Entering autos: discussion split from Glasgow crash thread

[Reely340]

The normal pitch blade angel should be adjusted just as it is nowadays.
That "ultra low" section of the pitch level travel would require considerable force to overcome the "protective spring" to get into and hold there.

Hence w/o actually postitively and deliberately wanting to go there one would
never reach that range. It should be an eyes popping out, "we're all gonna die" emergency option only.

Nevertheless pitch angle adjustment precision during maintennance would be more intricate, that's for sure.

[chopjock]

As currently "pitch fully down" is ~ 0° blade angle, we can stall blades due too low an RRPM, and lacking any negative angle we - even theoretically - cannot recover from that situation w/o engine power.


I made a similar observation / asked a similar question in post 267.

[Reely340]

I made a similar observation / asked a similar question in post 267. You did exactly what I meant! That spring loaded protection I was taking about should make sure one doesn't accidentally reach "negative blade angle" region of pitch lever travel during normals ops. So while your drone pitch stick probably has the travel evenly divided between say -12° and +12° blade angel, I'd like to have a very assymertic setup, that - unless applying great force - will behave exactly as the pitch levers do nowadays.

So, any idea why we are denied that vital last resort feature by the manufacturers?

[AnFI]

AnFI, I don't seem to be able to find the hp gauge in the cockpit so is my VSI calibrated in hp, brake hp or shaft hp?

Of course you know that hp is derived from torque at various rpm so you will need to know the exact rpm of the engine at any moment to calculate the hp - that's a lot of extra stuff to think about when you are flying but I know how brilliant you are;)

For those not stuck in the Dark ages - one hp equals 0.76 Kw (that is a kilowatt an FI, the watt being the SI term for power):E Or shall we just use the torque gauge that the nice man who made the helicopter gave us? (yes I know not every helicopter has a Tq meter but which RFM has limits based on hp????)

RotorIP - don't worry, he has got lots of stuff like this that he believes everyone should teach:ok:

Sorry Crab only just saw your (strangely rude, brash, sarcastic and unpleasant, why?) ref to my post.
I think you did possibly miss my point.
YES your VSI is effectively a Power Meter... where ROC or ROD are effectively measures of the Energy/Time (Power) either required from Fuel (most likely) to give you Height(energy)/time or the Energy rate (Power) contributed from Height (Loss) rate and so not required from Fuel (or Speed or RRPM).
So it just gives a handy picture of wtf is going on when you waggle your sticks around, in case you were interested. So a Torque meter doesn't do that for you.
The Hp is interesting because it fits elegantly with the units we use. You don't need a calculator to work out you need to put the lever down, but a little general understanding of the scale and value of the energy resource you have and the rate you use it under different circumstances isn't actually going to do you much harm, it might even help?
Each 330lbs your aircraft weighs is worth a Hp per unit on the VSI. - hardly rocket science. You probably know the Hp required for cruise, at least?
Brake or shaft:rolleyes: doh! haha neither its 'ball park' Hp (conversion efficiencies etc).
("ball or aersol" neither it's for my armpits)
( A Hp is 330lbs at 100fpm, of course you can do it all in SI if you want its just not as pretty and you will need a calculator:confused:
and yes I think at the least crusty old sea dogs like you should understand some of this stuff, maybe even enjoy, but... scoff if you like.:{ )

I'd probably listen respectfully if you wanted to tell me how to land in brown out on NVGs on one eye and landing light with the other eye, in 80kts wind, on a pitching deck 400miles out etc etc ooops :zzz: wtf can't u be slightly respectful?
Time of month again? BTW have you been pulled into this Civvy SAR thing yet?

.... and RotorIP you seem to have been corrected by Jim Eli I see (thank you) re 1sec/2sec.

[Lonewolf_50]

YES your VSI is effectively a Power Meter...
Huh?
AnFI, your VSI does not care if your are at full max gross weight or sucking fumes with no payload at min operating weight, or anywhere in between. At low gross weights you will get a different amount of power needed to successfully get a given climb, level, or descending performance.

The VSI measaures your rate of change of pressure altitude.

Granted, your power/pitch settings will result in a performance readable in rate of descent, but POWER has to account for weight versus performance desired.
So, NO, I don't think you are making a decent case for the VSI as a Power Meter.

It is, however, a performance instrument, which can indicate whether or not you have your power set for the performance desired. Perfect example is a constant airspeed descent, in instrument conditions. If you are not descending fast enough your VSI is a cue to adjust power (reduce), and if you are descending to rapidly, your VSI is a cue to adjusting power (increase) ... but the power meter is your torque gage. ;)

Depending on your GW, the DA, air temp, and other environmental factors, how much torque or power you need to get a given performance will vary.

[AnFI]

Huh?
AnFI, your VSI does not care if your are at full max gross weight or sucking fumes with no payload at min operating weight, or anywhere in between. At low gross weights you will get a different amount of power needed .............................


......... but POWER has to account for weight versus performance desired.

So, NO, I don't think you are making a decent case for the VSI as a Power Meter.


Don't see how you can say that it's not a good case when you appear to have missed the point about the weight.

I am clearly accounting for the weight - that is the point!!

Yes the Weight mulitplied by Vertical Speed is Power!!


the rest is fairly irrelevant (but pretty) about units:


Each 330lbs your aircraft weighs means 1Hp for 1 unit on the VSI.

or (in other words)

AUW/330lbs times VS (in 100fpm) is power.

or

Divide your weight in lbs by 330 and what you get is how many Hp each 1 unit on the VSI is worth.


It is effectively your Potential Energy Power required/gained.

As opposed to your Fuel Energy Derived Power (which is what your engine is does and you'll find information about that on a Torque Guage etc).

Please confirm that you were missing the point or have I misunderstood your point?

If you don't understand that or don't think it's pretty then f.. f... f... fine

[Lonewolf_50]

AnFI, I too went to college, majored into Engineering, and learned how to break things down by units so that units in solution are the same as units in the problem statement.

What you are doing is playing games with semantics. "Power" in a cockpit during powered flight is part of the "pitch and power equals performance" equation.

I understand the game you are playing, and am trying to point out to you that when flying, the semantic game isn't one worth playing. Power in powered flight has a particular meaning and nuance. Energy management doesn't need the units you are using to be effective: torque, or thrust, percent rated torque, or thrust, altitude, and airspeed are units sufficient to the task when operating in powered flight.

Thanks anyway.

[AnFI]

it is more than just dimesional analysis. it really is the Power where the energy element is Potential (Height) Energy. It's quite nice to know that 1 unit on the VSI is 10Hp for instance. I like it, others might - but you don't have to like it

[Boudreaux Bob]

YOl2YEH6wFU

[Lonewolf_50]

Video, from time 2:35 to 2:41.
As I've been saying, fly with both hands.

[JohnDixson]

For Reely340:

Articulated rotor heads have both droop and flap stops. Typically, the anti flap stops are single purpose: to prevent excessive flapping with blades at very low Nr or stopped. This function is primarily aimed at gusty wind conditions. The anti flap stops are single setting and designed to get out of the way at a reasonable Nr and cannot be contacted in flight.

Droop stops are another matter. There are two settings: one for ground operations and one for flight operations. Depending on the manufacturer, the geometry of his machine and the rotor characteristics, the ground stops are usually in a range of 0 to-1.5 degrees and the flight stops are somewhere between -4 to -6 degrees. The flight stops are there to prevent getting the blades into the cockpit roof, the engine cowl tops and the tail cone. I just mention this because some of the rigging geometry that you have proposed generates conflict with these other realities.

[gator2]

I got my PPL 140 hrs ago in a 22, and now flying 44s. Just so you all know, this thread was a real eye opener for me.

As a result, I hired an instructor and spent 4 hrs flight time over the last couple weeks with an inst entering autos from all different flight configurations, high speed low speed, hard climbs, etc. My instructors were a little bemused that I would do that, "as more accidents happen practicing than as a result of engine failure".

Don't know if that stat is with instructor or solo.

But, before I did this, I am sure that I would have botched an auto entry if the engine quit at 110kts. Every auto I entered while getting my ticket, and subsequent flight reviews was around 75kts. HUGE difference.

Now that I know what a 110 kts entry requires vs a 75 kts, it seems intuitive. Which explains, I guess, why instructors are bemused by a guy who wants to go up and practice stuff that is not required. But, looking at the diff as a rookie, not at all the same.

So, if the engine ever does quit on me, in spite of all pissing going on in this thread, if I make it the thread will have played a big part in my survival.

[[email protected]]

Good for you gator2 - hopefully you now fully understand what Lonewolf 50 means by As I've been saying, fly with both hands.

There is no 'one size fits all' technique for every situation so the more height/speed/power combinations you have practiced autos from the more likely you are to survive.

Now when you are flying around you can get into the mindset of 'what would I do and where would I go'? if the engine quit and learn to judge which landing areas are within reach of your new skills and which aren't.

[Boudreaux Bob]

The old saw of "Bad Approach means a Bad Landing" holds in auto's. Get the entry right and everything after that generally will fall into place. Get the Entry Wrong and rarely does it work out for the good.

Helicopter Pilots live and die by Rotor RPM. It is just like Air, too little and bad things happen.

You can arrive at the bottom with too little but rarely can you get there with too much?

[Pittsextra]

http://www.aaib.gov.uk/cms_resources.cfm?file=/4-1983%20G-ASWI%20Append.pdf

[DOUBLE BOGEY]

Errrrr, Bob, I think you got your logic wrong in your last sentence!!!

Surely you meant:

"You can arrive at the bottom with too MUCH, but rarely can you get there with too LITTLE"

DB

[[email protected]]

No, Bob's logic is sound - you can always get to the ground with too little Nr - plenty have managed it - it's just not a pretty sight when it happens.

Arriving at the bottom with too much Nr needs qualifying that the Nr is not so high that the blades depart due to stress on the blade root:ok:

Pittsextra - we used to do double speed select pulls on the Wessex during pilot training and the Nr decay was pretty quick! Lowering the lever and flaring worked every time but flaring and not lowering the lever didn't.

[rantanplane]

Basically, rotor RPM only matters for getting off the ground. Hence heli pilots surely die because of rotor RPM

[Boudreaux Bob]

A properly rigged and test flown to certify that, aircraft can not achieve such rotor RPM sufficient to "sling blades" during autorotation. Perhaps with some real effort one might overspeed the head but not to the point of a catastrophic failure.

Getting to the bottom of an autorotation with too few Revs....deadly situation.

If you get there with "Too Many"....raise yer f@cking lever a bit and use that excess to your advantage! Or perhaps not do as aggressive a flare and use the excess that way, but that excess is a bonus.

Think not....try the reverse where you don't have enough and see how it turns out.

A for instance is the Glasgow Pub Visit by Plod.

[Chairmanofthebored]

It seems clear to me that this pilot [Peter] just completed failed to react appropriately to running out of fuel. Forget the auto and all that - it was a case of incompetency. Just because one has flown for a long time, does not mean that in a situation of stress that a mistake can be made. It is completely bizarre that he didn't react to low fuel situation quicker.

[Non-PC Plod]

Bordeaux Bob - Its not difficult at all to overspeed the head on many aircraft, especially if you have a high DA, high AUM and then you load the disc by turning or flaring. In simulator training, I regularly see students going "off the clock" where the Nr indication is above 120%, and the readout shows "--- " instead of an actual figure, because it is so high it won't read it.

[SASless]

Sims are fine but is your Sim actually duplicating the reaction of a properly Rigged aircraft?

Also...what are the Transient Limits on the Aircraft you fly?

Most are very tolerant of transient over speeds....as there is a time limit associated with the Over Speed Limit.

Dig into your Aircraft Maintenance Manual for computing the Power Off Main Rotor RPM's for a given Aircraft Gross Weight, Pressure Altitude and OAT....and see what procedures are involved. Ensuring the Aircraft is tested in as close to the conditions as possible to how it will be flown operationally is important as well.

I will bet you that in reality it is very hard to harm an Aircraft if it is properly rigged per the Approved Maintenance Manual. My experience is that particular maintenance effort is not given the attention it should and close enough is good enough for far too many Operators.

The operative words here are "Properly Rigged".

My experience on over a dozen different Types tells me I am right. I have done all sorts of CofA Air Tests, Maintenance Test Flights, Production Test Flights and have never had a problem so long as the aircraft was properly rigged and flown.

All it takes to avoid any over speed is proper application of Collective....if the Main Rotor RPM starts to go high....simply input a bit of UP Lever....and that problem is solved.

The Danger is getting the rigging wrong and not having enough Autorotative RPM as there is not much One can do to remedy that situation besides turning or flaring but those gains are only temporary and result in either an increased ROD or loss of Airspeed....both of which are not desirable in an EOL situation.

I always tried to set the Autorotative RPM at the High side limit for that reason.

[SilsoeSid]

Sims are fine but is your Sim actually duplicating the reaction of a properly Rigged aircraft?

I would strongly suggest that a sim would give you far greater training value than this properly rigged aircraft of yours, and what about duplicating the reactions of the crew?

Don't forget that many factors affect how the aircraft will handle and the pilot react in any given situation, especially in autorotation. Factors such as density altitude, weight, rotor rotational speed, forward airspeed, visibility, sudden loss of ANR, disorientation, arousal, distraction, reaction, landing area available, etc.

All of these conditions can easily be factored in with a simulator yet highly problematic with the real aircraft. Real sights and sounds, varying environmental conditions, a police observer beside you, day/night and you'll find the sim will come into its own. You can even induce fatigue prior to the sim trip to simulate those those 4am round and round and round and round round and round and round and round …. tasks.

Powered autorotations in a real aircraft shortly after the sim trip would then compliment the training.

We all do auto training on the 6 monthly OPC, both day and night, to a clear area; but we also all know full well that when it happens its not going to be at 1500' over an airfield.

[Rotate too late]

Can I ask if any consideration has been given to the possibility that the reason for the agricultural evidence of a auto was that the inputs were not from the pilot? Any TFO with a bit of experience would know the basics of aircraft inputs, and let's face it the only control input they could have accessed is the collective. Just a thought....and clearly I'm just sorry that the families feel they haven't had the closure they wanted over this tragedy.:(

[SASless]

Sid,

Answer the question please.

How do you know your Sim is programmed to react as a properly Rigged Aircraft?

As you alter the Environmental and Operational Criteria on your Sim....does it also alter the Rigging Data?

My experience on Sims...having taught at two Factories is that the Sim only somewhat replicates those characteristics.

The Sim Operator can do workarounds on most parameters but the basic aircraft data can be hard to change.

Example....Israeli Defense Forces came to us wanting to do some Sim work and try to replicate a crash they had when a crew way overloaded an external hoist.

The only way we could do that was by adding seat weights on that side of the aircraft until we achieved both the Aircraft Weight and CG's both Lateral and Longitudinal. The question one would have to decide is if the Sim Aeronautical Model would then hold true for Instrument Indications and reactions to control inputs. The one thing we did learn is recovery from that situation was counter intuitive.....if our Sim was showing us accurate performance.

Sims are great for training but they are not exact duplicates of the actual aircraft.

They at best are just pretty good guesses by Aircraft Test/Design Engineers and Software Engineers as to how the actual aircraft reacts.

Anyone that thinks their aircraft shall react just like the Sim simply do not understand the complexity of computer modeling.

They are great for teaching procedures and CRM and other imitations of real life aviating but they very much have their limitations.

[SilsoeSid]

Of course you're right Sasless, every six months we will have every pilot in the company go up both day and night with the varying weights, air densities, etc etc etc in all weathers, in a real aircraft launching thenselves to the ground with no engines and fatigue setting in, all in the name of training .... oh yes, they'd have to be solo, with a TFO in the front seat, a TFO in the back and for good measure we can throw in a dog handler with their smelly dog. (Not all police dogs are smelly)

I'm not a sim expert, there may be some here, so how properly rigged do you need the sim to be to fulfil the above?

[JohnDixson]

Just a note that may or may not be applicable. FAA and I'd assume the CAA follows a similar criteria in this regard, does not require simultaneous dual engine cuts throughout the flight envelope. So, there would likely be zero flight test data with which the sim design staff could rely on for this failure case. Behavior of the rotor and aircraft in stall conditions following a dual cut can be highly non-linear, thus very possibly* beyond the ability of the existent stability and control math to predict with any accuracy.
*If one said " probably". I for one wouldn't disagree.

[SASless]

The Aerodynamic Model for a Sim comes from the Manufacturers Flight Test and Engineering Data as Brother Dixson confirmed. The Sim Geeks can only use the Data they have to create their Model. There lies one of the problems with making a Sim exactly mimic the actual aircraft.

Perhaps DB or someone with connections with some Sim Experts can confirm this.

[ShyTorque]

I wouldn't call myself an expert on simulators, however I was in the team who first introduced helicopter sim training to the RAF, using an existing commercially owned sim. I later ran the project for the RAF.

We were duty bound to find out how accurate the response of the simulator was. At first, it wasn't at all realistic, not surprising because it was designed around a later mark of aircraft, with a different cockpit layout, different engines, different aerodynamics.

The simulator programmer guru simply plugged in a keyboard, got out his computer language manuals (which he had written from scratch) and rewrote the programme it until it flew like the RAF version. We then had to select our version of aircraft when booting up the sim.

We later found that the sim would go into "crash mode" if certain parameters were exceeded, such as slight yaw or roll rate at touchdown. We were doing double engine failures to EOLs (in the dark, btw) and this was inconvenient because the sim needed to be reset each time, rather than just repositioned. This wasted valuable training time, let alone put the $hits up the average student because it could be quite violent, being a full motion sim. Again, the programmer simply rewrote the software in a couple of minutes, so it wasn't so sensitive. I spent a lot of time talking to this guy, over the years I was in that job. He told me that certain responses could never be assumed to have been programmed correctly. For example, tail rotor drive failures. No-one can be persuaded to deliberately fly an aircraft in this condition to obtain data, so an estimated response of the aircraft is all you can hope for.

As I understand it, these "best guesses" are known as "off model responses".
So, take simulators to be the "complete authority" of actual aircraft response at your own risk!

[SimFlightTest]

Any good heli sim will have an underlying physics model that gets the device a majority of the way to the correct behavior. The flight test data is then used to confirm correct simulator behavior, and if necessary tweak the simulator physics model to achieve a data match.

The black magic and art of creating a good heli model resides in the ability of the engineer to tweak the physics model using the flight test data without introducing incorrect behavior in the flight regime where no flight test data is provided.

These days, our ability to simulate helicopter behavior is pretty respectable. So while the sim might not be perfect, it should be accurate enough to give you some sense of how to survive an emergency situation in the actual aircraft, regardless of whether that situation has been validated by flight test data or not.

[JohnDixson]

Uh-oh. I can see that in spite of efforts from manufacturers test pilots all over the globe aimed at stamping it out, that dreaded virus " Simulitis " is still around. Beware!

[Lonewolf_50]

Uh-oh. I can see that in spite of efforts from manufacturers test pilots all over the globe aimed at stamping it out, that dreaded virus " Simulitis " is still around. Beware! How old does one have to be in order to be considered inoculated? :}

[ShyTorque]

I went to counselling and managed to get over it.

[DOUBLE BOGEY]

Apart from being a "Victim" of simulators for a good few years I had very little understanding of how these machines are built and work. I am slowly getting more knowledgeable in my current job.

This is what I Know (or think I know).

1. The best possible simulator is achieved by using the manufacturers flight data pack.

2. However, as someone already mentioned, there is little appetite amongst the Flight Test community to test dangerous failures such as TR drive and in some large MEH, full EOLs. Therefore some of the flight test data is absent to support all the failures in the RFM.

3. Contrary to many beliefs, an FFS is built to reflect the design and therefor the failure modes prescribed in the RFM. Going off piste by trying to simulate conditions not prescribed in the RFM is very problematic but far worse than that is someone trying to draw conclusions about the heli, in a sim that was never designed to meet the conditions applied.

4. The simulation of actual aircraft software behaviours such as AFCS, FADEC etc is very important in modern sophisticated helicopters so for the most part real black boxes/software should ideally be used. However, if the flying characteristics (flight loop) has not been accurately captured even this strategy becomes unrealistic.

In the end it then comes down to subjective opinion. Does it behave, feel, smell, sound right? The more experienced the source of that opinion, the better the result after subsequent tuning. IMHO the best source of that opinion is obviously the Type Certificate Test Pilot(s).

But to be honest, again IMHO, entering autorotation is often poorly trained both in FFS and the aircraft. So many times I see poor pilot performance matched only by the poor quality of the debrief points. Very very often Instructors fail to point out the relationship between collective and cyclic in respect of NR stability!

The collective sets the datum and the cyclic creates instability in that datum (when waggled around). In aircraft with good ATT AFCS mode, often a quick stab on the trim release and leaving the cyclic still for a moment, regenerates pilot capacity to process the subsequent actions. In this respect simulators are invaluable PROVIDED sufficient time on the OPC cycle is allocated to this exercise. Sadly, all too often, its squeezed in at the end of a session generally with little or almost no real training given.

I have to say that since this accident I genrally start the OPC cycle with a good hour of EOLs, TRDS, and TR malfunctions with the emphasis on Training the candidate rather than testing. Most pilots need this after 6 or so months blasting along in the cruise. I am very lucky, I have an FFS with the full OEM Datapack. Even so I am sometimes painfully aware hat I am training pilots to "Fly the sim" in respect to these exercises, where the aircraft may behave differently to some degree.

[HeliComparator]

I agree with much of your post but:


1. The best possible simulator is achieved by using the manufacturers flight data pack.


Do you have any justification for this point? My understanding regarding flight testing for the sim flight model is that the manufacture's flight testing is primarily about certification. The sim data is taken from that as a secondary consideration and thus the test flights are not optimised to sim flight model data gathering.

By contrast a third party manufacturer (Frasca in our case) does a lot of fully instrumented test flying dedicated solely to sim flight model data gathering. As a result, the flight model data is more comprehensive.

Well that's what Frasca told me anyway! And it does seem reasonable.



3. Contrary to many beliefs, an FFS is built to reflect the design and therefor the failure modes prescribed in the RFM. Going off piste by trying to simulate conditions not prescribed in the RFM is very problematic

It may be a bit problematic, but when the flight manual, is wrong, or has significant omissions in mentioned failure modes, there isn't much choice.

[DOUBLE BOGEY]

HC - Like I said, its my opinion (albeit informed)! Sorry it that makes you defensive but it is what it is.

[HeliComparator]

HC - Like I said, its my opinion (albeit informed)! Sorry it that makes you defensive but it is what it is.

Not defensive, I have no vested interest anymore. I was just interested in what the truth of the matter was. I got one side of the story, you got the other, I wonder where the truth lies?

[JohnDixson]

HC, you are correct in surmising that OEM's now typically add specific flight test data flights at the direction of the sim manufacturers design/software group.

Kidding about " Simulitis " aside, it is fair to say that the fidelity ( if that is the word ) of helicopter flight siimulation today is far superior to what it used to be, and is presently being pushed particularly by the OEM's effforts in bringing fly by wire technology into the industry. Still, as efforts in the RAH-66, S-92 Canadian MHP, X2 have shown to date, and now ( I'd expect ) with the 53K, the sim work allows flight test to proceed safely, but one should expect a good deal of flight control software mods based on flight test results.

Getting back to this accident, there are the questions re the reaction to the dual engine stoppage, and then the behavior of the rotor at perhaps very low Nr. Can we place any confidence in a present day flight simulation of this sort of event? I have a mental list of problems that showed up in flight test at SA which did not show up in preparatory Gen Hel simulations: empennage issues, rotor stability issues, that type of thing, and I think that some degree of skepticism remains a healthy attitude to take toward simulation applied to the edges of the flight envelope. Guess I'm saying that readers ought to pay attention to both HC and DB.

[SASless]

Flying on the outside of the Envelope is inherently dangerous and it is certain to me that thinking a Simulator is going to be dead nuts accurate in that same realm is very dangerous.

[JohnDixson]

SAS, you must be hanging around the upper management crowd: you took my three paragraphs and synthesized them into one sentence.

[Non-PC Plod]

We know that no simulator is going to be perfect, particularly in the double engine failure realm, where we don't have any subjective experience to fall back on when we are trying to assess whether the model is good or not.
But - if training attempts to combine the best available experience in both the real and the sim world we can at least arm pilots under training the optimum preparation for a real double engine failure.
In the real helicopter, we train autorotation entry (obviously without switching the engines off). It is a smooth lowering of the collective, in order to avoid overspeed, and then maintaining a stabilised descent before a power recovery.
In the simulator, we train a much more rapid lowering of the collective, because the model suggests a rapid Nr decay under most conditions, especially if you are not expecting the donk to stop. We can also train at more challenging weights and DA than any sensible person would choose to train at in the real helicopter. (Many operators are working at the edge of the envelope, for example hauling platinum out of mountain mining facilities in sub-tropical Africa).
Of course we cannot be 100% confident about the fidelity of the model, but it gives us something to hang our hat on which supplements the benign experience available for real helicopter training.

[SimFlightTest]

In my 17 years of experience in the simulation industry, I have never seen an OEM flight test package that doesn't have MAJOR issues with it as far as simulator development is concerned... and this includes all the major heli manufacturers. A good simulator manufacturer will always collect better data than the aircraft OEM. I'm 100% confident in that.

Regarding autorotation modeling in the simulator and how it's validated, obviously nobody wants to break the aircraft when collecting flight test data, so we have to stay within aircraft limitations. However, we do push to the edge of those limits so we can validate as much of the operational envelope of the simulator as possible.

During entry to autorotations, for example, we will instruct our flight test pilot to delay flight control inputs for as long as possible after the engine cut. Using a build-up approach of carefully increased delays, we can get NR down into the lower limits. We will also do "oh-sh#$t" throttle cuts rather than slow roll-offs. In twins, we'll do simultaneous cuts as well.

Sims aren't perfect, but modern ones are pretty good, and I'm confident they'll save your life. Take 2 pilots, both encountering a dual engine failure... one pilot did 100% of training for that maneuver using the actual aircraft, while the other pilot split training time between the aircraft and the sim. I'll fly with the sim-trained pilot every time.

[SASless]

Again....you are teaching procedures, reactions, concepts.....and that is very valuable and a desired practice. What you are not doing is flying the real aircraft but a very close simulation of a real aircraft and in your own words....only as good an approximation as the Sim Engineers can make it.

That is the key point.

I am an advocate of Simulator Training....done right.

[ShyTorque]

SAS, I totally agree!

In my earlier career, it was my job to make the sim training as realistic and relevent to the real aircraft as possible. We were tasked to develop a syllabus from scratch, based around existing procedures. We discovered at least one major error in the existing emergency drills. I know we helped save at least one crew from a major emergency. By the pilot's own admission he would previously have carried out the opposite of the procedure we developed and taught that saved him and his crew (high power tail rotor control failure over the sea).

However, what you must exercise caution about is believing that a simulator is 100% perfect with regard to real aircraft response in all situations, for reasons that I and others have already mentioned.

[SimFlightTest]

In order for a training organization to effectively integrate a simulator into their training syllabus, they first need to know the limitations of the simulation. Once they have a handle on that, even a low level simulator can be used effectively and improve safety.

A simulator is a tool, and like all tools it requires a skilled operator.

I'm a big advocate of getting simulator instructors involved very early in the process when developing a new simulator. If everything works as it should, the instructor is intimately familiar with the simulator shortcomings, why they exist, and how to mitigate them.

[ShyTorque]

As a fairly experienced, ex RAF simulator instructor, I found myself in a training session as a paying "guinea pig" pilot in a new simulator (actually a recently modified old sim). I already had about 1,000 hours on the type it was meant to represent. The "sim" flew nothing like the real helicopter and the responses of the trim release button and coolie hat trim switch was totally wrong. The sim also hunted in pitch, which could be felt through the cyclic. The simulator instructor had no hours on the real aircraft and not many in simulators. He wanted me to fly it only using the coolie hat, which was extremely slow to respond, unlike the real aircraft, and totally alien to everything I was ever taught. Things got totally unproductive and I eventually asked to terminate the session because it was a total waste of time and our money.