Could the Bf 109 E really out-turn the Spitfire Mk I? (3 Viewers)

[ThomasP]

re

Is that right?

Yes.

re

And is this ratio for one particular type of wing shape? Would the progression be different for a Spitfire or a Bf 109?

The basic progression works for all reasonably conventional wing shapes - from the Wright brothers thru to today on modern jets.

re

I wonder if we could build a chart from that relatively simple math for various (level flight) stall speeds and what that translates to turns at 2G, 3G, 4G, 5G, 6G etc.

Yes, it can be done to a close approximation.

I would have generated a combined lift curve chart for the Hurricane wing and a speed vs g-load chart (V-G chart) to go with it but my desktop is in storage at the moment, and I could not find any good representations on the net.

 

[Steamed_Banana]

So next question. If a Bf 110 is in a 2G turn at 200 mph, and a Hurricane is in a 2G turn at 200 mph, both at 5,000 ft, are they turning at different rates? I know they have different power to weight ratios and different amounts of drag so will be losing speed at different rates... (or this could possibly be sustained depending on altitude)

 

[ThomasP]

If the turns are sustained at the same g at the same altitude then both are turning at the same rate and have the same radius of turn. If they are not sustained then it depends on which has less of a deficit in power as to how much altitude is being lost or how quickly the g and turn rate drops off in a given amount of time while maintaining or losing altitude. If one has excess power then it could tighten its turn (if it has enough CL and Lift available) or climb while maintaining its turn rate.

 

[Steamed_Banana]

How does one determine what the G limits for turning are, other than the stall speed and the structural limit? Are these published generally? Presumably there are guidelines in some cases though in many (most?) aircraft used during the war they did not have G meters from my understanding...

 

[ThomasP]

re

How does one determine what the G limits for turning are, other than the stall speed and the structural limit?

If you know the angle of bank during the turn, the IAS, the altitude, and if you are maintaining altitude or not, you can calculate the g load. As a double-check you can record the compass direction at a given mark and the clock at the same time, yielding the turn rate. Performing multiple runs would allow you to average out the results and remove erroneous values.

Pretty much all aircraft had IAS, angle of bank, and altimeter gauges, and a compass and clock, so if you could record the readings on these 3 to 5 gauges in a time coordinated manner you could do the math.

Most of the more extensive tests done by the RAE and A&AEE used cinecameras trained on the gauges and/or moving paper strip & pen recorders depending on what they were looking for and what was easier/more practical. Many of the fighter cockpits were pretty cramped and the remote gauges and measuring instruments would be fitted in the fuselage behind the cockpit.

While g meters were not normally carried operationally by most aircraft during the war, starting in late-1941 the RAE/A&AEE did fit some in various aircraft that were used operationally - in order to get an idea of how many g the pilots were actually pulling in combat, and how often. I do not know which type of g meter they usually used but there are a couple of different possibilities.

One used a bob weight on the end of an extension coil-spring (think of the spring on your screen door) sliding over an inner rod - with a pen attached to the bob weight to draw lines on a moving paper tape - was one of the common early types. An extension coil spring will extend a given amount per g applied, so after zeroing the pen at 1g while sitting in flying attitude on the ground (setting the vertical), if you pulled 2g in flight and it moved a total of 0.5" from the 1g mark, then a 3g load would result in a total movement of 1" from the 1g mark, 4g would result in a total movement of 1.5", etc. They could also set up the same type of mechanism but with a cinecamera to record the movement of the bob weight.

Between the instruments and methods described above they could calculate the sustained g load at any point in the flight envelope, how long a given g could be maintained - sustained or not sustained - in a level turn, how quickly speed was lost, the rate of turn, the climb rate, the descent rate, the rate of acceleration in level and diving flight, etc.

I posted a summary report by ARC in another thread a while ago, that describes the results of some of the tests and conclusions.
"Lightweight Mustang (XP-51F/G/J vs H) in flight G loadings question/in general, what's a good G loading for a World War II fighter?"
There were an earlier series of the tests which cover some of the earlier Spitfire marks, the Hurricane, the Whirlwind, etc, but I have not been able to find a copy of it.

 

[ThomasP]

I am off to bed now.

 

[Greyman]

There was a huge propaganda drive to belittle the Merlin float carb weaknesses, and even modern understanding is weak on this subject. Remember, Quill was deeply involved in Spitfire development as a company man from just 3 weeks after the first Spitfire flight and he had already had considerable opportunity to comment upon negative G effects of the Merlin, but this had not been highlighted as a operational weakness until the BoB when the Germans had an advantage. So, Quill was somewhat invested in the situation with the Merlin float-carb situation. If you consider that problems with Merlin negative G cutting-out was "A minor handicap", how do you explain the storm of complaint about it in the BoB, causing the crash design by R-R of a new diaphragm carburettor at a time when R-R were so flat-out with workload that they cancelled the Vulture and Peregrine-workload made worse by the float carb problems? Two Squadrons were equipped with the new R-R diaphragm carb engine at North Weald for operational trials which failed, and the diaphragm carb crash program was all wasted. The panic response to the problem also included the work by the RAE with Beatrice Shilling that came up with the basic RAE Restrictor that reduced the total cut-outs that the basic float carb suffered. The RAE Restrictor was also a crash-program of modification starting in early 1941. The Germans had been aware of the Merlin negative G cut-out problem from at least the time that they had a captured Spitfire and the tactical advice to Luftwaffe fighter pilots' advantage was used extensively in the BoB. You will know that the RR/SU Merlin float carb was later redesigned with complicated anti-G features and this was another major modification to improve the Merlin operation in zero or negative G conditions. R-R were so badly placed by the whole saga that they had to see the Packard engines built with the superior and negative g capable US Bendix Stromberg PD 12 carb and Licence-build the later Stromberg PD 18 carb for the Merlin 66. After that, R-R were forced to develop single point FI, first with SU, and later with their own system.

Spitfire ailerons and roll performance was indeed another weakness. Here, there were large variations in individual aircraft, such that some were good and others poor. The general improvement of that problem was also protracted and seems to be another issue that was not fully appreciated before the BoB.

Eng

I'm not sure what the point of such a propaganda drive would have been. Who would they be trying to fool?

I also doubt Quill would be obscuring any drawbacks of the Spitfire. This would be in order to ... ? Again, I'm not sure what the point would be. He was critical enough about the ailerons, the windscreen condensation, the engine and oil cooling ...

I note he specifically mentions "... and their usual evasive action is a half roll and dive away -- the Me.109's being able to travel faster than a SPITFIRE in a dive" (bold emphasis mine). To support my point, I'd like to hang my hat on the fact that he doesn't deem the issue worthy of reporting on -- but I think it's just as likely that he would view the negative-G-cut as a Rolls-Royce problem, not one his firm can do anything about. As you said, there are plenty anecdotes from other pilots.

A minor handicap is still a handicap, and would merit attention. It is a very 'loud' problem, so to speak. Having your engine cut in the middle of a fight would be jarring (to put it lightly), but in my opinion it's just the cherry on top of the real problem: the 109 (and 190) having better acceleration and dive than the Spitfire -- engine continuously running full bore or not.

If -- in order to exploit the 'biggest weakness' of your opponent's machine -- you need him to be within lethal range and aspect ... that doesn't strike me as a game changer.

Also, if negative G manoeuvres in the Spitfire was a major drawback, how did the Hurricane have any hope?

 

[Gilder]

I'm not sure what the point of such a propaganda drive would have been. Who would they be trying to fool?

I also doubt Quill would be obscuring any drawbacks of the Spitfire. This would be in order to ... ? Again, I'm not sure what the point would be. He was critical enough about the ailerons, the windscreen condensation, the engine and oil cooling ...

I note he specifically mentions "... and their usual evasive action is a half roll and dive away -- the Me.109's being able to travel faster than a SPITFIRE in a dive" (bold emphasis mine). To support my point, I'd like to hang my hat on the fact that he doesn't deem the issue worthy of reporting on -- but I think it's just as likely that he would view the negative-G-cut as a Rolls-Royce problem, not one his firm can do anything about. As you said, there are plenty anecdotes from other pilots.

A minor handicap is still a handicap, and would merit attention. It is a very 'loud' problem, so to speak. Having your engine cut in the middle of a fight would be jarring (to put it lightly), but in my opinion it's just the cherry on top of the real problem: the 109 (and 190) having better acceleration and dive than the Spitfire -- engine continuously running full bore or not.

If -- in order to exploit the 'biggest weakness' of your opponent's machine -- you need him to be within lethal range and aspect ... that doesn't strike me as a game changer.

Also, if negative G manoeuvres in the Spitfire was a major drawback, how did the Hurricane have any hope?

Its my understanding that the Me109 had problems in the dive. Not the initial acceleration but its behaviour in the dive. The controls became heavy in a dive, not uncommon in most types of the time, but it was impacted more than most and care had to be taken to not leave pulling out too late. The 109 also had a problem with wing failure so much so that the VNE speeds were inserted into the cockpit.
If I recall correctly the 190 was much better in this regard.

 

[Steamed_Banana]

This is definitely true, it became a standard tactic for Kittyhawk and (especially cropped wing) Spitfire pilots in the DAF to dive and roll to the right when they reached 400 mph IAS to evade Bf 109s, because at high speeds they could not roll to the right. This was confirmed by testing captured Bf 109E, F and G.

Most of the US fighter groups had at least one captured 109 in flyable condition, to test and train with by early 1943. Several RAF units did as well including 3 RAAF and 260 RAF. This one is "Irmgard", owned by the US 79th FG.

 

[Holtzauge]

The longer video mentioned in the opening post is now finished and released on YouTube.

This video aims to answer the question as asked in the title: Namely, how close were they in terms of turn rate and radius during the Battle of Britain time period?

Which is an issue often hotly debated in aviation forums, and which even knowledgeable persons sometimes have very different ideas about.

And while there certainly is some historical data on this subject, this is often spotty and usually limited to sustained turns at just one altitude, meaning such data can only provide a snap-shot.

But how did they really compare at other altitudes, and with different flap and power settings?

And what about instantaneous turns? I.e. turns in which the pilot trades a speed loss for a better turn rate? How do they compare under such conditions?

Added to this we have ample anecdotal evidence on how the Spitfire Mk I and Bf 109 E compared in turns. But as this video shows, such anecdotal evidence often needs to be approached with caution, since it's not only affected by pilot skills, but can also be tainted by unrepresentative outliers.

Then there are a lot of myths surrounding the Bf 109's leading edge slats. Such as did they really come out "with a bang"? Or smoothly and gradually? And how much drag did they cause? And did they provide any advantage in turns? And if so, how large was this?

In addition, how do different general aircraft characteristics like wing and span loading, aspect ratio, maximum lift coefficient and power loading affect an aircraft's turn performance?

And all of these questions and more, are addressed in this longer video, which expands on the video linked in the opening post.

But there are probably other opinions on this, and perhaps even data, and it would be interesting to hear other takes on this subject.

As in is there any solid anecdotal evidence, or other data supporting or contradicting the conclusions drawn in this video?


View: https://www.youtube.com/watch?v=0h-F1-RK7ns

 

[Engineman]

I'm not sure what the point of such a propaganda drive would have been. Who would they be trying to fool?

Rolls-Royce were very aware of Float-type carburettor problems for decades before WW2. As a profit-making private company (even throughout WW2, like most UK companies) they were always in competition to make a profit, notwithstanding their strong position as a bastion of British engineering. RR were slow to appreciate the technology developments in carburation with pressure carbs and FI. Their position was that the use of developed Claudel-Hobson and SU type float carbs was satisfactory if they satisfied the customer. For early Merlin development, they tried competitive evaluation of both C-H and SU prototypes, the SU winning. RR liked the SU Variable needle jets type carb, it was simple and cheap. When the Air Ministry tried to interest RR in the RAE pressure carb developments, RR declined, and Bristol instead worked with the RAE/Ministry (slowly, Bristol engines not seeing the RAE pressure carbs until about 1942 in service). So, RR were really in a sticky position when Float carb limitations had real impacts on air fighting in the BoB and Air Ministry pressure was strong to sort it out! RR became very touchy about carburation and you can read all the information they spread at the time to try and deflect the criticism.

I also doubt Quill would be obscuring any drawbacks of the Spitfire. This would be in order to ... ? Again, I'm not sure what the point would be. He was critical enough about the ailerons, the windscreen condensation, the engine and oil cooling ...

There is no adverse comment upon Quill. However, again, as a Company man (Vickers) the company position would matter a lot, they would work for improvements but never criticise their own product to the detriment of the Company. Quill was no-doubt fully aware of the Merlin negative G cut-out problems in the 1930's but, I have not seen any evidence of a crusade to identify or cure them before the BoB. Here, he was no worse than anyone else in this debacle, pre BoB only the Germans, some in the USA and some at the RAE saw the real problems with float carbs.

I note he specifically mentions "... and their usual evasive action is a half roll and dive away -- the Me.109's being able to travel faster than a SPITFIRE in a dive" (bold emphasis mine). To support my point, I'd like to hang my hat on the fact that he doesn't deem the issue worthy of reporting on -- but I think it's just as likely that he would view the negative-G-cut as a Rolls-Royce problem, not one his firm can do anything about. As you said, there are plenty anecdotes from other pilots.

By this time, it was apparent that there were issues with Merlin carburation in negative G tactical manoeuvreing and too late to correct quickly.

A minor handicap is still a handicap, and would merit attention. It is a very 'loud' problem, so to speak. Having your engine cut in the middle of a fight would be jarring (to put it lightly), but in my opinion it's just the cherry on top of the real problem: the 109 (and 190) having better acceleration and dive than the Spitfire -- engine continuously running full bore or not.

It was a handicap.

If -- in order to exploit the 'biggest weakness' of your opponent's machine -- you need him to be within lethal range and aspect ... that doesn't strike me as a game changer.

Many pilots first knew they were a target when the bullets flew around them, having your engine keep going as you pushed hard was important. Note, the float carb was not only bad in negative G, it was grumpy in all manoeuvres.

Also, if negative G manoeuvres in the Spitfire was a major drawback, how did the Hurricane have any hope?

The Merlin in the Hurricane with float carbs had the same negative G issues. A good aircraft at the time, it was a workhorse. Later aircraft had the Bendix Stromberg pressure carb.


Eng

 

[GregP]

Do we have any data on stall speed for different aircraft while pulling increasing G loads? Does it scale up from stall speed in level flight in a predictable way?

There are aerodynamikcs formulas for stall speed with bank angle and stall speed with g-force.

If a plane weighs 4,000 pounds empty and stalls at 75 mph, then adding weight to get to 5,000 pounds is the same as turning at 1.25 g. So, 1.25 * 4000 = 5000.

The bank angle is acos (1 / g-force). So, acos (1/1.25) = 36.9°. New Stall Spped = square root of g-froce * 1-g stall speed. So, sqrt (1.25) * 75 = 83.9 mph.

 

[wrathofatlantis]

This is definitely true, it became a standard tactic for Kittyhawk and (especially cropped wing) Spitfire pilots in the DAF to dive and roll to the right when they reached 400 mph IAS to evade Bf 109s, because at high speeds they could not roll to the right. This was confirmed by testing captured Bf 109E, F and G.

View attachment 889362
Most of the US fighter groups had at least one captured 109 in flyable condition, to test and train with by early 1943. Several RAF units did as well including 3 RAAF and 260 RAF. This one is "Irmgard", owned by the US 79th FG.

You have this upside-down: The Me-109E (and this extends to the G) preferred right turns at high speeds, but did prefer left turns at speeds below about 220 mph indicated. The difference at low speed was around 20 seconds left to 22 seconds right in Russian tests, which is noticeable, but the real 109G figures (with 30% reduced throttle) are probably a second or two less. The high speed right preference was a very pronounced feature that extended to the G. There was even a joke: "You can tell a Me-109 pilot by his overdeveloped left leg."

This is why the Me-109 required right rudder on take-off climbs (low speed) and left rudder at high speeds. The P-40 was somewhat similar, so I doubt they had a huge advantage. They were very close in turning performance.

In dive the P-40's left roll was so compromised that the pilot had to brace his right elbow against the cockpit wall to keep from rolling right in dives 400 mph and over... And this remained true even on the improved P-40N...

On the Me-109 the weight on the left pedal started at around 220 mph indicated and climbed very rapidly even at 250 mph. I remember seeing weight figures of the effort and it was striking how suddenly it appeared and how fast it climbed, but it never got into an unreasonable range: It topped out at around 70 to 100 pounds depending on speed. But that is not pleasant...


M. B. Morgan & D. E. Morris, Royal Aircraft Establishment, Farnborough, Messerschmitt Me.109: Handling and Manoeuvrability Tests, September 1940, report RM 2361.

The relevant section is "Directional Trim." The passage reads:

"Absence of rudder trimmer is a bad feature…"

and then, crucially:

"At high speeds, however, the pilot is seriously inconvenienced, as above 300 mph about 2 1/2 degrees of port (left) rudder are needed for flight with no sideslip and a very heavy foot load is needed to keep this on."

A heavy foot load for just 2.5 degrees...

The report then makes the physiological consequence explicit:

"In consequence the pilot's left foot becomes tired, and this affects his ability to put on left rudder in order to assist a turn to port (left). Hence at high speeds the Bf.109E turns far more readily to the right than to the left."

And the G with the original tail was the exact same:

There is an important later source: Captain Eric Brown's 1944 evaluation of a Bf 109G-6, subsequently published in the RAF Yearbook article "Four of the Finest" (1975).

Brown wrote:

"Another inherent shortcoming was the lack of any rudder trimming device, necessitating the application of moderate right rudder during climb and considerable left rudder during a dive."

The P-51D was similar at low speeds, with a marked preference for low speed left turns below 220 ias, and a similar preference for right turns above that speed, though the pilot could relieve these intense rudder forces with the rudder trim tab. It should be noted that this relieved him from constant effort, but it did not change the aircraft's turn side preference.

Unfortunately for the P-51 pilots, the rudder was such a massive and powerful item that the trim tab response to pedal action had to be reversed from mid-B production onward, to prevent damage to the fin or hinges(!)... This meant the P-51D rudder forces were very heavy as the trim tab was now working against him... But all control forces were heavy on the P-51, so it kind of blended right in...

The P-47 Razorback also had a left turn preference, but it stayed the same at all speeds. The Bubbletop turned worse, but was probably more symmetrical.

The A6M Zero did not like high speed right maneuvers, either roll or turn.

The FW-190A could not make high speed hard right turns without flicking into spin (terrible high speed handling generally, one of the very worst at high speed of WWII), but it was otherwise unusually symmetrical, and the Spitfire was probably the most symmetrical of them all until the Griffon engines were installed.

Asymmetry was significant, and at least one P-51D pilot (with a tailing enemy) describes lowering the throttle during combat, just to get into the slower "left turn preference" zone. He noted: "The designers could not get them to be the same on both sides."

 

[drgondog]

Unfortunately for the P-51 pilots, the rudder was such a massive and powerful item that the trim tab response to pedal action had to be reversed from mid-B production onward, to prevent damage to the fin or hinges(!)... This meant the P-51D rudder forces were very heavy as the trim tab was now working against him... But all control forces were heavy on the P-51, so it kind of blended right in...

The reverse rudder boost tab was introduced to minimize over-control/ deflection of the left rudder in high speed dive and roll - particularly in a dive. At high speeds the left rudder has to be applied as the P-51B/D tended to hunt right. At lower speeds, and particularly in a roll or side slip - over deflection of the rudder placed great strains on the empennage (torque), exacerbated by the prop vortex upwash on left stab, ruder and downwash on right stab after Merlin was introduced with four blade prop. The RRBT was introduced in April 1944 on the same T.O. that accompanied the dorsal fin for both models.

Why do you say all control forces were heavy on the P-51? Pilots that flew with and without RRBT would agree that when so equipped, roll response was noticeably muted in comparison. High dynamic loads also contributed- but that is universal and the P-51B/D is pretty responsive in high-speed rolls compared to its contemporaries.

Asymmetry was significant, and at least one P-51D pilot (with a tailing enemy) describes lowering the throttle during combat, just to get into the slower "left turn preference" zone. He noted: "The designers could not get them to be the same on both sides."

Which pilot, and did you misread 'flaps' for throttle? It must not have been a 109 or 190 that he wanted to enter a low speed turn fight against.

 

[Engineman]

Unfortunately for the P-51 pilots, the rudder was such a massive and powerful item that the trim tab response to pedal action had to be reversed from mid-B production onward, to prevent damage to the fin or hinges(!)... This meant the P-51D rudder forces were very heavy as the trim tab was now working against him... But all control forces were heavy on the P-51, so it kind of blended right in...

As I understand it, the weighting of the rudder foot loads was modified to increase the foot loads at higher airspeeds where the tail structure could be overstressed. The use of an anti-balance function in the rudder trim was quite clever, the extra foot loads should not have been a problem at lower speeds where the tab made less effect but, it protected the structure at higher speeds. I also think that I am right that the dorsal fin modification was more of a structural reinforcement for the tail than an extra aerodynamic keel surface area fix.

Eng

 

[Steamed_Banana]

You have this upside-down: The Me-109E (and this extends to the G) preferred right turns at high speeds, but did prefer left turns at speeds below about 220 mph indicated. The difference at low speed was around 20 seconds left to 22 seconds right in Russian tests, which is noticeable, but the real 109G figures (with 30% reduced throttle) are probably a second or two less. The high speed right preference was a very pronounced feature that extended to the G. There was even a joke: "You can tell a Me-109 pilot by his overdeveloped left leg."

This is why the Me-109 required right rudder on take-off climbs (low speed) and left rudder at high speeds. The P-40 was somewhat similar, so I doubt they had a huge advantage. They were very close in turning performance.

In dive the P-40's left roll was so compromised that the pilot had to brace his right elbow against the cockpit wall to keep from rolling right in dives 400 mph and over... And this remained true even on the improved P-40N...

P-40s had a rudder trim tab, which was pretty easy to use, and that made all the difference, apparently (though still annoying to a lot of pilots, as it was another thing to be dealt with - trim had to be dialed out when climbing out of a dive), and the torque issue was largely eliminated when they lengthened the fuselage / tail by 22", according to pilots like James "Stocky" Edwards who found this issue particularly frustrating.

As for turning and general agility, pilots operating in North Africa and Italy, on both sides, seemed to agree that the P-40 easily out-turned and out rolled the Bf 109. Which isn't really surprising as it had a lower wing loading and a much higher rate of roll at all speeds.

Canadian ace James 'Stocky' Edwards

note that here is another reference to a captured Bf 109 being used for training.

This is from Ospreys "P-40 Aces of the MTO" (2002), page 34, last paragraph. Source is a letter from the pilot. Context was an early morning 24 March 1943, the 59th FS flew a sweep back over Djebal Tebera and "encountered opposition over the target". This is from an interview with Lt Richard E. Holcomb,. who was credited with one Bf 109 damaged on this engagement:

"Lt Harry Haines and I ended up in a ground-level dogfight right over the German airbase. It was quite a fight, as we were out-turning them and shooting up aeroplanes on the ground while they climbed to start the fight again. We would run for home until their cannon shots came close to Harry's tail and again we would out-turn them. I felt sure we at least two were damaged as they left the fight but we couldn't confirm them."

General Benjamin Davis of the 99th FS ("Tuskegee") had a lot of praise for and confidence in P-40s:

"The P-40 operations in the Pacific and Europe were much like the F-86 and the MiG in Korea*. All the MiG's had to do was stay away from the F-86's; yet we had an eleven-to-one kill ratio of F-86's over MiG's**. Same thing with the P-40 and the Me 109. If the German fighters wanted to stay away, the P-40's couldn't get them. When the Me 109's came down to engage the P-40's we were superior."
Interview Tom Russel

https://www.3squadron.org.au/subpages/AAWRussell.htm

"After 3 Squadron had gone through Hurricanes at that time and onto Kittyhawks, Kittyhawk could out turn a 109, it couldn't out climb, but it could out dive it too because of its weight. But the Germans learned very quickly against Peter Jeffrey and his men, not to fight on an equal level. So they would stand up above and come down and pick you off if they could. "

Interview Jack Doyle

https://www.3squadron.org.au/subpages/AWMDoyle.htm

"Climbing was the plane's weakness, I think, wasn't it?

Yes. Look, there are three things, if you can have one of those things and get into a fight with enemy aircraft you can stay alive - if you can out-climb them, if you can out-run them, or if you can out-turn them you can stay alive. If you can't out-run them you've got to stay and fight as long as they want you to fight, as long as you don't run out of petrol first you're relatively safe - I'm speaking in theory. You're not safe if there's ten of them and one of you. But in the main the Kittyhawk could out-turn most enemy aircraft so you could at least stay alive, but you might have to stay where they wanted you to and not where you wanted to be. "
This is from an interview with 3 RAAF double ace and squadron commander Bobby Gibbes interview: Australians at War Film Archive

"Well, against the Italians we probably had a superior aeroplane. But when the Germans brought the 109s in they were in many ways, almost every way, a very much better aeroplane. They could out-climb us, they were faster, they had a much better ceiling - in other words, they could get much higher - and they'd look down on us. We could never look down on them. The only .... Our ability, though, was we were able to out-turn a Messerschmitt and we could in actual fact, being a very heavy aeroplane, we could out-dive them. But when the Germans woke up to the fact that we could out-turn them, very seldom would they stay in and try and dogfight. They'd just generally dive - what they call `pick and zoom' - dive down, pick off a straggler, and then they'd climb up again and you'd probably only get a very fleeting shot at them because they'd be traveling at very high speed. Or else they'd dive straight past their target aircraft, keep on going down and with an initial speed there was no way you could catch them. We all, always tried to fly together as a team and not to work as individuals.

The first 109 I flew was a 109F and I carried out comparative tests with it with a Spitfire Mark V and the Kittyhawk. We all started in line abreast. The Messerschmitt ran away. The Spit V came fairly well after in climb and speed and they both left the Kittyhawk quite badly. And later when we captured the 109G at Gambut, it had been slightly damaged and it was repaired by my squadron engineering officer, Ken McRae. I then flew it forward to the base at Mersa Matruh - no, from Gambut up to the Martuba aerodromes, escorted by two Kittyhawks. While I had it there I carried out some simulated attacks on my squadron. By then the German Air Force had retreated out of range so I was able to do this with safety. My people knew I was up there. The purpose had been basically to let them see - some of the new boys see - what a 109 looked like. But its performance was quite terrific. Kittyhawk could out turn it quite comfortably and if the Messerschmitt boys came in and tried to dog fight, they were gone. We could dive away from them. If we started with same speed and they dived away, we could catch them in the dive."

As I noted previously, they captured several Bf 109s and tested with them.

The Germans by the way also drew very similar conclusions. These excerpts are from interviews transcribed in Shores Mediterranean Air War Volume II:

This is Rudolf Sinner, technical officer of II./JG 27 in 1942:

Frederich Körner Oblt I./JG 27 until shot down on 4 July 1942

Ernst Düllberg, Staffelkaptain of II.Gruppe JG 27 and later Kommandeur of II Gruppe

There were numerous references and claims, and attribution of combat losses, to the non-existent P-46 which is the long-tailed P-40F and L, and maybe also the K

Werner Schrorer, 'experten' ace with I and III. / JG 27:

"The superiority of the British types in dogfights was notorious"

The P-40 could out-turn the slightly more agile MC 202 as well:

This was from a letter by Lt Richard T Conly of the 315th FS / 324th FG describing an April 29 encounter over Tunisia in which he scored his first confirmed victory:

'When I pulled back up, I had just climbed to about 7000 ft when another '202 jumped me at nine o'clock high. I turned into him, and he started turning to get on my tail. At this point I really swore by a P-40, because I could dogfight and out turn him with ease. He saw I was going to get a shot and headed for the deck, strait down. I never got farther than 100 yards behind him, and he stayed right in my sights. I watched my tracers pound into him all the way. Those good old six "fifties" raked him from the tail up. He hit the deck about 50 ft just offshore and went strait in. I almost got wet in the splash.'

On the Me-109 the weight on the left pedal started at around 220 mph indicated and climbed very rapidly even at 250 mph. I remember seeing weight figures of the effort and it was striking how suddenly it appeared and how fast it climbed, but it never got into an unreasonable range: It topped out at around 70 to 100 pounds depending on speed. But that is not pleasant...

M. B. Morgan & D. E. Morris, Royal Aircraft Establishment, Farnborough, Messerschmitt Me.109: Handling and Manoeuvrability Tests, September 1940, report RM 2361.

The relevant section is "Directional Trim." The passage reads:

and then, crucially:

A heavy foot load for just 2.5 degrees...

The report then makes the physiological consequence explicit:

And the G with the original tail was the exact same:

There is an important later source: Captain Eric Brown's 1944 evaluation of a Bf 109G-6, subsequently published in the RAF Yearbook article "Four of the Finest" (1975).

Brown wrote:

I think the high speed roll issues and lack of a rudder tab were pretty well known problems with the Bf 109

The P-51D was similar at low speeds, with a marked preference for low speed left turns below 220 ias, and a similar preference for right turns above that speed, though the pilot could relieve these intense rudder forces with the rudder trim tab. It should be noted that this relieved him from constant effort, but it did not change the aircraft's turn side preference.

Unfortunately for the P-51 pilots, the rudder was such a massive and powerful item that the trim tab response to pedal action had to be reversed from mid-B production onward, to prevent damage to the fin or hinges(!)... This meant the P-51D rudder forces were very heavy as the trim tab was now working against him... But all control forces were heavy on the P-51, so it kind of blended right in...

The P-47 Razorback also had a left turn preference, but it stayed the same at all speeds. The Bubbletop turned worse, but was probably more symmetrical.

You are conflating a difference in turn rate with the actual locking up of controls, which isn't the same thing. Many aircraft had different rates of roll left or right vis a vis engine torque.

The A6M Zero did not like high speed right maneuvers, either roll or turn.

The A6M did also have a similar 'locking up' problem at high speeds. And a very similar escape maneuver was used with P-40s, P-39s, F4Fs and F4Us against the A6M ...

The FW-190A could not make high speed hard right turns without flicking into spin (terrible high speed handling generally, one of the very worst at high speed of WWII), but it was otherwise unusually symmetrical, and the Spitfire was probably the most symmetrical of them all until the Griffon engines were installed.

It's also well known that the Fw 190 did not turn well, though some people will insist to the contrary in the face of all evidence. Of course you can always find outliers e.g. Clostermann

Asymmetry was significant, and at least one P-51D pilot (with a tailing enemy) describes lowering the throttle during combat, just to get into the slower "left turn preference" zone. He noted: "The designers could not get them to be the same on both sides."

Actually many aircraft dealt with the torque by having one wing slightly shorter than the other (as on the MC 202) or having a canted vertical stabilizer (as also seen on the MC 202 and several other WW2 aircraft)

 

[Engineman]

The real cure for torque is the Contra-Prop!

Eng

 

[Steamed_Banana]

By the way, I looked up April 29 1943 per that last anecdote in MAW III. It was a busy day.

British Spitfire Vc pilots from 3 squadrons claimed 2 x Bf 109 and two probables, plus 3 x MC 202. One probable 109 was also claimed by a Kittyhawk III pilot from 450 RAAF
(one Spitfire was lost and a Kittyhawk III was damaged 'cat 2')
US B-25 gunners claimed 2 x Bf 109s
US P-38F and G pilots from 1st and 82nd FG claimed 9 x Bf 109s and 3 probable 109s, (and lost 7 x P-38s)
US P-40F pilots from 79th and 324th FG claimed 2 x Bf 109 and 3 x MC 202, plus two probables (P-40 units took no losses)

German pilots claimed 1 x Spitfire, 1 x P-40, and 7 x P-38s (accurate!)
Italian pilots claimed 8 x Spitfire and 4 probables (I think less accurate)

German losses were 6 x Bf 109G4 and G6 (one says "destroyed in combat with P-38", the others were unattributed) and 1 x Fw 190A-5 lost, plus a Ju 88 and an He 111 that nobody claimed so maybe to flak or accidents (no info given)
Italian losses were 3 x MC 202 lost and 3 x "damaged in combat"

Allies lost 8 fighters and 1 damaged, Axis lost 10 and 3 damaged. But it's not really clear who exactly got whom.

 

[drgondog]

As I understand it, the weighting of the rudder foot loads was modified to increase the foot loads at higher airspeeds where the tail structure could be overstressed. The use of an anti-balance function in the rudder trim was quite clever, the extra foot loads should not have been a problem at lower speeds where the tab made less effect but, it protected the structure at higher speeds. I also think that I am right that the dorsal fin modification was more of a structural reinforcement for the tail than an extra aerodynamic keel surface area fix.

Eng

Everything you stated up to "the dorsal fin modification was more of a structural reinforcement for the tail than an extra aerodynamic keel surface area fix" is correct. That said, the dorsal fin is strictly an aerodynamic feature with next to zero structural benefit. It was attached with nutplates and any side load path will tend to 'oilcan' the top surface of the aft fuselage skin.

 

[Engineman]

Everything you stated up to "the dorsal fin modification was more of a structural reinforcement for the tail than an extra aerodynamic keel surface area fix" is correct. That said, the dorsal fin is strictly an aerodynamic feature with next to zero structural benefit. It was attached with nutplates and any side load path will tend to 'oilcan' the top surface of the aft fuselage skin.

Interesting, because I did read that the mod for the fin did what I wrote. Was the dorsal fin mod combined with other internal updates that achieved strengthening? I seem to recall that
there were some enlarged fasteners. Anyway, looks like I will have to refresh on that!
BTW, it does remind me of doing inspections on the BAe Nimrod (DH Comet based) which had a large Dorsal fin mod. It surprised me how lightweight the dorsal fin was, bearing in mind it's size.
Cheers

Eng