Bf 109F & G wing area.

[CORSNING]

I need help guys. I have seen several different listing for the wing area of
these fighters, anywhere from 173.3 to 174.376 sq. ft. I am trying to clean
up all the posts I made on the warbirdsforum. I have accumulate much data
since that forum closed. I do not have a location for all the performance
information that was posted there at this time. I am currently studying
graphs of the Bf 109G-6/R2, Bf 109G-8, Bf 109K-14 and the Bf 110G-2/-4.

I am trying to find the true Wing Area for the Bf 109F & Bf 109G.
Any help will be greatly appreciated.

Thank you in advance guys, Jeff

 

[tomo pauk]

Jeff, seems like two values are in play for the Gs - 16.2 m^2 and 16.05 m^2.
edit: for the F-4 - 16.05 m^2.

 

[CORSNING]

Tomo,
I absolutely agree my friend. I am fine tuning all the information
I have put together. Next time I post AIRCRAFT PERFORMANCE
I want it to be as accurate as possible. That my good friend is exactly
why I am asking for help now. The next time I spend hours, days,
weeks and years posting, it isn't going to be just me and the information
I can find. It will be us and what we all can find and put together as
a group. WW2 fighter aircraft performance from all nations.
I have already done this on warbirdsforum. But I believe with the
input from the extremely knowledgeable members of this community,
a very accurate posting of a WW2 fighters abilities might be possible.

God bless you and your family Tomo, Jeff

 

[KiwiBiggles]

I'm not sure there is such a thing as the 'true wing area' for a WWII fighter, at least not to within an accuracy of ±1 sq.ft. Where at the root do you start the wing, bearing in mind that designs of that time all had a wing-root fillet where the wing joins the fuselage? With a wing-root chord of, say, 8 ft, you would have to determine where the fuselage becomes the wing to a precision of less than an inch, to be able to specify the wing area to within 1 sq.ft. Just look at the size of the fillet on a Spitfire, and tell me you can say where the fuselage stops and the wing starts, to within half an inch.

 

[swampyankee]

There is also at least two ways of measuring wing area, just to add to a bit more confusion.

 

[fliger747]

Yes, sometimes the wing area includes the fuselage.

Wing area and wing loading offer some insight into an aircraft's maneuverability, but that has to be integrated with the curves of lift/AOA at likely Reynolds Numbers as well as the effect of any high lift devices that may modify the basic wing section behavior. Slats or Slots for instance, if only on the outboard of the wing improve and help retain roll response and roll stability at high AOA values but may not reduce the stall speed much.

Most of the WWII aircraft had low enough wing loading and low enough stall speeds that they could get away from exotic high lift implementation. For large transport jets which have a large possible variation in weight, these become quite necessary. The CL of a transport clean might be only around 1.4 or so, but 2.5 or higher with all the "crap" thrown out. Taking off at a bit under (not much) a million pounds in a 747-8 flaps up maneuvering speed was something like 275 knots IAS.

the all up weights of some of the short range WWII fighter missions did not involve huge weights of fuel and ammo, relatively speaking. Now for a Mustang, fully tanked for a long mission, pretty poor flying machine till you burned a lot of that off!

 

[Milosh]

Now for a Mustang, fully tanked for a long mission, pretty poor flying machine till you burned a lot of that off!

Only required about 50 gal used from the aux tank.

 

[Shortround6]

Yes, sometimes the wing area includes the fuselage.

It almost always includes the fuselage. I was interested in this at one time and compared a few American planes (since the data was in America's Hundred Thousand) and for most skinny fuselage planes (P-39/P-40/P-51) the "net" wing area was in the low 90% range compared to gross (includes fuselage) wing area. Fat fuselage like the Brewster Buffalo got into the 80% range but then most of the other fat fuselage American Planes (f4F/F6F/P-47) really big wings so the percentage wasn't that different than the skinny fuselage planes.

 

[CORSNING]

Great information guys. I am aware of the difference of the
wing area normally given in most published material vs.effective
wing area. And while the latter has more actual affect on an
aircraft's performance, it is a very rare listing. In every WW2
military and manufacturer's report I have seen, they all list
'gross' wing area. As much as I would rather use the effective
wing area, it is not available enough for comparison purposes.
When I designed and posted the AIRCRAFT PERFORMANCE
section on Warbirdsforum, being able to readily compare aircraft
was what it was all about.

So, I am just after the true gross wing area of the Bf 109F & G.

I still love to read all your input, so have at it and thanks guys.

 

[Ivan1GFP]

Hello Corsning, et al.

I play around with 3D models quite a bit and after working with my Son a couple years back when he was taking Geometry (?), decided to write a program that would calculate the area of a convex polygon using Heron's Formula.
While this won't give you the exact number you are looking for, it is often useful for estimating areas.
I don't believe I have found even one model (including my own) that measure correctly yet and I am certain the program is mathematically correct.

- Ivan.

 

[special ed]

If I may add to the confusion, I remember back, I think the late 60s, an IPMS newsletter contributor wrote after a visit to Britain and Chicago's museum to measure the Stukas, he found a 2 inch difference in wingspan. After much consternation, it was decided the difference was because they were built in different factories.

 

[Ivan1GFP]

If I may add to the confusion, I remember back, I think the late 60s, an IPMS newsletter contributor wrote after a visit to Britain and Chicago's museum to measure the Stukas, he found a 2 inch difference in wingspan. After much consternation, it was decided the difference was because they were built in different factories.

How did the actual aircraft compare to their technical drawings?
Which one was closer?

 

[special ed]

It has been so long ago all I remember is the heated discussion. I do know that there are differences to anything in spite of drawings. Ten cars built on the same line with the same engine and trim will have differences. These same cars will have eight different top speeds with, if you are lucky, only two matching. The same goes for aircraft. If you want proof, the next time you're in Wall Mart look at the row of thermometers and see how many match. The same goes for tire gauges in automotive. In our C-119 group, we had one which always used more fuel in formation and took more effort flying. About two years before the birds went to the bone yard, a Fairchild rep showed up and it was determined that the wing was out of trim. As Fairchild no longer had tools and such, a special seven point socket in half inch drive had to be made. There was much activity in the machine shop and I was one of the spectators. When the socket was finally finished and about to be taken to the plane, one of the guys said " Wait, it's not finished." He took it to the machine that impressed letters into steel and wrote "manufactured by screw off tool company" on the socket and then it was ready. By the next drill, triple nickel was the best flying 119 in the group. Much work was done crawling inside the wing. That's why I don't get worked up over such numbers as "the top speed of the P-51D is 440mph--No no it's 435mph". Right off of the line, both are correct with different airplanes.

 

[Ivan1GFP]

Hello Special Ed,
I agree completely with your statements but only in regards to performance.
There will always be tolerances and faults in manufacturing and the end product may be somewhat different from the "design" specification. That is why in general, with a production engine and vehicle, it is often possible to gain noticeable improvements in performance by "Blueprinting" the engine, align honing cranks, balancing the rotating assemblies, etc.
The same can be shown with firearms when a mass produced gun can be substantially improved in accuracy by simply fitting the pieces together in the manner that they were DESIGNED to operate.

What I was commenting about was somewhat different.
For aircraft and other manufactured goods, there are drawings which specify the intended length (often with a tolerance measurement included) and my question was how closely each of the Ju 87 matched to that drawing. With a two inch difference in wing span, at least one of them is bound to be different from the specification.

The point here is that there is some dimension specified in the design even if the specific examples in hand deviate from that specification.
For the tire gauges and thermometers on a shelf, some of them may be a bit less "correct" than others, but to say there is no such thing as correct temperature or pressure is ridiculous. The question is really whether or not you have an accurate tool to measure.

Your experience with the C-119 is actually a great example.
When the Fairchild rep and your techs crawled through the wing structure, I am certain that the Fairchild rep wasn't inventing anything on the spot. He was basically looking for trouble spots: places where the example aircraft deviated from the intended design. Along the way, he probably corrected a few issues that were perhaps not out of tolerance but had room for improvement. The net effect as you observed was a vast improvement.
The point again is that for the manufactured pieces and their assembly, there was a set of specifications and the Fairchild guy was just correcting your aeroplane to match those specifications.

- Ivan.

 

[special ed]

Your point is on target. Possibly both Ju-87s were off spec. As an example. when the British order of P-40s was to be sent to the AVG, the back order of engines was made up by Allison calling in supervisors (possibly because of union costs) on weekends to assemble engines from parts rejected. According to the Allison book, the long nose gearbox began having failures much above 1150 HP. Since, in Dwane Schultz's book on the AVG they had often gearbox failures, it looks like the old hands built a stronger HP engine.

 

[GregP]

About post # 6, wing area ALWAYS include the fuselage between the wing roots, not sometimes. Some people try to break out the wing area minus the fuselage area, but they are not dealing with design reality. Aerodynamic formulas include the fuselage area.

In the case of something with an extreme rearward canopy, say ... like the XP-37: https://i.pinimg.com/originals/2a/54/8d/2a548dff85c7a760b9c2c6282350b6eb.jpg

there may be some justification for not including the fuselage area, but the formulas do not allow for that. If you calculate that way, you numbers will be out of step with all other aerodynamic wing loading calculations. Finding the area is simple. The leading and trailing edges are usually in a more or less straight line where they intercept the fuselage ... even in a Spitifire. Just connect them and figure the area.

Same with the horizontal stab.

 

[Ivan1GFP]

Hello GregP,

Why would you treat the XP-37 any differently?
Where the Cockpit / Canopy is located would not greatly affect the planform as I see it.

- Ivan.

 

[GregP]

Well, the leading edge of the windscreen is at the wing's training edge. So the fuselage between the wings is just a cylinder (or close to it). There is no lift over the top of that fuselage as there is in all real production WWII fighters with bulging canopies over the wing that create some lift at almost any speed.

Still, it gets treated like every other airplane and the wing area includes the fuselage.

 

[special ed]

And the P-38?

 

[CORSNING]

A very knowledgeable computer friend recently sent me a PM with this
quote.
" Aerodynamics for Naval Aviators" notes (p.61): "Although a portion of
the area may be covered by fuselage or nacelles, the pressure carryover
of these surfaces allows legitimate consideration of the plan are."

He continued on by saying something I very much agree with.
" The area "enveloped" by the fuselage is aerodynamically effective in
producing lift anyway, so carefully measuring just the exposed wing area
for the typical performance calculations would give a wrong impression."

Gross wing area for calculations it is for me.