Stability and Control characteristics of the Early Mark Spitfires

[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

[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.

[IvanK]

"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."

Other than quoting reams of academic data this is the very thing you are yet to prove.

You have raised a Bugtracker tracker entry on a subject but have yet to provide any proof to support it that in fact it is a bug in game. You have by your own admission not flown the Sim that much or for example kept up to date with the numerous Beta patches. You opined that gun recoil should be modelled, If you flew the sim you would know that in fact it is.

When you started this thread its purpose was to discuss this issue as it pertained to early mark spitfires IRL, not for a bug tracker entry. It then morphed into this academic treatise that spawned your bug tracker entry. When are you going to actually do some some in game flight testing to actually substantiate your claim that the FM is porked in the Sim ?

[NZtyphoon]

Originally Posted by Crumpp

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.

What a sad, sad commentary on Crumpp's attitude towards test pilots who often put their lives on the line in all countries. I wonder what Chuck Yeager, Richard Bong or Bill Bridgeman and others would say and do to Crumpp were he to tell them that they were nothing but monkeys in a cockpit operating measuring equipment and flying set profiles...one can only dream!

[Crumpp]

You have raised a Bugtracker tracker entry on a subject but have yet to provide any proof to support it that in fact it is a bug in game.

Dive to Vne, stomp on the rudder, and pull back as hard as you can.

Fly the airplane in the buffet and time your turn.

Pull back on the stick, release, and note the behavior of the airplane.

Fly at Vmax, pull hard back, hold it at full deflection, and note the behavior.

Fly the airplane trimmed for slow flight, let go of the stick, fire the guns, and note the behavior.

I have played the game and note the behaviors as I play. Just because I don't spend my time making excel spreadsheets does not mean the points are invalid.

NZtyphoon

[Crumpp]

The job of a Test Pilot as per MIL-Spec Standards...



Same as it was under the NACA.

[DC338]

Why don't you read the rest of the statement. The must be some pretty smart monkeys.
Still waiting for analysis of figures 16 17 18 and why 15 isn't an anomaly.