Stability and Control characteristics of the Early Mark Spitfires

[CaptainDoggles]

Originally Posted by NZtyphoon

What we have is people putting forward alternative POVs, with documentation - democracy in action, yet this is belittled as "fanaticism".

Spare us the rhetoric and emotional appeals. That's not what democracy is and you know it.

[fruitbat]

ahh, the blue smileys are catching.

[NZtyphoon]

Originally Posted by CaptainDoggles

Spare us the rhetoric and emotional appeals. That's not what democracy is and you know it.

Democracy

[CaptainDoggles]

Didn't watch the video, too busy watching the Mars landing. Democracy is a system of government. A bunch of people shouting at each other on a forum is not democracy.

You used that word because you thought it would be more persuasive.

[Crumpp]

Crumpp. I do not understand actually what you want? I understand the Spit control and stability tests. I do not understand how to realize these characteristics in the game, where the players have completely different controller (stick length, stick dimensions, turning points of the aileron and elevator)? If the old, unique stick characteristics want to apply to the most common joy forms, the "historically correction" compromised in any case. Not to mention that you can change all handling characteristics with the joy softwares.

Therefore, I vote against it. Not against of historical authenticity, but the applicability in the game.

Tom,

It is not just stick settings.

1. The aircraft moves to trim speeds but overshoots. That means it is always in motion and must be controlled.

Can it be controlled? Yes of course.

Is it easy to accurately aim while doing that? Not at all.

So while a player might mitigate the sensitive elevator and heavy ailerons, they would still have to constantly control the aircraft motion. This is especially noticeable in accelerated flight or turn.

A reworking of the stick settings would eliminate this and allow the stability and control features of each aircraft to be more accurately modeled. Just go the a dead zone to 100% curve. That way, somebody could flatten out response around the dead zone but the slope of the curve increases as we get closer to full deflection. One could "pick their poison" so to speak but could not eliminate modeled behaviors.

The developers can also model the airframe limits. Currently, you cannot bend or break the airframe and the accelerated stall is non-existent.

The aircraft's reaction to gun recoil could also be modeled. As an unstable platform, the arm is shorter which means less resistance to motion.

The penalties on turn performance for riding the buffet or pulling into it. Completely independent of stick settings.

The idea is to get player in the mindset of a WWII pilot flying the modeled type of aircraft. That is IL2 Cliffs of Dover main strength IMHO and why I got the game.

We have all seen the RAE concerns about pilot's not pushing the aircraft to the limits because of their fear of the flying qualities. That is fear is justified by the measured results of the NACA. Yes, the airplane had great stall characteristics too. The caveat being what is emphasized in the Operating Notes, correct and immediate application of the controls. The right control movements at the right time. If the pilot did not immediately make the correct inputs, the aircraft would spin after flicking out of the turn on a reciprocal course.

If he made the correct inputs, the aircraft recovered and even maintained a relatively high degree of aileron control just above stall. The NACA mentions that because it is unusual. Touching the ailerons on a stalled wing in general is not a good idea. Cessna drivers do it all the time, though, LOL. In most aircraft the rudder is the only effective control immediately post stall.

It does leave the aircraft with its tail toward the enemy and the choice of continuing with a slight altitude loss in slow flight or diving for more airspeed.

So the penalties for the buffet and the accelerated stall characteristics can also easily be modeled.

To mitigate the fact players could dial out the most important characteristic that made an early mark Spitfire unique, the sensitive elevator and heavy ailerons. Since players are going to cheat, developers can too. I did this in Warbirds and it worked great when I did the Bf-109 and Spitfire models.
If an accelerated stall is reached, the aircraft spins. This keeps players in the mindset to stay off the stall point.

So it eliminates a nice feature of the Spitfires stall characteristic but realistically, Spitfire pilots did not seek the stall except as rare method to escape an unwanted combat. If the players are going to cheat, let the developers do so as well.

[NZtyphoon]

Originally Posted by Crumpp

The aircraft's reaction to gun recoil could also be modeled. As an unstable platform, the arm is shorter which means less resistance to motion.

Documented evidence for this, please.

Alex Henshaw's comments make interesting reading on the Spitfire as a gun platform and on its elevators:



Note Henshaw comments that the Spitfire's elevators were light cf those of the Tiger Moth or Magister on which pilots trained....

Now, a comment on the Pilot's Notes used by Crumpp which can be found here: http://www.scribd.com/doc/4598146/Pi...lin-XII-Engine - this is a most unusual set of PNs, even for a reproduction. For one thing these have detailed information and comments on combat skills and aerobatics, which few pilot's notes normally had.






These were not the standard PNs issued to pilots on frontline units - those ones invariably had blue covers: the notes that were issued to trainee pilots at OTUs had orange covers and these notes were conservative in their approach to ensure hotdog young pilots, who had gotten used to heavier elevators on the Tiger Moths etc, were made fully aware of the lighter Spitfire controls.

Originally Posted by Crumpp

Again, the RAE may have blamed it on that (overloading at a squadron level) but they were also behind in Stability and Control research.

Wrong, once again, as Jeffrey Quill made quite clear he witnessed what had happened - unless Crumpp can show that he knows better about what happened in 1942 than Quill...nothing but speculation.

As for Crumpp's continued assertions about how hapless the Brits were when it came to defining control and stability? The first page shown by Crumpp is talking about 1910-1912: it has no relationship to the 1930s and the Spitfire whatsoever!
This is page 5 from the Von Karman Lecture 1970:


Page 6 - the one posted by Crumpp


What has what happened in1910-1912 got to do with ANYTHING in this thread???

CF: 1937 ARC report





CF: the 1939-48 ARC report

[Crumpp]

Do you read what you are highlighting or posting?

The Operating Notes almost verbatium repeat the exact same warning for the Spitfire Mk II AS THE MK I.

In fact, you have saved me the trouble of posting them.

What has what happened in1910-1912

Bryan's theories were developed before WWI but the attitude that pilot's determine flying qualities over the engineer persisited until after World War II.

It was not until AFTER World War II that the ARC developed a standard that all designs had to meet.

That is a fact.

The article you posted points this out.

First it concludes that the Aeronautical Research Council made the mistake of regulating stability and control engineering to an academic exercise leaving the practical to the opinion of pilots. Exact same thing the AAIA article I posted relates.

Then, the ARC concludes that a foundation was laid during the war for estabilishing a defined set of standards for stability and control.

[Crumpp]

Documented evidence for this, please.

MMM, It is in the thread already. Read the stability characteristics of the Spitfire. You seem to not understand it or ignore it. Instead, you place more value on anecdotes which are impossible to quantify.

You also quote the lone voice in the wilderness from Alex Henshaw who never fired a shot in anger.

Let's get some from guys who flew both in combat:

This is the reality. The Longitudinal stability is a defining characteristic of the early Mark Spitfires. It is part of what makes the airplane unique and gives it personality.





Wow, check that out. The first pilot could not make a kill because when he touched the firing button, the nose pitched down due to the longitudinal instability.

The second pilot disliked doing aerobatics. He felt the ailerons where too stiff, the elevator to sensative, nose too long, and the cockpit too cramped.

You can google "Hurricane vs Spitfire gun platform" yourself and not the results. A defining characteristic of the early mark Spitfire is it's twitchiness as a gun platform. Yes, it too, is a function of the longitudinal instability.


The Spitfire was not a an airplane for the inexperienced or average pilot. It was a pilot's aircraft and demanded skill. For that skill, it rewarded those who mastered it with exceptional performance. That breeds affection.

robtek says:

I think of the Spit like a Porsche 911, a great car which is a delight to drift around corners, but you really have to work to hold the thin line before it bites you in the a**.

With a regular driver it is still a great sportscar and outperforms many of its competitors, but to have the edge you have to be a pro.

The same will be with the 109, where the pilot has the opposite problem of too high stick forces at high speeds.

Each needs his own tactic to use the quirks of ones plane for optimum efficiency.

Good analogy.

IMHO, the generalize the three fighters of the BoB....

The Spitfire is sportscar. The Hurricane a workings man's tool.

The Bf-109 is a shooting platform for a machinegun with an airplane built around it.