low rotor inertia helicopter.

I know you are referring to my comments on the 'cap thrown at helicopter' thread but many people fly low inertia rotor systems and if they think they can get away with EOLS from deep inside the HV curve they are wrong.

Bear in mind 2 things - 1. you were practising these hover EOLs ina controlled environment, you knew the failure was coming and therefore there would be no delay between throttle chop and lowering the lever (not a realistic representation of the real world or the HV curve data) and 2. you were doing them to water with big cushioning floats on, not with skids to a hard surface (again not representative of the real world).
You mentioned in your post on the other thread that when you did this the lever had to go down and up again lightning fast and the resulting landings put "crayfish on the windshield" so if the student made any error at all how was the instructor going to rectify the situation?
I am sure it was great training but at what potential cost? how many pilots have had to auto to the water following an engine failure in a single from a high hover? very few I guess.
You just gave me one more reason why I never want to fly an R22!
About the potential cost? . . . . if big companies such as PHI do it, I think the cost is worth it, at least it has given me a potential life saving skill, and I think it was worth it.





tecpilot

After initiating an auto (after engine failure) it needs 2-10 seconds to establish the autorotive airflow on the blades and the rpm is decreasing meanwhile. During the stabilized auto the rpm is ok, but the sinking rate is very high especially on low airspeeds. To high for a safe touchdown with only the rotor inertia! Therefore you need some speed for a flare

You mention you need to get airspeed for the flare, and this it what the instructors that teach this tell exactly NOT to do, and name as the primary cause of fatalites in this type failure, from 100FT you can't: establish and auto, gain airspeed, flare and land, that's why PHI teaches people just hold a slightly nose down attitude until about 5 seconds later you only level the thing and pull collective, this is if your intention is not to crash nose first into the ground. You are right about the sink rate, it not really a sink rate, its more like a flying anvil, also I am sure the the reaction in real life is much more drastic but at least you learn a technique that could with some divine help could save your life.





Ascend Charlie
So we are not supposed to operate inside the shaded area??
So why do people fit winches?
Any hoisting op is going to be in the shaded area, as is any longline job. All it means is that if the engine quits, the aircraft is likely to be damaged, and possibly the people too. The risks of demostrating it (rather than regularly practising it) were balanced by the "Wow, i didn't know you could do that!" revelation.
In the RAAF in the 70s we carried out "engine failures in the hover" (because as explained above, you are not truly in autorotation) from heights of 60 and 100 feet. Remember that the Huey has a 275-ft hoist cable - you can be in a 250-ft hover over some of these big ghost gums.
The technique - and we were ready for it - was to dump the lever, hold attitude, and when you see the ground coming and you think "Oh, 5h1t!!" you take a sharp pull on the lever (makes a loud wok-wok sound) and then assess the cushioning pull in the normal manner. The first sharp pull also seemed to make the machine move forward at a fast walking pace - we didn't consciously lower the noes attitude.
One instructor advocated the "broomstick auto" - cut a circular hole through the floor under the collective, and poke a broomstick through it. Engine fails, put the lever to the floor and relax. When the chopper gets close to the ground, the broomstick pushes the collective up and the landing is smooth. or so he said...
You know what you are talking about and the tecnique you describe is just like I understand and was taught it should be performed, its accurate even up to the sound effects ("Oh, 5h1t!! and "makes a loud wok-wok sound") I agree with what you said in that, at least it should be demostrated to pilots. (maybe not R22 pilots, since this like many other things in the R22 are too dangerous)




GLSNightPilot
The technique is to get the pitch down (not in a huge hurry, certainly not as fast as you can) and lower the nose a few degrees. In 2 or 3 seconds, the RPM in a 206 won't decay all that much. There is no negative G load, unless you screw it up. If you get the entry even close to right, you end up in a normal auto, with just enough airspeed on the bottom.
From 100FT there's no way you are going to be able to do this, there is absolutely no time to gain airspeed to end up in near normal auto, flare and land. Sorry.
You DO have to lower pitch ASAP
From 100FT you will be on the ground in a llttle more than 5 seconds, trying to go for airspeed and then flare will just plant you on the ground Nose First.



And then again to all of you,

I just want to say that I really respect companies like PHI (nerver worked for them) that care enough about peoples lives and are willing to take the necessary steps and train their pilots beyond the minumum skills, I wish there were more companies like that. (plus its fun to see the the crawfish end up on the windshield!)

[Old Man Rotor]

My single engine flying is in the distant past now....and I guess so are some of the techniques that I have forgotten on the SE.....or never learn't.

There are a number of companies around the world that teach as a matter of normal Checking and Training all sorts of "Save your ass techniques".......maybe fewer than there should be...but their there!!

In a multi-engine helicopter coming off any helideck, the flying pilot calls "Committed"....committed being the nano second that he starts the forward movement of the helicopter. Any engine power output problem after committed is carried into flight. In the multi engine world, any delay to put upto 20 degrees nose down in the presence of a power failure [15 on average for most types] and any reduction of the collective position will just about gaurantee you striking that long tail on the deck edge. [I appreciate your Nr will be compromised]

Of course once clear of the deck, OEI transient power is considered.

Blender, not that I doubt the wisdom of your [PHI] technique......what would your action be if the engine coughs as you commit.......I would be very worried about my tail????....as the 206 would have to move around 20 metres horizontally before the tail clears the deck in a level attitude.....surely you would be nose down as well???

[tecpilot]

@ blade strike

I know that is it impossible to gain airspeed from a 100 ft hover ;)
i only tried to explain the "normal" safe way of an auto. And without any questions a greater nose down attitude from hover is deadly. Don't forget the steering delay due to the low RPM and the transition into autorotative airflow ... An a/c in transition to auto or in the auto reacts not as soon as normally. Also on the twins it's sometimes not easy to flare the 20-25° nose down attitude after engine failure in hover... from a 100 ft hover you are down within 2-3 seconds.


There was a question about the long line hovers...
Forget it that you have enough RPM and inertia after 2-3 seconds :yuk:
Don't think, that the a/c and RPM reaction in a schoolish helicopter is the same than on a working horse with max payload onboard in hover and high blade angle. Also on a 206 in 2-3 seconds you are down to 80-85 % RPM. It's absolutely different in hover to an engine cut while cruising flight.
That's why i'm saying hands off from high hover autorotations.
To try it with uncle franks toys or the 300's or 500's or other low inertia ships is a planned suicide.

[paco]

This was almost the first thing that was taught (not demo'd) to me when I left the military, and this was a small company in Scotland - as the man said, they are out there! Having come directly from the Scout, it wasn't that scary, but it was a 206, and I was told not to trust anything other than a Bell product if I had to rely on it (like any good Chief Pilot, he also told me not to get into a situation where I had to).

The robbie wasn't around when that happened, but if, as I hear, you have .9 seconds to get the pole down, you gotta be nuts to try it.

Phil

[Bladestrike]

Used to be the reason to use a longline was because the hole was too small to get into, and required less cutting of trees, or the area you were picking out of was inhospital to begin with, off the side of a hill, plenty of debris to blow around, etc. and generally, you have a load below you and more often than not, ground crew. So if you're in a single and it decides to call it a day, your chances are slim, the aircraft will be written off but just maybe you can save your back.

I guess I forgot how hairy they were, so I won't advocate chopping the throttle and practicing full-on autos, although this is what I was taken through. I'll admit that it is very dangerous and unwise. Getting the throttles back up for a power recovery would be dubious, but perhaps dropping the pole and letting her fall to give you an idea what to expect if the worse should happen, could save your bacon some day.

[KENNYR]

Did 100' hover autos on a regular basis in the 206, but would I try it in the Scout or Gazelle............nope! Hi inertia systems allow this manoeuvre to be safely carried out without any drama or panic.

[SASless]

Old Man Rotor.....

206 has to move 20 plus meters to clear the deck? I assume you suggest starting the takeoff from a position other than at the very edge of the upwind portion of the deck for that to be so. I realize there are almost as many "unique" ways to correctly depart a deck as there are pilots among us....but I prefer easing up to the upwind edge...seeking the elevator....and upon catching it....use the uprising air to assist my departure. It makes the transition into forward flight much more rapid by generating a bonus lifting force which I transfer into "power" and "acceleration".

About a year ago I started a thread on takeoffs from elevated decks in Bell 212/412's and got a very interesting feedback from other posters. A search of the archives might result in some good reading.

I think it was the thread....Offshore Rigs/Elevated Deck takeoffs in Bell 212/412's

[Old Man Rotor]

What I was trying to get at was...........as the B206 [nice gentle old thing it is]....is around 40 ft long....or around 12.2 D from memory.....if you use the "Front edge of the Rotor Disc level with the edge of the Helideck" position to commence your vertical climb prior to calling "committed", then in the event of some downward influence [engine power reduction] [assumming Committed] you have to move forward at least 12.2 metres PLUS the 150 degree ICAO standard 5:1 drop off ratio PLUS a few extra % for Good Luck....and hence you have around 20 metres......or that deck is going to be very very close if you don't pluck up your tail as you go down....;)

I knew there was a good reason the boss pays me more to fly the easier machines.....

Just interested as to the SE procedure regarding OEI a nano second after the committed call in a SE....?...assumming skids level descent.

Yes Sas, I think I can recall those old posts........perhaps a Resurrection is called for?

[SASless]

OMR....adding a bit of margin for Mum and the Kids is always a good thing to do....sometimes the math gets fuzzy when trying to do so without showing it on paper.

[t'aint natural]

I believe there's a case going through the courts at the moment of an insurance company that refused to pay out after a Hughes 300 was written off following an engine failure in a high hover.
Beware, the avoid curve is very real to insurance companies.

[BlenderPilot]

You have a very good point, if haven't cleared the tail properly you are pretty much screwed, but let's say you have already cleared the tail and you have about 5 or 10 kts. and the engine goes bye, bye?

This is where my point comes in.

A lot of pilots would try to dive for airspeed and then try to complete a normal flared auto. This will most likely plant them into the ground nose first.

If you know what to do, at least you can TRY to save yourself by doing the previoulsly taught/demostrated procedure (previously called "broomstick auto")

When you are taught and demonstrated this manuver in the 206, you realize there is a certain altitude-speed combination in which you should just NOT try to go for airspeed for a normal flaring auto, you should try what some have already previously described, its your ONLY chance.

Its sad to see not many helicopters have the capabilities to perform this, and I feel for the guys that during those critical seconds (LDG/TO) have no options due to their equipment or lack of training, especially if you realize that if an engine is going to fail this is where it will probably want to do it.

I don't fly offshore for now, but the heliport in this picutre is one of many similar that I usually operate, and if you look at the HPAPI the approach/departure is over the street due to the surrounding bldgs, myself I feel safer that if the engine quits just as I am TO or LDG at least I will try to save myself by trying to perform a previoulsly taught and demo'd procedure, and not just sit there or try foolishly to dive for AS and then flare from 100 FT.

I'm glad to see from previous posts that some individuls have been fortunate enough to have been taught this.

http://homepage.mac.com/helipilot/PPRuNe/helipuerto.jpg

[Old Man Rotor]

Your photos are worth a thousand words............

I was just trying to illustrate that in both SE and ME ops from Decks [on rigs or buildings etc]...your worst enemy is the deck edge itself. After "Committed" and in OEI, if you can clear that edge by whatever technique your company uses, then any subsequent landing should be the correct way up!!

[GLSNightPilot]

OMR, a 206 isn't 40' long, and the technique used here is to put the nose at the edge, not the end of the rotor. Most platforms the 206 flies to won't allow that anyway, they're too small, often smaller than the rotor diameter. The technique I used was to get to a hover with the nose at the very edge of the deck, at or near 100% torque, & wait for the wind to get you flying - you can feel when it starts to fly, and then you just transition into flight. The same technique is used with the 412. You just have to accept the fact that if the engine quits in the second or so it takes to clear the deck, you'll have many parts in many places. There just isn't any other choice in the summer with max gross loads, & there isn't any choice but to take those loads, other than resigning & going to Europe. Most of us choose not to do that.

One of the benefits of flying at night is that it's cooler and the loads are usually lighter, so the climbout is quicker with less power. There has to be SOME benefit, right? :ooh:

OMR, a 206 isn't 40' long, and the technique used here is to put the nose at the edge, not the end of the rotor. Most platforms the 206 flies to won't allow that anyway, they're too small. The technique I used was to get to a hover with the nose at the very edge of the deck, at or near 100% torque, & wait for the wind to get you flying - you can feel when it starts to fly, and then you just transition into flight. The same technique is used with the 412. You just have to accept the fact that if the engine quits in the second or so it takes to clear the deck, you'll have many parts in many places. There just isn't any other choice in the summer with max gross loads, & there isn't any choice but to take those loads, other than resigning & going to Europe. Most of us choose not to do that.

[Old Man Rotor]

I take your point about the size of some decks....and sometimes we have to take what we can get!!!

The photo from Blender certainly suggests that not all 206 ops are from those tiny decks. Sure sometimes you may not have the extra deck space to use....but if you have, get the IGE in your favour by placing the leading edge of the disc over the departure edge of your deck....don't waste that IGE.

The "Length" or "D" value of a 206 is 39.29 ft or 11.95 M....considered a 12 D aircraft......sorry after 15 years I lost 10 inches!! [Had to get the old notes out thou]

I must take issue with you regarding the logic of operating at 100% and waiting for nature to blow a puff of fresh air to get you flying. I'm not saying it doesn't happen in practice.....but if your at 100% and IGE and not flying.....mate your too heavy.

The logic of doing that in a B412 is horrific and not the best Industry Standard.....try convincing an Insurance Company Lawyer in Court that you crashed due to you not being able to climb vertical, committ from around 15 ft above the deck and safety avoid the deck, and things under the deck after one PT 6 does its own thing.....whats done, whats talked about, whats legal, and what the court decides are all different.

Try using OGE weights as a upper limit for deck departures, and reduce this weight by a factor of 500 lbs if the deck is less than 50' AMSL...eg a Workboat, MSV Seismic etc.

[GLSNightPilot]

OMR, try operating at Cat A gross weights here, & you won't last long. In the summer, at 90+ deg F, you're expected to operate at max certificated gross weight. OGE does not apply at all, and if you can't or won't fly the load, they'll get someone who can & will.

On an offshore platform, indeed any elevated helipad, if there is any wind at all, even a couple of knots, the best way to get off is to get the rotor over the edge of the deck, and allow the wind, which hits the side of the platform buildings, etc, then blows up, to blow up into the rotor & provide lift. You'll get off with less power than trying to hover with the edge of the disk over the helipad, theoretically IGE, but really with a wind blowing down on you as it curls over the edge. It's critical to keep the controls as still as possible - moving the collective up & down will ruin it, as will stirring the cyclic. This isn't anything new - the technique has been used since platforms were put offshore. Interestingly, this doesn't work as well with the S76, apparently because of the different rotor design. In the S76, we get to the edge of the deck on the wheels, with the nosewheel as close as possible to the edge, then pull all available power & ride it on up & out, you can feel "the bubble", and you try to ride it up. If it won't go, just put it back on the deck & either try again, try in a different direction, or as a last resort, kick off some weight. But that's an absolutely last resort. In Europe, maybe you can do what you advocate. But here, the oil companies will run you off in a heartbeat if you can't carry the max gross load. Things don't work here like they do in Merrye Olde, as far as I can see. As for the insurance company, if you're within gross weight & CG limits, they'd have a hard time refusing to pay. I've never heard of a problem in this area. Cat A is specifically not required for offshore takeoffs in the FAR's, so if you're legal, I don't see how the insurance company can weasel out. Again, this is not the UK, and UK rules and legal requirements don't apply.

[Old Man Rotor]

Your points are worthwhile.......all be it far from the [Non GOM] Offshore Industry Standard.......

Try taking such a risk [commercial attitude] where I fly and you would certainly not be allowed back.....and that would be an Oil Company Statement....Loud and Clear.

I can also remember the good old days of hovering, facing 180 degrees off heading in nil wind.....and minimising your left [power consuming] pedal until you were Committed.......how ones viewpoint changes with time.
:yuk:

Its sad that there are still parts of the world that "Managers" demand/expect pilots to fly along the edge....and threatening them with replacement???...what a shame.

PS....I never mentioned CAT A......I did suggest that OGE weights will normally give you "some" vertical climb performance in nil wind.....but thats not CAT A as you know.

[PPRUNE FAN#1]

GLSNightPilot: With regard to Old Man Rotor's sniffing and dismissive comment about how Gulf Of Mexico operations are not up to par with "the [non-GOM] Offshore Industry Standard....."

There have been underpowered, heavy twins such as the Sk-76A operating in the Gulf Of Mexico for at least a couple of summers now, eh? I suppose one could ask how many total accidents have occured in the takeoff phase of flight where an aircraft went in the water whilst it could have flown merrily away had it been at some lighter weight?

Secondly, Old Man Rotor states:Try taking such a risk [commercial attitude] where I fly and you would certainly not be allowed back.....and that would be an Oil Company Statement....Loud and Clear.I wonder which oil companies that would be? ...Royal Dutch? BP? Exxon? The same ones that GLSNightPilot likely flies for in the GOM? Funny how their standards change to suit the regulatory requirements of the country/area they're operating in.

Finally, I cannot resist this one. GLSNightPilot wrote about having to operate from small decks offshore. OMR chimed in with:I take your point about the size of some decks....and sometimes we have to take what we can get!!! The photo from Blender certainly suggests that not all 206 ops are from those tiny decks.Gave me a right good guffaw, it did! If anyone thinks that decks that size are the norm in the GOM, he's got a few misconceptions about the industry.

[John Bicker]

Just to go back to the 100' Hover and subsequent autorotation. Has anybody considered the following:

Chopping the throttle in an Allison is not the same as a failure. The engine could take as long as 5 seconds to achieve IDLE power. Any less than 2 and you have a problem and can risk a flameout. Everyone still does the slam decel test don't they? At idle the engine can generate from memory as much as 30 HP. I would guess that in this maneuver there could be a lot of HP still around to make it achievable and able to be demonstrated. It ain't the same when it really stops!

Flick the fuel valve off and have a go next time, adds a bit of suspense as well since you don't know exactly when it will stop.No big deal since a power recovery isn't really much of an option in this maneuver. I think you will get a huge fright yet it still may be doeable considering the adrenaline quantities involved.

[Red Wine]

Thats an interesting point...............A while ago there was a post here about a Melbourne [Australia] CFI who had a ?? throttle cable problem and could not lower the collective without overspeeding [maybe a governer] [H300]......he climbed into CTA trying to get back to his airport...over the top he asked his student to select idle cut off with the mixture control.

The power of the yaw and other aspects of really having NO engine surprised him, and that is dispite him doing thousands of "practice" failures.

[Old Man Rotor]

Your assumption about the UK industry is a guess.

Did'nt think there were any B412's in the UK???

Maybe the GOM [we called in the FGOM] when I was in MC, has changed a little, but the operation of the mediums then was quite normal, no high pressure "Get it done Attitude".

We called our SK76's "Medium" class of helicopter rather than "Heavy"....

Presently we utilise three limitations when operating 412's as far as AUW is concerned. Our Take Off Weight must be the lessor of:

1. MTOW [11900 lbs]
2. WAT Chart [Limitations Section of the RFM]
3. OEI capacity at MC or 30 mins to maintain zero % climb gradient at 500 agl [VFR]..... or 1% climb gradient at LSALT in IFR.

There the "Legal" limitations....

Inhouse ones regarding limiting deck take offs to OGE weights [as previously discussed] are based on a common local industry standard. Both client and operator [Government folk are not in this loop] support this standard.

Depending on what model of 412 you have the pleasure of flying.....in an SP, the WAT Chart would not allow you to take off at 90 F at full Max Certificated weight...I assume your meaning MTOW.....if your in an EP, then your smiling all the way home.

[BlenderPilot]

John B. and Redwine

You both have good points which were previously mentioned, is no secret that when the engine actually quits, things are much different than just rolling the throttle to idle.

Now imagine if pilot who has never practiced the previoulsy mentioned autos gets an engine failure on a tough spot . . . . . my guess is its not gonna end pretty.

At least if everyone got to practice this type of manuver at least once, then maybe you can at least have an idea of what it feels like and TRY to do something about it.

Remember there are many pilots who spend a lot of time hovering in the dangerous area of the HV diagram, even if you try to avoid it, suppose you are taking off from a pad like the one in the picture and the engine decides to quit just as you are off the pad? What would most pilots do? Its a normal operation for many pilots to use these pads, its better to be prepared.

Look at my webpage

http://homepage.mac.com/helipilot/helicopterpictures/PhotoAlbum15.html

GLSNightPilot

I'm confused about something you said,
The point of doing this is to simulate an engine failure on takeoff from a platform - most offshore platforms are in the general neighborhood of 100'

The technique is to get the pitch down (not in a huge hurry, certainly not as fast as you can) and lower the nose a few degrees. In 2 or 3 seconds, the RPM in a 206 won't decay all that much. There is no negative G load, unless you screw it up. If you get the entry even close to right, you end up in a normal auto, with just enough airspeed on the bottom.

I've done this in the 206, & do it annually in the 412 and the S76.

You said in as quoted above in one of your previous posts that you have done this before in the 206, and that starting from around 100 FT you then go for airspeed to achieve "just enough airspeed on the bottom" for a normal auto? Are you sure about this? I think if you try to go for airspeed from a 100FT hover to try to do a normal auto you are going dive into the ground nose first. I'm just thinking somebody could read this and leave thinking they could get away with something like this.

[John Eacott]

OMR,

The Griffin is used for mil training in the UK, details here. (http://www.raf.mod.uk/equipment/griffin.html)

[PPRUNE FAN#1]

John Bicker mentioned the "scheduled decelleration" of the Allison engine and he is correct. However, while the C-20 series has this characteristic, the more powerful versions (C-28, C-30, C-47) do not. They *do* however produce some horsepower, even at "idle" as has been noted. It is generally accepted that this "residual" horsepower does help in a practice auto.

If it is that important, the only way to truly simulate the torque-snap and sudden r.p.m loss of a real power failure in a 206 is to do it in a later model Bell 47 with a no-bar kit and the metal, high-inertia blades. These ships, especially a wide-cabin G-4 fly surprisingly similar to a 206B...up to about 80 kts, of course ;)

Here is the thing about engine-failures whilst inside the shaded area of the H-V diagram. You must be ready for them, period. Your hand must be on the collective and you must not let the failure take you by surprise. Your reaction must be immediate and correct. It goes without saying that you must also be into the wind and have a decent landing area right underneath you.

To Blender, I'm sure you must realize that if you are operating from a rooftop structure such as that in your photo, an engine failure on takeoff is going to put you in a very bad situation. I'm sure you've rationalised this or come to terms with it in some way. You cannot control the thoughts/actions of other pilots, so do not worry about them. Just make sure that if the donk ever quits on you that you are up to the challenge and can put the aircraft down safely (hopefully without getting run over by a crazy Mexican cabbie). Maybe you'll bend it...maybe you'll get lucky and not.

[GLSNightPilot]

Blender, I didn't mean you get as much airspeed as you'd have in a 'normal' auto, I meant enough for a successful auto. There won't be much, and I don't mean dump the nose, either. We're talking about the same thing. And I agree with you completely about the practice - even though a real engine failure will be different from, & worse than, a practice auto, slightly unreal practice is better than no practice at all.