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Actually rudder force is the amount of force it takes to achieve the desired response, which is not the same as achieving a specified number of degrees of deflection. It's a dynamic rather than a static thing.
Having the stabilizer/rudder directly in the propwash is a two edged sword. It helps by making rudder effectiveness more proportional to engine power, and hence to thrust asymmetry, and it can hurt by making rudder forces very high at high power settings if not very carefully designed. Designers new to multi engine design, especially in the early days of twin engine monoplanes, sometimes took awhile to sort out the nuances. Look at the plethora of twin tail designs of the 30s and 40s. Even down to the miniscule Ercoupe! Two rules of thumb seemed to prevail: "2 tails are better than 1", and "size matters; bigger is better". Compare the XF5F with its vestigial tailfeathers and its heavy rudder forces and the B25 with its large double tail and its legendary single engine handling.
A larger rudder/stabilizer combo requires less deflection to achieve the same result because of surface area and Reynolds number. The less deflection allows better mechanical advantage between rudder pedal and control surface. Witness shot up B17s, with only one outboard engine running, drifting slowly downward, held straight by an UNBOOSTED rudder and two exhausted pilots as they put miles behind them from the target area and hoped for the Channel.
Hope that answers your questions.
Cheers,
Wes
Yup, and if you don't believe it, try flying the dang thing at night in the soup, dodging thunderstorms, lit up by St Elmo, a cabin full of panicky passengers, and destination and alternate below minimums.As usual and like most other things there is never a straight simple answer, everything is a balance based on dozens and dozens of other factors.
Nice plane, good performance, similar to Whirlwind. Perhaps like the Whirlwind was twice the price of a Spitfire, the Skyrocket was twice the price of a Wildcat? Like the Whirlwind, unless you change the engine, it has limited development potential. It requires extra training as its a twin. War is just around the corner in 1941 when perhaps production could have been authorised. The Corsair is a similar size,not a twin, an engine with development potential and faster in both level flight and the dive, Skyrocket only does 450 mph so not that good. The F4F-4 can dive 65 mph faster, so go with the F4F-4, start development on the F6F and modify the Corsair to production standard. The Skyrocket is a dead end just like the Whirlwind.I bought the paperback book on the F5F. Pretty interesting. Long periods between stuff happening on the project, I imagine that Grumman was busy working on the F4F-3 prototype. I'm sure the F5F wasn't perfect but the Corsair was full of flaws even after it deployed. There is a test on the F5F that is official, giving altitudes, horsepower, speed etc. 10,132 was light weight loading on fuel and apparently ammo. Top speed is listed as 357 at 17,000, with last hp given as 900 per engine at 14000 so what ever they would be down to at 17000. 10,892 was 'overload fighter' with 278 gallons of fuel and apparently ballast for a full ammo load. I broke all that down on I think 2 different threads on here as far as the weight of fuel, pilot, oil etc and there was about 900 pounds left over which had to be ballast for weapons. Search F5F and you should be able to find them. I'll look when I can and put the link on here.
It did not have armor (easy fix) and the 278 gallon tank was not self sealing (harder fix, or at least expensive fix). The entire wing between the 2 engines was a fuel tank and it was a single large aluminum extrusion. Evidently it had internal bracing which precluded the addition of a self sealing rubber bladder. Probably nothing a redesign wouldn't take care of, but that costs money and time and I think Grumman was just too busy with the F4F-3 to fix it. In my fantasy F5F I add 150 pounds of armor and 200 for a self sealing tank (the corsair tank was 177 pounds of self sealing material for a 237 gallon tank). It might have done fine without turbochargers, because it was fast up to 20,000 feet, but turbochargers give it 2400 hp up to 25000 feet or maybe 27000 feet depending on exactly which ones you choose. Quite an increase for 500 pounds. I figure while you at it you might as well add some 65 gallon or so sized fuel tanks in the outer fold up wings. It also folded up to about the same size as a Corsair or Wildcat, about 21.5 feet.
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Nice plane, good performance, similar to Whirlwind. Perhaps like the Whirlwind was twice the price of a Spitfire, the Skyrocket was twice the price of a Wildcat? Like the Whirlwind, unless you change the engine, it has limited development potential. It requires extra training as its a twin. War is just around the corner in 1941 when perhaps production could have been authorised. The Corsair is a similar size,not a twin, an engine with development potential and faster in both level flight and the dive, Skyrocket only does 450 mph so not that good. The F4F-4 can dive 65 mph faster, so go with the F4F-4, start development on the F6F and modify the Corsair to production standard. The Skyrocket is a dead end just like the Whirlwind.
For better or worse I think that's the dynamic that makes it so hard to get new ideas, aviation or otherwise, off the ground.The Navy is a pretty tradition bound outfit, so Adm Towers would be most likely not to go with a twin. The heavy fighters such as the Bf 110 didn't do so well, though the F5F is more like a proto Tigercat. He didn't want to be hung out to dry for a possible failure of a new idea.
For better or worse I think that's the dynamic that makes it so hard to get new ideas, aviation or otherwise, off the ground.
The Whirlwind was operational 2 years before the XF5F MIGHT have been. Strip the armour, self sealing tanks, cannons+ammunition, wartime paint and other operational items out of the Whirlwind, and you would have a different animal. As far as I know, the XF5F never flew with a full operational load out, so its performance numbers in comparison to operational types needs to be taken in context.The XF5F always looked really good to me on paper. Basically the US Navy equivalent to a Westland Whirlwind, but unlike the Whirlwind, it supposedly had a 1200 mile range on top of being a bit faster and having an even better rate of climb
I thought the problem with the Whirlwind was mainly range? Altitude performance wasn't as crucial in the Pacific as in the BoB, and the F5F had a pretty impressive range of 1200 miles at least per the wiki. The extraordinary climb rate would probably be particularly useful for a carrier fighter, the typical problem of taking off and needing to climb to altitude, or chasing torpedo bombers when the alert for the dive bombers comes out could be far better alleviated with a fast climbing plane. Especially since the F4F was such a slow climber.
Twin engines requiring more training though is definitely a valid point, as is (to a lesser extent) the added expense of the second engine. For the US the bigger issue was probably training time since there was a bit of a bottleneck early on and carrier pilots already had a lot to learn.
The Whirlwind was operational 2 years before the XF5F MIGHT have been. Strip the armour, self sealing tanks, cannons+ammunition, wartime paint and other operational items out of the Whirlwind, and you would have a different animal. As far as I know, the XF5F never flew with a full operational load out, so its performance numbers in comparison to operational types needs to be taken in context.
I'm not picking on the Whirlwind, trust me. I am a fan. Just went by what was on the Wiki.
Rolls-Royce mod'ed a Whirlwind and put the radiators under the engines, it was 24 mph faster at sea level. That would free up space where the wing leading edge radiators were for extra fuel tanks. Whirlwind range was as per Kittyhawk so good, except for price of 2 x Spitfire, not so good. My guess would be 1200 mile range without drop tanks unlike F5F which was same as Wildcat with / without drop tanks.
I agree, all dive bombers were vulnerable to enemy fighters. The RAAF never lost a vengeance to enemy a/c. The vengeance was still useful in 43-44, if you look at the missions the RAAF was using them for in New Guinea they were perfectly suitable for the task. They were flying CAS and targeting enemy troop positions often located on ridge lines and in mountainous terrain. Often the target would be indicated with smoke either from army mortars or Boomerangs. Precision was crucial here and I'd argue dedicated dive bomber were more accurate then fighter-bombers in these situations. It must be noted though that RAAF vengeances were operating under total allied air superiority.Definitely not an expert, I was just going by what the Wiki said which sounds like there was people on both sides but that at least some of the Aussies thought they kind of got ripped off by being given them. It doesn't seem like too bad of a plane to me but it's just another matter of it being more of a 1942 plane being used in 1943 and 44. Probably pretty vulnerable to Zeroes and Oscars?
Whirlwind had 134 Imp gal plus either 45 or 90 gal drop tanks.View attachment 542607View attachment 542608
Those are 80 gallon tanks in the Whirlwind wings. Those wings are much smaller than the F5F wings. You could easily add 80 gallon tanks per side on the F5F, add that to the 278 it already carried and you have a lot of fuel. Turbocharge the engines to make up for weight gain and you have a 2400 hp plane that still weighs 1500 pounds less than a P38 with 300 gallons and it's carrier capable.View attachment 542609
Could British torpedoes be dropped at higher speeds and could B-26 carry British torpedoes?