Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

Please note that this happens with a full bomb load (1,000 lb) and the extra rear internal fuel tank. Obviously neither of these were around until late 1944

Right and has nothing to do with piles of bent wings at the repair depots during the Battle of Britain.

[bongodriver]

Originally Posted by Crumpp

Right and has nothing to do with piles of bent wings at the repair depots during the Battle of Britain.

That are purely anecdotal

[Crumpp]

must be 'Joe Average' for all pilots,

The NACA did a study as part of the stability and control standards on the forces an average pilot can exert.

I am sure that data could easily build an "average joe" pilot.

It would be easy to implement a fatigue model as well.

It is very interesting, btw.

The current FAR's are based in this same research. The formula for minimum stick force per G required in a stick control column aircraft is:



(Weight of Aircraft / 140lbs) / (structural damage limit - 1)

So a 6500lbs aircraft using a stick as the control input and is fully aerobatic at a structural damage limit of 6G:

(6500lbs/140) / 5 = 9.28Lbs per G minimum required.

[NZtyphoon]

Originally Posted by Crumpp

The NACA did a study as part of the stability and control standards on the forces an average pilot can exert.

I am sure that data could easily build an "average joe" pilot.

It would be easy to implement a fatigue model as well.

It is very interesting, btw.

The current FAR's are based in this same research. The formula for minimum stick force per G required in a stick control column aircraft is:



(Weight of Aircraft / 140lbs) / (structural damage limit - 1)

So a 6500lbs aircraft using a stick as the control input and is fully aerobatic at a structural damage limit of 6G:

(6500lbs/140) / 5 = 9.28Lbs per G minimum required.

Please explain how this translates to a computer sim, and how will the developers adapt this formula to cater for the different types of joysticks/rudder pedals used by members of the IL2 community?

[Crumpp]

PS I do owe you an apology.
You said that the design of the Spitfire wing was done at a number of colleges and I asked you which to which you gave me a number. It was a trick question which you fell for.
You may or may not know what is taught at the establishments you named, but you would not know what they use in their lectures unless you had done the course so your list must have been made up.
Also you said Cambridge as one of the establishments. Cambridge isn't a place where you study. Cambridge is in effect an admin centre for 31 Colleges or to be more precise seats of learning and none of them do aerodynamics.

I can tell you that Cranfield is the premier University for Aerospace in the UK its very advanced with their own test fleet of aircraft. We had visiting lecturers from Cranfield come to HMS Daedalus for some of our studies which included Hovercraft

Which has what to do with anything?

I never claimed to go to Cambridge. I went to Embry Riddle. I do have friends who went to other colleges and they also know of the Spitfire's instability.

What does your point have to do with that fact or any fact relevant to this discussion?

Or the fact, it is Cambridge University that published the book??

Cambridge University, Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK
Tel: +44 1223 332600, Fax: +44 1223 332662

Before coming to Cambridge in October, you must complete this booklet of problems, produced by the Department. It contains questions on mathematics, geometry, mechanics, DC electrical circuits and electromagnetism, to help prepare you for lectures. There is a supporting Website containing guidance notes and links to learning resources (as well as
the booklet itself in PDF format). Your college will send you a username and password to access the material online, and will either send you a hard copy of the booklet, or direct you to print your own copy from the Website. Your
Director of Studies will give you further guidance on tackling these problems, and may ask for the work to be handed in at the start of your first term, for discussion in your first supervisions.

http://www.eng.cam.ac.uk/teaching/index-freshers.html

http://maps.google.com/maps?q=Cambri...m&z=16&iwloc=B

[Glider]

Originally Posted by Crumpp

Which has what to do with anything?

I never claimed to go to Cambridge. I went to Embry Riddle. I do have friends who went to other colleges and they also know of the Spitfire's instability.

I know that you didn't go to Cambridge as to Embury Riddie that may or may not be the case. I do know that when you offerred to debate Longitudional Stability by standards one was to do with roll rates and nothing to do with what you wanted. I believe that one of the other standards you wanted to use is to do with ordering spare parts, not exactly stability. I wouldn't expect a graduate from Embry Riddle to make that kind of mistake, its possible of course but it is a basic error

But you did say that Cambridge and others used the Spitfire wing when you clearly don't know

What does your point have to do with that fact or any fact relevant to this discussion?

Because its another example of you making up statements without foundation to support your case.

Or the fact, it is Cambridge University that published the book??

Cambridge University Press is a publishing house NOT a University. The University is an admin for the collages not a seat of learning and supplies support to the member seats of learning, including publishing.

http://www.eng.cam.ac.uk/teaching/index-freshers.html

http://maps.google.com/maps?q=Cambri...m&z=16&iwloc=B

These tend to prove that you trawled for something to support your statement rather than have actual evidence

Speaking of evidence and more importantly, we are all waiting for your source or evidence re piles of bent wings in the BOB waiting for repair. I produced two pieces of evidence you have have yet to produce anything.

You once accused me of being unprofessional so either substantiate your claim or withdraw it, its the professional thing to do

[Crumpp]

From "Aerobatics Principles and Practice" by David Robson, ex Fighter Pilot,Miltary test pilot (ETPS graduate.)

Right....

Edge of the Buffet is not IN the buffet.




If you have no other guide, the buzz is useful for finding CLmax. Don't fly in the nibble but back off to just before though IF you want maximum turn performance.

Lift varies with angle of attack and airspeed. The highest useful angle of attack is just before the critical angle, about 15 degrees. At this high angle of attack, maximum CL, considerable drag is produced, and if the aeroplane stalls, or the buffet is reached, the drag will increase dramatically. Ideally, sufficient backpressure should be applied to activate the stall warning (if it is operating) on its first note. Alternatively, the very edge of the buffet will need to be used as a guide to maximum CL.


http://www.caa.govt.nz/FIG/advanced-...ate-turns.html

You can fly in the nibble if you want, IvanK. However somebody that is turning in the same airplane at the point of smooth air just before the nibble will out turn you. That is how the physics works.

Its not a case of not "wanting" to be in the situation... Operational pilots often find themselves in situations they dont want to be in. The question put was quite specific, a Spitfire MKI no AOA gauges no accelerometers just you the pilot and your basic airframe.

Right.....Again, I would not want to be in that situation with a neutral or unstable aircraft with a light stick force per G and extremely small amount of available stick control.

That why we see charge sheets with "structural failure" and "wings came off in aerobatic flight".

But you did say that Cambridge and others used the Spitfire wing when you clearly don't know
Quote:

Making up what????

Start another thread on this off topic sideshow. Cambridge awards degrees, they published the book, and it is used as a reference in many engineering curriculuums.

If you don't like those facts, tell Cambridge not me.

[Crumpp]

either substantiate your claim or withdraw it

Why don't your read Morgan and Shacklady. They have a list of the serial numbers and known fates of many of the Spitfires.

They even have pictures of the remains of some of the aircraft that shed wings during high speed maneuvering.

Are you going to make me scan them or can you just pick up the book and read it?

[Glider]

Originally Posted by Crumpp

. Cambridge awards degrees, they published the book, and it is used as a reference in many engineering curriculuums.

If you don't like those facts, tell Cambridge not me.

Cambridge don't issue degrees, they do publish books which are used in institutions but they do not teach.

However and most importantly we are still waiting for your evidence to support your statement about piles of bent wings in the BOB.

Without evidence your statement is useless, should be withdrawn and without it your argument goes with it.

You will agree I am sure that it the professional approach

[Crumpp]

The very first onset is referred to as the the "Buzz" or the "Tickle"

Right, which has what to do with the fact some airplanes have higher energy stall warning's including buzz than others?

Also, what does that have to do with the ability of a pilot to precisely fly to the nibble and precisely back off to smooth air in order to maximize his aircraft's turn performance?