Stability and Control characteristics of the Early Mark Spitfires

[NZtyphoon]

Thanks Ivan.

Originally Posted by Crumpp

NzTyphoon,
Why do you keep confusing individual research with an established standard for all????

This mumbo-jumbo is an example of Crumpp's intellectual dishonesty coming to the fore - the document he has cited in an attempt to bolster his "case" has nothing to do with the point he is trying to prove. "The Development of Airplane Stability and Control Technology" has done no research into British aeronautical development after 1913 and, as such, it has nothing whatsoever to do with the Spitfire's longitudinal stability. Crumpp has not bothered evaluating the sources used by a publication before citing it as "evidence" - this is one of the basics of historical research.

During October 1944, the National Advisory Committee conducted a series of conferences with the”Army, Navy, and representatives of the aircraft industry for the purpose of discussing the flight-test procedures used in measuring the stability and control characteristics of airplanes. The conferences were initiated by the Army Air Forces, Air Technical Service Command, to acquaint the flight organizations of the industry with the flight test methods employed by the NACA and to standardize the techniques insofar as possible as they are employed by the various manufacturers and agencies engaged in determining the flying qualities of airplanes.

So, while NACA had formulated a set of specifications they had yet to be properly standardised because as late as October 1944 NACA was still discussing how to implement the specifications with representatives of the Army, Navy and aircraft manufacturers. This does not say anything about the specifications being adopted in 1944 - just being discussed pending adoption.

Now, Crumpp insists on an Aeronautical Research Committee report confirming British standards in control and stability; what Crumpp doesn't seem to realise is that the ARC is an advisory body which works to distribute information and reports to the likes of the National Physical Laboratories, RAE and manufacturers (para 2 Policy of the Committee). Unlike NACA it does not do its own research: unlike NACA papers on stability and control can only be accessed via archives such as this entry, NA Kew.



Reports tabled in ARC report 1939:


As it is bug tracker #415 won't be gaining any traction at any time soon, so there isn't much future in pursuing this thread any further.

[bongodriver]

So.....can we have that 109 thread now?

[Crumpp]

It is very simple NzTyphoon.

Post the standards developed by the ARC.
Thanks!!

"The Development of Airplane Stability and Control Technology" has done no research into British aeronautical development after 1913

Wow,

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

Are you referring to the bob weight in the pitch circuit or increased balance area on the elevator as fitted to MKV's ???

No, I are referring to the one fitted to Spitfire Mk I's to correct the longitudinal instability.

[bongodriver]

No, I are referring to the one fitted to Spitfire Mk I's to correct the longitudinal instability.

Never happened, only the MkV was 'ever' fitted with a bob weight.

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

God forbid that when designing something to be operated by a human you would ever actually ask those humans for any advice.

I wonder why on some adverts the slogan 'designed by XXX for XXX' is used, it's almost like the oppinion of the end user counts for something.

[NZtyphoon]

Originally Posted by Crumpp

It is very simple NzTyphoon.

Post the standards developed by the ARC.
Thanks!!

Having wasted hours trying to get Crumpp to provide some documentary evidence to prove his cock-eyed theories on 100 octane I am not interested in complying with these demands.

Originally Posted by Crumpp

Wow,

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.

Let me complete that for Crumpp:

"The Development of Airplane Stability and Control Technology" has done no research into British aeronautical development after 1913 and, as such, it has nothing whatsoever to do with the Spitfire's longitudinal stability

The only one being obtuse is Crumpp, who tried to use an irrelevant paper to bolster his "case". Anyway I'm done wasting time on Crumpp flogging his dead horse and pointless bug tracker - he can waste as much time as he likes here.

[Crumpp]

Spin trials by RAE on the MKII and MKI (as posted earlier in this thread) generally considered spin characteristics as normal ... no real drama.

Except that spins are prohibited.

They never changed the Operating Notes. It is not because they are lazy. Nor is it because they want to "reduce risk" by not training their fighter pilots in spin/upset/unusual attitudes.

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

I said from the begining, any engineer can look at a design sitting on the tarmac and know if the airplane has a high chance of normal spin recovery assuming the CG is normal or forward. The Spitfire has all the characteristics required to spin normally.

Therefore, the only real issue is the longitudinal instability.

The never changed it because a high speed dive is generally the result of spin recovery and a Spitfire pilot could break the airplane rather easily.



I was just curious if spin trials were done after the longitudinal instability was fixed in the Spitfire Mk I's.

The approval to train after being checked out by a Squadron Commander or CFI at an OTU certainly did not appear until the airworthiness directive fixed the instability.

[Crumpp]

documentary evidence to prove his cock-eyed theories on 100 octane I

You mean like the fact it is not the specified fuel in the portion of the Operating Notes entitled "Notes on a Merlin Engine" is a strong indicator the fuel is still undergoing service testing?

I never disputed the fuels use, just the silly notion it was the only fuel available and the adopted service fuel.

Who would ever suggest they were still undergoing 100 Octane fuel testing in August of 1940 simply on the basis the facts do not align?



100 Octane is completely off topic. Start your own thread if you want to debate it.

[Crumpp]

NzTyphoon,

It is not my theory nor is that one report the basis of the conclusion the United Kingdom aviation authority did not have stabilit and control standards.

Simply post the ARC standards used during the war. They will be written in a simliar fashion to EVERY other stability and control standard in the world.

They will define the acceptable qualities in an airplane.

Just like the NACA did!!

Here is the link to the UK ARC reports:

http://aerade.cranfield.ac.uk/listarcrm.php

[Crumpp]

Honestly I always thought a high speed dive is the typically the result of a prolonged dive. Is diving also prohibited?

What does a deliberate dive have to do with a spin?

In spin recovery with longitudinal instability, if the airplane is below Va, the risk of secondary stall is greatly increased.

Above Va, the risk of airframe destruction is greatly increased.

Understand?

[Glider]

Originally Posted by Crumpp

You mean like the fact it is not the specified fuel in the portion of the Operating Notes entitled "Notes on a Merlin Engine" is a strong indicator the fuel is still undergoing service testing?

I never disputed the fuels use, just the silly notion it was the only fuel available and the adopted service fuel.

Who would ever suggest they were still undergoing 100 Octane fuel testing in August of 1940 simply on the basis the facts do not align?



100 Octane is completely off topic. Start your own thread if you want to debate it.

These tests were on the 100 octane fuel produced in the UK as a back up in case the supplies from the USA were insufficient