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They were using variable pitch propellers (at the least) on 109Cs. Variable pitch doesn't always mean constant speed. Variable pitch can mean two pitch, course and fine, with nothing in between. It can mean the pilot can, by means of a control, adjust the pitch anywhere between the two limits. Constant speed propellers have a governor that automatically adjust the pitch to keep the propeller turning at a preset value. Translation of books from one language to another often confuse the terms much like two speed and two stage superchargers. Perhaps the E-4 got a different type of propeller control for the same mechanism? Or different control lever arrangement? When did the Germans go to a single lever control? one lever to control the rpm, boost, and prop pitch?
Hamilton Standard introduced a constant speed propeller to the commercial market in 1935. They had introduced their variable pitch (2 pitch ?) prop in either 1930 or 1932. They were certainly not the first to build such propellers but were the first to achieve commercial success. The idea (and experimental) variable pitch propellers go back to before WW I and pictures show an S.E. 5A with an experimental variable pitch prop (continuously variable?) in 1917. The British had fooled around with several other designs of variable pitch props in the early 20s but all had faults or problems that could not be overcome at the time. This soured the air ministry on variable pitch props and it took a lot time and success by other countries (and a few forward thinking British companies) to change the air ministry's collective mind. It doesn't do a lot of good to licence a design if the air ministry won't buy them. The Air Ministry was changing it's mind by 1939 (if not a bit before) but by then they were facing a rapid increase in production of all types of aircraft and the demand exceeded supply (due to low orders in the mid 30s) for a while until the propeller factories could be expanded.
The US had been using 2 pitch propellers on the Boeing 247 airliner and others in 1933.
Hamilton Standard introduced the Hydromatic propeller in 1937 and this allowed full feathering of the propeller instead of setting the prop on the bad engine to course pitch and was a major change in twin engine safety.
Understood but your original post specifically mentioned constant speed. I'll try to do a better job in future of reading your mind before I respond so I can understand what you meant rather than what you wrote (and, yes, I say this entirely tongue in cheek).
IIRC the DH props were converted to constant speed propellers.
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I don't disagree but it was Shortround who specifically called out constant speed props. That said, having variable pitch sooner wasn't going to change fundamental issues in the design of fighters in Europe. Early war European fighters of all nations lacked the range and were typically of smaller size compared to their US equivalents. Both factors limit the adaptability of aircraft like the Spitfire and Bf109 into the fighter-bomber role. In the late-1930s, there was simply no envisaged role for fighter-bombers but the role evolved as the light bomber concept proved flawed and the need for CAS-type missions became increasingly significant. The Hurricane rather fell into that role once it became obsolete as a fighter.
How much difference would the Hispano really make given that it only saved a couple hundred Kgs per engine and had a higher specific fuel consumption? The better French Hispanos require 100 octane fuel too.As for the Fw-187 as a fighter bomber - I'd have them with Hispano 12Y engines once Czech factory is in German hands (from spring 1939, so it can be in service for the Western campaign). Not that powerful as the DB 601, but weight penalty is far lower, comparable with Jumo 210, and with notably more power than it.
Once France falls, a bit better 12Ys can be installed. Then also the G&R 14N might be contemplated for the Fw 187.
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The Gnome-Rhones are interesting but they will NEVER put out the power you see listed in Wiki. Please remember the 14N is a two bearing engine. the 14R got the center bearing and gained hundreds of pounds of weight.
See Russian M-88 engine for practical power with better than 87 octane fuel and a two speed supercharger.
And even so, a basic 2-pitch system is still better than fixed pitch.Exactly, and earlier Bf 109s did have a variable speed airscrew. The control, like a rocker switch, was positioned on the throttle lever and the pitch indicator was the dial at the lower right of the instrument panel, sensibly next to the engine tachometer.
Whilst a manually controlled variable pitch unit is much superior to a fixed or two pitch system it did need training to be used correctly. There are accounts from the latter stages of the BoB which show that some of the Luftwaffe's inexperienced replacement pilots struggled to operate the system even when flying in formation, never mind under the stress of combat. In this sense a constant speed unit gives an advantage.
Yes, the likes of Kestrel and Mercury fighters should have been adopting DH 2-pitch props in the early 1930s alongside their airliners, racers, and mail planes. (possibly 2-bladed units similar to those later used with the Gipsy Twelve ... or the Jumo 210 powered 109s)Well, the Rotol was constant speed and the DH 2 position props were converted to variable between the limits if not full constant speed (to avoid mind reading I mean I am not sure, the conversion may have been to full constant speed operation). The thing is that fitting such propellers in the summer of 1940 was 3-4 years late. Fitting 2 pitch propellers in 1939 was 5-6 years late. The British should have been in the leading ranks of the change over if they couldn't be the first, not being dragged kicking and screaming into modern propellers
That's very slightly reminiscent of the RAF .50 cal gun trials where .303 was seen as more efficient and 20 mm as the more realistic follow-on and no interest was given in replacing the .50 vickers with a browning derivative firing the same cartidge. (granted, had they hedged their bets for the hispano with the Oerlikon FFF -or possibly FFL- rather than the FFS with bulk, weight and recoil closer to the Hispano, that may have been a non-issue -I find it very unlikely that 4x FFF cannons wouldn't have been satisfactory in the Hurricane Mk.I)The British had experimented with a variety of variable pitch designs back in the 20s and found a number of drawbacks/problems. This colored their thinking in the 1930s despite an almost universal adoption of the variable pitch and constant speed propellers by just about every other major country.
The Hispano engine is definitely an interesting option and perhaps more attractive than the Jumo 211, at least as a fighter. (a little less so as a fighter-bomber)The Hispano might be a good choice, the FW 187 might not need much, if any beefing up as it was designed to use DB engines in the first place and only used the Jumos because of DB shortages.
The Gnome-Rhones are interesting but they will NEVER put out the power you see listed in Wiki. Please remember the 14N is a two bearing engine. the 14R got the center bearing and gained hundreds of pounds of weight.
See Russian M-88 engine for practical power with better than 87 octane fuel and a two speed supercharger.
The early cowling tests on the XP-42 were pretty worthless, it's only the later refinements to using a short, tight cowling with fan and large spinner (not unlike that of the Fw 190, XP-47J or Tempest II) that it was actually worthwhile.the XP-42 suffered from both vibration and cooling issues. Something else is that the Army wanted around 500 fighters (it ordered 524 P-40s initially) and Seversky had built under 100 planes in the companies existence and Bell had built under 20. That left Lockheed and Curtiss as established mass manufacturers. Since the P-36, XP-37, H75R, XP-42 and XP_40 all used essentially the same wing, tail and landing gear and Curtiss had built 210 P-36s and had orders for 200 Hawk 75s for France on the books in the spring of 1939 while Lockheed, despite building several hundred twin engine Airliners and Hudsons had no production set up for the P-38. Selection of the P-40 seems to have been a no-brainer, delivers to squadrons could start months if not a year earlier than most of the other contenders.
Indeed, I rather doubt the Bramo powered 187 would have managed much beyond 340 MPH and a significant decrease in range, but improved max takeoff weight, somewhat improved climb and slightly superior speed to the Hurricane and Bf 110. (without water injection, the 2-speed Bramos managed 100-175 PS less than the DB-601A depending on altitude) As a fighter, I'm not sure the losses in range and -likely- roll rate plus reduced cockpit visibility would be worthwhile, especially with weight savings in a single-seat configuration. Plus the single-seat prototypes were never tested with the slightly better performing 210G engine. (the 2-seater models also resorted to simpler fixed radiators rather than the more streamlined retractable units)Another BTW, the figures in wiki for the XF5F are way off if that is what you are going by, those are projected figures which were never reached and the plane never flew with armament installed.
And even then, the Ju 88C ended up pressed into more or less the same role the mid 1930s Kampfzerstorer concept failed in, admittedly more akin to the likes of the early A-20 at that point, but underpowered. (though I still think the Ju 88 might have fared better in a more Mosquito-like configuration -if still not quite that capable, especially with BMW 801s)
That's very slightly reminiscent of the RAF .50 cal gun trials where .303 was seen as more efficient and 20 mm as the more realistic follow-on and no interest was given in replacing the .50 vickers with a browning derivative firing the same cartidge. (granted, had they hedged their bets for the hispano with the Oerlikon FFF -or possibly FFL- rather than the FFS with bulk, weight and recoil closer to the Hispano, that may have been a non-issue -I find it very unlikely that 4x FFF cannons wouldn't have been satisfactory in the Hurricane Mk.I)
The Yugoslavians used some Do 17s powered by Gnome-Rhone engines so a lot the engineering work was already done.The 14N wouldn't be that much more attractive than the Bramo 323 and unlike the Bramo (but like the Hispano) wouldn't have been a pre-war option at all. Granted, a 12Y powered 187 could have entered production prior to the Battle of Britain, perhaps even early enough to serve there (certainly in time to be useful in Norway).
The only reason I seriously mentioned the Bramo engine was as an alternative to the Jumo 210, nothing else. The resistance to ground fire would be an added bonus, but not a deciding factor.
And while the P-40 was certainly compelling and worth production, my point was that continuing development of radial-engined counterparts would still have made sense. By the time of the P-40B/C, the Wildcat had already entered service, and by the time the improved cowling of the XP-42 was tested the initial shortages of 2-stage engines would have been well resolved. (not only that, but R-2000s would have been around) As far as I'm aware, the late XP-42 cowling was never mated with a 2-stage R-1830 for testing. (granted, for ground attack, the better low alt performance of the R-2000 would be more interesting, but by that time other aircraft were probably much more useful as fighters or fighter-bombers)
And even then, the Ju 88C ended up pressed into more or less the same role the mid 1930s Kampfzerstorer concept failed in, admittedly more akin to the likes of the early A-20 at that point, but underpowered. (though I still think the Ju 88 might have fared better in a more Mosquito-like configuration -if still not quite that capable, especially with BMW 801s)
From the other thread, I'm not sure the AR 240 had any issues that couldn't have been solved satisfactorily.
The main issues seem to have been marginal stability and that should not be "unfixable" for any design. The performance potential was certainly there and I think it could have been a good one ... but I'm also not sure it would have been, of course. But stability issues are correctable. perhaps it also had system or airframe problems that, taken together with the rest, made it seem not worth the effort.
In fact, I have bever seen a choerent explanation of why they didn't proceed with it. The closest I can come with an educated estimate is that the design team was asked to fix the stability issues and was given time to do it but they didn't succeed at it. If that happened, it might be the end of it in a wartime situation despite the obvious potential.
In wartime asd in peacetime, politics also plays a part and the third Reich was fond of letting people and companies "fight it out." Perhaps Arado was beaten in a conderence room.
With those early tests, the Vickers .50 gun was superior anyway. I'd have expected adoption of that gun and later transition to similarly chambered updated derivatives of the browning would have been more plausible. (similar to the transition to the .303 browning)To be somewhat fair when the British conducted their trials the American .50 gun was using the 2500fps MV ammo. Since the striking energy is in proportion to the square of the velocity this means the ammo was about 75% as powerful as the ammo actually used in WW II and at short ranges (200-400yds) offered little or no advantage over the .303 for deflection shooting. Weight and bulk of the gun/ammo was the same though. one .50 cal round and link weigh about as much as 5 .303s or US .30cal.
With the exception of fuel injection (I don't think any of the GR engines used pressure carbs), the 14N would seem to be a superior design all around, counter-rotating models included.The G-R engines were 38.6 liter engines compared to the 26.8 liter Bramo and while their peak power was limited by the strength of the engine (and cooling on the older ones) they may have been able to offer higher climb and cruise power ratings on 87 octane fuel. Altitude performance may have been better too as they operated on pretty low boost. Some sources say the -21 and -25 versions could make 1080hp at 5100 meters. They were throttle back for low altitude and take-off as they were single speed engines. They also had about 86% of the frontal area of the Bramo. Granted a good cowling can help make up some of the difference.
I meant that the Jumo powered Ju 88C 'fighter-bomber' was an example of the rather problematic pre-war Kampfzerstorer concept still dragging on and the idea of 'bombers that can be **fighters' being seemingly more emphasized than 'fighters that can be bombers.'Again you have timing problem. The Ju-88 first flew at the end of 1936, it is not quite as modern as some people believe. BMW only proposes and starts work on the BMW 801 in 1938 and gets one to run in April of 1939, a commendably short time but way too late to re-configure any existing aircraft like the Ju-88 without a massive disruption in production plans.
It really is unfortunate that Jumo, DB, and BMW seemed to avoid production of opposite rotating engine models. That would have improved handling (possibly speed/climb slightly too due to the lack of rudder trim drag) significantly on 2/4-engine aircraft.I think they were after counter rotating props as well.
It may have been the pin-hole aperture effect coming into play, and an interesting note to be sure.The system worked very well, the rear gunner reported being able to see through a periscope at night much better than through bulled proof glass, suggesting some light gathering amplification.
BTW, according to one source the Bramo was a whopping 12mm smaller in diameter than an R-1820. 1388mm vs 1400mm. abut 0.3 sq ft smaller in frontal area. The R-1820 offered anywhere from 200hp more HP at take-off and low level to 60hp more 1000ft higher at altitude. And that is compared to the 2 speed Bramo engine without water injection. Single speed Bramos offer either good performance at low altitude or sort of medium performance. The single speed engine that offered 900hp for take-off was rated at 1000hp at 10200ft. However the climb rating was 720hp at sea level and 820hp at 14,000ft. Seems like the power is close to a Whirlwinds in a bigger/heavier/ much draggier airframe? Changing the gear ratio for low altitude gave 1000hp for take-off but the climb power ratings changed to 820hp at sea level and 840hp at 6600ft.
Was the 2 speed Bramo available in 1938/39?
Another BTW, the figures in wiki for the XF5F are way off if that is what you are going by, those are projected figures which were never reached and the plane never flew with armament installed.
With those early tests, the Vickers .50 gun was superior anyway. I'd have expected adoption of that gun and later transition to similarly chambered updated derivatives of the browning would have been more plausible. (similar to the transition to the .303 browning)
I meant that the Jumo powered Ju 88C 'fighter-bomber' was an example of the rather problematic pre-war Kampfzerstorer concept still dragging on and the idea of 'bombers that can be **fighters' being seemingly more emphasized than 'fighters that can be bombers.'
That said, with the Bf 110 breaking from the Kampfzerstorer requirements in terms of internal bomb bay, it's still rather odd that it wasn't planned with external bomb carrying capabilities in mind from the start. (and unless I'm mistaken, wasn't carrying bombs prior to the BoB or the C-4/B model)
The earliest I can find the two speed, fuel injected, Bramo 323R2 is the Fw 200C-3 in early 1941. The power was 1200hp at optimal altitude, sea level power was 1000hp but could be increased to 1200hp with water injection, which appears to have been used when the Fw 200 carried extra fuel and was in 'overload' condition.
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