Why Carson was an idiot BACK TO MAIN PAGE

Why Col. "Kit" Carson was wrong

This text refers to a famous article,
"The Best of the Breed", Airpower, July, 1976 Vol. 6 No. 4 by Col. "Kit" Carson

Intention of this page here is to correct serious errors in this particular article, which happened due to a serious lack of knowledge about the 109 technics and design history. It begins right here (quotes from the article in “italics”):

"But another household work, the highly propagandized Me-109G, was obsolete when it was built and was aerodynamically the most inefficient fighter of its time. It was a hopeless collection of lumps, bumps, stiff controls, and placed its pilot in a cramped, squarish cockpit with poor visibility."

I don´t want to talk about how much propaganda was done around the spitfire or for american fighters (usually by economic backgrounds or to find new volunatry pilots), let alone russian products. There exist in every country enough "propaganda", so shssst.

About the aerodynamic efficienz: The efficienz of the 109 airframe was proven very early in 1937, when a Emil airframe was prepared and a DB-601 engine was tuned to deliver 1700PS. This machine reached 611km/h at sealevel, world record. Except for a very careful surface finish, all difference to the serial 109E were a different spinner, no weapons, and a modified hood (This is not the 209, also called 109R, which reached later a much higher speed). Even 8 years later this speed was barely reached with such a power.
The aerodynamic efficienc of the 109 was based on several reasons. The three most important were:
- Small overall surface, especially wingarea. To compensate for the high wingloading during takeoff and landing, very efficient slats and flaps system was installed. The usually turbulent flow in the tail section lead to a very low overall surface area in this area.
- Inverted V-engine, giving the airframe an larger angle to the usually low mounted wing. This reduced interferenz drag and THIS was also the reason why the pilot head space was rather small. Nevertheless it was one reason why the 109 had a surpisingly high diving speed (only fools believe those spit dive tests with Mach numbers up to 0.9 btw.) what saved also their lives quite often.
- Centered propellor position, thrust line going right through the COG, also allowing for better view forward down

Spit and Hurricane pilots did often use mirrors. Why did they use them when they had such a superior sight? Germans went out in "Rotten", so there did not exist a dead spot. The view over the nose, once airborn, was good due to the lower prop position. The often quoted bad view refer to taxing on ground!

We go more into detail soon, but let´s see what Carson writes. Oh wait, he doesn´t quite often write his OWN opinion, but is quoting from time to time the test report. Anyway, let´s see:

"An intact Me-109E with wing cannon was captured by the French in the summer of 1940 and was flown to England for flight test and evaluation."

Nothing wrong here. But listen up: Just ONE Emil was captured and evaluated in Britain, so the opinion is based on just ONE airframe that SAW plenty of service and which was flown already in France by the allied.

" the engineers screwed up the center of gravity, and 60 pounds of permanent ballast had to be added to the rear of the fuselage to get the C.G. back."

An incredible 1.1% or less weight was added. Boah, what a big deal when it helps to improve fyling characterists, eh? But it´s getting even better. Look at this weight statistic of a Spit9:

What can we see? Spit 9 carried 5x17.5lb = 87.5lb ballast weight. Isn´t it interesting that Carson considers the ballast/trim weight on a 109E as an incredible design fault, but obviously didn´t know (or avoids to mention) that the Spitfire series (at least the 9) was blessed with even more ballast weight? This alone says a lot about the bias of Carson and his poor knowledge of WW2 fighter technics.

"In size the Me-109, all models, was the smallest fighter produced by Germany or the Allies. That gave it a high wing loading for that time, about 32 lb./sq. ft. for the "E". The Spit I and the Hurricane I were about 25 lb./sq. ft. at their normal combat weight. The 109-G was about 38 lb./sq. ft. as compared to 35 lb./sq. ft. for the P-51B."

It should be noted that wingarea is not a guarantee for lift. Wingloading is not equal to "liftloading". Airfoil, Angle of Attack (AoA) in a particular situation, Aspect ratio determine the amount of lift. No allied figher back then except for the russian Lagg and La series used slats to keep airflow in the aileron section but used washout. Though washout is an easy and uncomplicated way to achieve good handling characteristics at high AoA, it reduces total possible lift. So what lift coefficients were possible to achieve for the named fighters? This is difficult to say, because there exist no test of all aircraft from ONE windtunnel. Results of different measurements, quite often depending on correction factors, Reynolds number and other influences (wind tunnel geometry) may vary. Let´s compare the following numbers:

SpitV: 1.12 from "Stalling characteristics of Supermarine Spitfire VA airplane" 1)
P-51B: 1.28 from Naca Report 829, Page 26 in the PDF of the Naca Report server
109E: 1.48 from full scale Windtunnel test in Charlais Meudan 2)

1) The report is located on this server
2) The test was for a prototype of the new 109F, the machine was called V24. It did not have the round wingtips, thus the wingarea was slighly lower (15.1m^2) and even more important, it had a worse aspect ratio. Due to numerous component exchanges, the overall condition of this machine was rather poor. No flaps and no slats were used. The number given can be seen as realistic, maybe even too low!

If we calculate now a "liftloading" by dividing wingloading with maximum lift coefficient (The formula used is: LL = Weight/(Wingarea*Max_Lift_Coeff.), we get the following values (lower is better):

Aircraft	Weight [lb]	Aspect Ratio	Max. Lift Coefficient	Wingarea [ft^2]	Liftloading [lb/ft^2]
Spit 1 1)	6050	5.62	1.12	242	22.3
109 E	5600	6.0	1.48	174	21.7
P-51 B 2)	9400	5.815	1.28	234	31.4
Spit 9 1)	7450	5.62	1.12	242	27.5
109 G6	7159	6.0	1.48	171	28.3

1) The airfoil of the Spitfires did not change, thus the data from the SpitV wing was taken.
2) The wingload of a P-51B based on 9400lb is 39.9 lb/ft^2 and NOT only 35, the value Carson uses!

The Emil´s liftloading is even slightly better to the spitfire ones´. The G2 would beat the Spit9, but the G6 is slightly worse. On the other hand even a G6 is clearly better than the P-51B´s. This data is without the usage of slats and/or combat flaps!
There exist also a statement by the german Erwin Leykauf, describing how he was able to outturn Spits in the BoB with his 109 by using slats...
In the table the aspect ratio is included. It´s important to know that the 109 had a higher aspect ration than a Spit. Often people think the elliptical wing of a Spitfire had huge advantages. They´re wrong. The influence of wing shape and aspect ratio is discussed here.
"The fastest "G" subtype was the G-10 capable of 344 mph at SL or 428 mph at 24,000 ft. with a meager range of 350 miles and an endurance of 55 minutes, but it wasn't introduced until the spring of 1944. Too little, too late, and still lacking in rnage and endurance."1

It´s still not clarified what was the topspeed of a "clean" G-10 without gondolas or fuel tank. From the current point of knowledge it can be said that it was faster, however.
Range depends on power and RPM setting. With very low RPM settings the 109 could stay longer than 55 minutes in the air, especially when using a drop tank. However, like the Spit the 109 was never a long range escort fighter, of course. But this was not the fault of Messerschmitt. The philosphy in Germany about the bomber development was influenced by the experiences in the mid-30ies, when bomber proved to be faster than contemporary fighters. Thus, long range escort fighters (and heavy self-defence) for bombers were considered to be not necessary.

"In principle the DB601 and 605 series engines were the same as the Allison or Merlin, except they were inverted and had direct fuel injection; otherwise they were 12-cylinder, 60 degree Vee, glycol cooled engines. The prop was a 10.2 foot, 3 blade variable pitch mechanism of VDM design. here is another major difference between their design approach and ours. The pitch on the Me-109 prop could be set at any value between 22.5 and 90 degrees, a visual pitch indicator being provided for the pilot. There was no provision for automatically governing the rpm. We did just the opposite, using a constant speed governor and flying by a constant tachometer indication of rpm. For any flight condition the rpm remained constant. We did know, or care, what the blade angle was."

Surprisingly (oh well, actually no surprise at all) he does not mention the outstanding advantage of the DB engine, the direct fuel injection, allowing an position independent supply of fuel to the engine and avoiding backfire problems.
In case of the Emil Carson is correct that the pitch had to be adjusted manually by the pilot. But the most important usage of the prop pitch mechanism is changing pitch for takeoff and landing anyway. In manoevering fights pitch rests rather constant. Early spitfires did have only 2-pitch settings for their propellor, one for takeoff, one for the flight! Of course Carson "forgets" to mention that from the F on, the 109 had a constant prop pitch mechanism too, which furthermore was coupled to the throttle, thus giving the pilot a wonderful single lever control. This principle was copied later for the Spitfires.

"The absense of a rudder trim control in the cockpit was a bad feature at speeds above cruise or in dives."

Usually pilots used the fixed tab to trim for fast flight. Logically it was easier to use rudder in a climb where forces were lower. The quesiton is: Why wasn´t it done by the RAF this way? Lack of experience?

"If the airplane was trimmed for level flight, a heavy push on the stick was needed to hold it in a dive at 400 mph. If it was trimmed into the dive, recovery was difficult unless the trim wheel was wound back, due to the excessive heaviness of the elevator forces."

There´s nothing special about it. Actually, elevator heaviness and slow response can have other reasons, like gustwind areas. Due to the 2R1 airfoil pitching moments were rather small compared to the outdated 4-digit airfoil of a spitfire for example. The balance effect was not the best, true, but german pilots succesfully got the nose up by violence or by trim. A hard elevator also protected the airframe from too high G-forces. It should be noted that the trim system, changing the AoA of the whole horinzontal stabilizer, was outstanding and, if compression happens, usually the only possibillity to get the nose up again. Today´s high speed aircraft usually use the whole horizontal stabilizer even as elevator!
It´s noteworthy that Carson doesn´t mention the positive flying qualities of the test report. He goes on with the next negative point he found in the report...

" (1) Due to the cramped cockpit a pilot could only apply about 40 pounds side force on the stick as compared to 60 pounds or more possible if he had more elbow room.

(2) Messerschmitt also penalized the pilot by designing in an unsually small stick top travel of plus or minus 4 inches, giving very poor mechanical advantage between pilot and aileron.

(3) At 400 mph with 40 pounds side force and only one fifth aileron displaced, it required 4 seconds to get into a 45 degree roll or bank. That immediately classifies the airplane as being unmaneuverable and unacceptable as a fighter. "

Well, "unmaneuverable" is tough eh? What Carson doesn´t say is that the same report mentions equal roll rate of a Spitfire and a 109 up to 400mph... so the Spit was an unmanoeverable aircraft too?? I already said that Carson is often quoting the RAE test report of the 109-E. In the very same document, the following chart is included, comparing the aileron force of a 109-E to the Spit-1:

Now what does this chart tell us? The 109-E needed for a 1/5 aileron deflection at 400mph 37lb stick force, the Spit-1 57lb. This is a 54% higher stickforce for the Spit pilot. To build up the same moment like in a 109, the stick of a spitfire must have been 54% longer, so it probably would have looked out of the roof window...
Why didn´t Carson mention the worse stickforce characteristics of the Spit-1, which is written down in the same report he uses for his article? I think you, the reader, slowly gets an impression about the bias of Carson and the way he choses and presents his data...

It also should be noted that in technical language you distinguish between an observation, a judgement based on given requirements, and a conclusion. Of course the ailerons of the 109 were never as light and as effective like the FW190 one´s, BUT the german chief test pilot Heinrich Beauvais did very early disagree with the negative judgement and tactical conclusion of the RAF. It should be noted again that the english test is based on a SINGLE aircraft that saw plenty of service already. Beauvais tried to get into contact after the war with Eric Brown who also critized the 109. His major critic points were:
- Bad control harmony characteristics
- Bad wheel brakes
- Aileron impuls during opening of the slats
Guess what, strangley Eric Brown REFUSED to get into a discussion about such questions. Did the 109 has to be bad for the english? Handley Page would have known how to solve the unsymmetric opening, why did noone from the RAF ask them?
There exist german test report where aileron forces of over 45lbs are mentioned. So high stick forces WERE possible also in the 109!

Let´s go on:

"To black out, as a limit to the human factor in high speed maneuvers, would require over 100 pounds pull on the stick."

100lb, 45kg, so what? This is no extraordinary high force for pulling. Did english test pilots lack muscles?
The following document shows that the 109G was designed for elevator stick forces of even 85kg!! And this was a realistic assumption!

All right. Now let´s jump to this quote:

"Turning Radius
At full throttle, at 12,000 feet, the minimum turning radius without loss of altitude was about 890 feet for the Me-109E with its wing loading of 32 pounds per square foot. The corresponding figure for the Spit I or Hurricane was about 690 feet with a wing loading of 25 pounds."

I already discussed the influence of lift coefficient. What the report assumes is simply the same lift coefficient for the 109 and Spit. Of course, if we calcualte just with wingloadings then we get for the radius of the Spit: 829feet / 32 * 25 = 695feet ~690feet
Unfortunatly - i can´t say it often enough - it´s lift/weight that determines the minimum radius and not just wingarea/weight. The people who wrote the report and Carson are doing calculations on such a simple mathematic and aerodynamic basis that i´m wondering how they got their degree in mechanical engineering or aerodynamics!

After quoting so much from the Emil test report, he goes on with his own opinion. Let´s look at his summary

(1) Ailerons and elevator far too heavy at high speed.
(2) Poor turning radius.
(3) Absence of rudder trim control in cockpit.
(4) Aileron snatch (grabbing -- uneven airflow) when slats opened.
(5) Cockpit too cramped.
(6) Visibility poor from cockpit.
(7) Range and endurance inadequate.

My answer in short:

(1) Not true, ailerons even lighter than those of a Spitfire at high speeds. 109 test shows rollrate of over 80° at speeds over 450km/h, stickforces of more than 25kg possible!
(2) Not true, radius smaller than USAAF aircraft, experienced pilots could turn into Spitfires. Btw, it´s a (german born) myth that Me-110 or Fw-190 could turn faster. In both cases where pilots of these machines wanted a trial against a 109 flown by german test pilot Beauvais, they lost!
(3) Rudder and aileron trim had to be installed back then in germany for aircraft over 5 tons weight only. No long range flights possible anyway, so fatigue was no problem.
(4) Unsymmetrical aileron openings could have been avoided by aileron adjustment. Aileron "hits" while opening were adressed with the F on (roller bearings, new design)
(5) Pilots enjoyed it, they felt "one" with the machine. Everything close. Low drag design except for steep, but on the other hand small front window
(6) Partly correct, but view forward down was better than that of many other fighters. Erla hood was later an overall improvment
(7) Not true for interceptor role. True for long range escort tasks.

Carson goes on to describe the 109 as obsolete in 1942 and writes

"Furthermore, no designer in that period would pretend that he could stretch the combat effectiveness of a fighter for 7 years, 1935 to 1942, without major changes in power plant or aerodynamics, or, better yet, going to a new design."

First: The 109 made 2 major development "jumps". The first one was from the Emil to the Franz (or Friedrich), the next one was from the G to the K which is not as clear to see, because many components designed for the K (being basically ready at the end of ´43) were used first for the late G-6, G-10 and G-14 before they finally introduced the K-4.
So it wasn´t the same aircraft anymore in ´44 than in ´38, actually in ´42 it was already much improved. Let´s look at the power and weight development: During 10 years, power was increased by a factor of 2.5, while weight increase could be held down to a factor of only 1.6!
Another fact: Though the Spitfire was introduced 3 years later, it was right from the beginning and throughout it´s life inferior to the 109 from a technological viewpoint.

First Spitfires did NOT have:
- direct fuel injection 1)
- variable pitch propellor
- slats, combat flaps 1)
- central mounted weapons 1)
- movable horizontal stabilizer for high speed flight/trim 1)
- inclined seat position for better G-load resistance
- Advanced airoil 1)

1) Even not introduced for late war Spitfires.

I could go on with other disadvantages of a Spitfire, namely in field service. No detachable wings, difficult mounting of propeller/propeller gear and so on.
From a technological, service, cost and production time viewpoint, the 109 was superior and was very difficult to replace. Few other fighters could have been produced in such numbers.

"The Spitfire was an aerodynamically clean airplane to start with, having a total drag coefficient of .021 at cruise. The Me-109 had a coefficient of .036"

0.36 for the 109 is plain BS. Tests in Charlais Meudon with the 109V24, a prototyte of the 109F, showed a CD of 0.24-0.3, depending on surface condition. 0.36 is close to the test with a 500kg bomb. Somebody must have mistaken the test with the installed bomb as a test for a clean 109. What an error! And this is once more just the CD value, to know more about total drag characteristics you have to multiply it with wingarea. Well, the Spit did have a lot of wingarea, right? Let´s see:
Spit: 0.21*244 = 51.24
109: 0.3*171 = 51.3
The 109V24 is equal to a Spitfire, even assuming a really bad drag coefficient for the 109, and the best you can find for the Spitfire. Oh wait, i made a mistake. the CD is for the 109V24 with a wingare of only 15.1m^2 or 162ft^2. It´s for a rough camouflage painting btw, so really the worst you can expect. Now... :
109V24: 0.3*161 = 48.3
Fact: Even in the worst condition you can expect, the 109 posessed a lower drag than a Spitfire in best condition! History also tells us that 109 usually was faster when both fighters used same power settings.

"Messerschmitt practically ignored the subject of low drag aerodynamics"

This is the biggest joke in the article. From 1937 on the world record for top speed was in the hand of Messerschmitt with a short interruption by Heinkel. The record for the 209 lasted over 30 years, though the upcoming jet age definitly helped that it survived so long. The interest for jets simply drew away attention from the prop driven aircraft, until it was broken 30 years later by rather sportive reasons. However it clearly shows why Messerschmitt is still known as a pioneer in low drag and light construction.

Now Carson goes on, and it´s becoming almost ridicolous:

"Object: to make it a 400 mph plus airplane"

Above he mentions the G-10 with 425mph, did he already forget that the 109 was able to go as fast?
There follow 7 "improvment" proposals, which seem to be again not based on Carson´s opinion only, but seem to have the origin in a german work about aerodynamic drag, which is unfortunatly not 100% correct. Anyway:

(1) Cancel the camouflage paint and go to smooth bare metal. Besides the weight, about 50 pounds, the grain size is too large when it dries and it causes turbulent friction over the entire airplane surface. That may take a phone call to the brass. They're emotional about paint jobs. "Image," you know.

Bare metal would have rusted quickly. At high altitudes you better don´t want to "blink" anyway when you try to get through hundreds of enemy fighters. BS! The weight, once the paint is dry, is not so high. The grain size maybe was high, but machines were polished or waxed anyway by the mechanics. It should be also noted that a smooth surface can be easily destroyed by dirt, flies or dust. Just read the report on this page about the P-51 dive tests and the different resualts depending on dust alone!

(2) Modify the cockpit canopy. Remove the inverted bathtub that's on there now and modify as necessary to fit the Me-209-VI canopy. That's the airplane that set the world speed record in 1939.

Bullet proofed glass could not have been manufactored in a round way back then, maybe even not today? So once more BS! Btw, the razorback design of the P51-B was considered to have less drag than the later bubble canopy of the D.

(3) Get rid of the wing slats. Lock them closed and hand fit a strip, upper and lower surface, that will close the sheet metal gaps between the slat and wing structure. That gap causes the outboard 15 feet of each wing to be totally turbulent.

Again BS and depending on aileron adjustment. Huh, with 45% turbulent airflow the 109 could barely fly! BS, really BS! Furthermore, the slats are in the area where air is accelerated, thus the air won´t separate as easily.
(4) As aerodynamic compensation for locking the slats, setup jigs and fixtures on the assembly line to put in 2 degrees of geometric twist from the root to tip, known as "washout."

Ok, here i have to write a bit more. Carson really does know nothing about the 109, and even worse, he obviously did not inform himself before writing such an article.
It´s a fact that Messerschmitt wanted to get rid of the slats too, but not on grounds of aerodynamically inefficience, but because they were disturbing in a mass production. Complex part, fine adjustments necessary, expensive. Messerschmitt ran several wing tests for the new F series. Background was a very dangerous behaviour of aircraft at this time for sudden wing drops at high AoA, an almost completly, sudden loss of lift on one wing. The DVL ran several test on a 109B to find out the reason behind the phenomen. Bölkow(he died recently), who was responsible for the development of the K, tried later to avoid this problem during landings with the longer tailwheel, that saw service in the G-10, but this did not found support at Rechlin

The "flying wind tunnel", a prepared 109B

They found out that the proposed "washout" did not help but made the stall characteristics worse! Yes, Mr. Carson, it made it worse!! Germans and Willy DID know about washout! So take you poor schoolar knowledge you learned from some books and :/$/"§$!"§$ !!!
Now, furhter investigations showed an airstream running across the leading edge or front part of the wing right before such a sudden drop occured. The engineers made an experiment: They mounted vertical stripes on the wing which should prevent this crossflow. It was a HUGE sucess, nevertheless it was not introduced. Why? Slats were still more effective, and it was expected that this fence was disturbing for the laminar wing which was expected in near future.
After the war exactly the same "boundary layer fence", today´s expression, was used for the 109 build in Spain which lacked the slats. The 109 was the first aircraft to carry boundary layer fences, even before the war!

Spanish build 109 with boundary layer fences

(5) Modify coolant scoop inlet fairings. The square corners that are there now induce an unnecessary amount of drag. Also lower the inlet 1 to 2 inches below wing surface to get it out of the turbulence of the wing surface.
(6) Install complete wheel well farings that cover the openings after the gear is retracted.
(7) Retract tail wheel.

The rest can be considered ok, but not deciding. The tailwheel influence showed up in wind tunnel tests only at high AoA. At low AoA it "hides" itself behind the fuselage.

That´s it!