Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

I should add that to say that a high speed dive is generally the result of a spin recovery is rubbish

Read the Operating Notes.....

150 mph, in a vertikal dive

BTW, you are not necessarily going to be vertical nor is certain you will enter a high speed dive.

There is a good possibility of that happening.

[Sandstone]

Wow, Lacey must be one of the oldest aerobatic pilots flying. At least 92, I'd guess, if he flew in WWII. Good for him!

[Glider]

A couple of obvious points,
1) if you are in a verticle dive then you are already going 150 + or will be in seconds so there is no delay
2) gradual will be smoothly for obvious reasons you dont want to exceed VNE or hit the ground, its a balance.

And we still don't have any accidents the acid test of fragility

PS please show me where is says that a high speed dive is generally the result of a spin recovery

[IvanK]

"Spin training, upset, and unusual attitude training is essential to a fighter pilots core mission."

Actually Crumpp I think you might find that in EVERY current front line fighter deliberate spinning is prohibited !

Upset and unusual attitude training is in fact an essential requirement for every pilot, its mandated for Instrument ratings (in most countries). These terms were not used in WWII and are relatively recent terms.

As for spin training that should imo be mandatory as well ... sadly however it has been removed from the basic syllabus in a lot of countries.

As to this importance being placed on 150MPH before attempting recovery ... baloney !! that is a typical academic approach (as is this entire thread !) to the written word. Its in there to provide guidance to the lowest common denominator. As we all know after recovering from an unintentional spin, its simply a matter of getting your s... in one pile then smoothly recovering from the dive ... no magic just normal piloting to not depart the thing again. Its just like the 90degree nose down at low level scenario (you know the one you didn't want to be in in an aeroplane with stability issues) I suggested earlier .. you going to wait for 150 and risk hitting the ground or get on with your pilot stuff and "Fly the aeroplane" !

We should be able to crack the 1000post mark on this "never ending story" soon... just 100 posts to go.

By the way where is the in game test data in in Ver 1.08.18956 to support your bugtracker entry ?

[Glider]

Originally Posted by IvanK

As for spin training that should imo be mandatory as well ... sadly however it has been removed from the basic syllabus in a lot of countries.

Its mandatory in the UK for Glider Pilots before they go solo. The test is to enter a full spin at 1,000ft (yes one thousand) from a variety of different scenarios and recover. Trust me at that height you dont see the world go around, just the tree that is in front of you. Its always a B_____ C_____ moment the first time you let a student do it

[FS~Phat]

This thread has run its course and im a little over the number of reported posts from both sides of the argument.

If Crump wants to provide Game test data or observed and documented characteristics and furnish the developers with the supporting valid realworld data (NACA or other I dont care). He can do it in private directly to Ilya, this thread has had more than enough time and data thrown at it to "prove" his theory if its correct. This thread is just causing more and more heated arguments and personal attacks and has failed to be objective. And yes I have read most of it because Ive had to moderate it continuously.

Personally I dont see the point of wasting this much energy on a single characteristic of a single aircraft at the expense of all other aspects and all other aircraft. In doing so it would unbalance the game and overall flight model of the aircraft in question. I would also have to question whether Crump holds an objective view of this flight characteristic and flight data given the single bloody-mindedness of the argument.

The developers have their criteria and approach to modelling flight characteristics and should not be pushed to change a FM based on one persons argument against the community. While I am impressed by the amount of research and data and the extreme effort to prove the spit was unstable, where was the game testing data to back up that infact the FM is incorrect? Nada, zero, zilch... so I have to conclude this is just a massive one-man-band trolling of the community.

"bloody-minded - stubbornly obstructive and unwilling to cooperate"
Sound like some people we know? I dont mean just Crump either.

Sorry If im a little blunt and short on patience but Ive put up with the fallout from this thread for almost a month now and I think thats a pretty fair run given how badly it deteriorated on more than one occassion!

I hope you see Ive tried to be fair but its now passed that point and Ive given Crump advice on how to continue his effort if he chooses.
We have more than 30 reported posts from this thread. I think that says enough.

[NZtyphoon]

Getting back to Crumpp's very first posting to start this thread

Originally Posted by Crumpp

Amoung the Western Front warring powers during World War II, only two nations had measurable and definable stability and control standards. The two nation were the United States and Germany.

We also have Crumpp stating:

Originally Posted by Crumpp

Here is the USAAF and USN standards adopted in 1944.

Ergo: Not one of the aircraft fielded by the Americans during WW2 was designed to Crumpp's set of "standards" - until things were standardised some time after a series of conferences held in October 1944 the American aviation industry was operating to a similar system to that of the British. This whole waste of time argument has been a huge red herring by Crumpp because it is completely irrelevant to anything to do with the design of the Spitfire.

Originally Posted by Crumpp

Let's not be obtuse. I never said there was no research in stability and control.

I said they stagnated into an attitude that flying qualities was an academic exercise and that the pilot's opinion was what was practical.

Big difference from what you are claiming.

The NACA took a different route. They developed techniques as well as equipment to measure and quantify behaviors. Part of that system was training test pilots and developing manuevers to define behaviors within flying qualities. In fact, it was Cooper's experience as a test pilot at the NACA that led to the development of the Cooper-Harper Rating scale.

http://www.google.com/url?sa=t&rct=j...zIxnwH4SfCszng

And When did Cooper become a Test Pilot for NACA? 1945! NACA was as dependent on test pilot's opinions as any other nation throughout most of WW2 and probably beyond.

The fact that the Spitfire did not meet some of NACA's criteria, formalised in 1941, should be of no surprise to anyone - I would suggest very few aircraft designed during the late 30s would have met NACA's criteria in full. This thread has been a complete waste of time.

[Crumpp]

Who said anything about infinite acceleration?

....if you are throttle closed then there is no thrust vector

Did they teach you this in your flight training? I highly doubt it.

Wow, guy....

lift opposes weight and thrust opposes drag,

Only in level flight...

Check out a climb triangle, pilot. A dive is the same as a climb, only difference is how we sum the force vectors.

Weight changes at the sine of the angle.

Sine 90 = 1

When you point the nose straight down (90 degrees), all the weight becomes thrust.

So even though you pull back the throttles on your 2000 hp WWII fighter that weighs 7000 lbs....

Let's see...

Sine 90 * 7000lbs = 7000 lbs of thrust going straight down!

Compare that too:

2000hp*.8np = 1600thp

Thrust @ 150 mph = (1600thp*325)/130.35Kts = 3989.26lbs of thrust.

So you instead of the 4000lbs of thrust available from your engine at full throttle, you have only added almost twice as much at 7000lbs!!

lift actually adds to drag because lift generates induced drag, if you fly at 'zero lift' then there is no induced drag.

The lift vector is now shifted 90 degrees. The wing still generates lift but it is only opposed by drag. (Weight cosine 90 = ZERO)

The plane will not fly straight down unless held at the zero lift angle of attack. Instead, lift will accelerate it on x-axis or what you know as the Thrust and Drag axis from level flight.

Yes there is induced drag too.

since when did lift oppose drag?,

In a verticle dive.

All this is off topic, take it somewhere else.

Start a new thread if you want to understand the forces of flight.

Actually Crumpp I think you might find that in EVERY current front line fighter deliberate spinning is prohibited !

Most fly by wire systems are set up to act as antispin devices. It does happen on accident though. It is generally not recommended for training because of the relaxed stability of most Fly by Wire fighters.

Sort of like the longitudinal instability of the Spitfire...only much more extreme.

As for spin training that should imo be mandatory as well ... sadly however it has been removed from the basic syllabus in a lot of countries.

Absolutely. It was a requirement for my CFI. Accelerated stalls are back too for Commercial certs. I was glad to see that.

[Crumpp]

NACA was as dependent on test pilot's opinions as any other nation throughout most of WW2 and probably beyond.

No, it was dependant upon a set of defined standards and measured results.

Pilot opinion was a factor of secondary importance. He was a monkey in the cockpit that operated the measuring equipment and flew the specific profiles.

He did not fly around on a sunny day to report back how wonderful the airplane felt.

[Crumpp]

Ergo: Not one of the aircraft fielded by the Americans during WW2 was designed to Crumpp's set of "standards" - until things were standardised some time after a series of conferences held in October 1944 the American aviation industry was operating to a similar system to that of the British. This whole waste of time argument has been a huge red herring by Crumpp because it is completely irrelevant to anything to do with the design of the Spitfire.

Only a few narrow minded individuals see this as some attack on their favorite gameshape.

It is the measured and defined flying qualities that make up the "personality" of the airplane.

These characteristics are what make an early Mark Spitfire a unique airplane with its own individual behaviors.

Of course, not all of the airplanes, like the Spitfire, met every requirement. Nobody has claimed anything different. Most were designed before there were any defined standards.

The NACA standards provide a good frame of reference to model these behavior because they measured and defined so many of the WWII aircraft. Most of these airplanes were fixed as a result but many served for long periods of time before their flying qualities were evaluated under a measured and defined system.

That gives us some great information to see those flying qualities added to the game.

Otherwise, it is not much of simulation of a specific airplane if the gameshape does not have the same flying qualities as the airplane it supposed to represent.

This has nothing to do with how well an airplane turns, how fast it goes, climb, or any specific performance. This has to do with how the airplane behaves in achieving that performance.