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#101
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Indrek Aavisto wrote:
Guy Alcala wrote: prune Can you name another 4 turboprop western tactical airlifter with semi-STOL capability that was available in the 1955-2008 time frame? I Short Belfast comes to mind. It had a similar configuration, though I daresay its capabilities fell short, or more of them would have been built. I'd say the Belfast was more of a strategic airlifter (in cargo size) than a tactical one. It seems to be about halfway between the C-130 and C-133 in size. I stand ready to be corrected, but was it stressed for tactical missions, maneuverable enough to do them, and of sufficiently low ground pressure to operate off paved runways? Guy |
#102
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Subject: More long-range Spitfires and daylight Bomber Command raids,
with From: Guy Alcala he also says that Mitchell wanted to stick with the tailskid, but the Air Ministry insisted on the tailwheel, because they knew (but couldn't tell Mitchell at the time, because it was classified) that they were going to lay down all-weather (i.e. paved) runways at all the fighter bases, and the tail skid wouldn't last long under those conditions. This thing's just filled with great info. Guy It seems as though the Air Ministry didn't entirely trust Mitchell. Imagine being an aircraft designer and having th air ministry withhold info that would impact on your designs. The mind boggles. Arthur Kramer 344th BG 494th BS England, France, Belgium, Holland, Germany Visit my WW II B-26 website at: http://www.coastcomp.com/artkramer |
#103
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" wrote:
Guy Alcala wrote: snip [skipping a bit] "Tilting the wing upward during landing maneuvers allowed a relatively slow landing speed, yet kept the F-8's fuselage at an AoA of about 5.5 deg. rather than 12.5 deg. as required with its wing down." Guy, can you expound on that a little? I can't see how the angle of the fuselage (AoI?) has any effect on the 'landing speed'. snip I think you're overanalyzing this. If the wing didn't tilt, then the whole fuselage (assuming an AoI of 0 deg.) would need to be at 12.5 deg. AoA to have a sufficiently slow landing speed. Instead, they achieved that low landing speed by tilting the wing, which also gave them the benefit of a lower fuselage AoA for view/clearance. Guy |
#104
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Guy Alcala wrote:
Geoffrey Sinclair wrote: snip snip PR data From Spitfire by Peter Moss, the initial hand converted PR versions from Spitfire I had a 29 gallon fuel tank under the pilot's seat and a 64 pound camera installation behind the cockpit, no radio though. It all worked because there was 32 pounds of removable ballast in the tail to compensate for the mark I moving to a heavier 3 bladed propeller. If the ballast figures are correct there is obviously some room for extra fuselage tanks, the maximum take off weight comes into play though. snip fuel weights Price says the Mk. I was designed to take either the two-blade wooden FP prop or three blade metal two-pitch prop, and ballast had to be provided accordingly. With the wooden prop (83 lb. vs. ca. 350 lb. for the metal prop), 135 lb. of lead ballast had to be carried in the nose, on both sides of the front of the engine at the bottom, roughly under the first two cylinders and the aft end of the coolant tank. He includes a picture showing the weights installed. By the time the MK.V came around the CS prop was standard, which I believe was even heavier (can't find the figure yet). As always, thanks for posting the data. Guy Okay, I've got Price's "The Spitfire Story," which is very helpful. Here's what Wing Commander Tuttle, former head of the PRU, told Price about the handling of the hand-modified PR.1Ds (normal 84 gallons forward, 114 gallons in the wing L.E., 29 gallons behind the pilot, plus two cameras further back (but no radio): "You could not fly it straight and level for the first half hour or hour after takeoff. Until you had emptied the rear tank, the aircraft hunted the whole time. The center of gravity was so far back you couldn't control it. It was the sort of thing that would never have got in during peacetime, but war is another matter." What may be barely acceptable for a PR bird flying solo in VFR conditions by experienced pilots not making any radical maneuvers, is definitely unacceptable for formation or combat flying by less experienced pilots. Later, the production PR.1Ds had the aft tank removed, the radio reinstalled, and the L.E. tanks enlarged from 57 to 66.5 gallons each side, to improve the handling (L.E. tanks were forward of the datum). They also got somewhat heavier Merlin 45s. Guy |
#105
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ArtKramr wrote:
Subject: More long-range Spitfires and daylight Bomber Command raids, with From: Guy Alcala he also says that Mitchell wanted to stick with the tailskid, but the Air Ministry insisted on the tailwheel, because they knew (but couldn't tell Mitchell at the time, because it was classified) that they were going to lay down all-weather (i.e. paved) runways at all the fighter bases, and the tail skid wouldn't last long under those conditions. This thing's just filled with great info. Guy It seems as though the Air Ministry didn't entirely trust Mitchell. Imagine being an aircraft designer and having th air ministry withhold info that would impact on your designs. The mind boggles. It wasn't a case of trust, just a case of need to know. Mitchell only needed to know that a tailwheel was a firm requirement, not the rationale behind it, to design one. I imagine the spec change to increase the armament from 4 to 6 or 8 x ..303s was handled the same way -- they told him what they wanted and asked him if it could be done, but probably not the reasoning behind it. Whether the tailwheel case was an example of the government being classification happy is another matter; the Brits tended to be (and still are, to a great extent) a lot more reluctant about releasing such details, even when they're apparently innocuous, than we were/are. OTOH, there were some probably unnecessary security concerns over Mitchell's technical assistant, S/Ldr H.J. 'Agony' Payn, AFC RAF (ret) because he'd divorced and his second wife was foreign (maybe German; I forget). After Mitchell died he was named manager of the Design Department at Supermarine (not Chief Designer, the post which Mitchell had held). The Air Ministry forced Supermarine to remove him from work on the Spitfire or anything else classified because of this, and in fact the company fired him. Supermarine tried two different designs, a single wheel and one with dual wheels (side by side). The latter tended to get clogged with mud, so they went with the single. Guy |
#106
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Guy Alcala wrote:
" wrote: Guy Alcala wrote: snip [skipping a bit] "Tilting the wing upward during landing maneuvers allowed a relatively slow landing speed, yet kept the F-8's fuselage at an AoA of about 5.5 deg. rather than 12.5 deg. as required with its wing down." Guy, can you expound on that a little? I can't see how the angle of the fuselage (AoI?) has any effect on the 'landing speed'. snip I think you're overanalyzing this. If the wing didn't tilt, then the whole fuselage (assuming an AoI of 0 deg.) would need to be at 12.5 deg. AoA to have a sufficiently slow landing speed. But saying it that way makes it seem as if 'tilting the wing up' (which you're not actually doing of course) makes it possible to fly slower when actually you're tilting the *fuselage down* so as to make it possible to land on a carrier. You're not *tilting the wing up*, you're *tilting the fuselage down*, right?. I know that it's just semantics but saying that this system 'allows slower flight' isn't true is it?. I suppose you could say that it allows slower flight *without banging the tail on the deck etc* but it doesn't allow the a/c to 'fly slower' in the sense that flaps do right?. Instead, they achieved that low landing speed by tilting the wing, which also gave them the benefit of a lower fuselage AoA for view/clearance. Guy Well now, lessee... -- -Gord. |
#107
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" wrote:
Guy Alcala wrote: " wrote: Guy Alcala wrote: snip [skipping a bit] "Tilting the wing upward during landing maneuvers allowed a relatively slow landing speed, yet kept the F-8's fuselage at an AoA of about 5.5 deg. rather than 12.5 deg. as required with its wing down." Guy, can you expound on that a little? I can't see how the angle of the fuselage (AoI?) has any effect on the 'landing speed'. snip I think you're overanalyzing this. If the wing didn't tilt, then the whole fuselage (assuming an AoI of 0 deg.) would need to be at 12.5 deg. AoA to have a sufficiently slow landing speed. But saying it that way makes it seem as if 'tilting the wing up' (which you're not actually doing of course) You are, with reference to the fuselage and virtually any other a/c, but then the whole description is relative to the datum you use. makes it possible to fly slower when actually you're tilting the *fuselage down* so as to make it possible to land on a carrier. You're not *tilting the wing up*, you're *tilting the fuselage down*, right?. I know that it's just semantics but saying that this system 'allows slower flight' isn't true is it?. I suppose you could say that it allows slower flight *without banging the tail on the deck etc* That would be the correct phraseology, and includes the assumption that I (at least) made. After all, if your a/c design can only make one landing on a carrier deck before being hauled off for scrap, NAVAIR would probably take a few points off your score;-) but it doesn't allow the a/c to 'fly slower' in the sense that flaps do right?. Right. Instead, they achieved that low landing speed by tilting the wing, which also gave them the benefit of a lower fuselage AoA for view/clearance. Guy Well now, lessee... Very simply, the wing had to fly at a high-enough AoA to fly sufficiently slowly for the a/c to land on Essex class carriers. In order to achieve that AoA with the wing rigidly attached to the fuselage, they would have had to chop off the after part of the fuselage, mount the wing at a much higher fixed AoI, and/or give the a/c a taller landing gear (to avoid dragging the tail), any of which would have been detrimental to its performance. In addition, the pilot would have had to be sitting much higher to have adequate view on the approach, also at a detriment to performance. CVA had already designed the F7U Cutlass once, and had no wish to repeat it;-) Guy |
#108
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In article , Guy Alcala
writes ArtKramr wrote: It seems as though the Air Ministry didn't entirely trust Mitchell. Imagine being an aircraft designer and having th air ministry withhold info that would impact on your designs. The mind boggles. It wasn't a case of trust, just a case of need to know. Mitchell only needed to know that a tailwheel was a firm requirement, not the rationale behind it, to design one. I imagine the spec change to increase the armament from 4 to 6 or 8 x .303s was handled the same way -- they told him what they wanted and asked him if it could be done, but probably not the reasoning behind it. Whether the tailwheel case was an example of the government being classification happy is another matter; the Brits tended to be (and still are, to a great extent) a lot more reluctant about releasing such details, even when they're apparently innocuous, than we were/are. OTOH, there were some probably unnecessary security concerns over Mitchell's technical assistant, S/Ldr H.J. 'Agony' Payn, AFC RAF (ret) because he'd divorced and his second wife was foreign (maybe German; I forget). After Mitchell died he was named manager of the Design Department at Supermarine (not Chief Designer, the post which Mitchell had held). The Air Ministry forced Supermarine to remove him from work on the Spitfire or anything else classified because of this, and in fact the company fired him. Supermarine tried two different designs, a single wheel and one with dual wheels (side by side). The latter tended to get clogged with mud, so they went with the single. Guy The 'need to know' principle is at least a couple of hundred years old in UK government. The notion (valid, if infuriating at times) is that even the most innocent details can be amassed and used, for instance to gain knowledge of civil service culture to the point that someone can masquerade as a government official and dupe another official into giving away secret stuff. One of the acknowledged masters of building up a mass of cultural information to get more out of people was Hanns Scharff, who got tons of operational information out of captured allied aircrew just by having friendly chats with them. His approach worked where 'roughing up' had failed. A double wheel, like the Mosquito, was it also an anti-shimmy measure? Cheers, Dave -- Dave Eadsforth |
#109
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Guy Alcala wrote:
Very simply, the wing had to fly at a high-enough AoA to fly sufficiently slowly for the a/c to land on Essex class carriers. In order to achieve that AoA with the wing rigidly attached to the fuselage, they would have had to chop off the after part of the fuselage, mount the wing at a much higher fixed AoI, and/or give the a/c a taller landing gear (to avoid dragging the tail), any of which would have been detrimental to its performance. In addition, the pilot would have had to be sitting much higher to have adequate view on the approach, also at a detriment to performance. CVA had already designed the F7U Cutlass once, and had no wish to repeat it;-) Guy ROGER!!...very good, thanks Guy...I'm sure that I understood it properly all along but I wasn't very good at explaining my thoughts. Plus, I kept getting waylaid by someone who has the wrong understanding of it, but that's fine, at least I'm comfortable with my understanding of it now. -- -Gord. |
#110
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In article ,
Mike Marron writes: Guy Alcala wrote: I imagine the longevity of all of these (certainly the Shackleton) has more to due with lack of money for replacement, than finding the right niche. Exactly right. In the grand scheme of things the RAF really didn't have much to brag about throughout the Cold War years compared to their American and Soviet (and even French) counterparts. The Brits certainly produced a good number of ass-kickin' Rock 'n Roll bands back in the '60's and 70's though. -Mike (can't get no satisfaction from a Shackleton) Marron Oh, I dunno. As the Shackleton folks used to say when the RAF was considering reconstituting the remaing Shack AEW Squadron as a Canberra outfit, "Eight Screws beats two blow-jobs any time." To each their own. -- Pete Stickney A strong conviction that something must be done is the parent of many bad measures. -- Daniel Webster |
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