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In message , ArtKramr
writes Let's take two planes going on low level support missions. They will have to fly through heavy ground fire including small arms fire. One plane is equipped with a radial engine,. let's say an R-2800. The other with a jet engine. Which plane would have a better chance of survival inder these conditions?. Opinions? My gut feeling is the jet, if only because it's faster and spends less time being shot at (and the higher deflection makes it harder to hit). Also, jet aircraft can be pretty tough; stories around about them surviving assorted insults (going as far as F-105s flying with destroyed engines, using the afterburner as a sort-of-ramjet) so the survivability between a jet and a radial recip isn't as pronounced. After all, either aircraft is equally at risk from hits to pilot, control surfaces, fuel tanks et cetera... superior survivability of the engine is a factor, but not the only one (vice the use of P-51s rather than P-47s in Korea) -- When you have to kill a man, it costs nothing to be polite. W S Churchill Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk |
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On Sun, 7 Dec 2003 16:56:41 +0000, "Paul J. Adam"
wrote: In message , ArtKramr writes Let's take two planes going on low level support missions. They will have to fly through heavy ground fire including small arms fire. One plane is equipped with a radial engine,. let's say an R-2800. The other with a jet engine. Which plane would have a better chance of survival inder these conditions?. Opinions? My gut feeling is the jet, if only because it's faster and spends less time being shot at (and the higher deflection makes it harder to hit). Also, jet aircraft can be pretty tough; stories around about them surviving assorted insults (going as far as F-105s flying with destroyed engines, using the afterburner as a sort-of-ramjet) so the survivability between a jet and a radial recip isn't as pronounced. After all, either aircraft is equally at risk from hits to pilot, control surfaces, fuel tanks et cetera... superior survivability of the engine is a factor, but not the only one (vice the use of P-51s rather than P-47s in Korea) Seems to me that you need to define a lot of additional parameters before you can reduce the discussion to whether a radial is more survivable than a jet. If you say same speed, same profile, same airframe, same tactics, same thrust(power) to weight, same performance, then I'd go to the radial engine as being one that sustains a bit more insult. But, we've not added the factor (significant in my mind) about the volatility of AvGas over JP-4 (JP-8). Wet wing airplane taking a hit in the fuel tanks? Not pretty. But, if you let your jet go faster, pull more G, maneuver more aggressively, build a tactics package that suppresses the defenses, etc. then you come up with the undebatable conclusion that the jet does better. Have I ever mentioned that FAST is better? |
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Subject: Survivability in Combat
From: Ed Rasimus Date: 12/7/03 9:59 AM Pacific Standard Time Let's take two planes going on low level support missions. They will have to fly through heavy ground fire including small arms fire. One plane is equipped with a radial engine,. let's say an R-2800. The other with a jet engine. Which plane would have a better chance of survival inder these conditions?. Opinions? My gut feeling is the jet, if only because it's faster and spends less time being shot at (and the higher deflection makes it harder to hit). Also, jet aircraft can be pretty tough; stories around about them surviving assorted insults (going as far as F-105s flying with destroyed engines, using the afterburner as a sort-of-ramjet) so the survivability between a jet and a radial recip isn't as pronounced. After all, either aircraft is equally at risk from hits to pilot, control surfaces, fuel tanks et cetera... superior survivability of the engine is a factor, but not the only one (vice the use of P-51s rather than P-47s in Korea) Seems to me that you need to define a lot of additional parameters before you can reduce the discussion to whether a radial is more survivable than a jet. If you say same speed, same profile, same airframe, same tactics, same thrust(power) to weight, same performance, then I'd go to the radial engine as being one that sustains a bit more insult. My inquiry was only about engines. Thanks. But, we've not added the factor (significant in my mind) about the volatility of AvGas over JP-4 (JP-8). Wet wing airplane taking a hit in the fuel tanks? Not pretty. I had not included wing design in my orignal question. But, if you let your jet go faster, pull more G, maneuver more aggressively, build a tactics package that suppresses the defenses, Tactics packages that supress defenses vary in their effectiveness and there are never any guarantees. etc. then you come up with the undebatable conclusion that the jet does better. No issue is undebateable. Have I ever mentioned that FAST is better? Yes Fast is better has merit, But there are no gaurantees. There are never gaurantees, Thanks for the input. Regards, Arthur Kramer 344th BG 494th BS England, France, Belgium, Holland, Germany Visit my WW II B-26 website at: http://www.coastcomp.com/artkramer |
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Ed Rasimus wrote:
On Sun, 7 Dec 2003 16:56:41 +0000, "Paul J. Adam" wrote: In message , ArtKramr writes Let's take two planes going on low level support missions. They will have to fly through heavy ground fire including small arms fire. One plane is equipped with a radial engine,. let's say an R-2800. The other with a jet engine. Which plane would have a better chance of survival inder these conditions?. Opinions? My gut feeling is the jet, if only because it's faster and spends less time being shot at (and the higher deflection makes it harder to hit). Also, jet aircraft can be pretty tough; stories around about them surviving assorted insults (going as far as F-105s flying with destroyed engines, using the afterburner as a sort-of-ramjet) so the survivability between a jet and a radial recip isn't as pronounced. After all, either aircraft is equally at risk from hits to pilot, control surfaces, fuel tanks et cetera... superior survivability of the engine is a factor, but not the only one (vice the use of P-51s rather than P-47s in Korea) Seems to me that you need to define a lot of additional parameters before you can reduce the discussion to whether a radial is more survivable than a jet. If you say same speed, same profile, same airframe, same tactics, same thrust(power) to weight, same performance, then I'd go to the radial engine as being one that sustains a bit more insult. But, we've not added the factor (significant in my mind) about the volatility of AvGas over JP-4 (JP-8). Wet wing airplane taking a hit in the fuel tanks? Not pretty. Glad someone mentioned the fuel difference. Early on, the USN and RN blended AvGas with kerosene for jets on their carriers, as they still had a lot of piston a/c on board. The stowage requirements were very different; Kerosene fuel could go in unprotected fuel tanks just like ship fuel oil, while AvGas had to be carried in tanks inside the ship's armored box. The British were even more careful with AvGas than the US was -- they kept it inside the armored box in cylindrical tanks totally surrounded by water filled compartments. This restricted their AvGas stowage even more, which is one reason why the British carriers were unable to operate as many a/c as US ones did. It was also found that 62% of the single engined jet losses in Vietnam and the middle east were due to damage to the fuel system. Given the far greater likelihood that a hit in a fuel tank or line containing AvGas would cause a fire, it seems reasonably safe to assume that this was the cause of at least as high a percentage of piston-engined fighter losses in WW2, although no statistical data seems to have been gathered prior to Vietnam as to specific causes of loss. FWIE, the remaining causes of loss were pilot incapacitation, 18%, 10% to control damage, 7% to loss of engine power, and 3% to structural damage. So engine toughness per se was a relatively minor part of single-engined jet combat losses, at least in the 1960s. The use of AvGas made it difficult to radically increase the a/c fuel carried by the Essex class carriers postwar (to meet the needs of thirstier engines), owing to the fire danger and stowage requirements. The swirtch to a higher and higher percentage of jets meant they could carry more fuel just about anywhere, allowing over a 100% increase in a/c fuel carried, which was very necessary to handle the jets' greater thirst. But, if you let your jet go faster, pull more G, maneuver more aggressively, build a tactics package that suppresses the defenses, etc. then you come up with the undebatable conclusion that the jet does better. Have I ever mentioned that FAST is better? The early centrifugal jet engines like the Nene and Tay seem to have been quite damage tolerant (the early axials less so, but design has improved a lot since then). Hre's Gabby Gabreski on his first MiG kill, firing from dead six on a non-maneuvering target: "When the sight was squarely on his mid-section I fired a short burst of armor-piercing and incendiary from the six fifties. I could see strikes all over the lower section of the fuselage, I kept firing for a couple of seconds and was now directly astern, about 600 feet back. I centered the sight on his tailpipe next and gave him another burst. I saw strikes again, around the engines as well as the wings. Now he went into a slight dive and smoke began to stream back from the tailpipe. "I passed over him and broke off to the right and he started down and I kept him in view. He was losing altitude but much to my amazement, was still under control. I decided to make another pass from above right; my three Sabres were now strung out behind me. There was grey smoke from the MiG; he had decelerated. In a matter of seconds, I closed for another pass, coming in from astern, I got very close and gave him a good, long burst. This time pieces of his aircraft began to fly off. They might have been turbine blades from the engine and they passed me on the right. The canopy flew off. Then the pilot ejected. His parachute opened. We turned on course for home. "I was surprised to see how hard it was to bring down a jet, how much damage he absorbed before he finally went down. Later, of course, we got the bigger guns [Guy: 4 x 20mm M39] in the Sabres . . . these were fifty calibre shells. It took a lot of them to bring one down." [Quoted in "F-86 Sabre," by Maurice Allward] The six .50 cal. M3s in the Sabre fired about 50% faster than the WW2 era M2s in the P-47, and unlike the P-47 they were all mounted in the nose rather than the wings, so when you were on target, you were _really_ on target; no need to worry about convergence range. Elsewhere in the same book, Col. Eagleston (former 354th 'Pioneer Mustang' group leading ace, IIRR commanded either the 4th Group or Wing in Korea; I forget which, but both echelons existed) is mentioned as preparing a report stating that of every three MiGs hit by his Sabres, two had escaped, and that to destroy a MiG, an average of 1,024 rounds of .50 caliber had been fired. Russian MiG pilots had a high opionion of the damage tolerance of their MiG-15 engines (essentially reverse-engineered R-R Nenes), but had a lower opinion of the toughness of the Sabre's GE J47 axial engine. To be fair, their guns were a lot more powerful than the Sabre's .50s, so the comparison isn't exact. How well the MiG-15 would have held up under the fire of a 37mm and two 23mms is an interesting question. ISTR seeing navy stats that showed Navy and Marine Panthers suffered a lower loss rate than Corsairs and maybe ADs on ground attack missions; the Panther also used a license built Nene (J42), and later the larger but also centrifugal R-R Tay (J48). I don't know how the Banshee, which used a pair of axial engines IIRR, stacked up, but its involvement in Korea was limited. It's impossible to make such a comparison on the Air Force side of Korea, as the only piston fighter they used for ground attack was the Mustang, and there's absolutely no doubt that a jet is superior to a water-cooled engine in damage tolerance. I've got the USAF fighter statistical data for the Korean war, and the Mustang's loss rate is far higher than either of the two USAF jet fighters that were largely dedicated to ground attack. Here's the Korean War total combat sorties / losses credited to ground fire / % loss rate (credited) to ground fire per sortie for the F-51, F-80 (centrifugal) and F-84 (axial). I've left out the losses credited to aircraft and unknown causes: F-51: 62,607 / 172 / 0.27% F-80: 98,515 / 113 / 0.11% F-84: 86,408 / 122 / 0.14% The Republic F-84's higher loss rate compared to the F-80 may be due to a higher vulnerability of its J35 axial engine compared to the F-80's centrifugal J33, but it's also possible that other factors unrelated to the engine may be the cause. Early on the F-80 flew a fair number of A/A sorties, and while the F-84s of the 27th Fighter-Escort Wing also flew some, I suspect that the F-84 flew a higher percentage of its sorties air to ground. The F-84 also came into the war well after the F-80, so it may be that it was just facing stronger defenses, especially after the front line had stagnated. The type of ordnance employed may also have affected the time spent in threat zones, and thus loss rates -- the F-80 fired almost 4 times (80,935 vs. 22, 154) as many rockets as the F-84, while the latter dropped a considerably higher tonnage (55,987 vs. 41,593 tons) of bombs. I lack the data to reach any hard conclusions, but the F-84, being from the Republic 'Foundry, certainly had the reputation of being able to take more damage than its USAF fighter contemporaries. All in all, though, I'd say the jets have it hands down over pistons, air-cooled or otherwise, although control issues (loss of hydraulic fluid) for jets that lack manual reversion or FBW slightly skew things. Given the choice of doing Art's mission in a P-47/Corsair/Skyraider, or an A-10, I know which one I'd choose, but that's talking a 30 year technology difference. Guy |
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![]() "Guy Alcala" wrote in message . .. Ed Rasimus wrote: It's impossible to make such a comparison on the Air Force side of Korea, as the only piston fighter they used for ground attack was the Mustang, and there's absolutely no doubt that a jet is superior to a water-cooled engine in damage tolerance. I've got the USAF fighter statistical data for the Korean war, and the Mustang's loss rate is far higher than either of the two USAF jet fighters that were largely dedicated to ground attack. Here's the Korean War total combat sorties / losses credited to ground fire / % loss rate (credited) to ground fire per sortie for the F-51, F-80 (centrifugal) and F-84 (axial). I've left out the losses credited to aircraft and unknown causes: F-51: 62,607 / 172 / 0.27% F-80: 98,515 / 113 / 0.11% F-84: 86,408 / 122 / 0.14% It should be possible to compare the loss rate of the A36 (ground attack version of the P51 in WW2) with the loss rate of the P47 in WW2 to extrapolate the possible loss rate of a hypothetical F47 of the Korean war. In this way we could compare this hypothetical F47 radial with the above Jets. |
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![]() "The Enlightenment" wrote in message ... "Guy Alcala" wrote in message . .. Ed Rasimus wrote: It's impossible to make such a comparison on the Air Force side of Korea, as the only piston fighter they used for ground attack was the Mustang, and there's absolutely no doubt that a jet is superior to a water-cooled engine in damage tolerance. I've got the USAF fighter statistical data for the Korean war, and the Mustang's loss rate is far higher than either of the two USAF jet fighters that were largely dedicated to ground attack. Here's the Korean War total combat sorties / losses credited to ground fire / % loss rate (credited) to ground fire per sortie for the F-51, F-80 (centrifugal) and F-84 (axial). I've left out the losses credited to aircraft and unknown causes: F-51: 62,607 / 172 / 0.27% F-80: 98,515 / 113 / 0.11% F-84: 86,408 / 122 / 0.14% Guy, these numbers do not necessarily support your contention that, "...there's absolutely no doubt that a jet is superior to a water-cooled engine in damage tolerance." You are entering the "post hoc, ergo propter hoc" arena with that claim supported by these numbers. How can you be assured that the numbers purely reflect a result of "damage tolerance"? Could they not also be influenced by other factors, such as the increased attack speed (especially in the case of the F-84) versus the P-51? Being a more difficult target to hit may have been as much a factor in the jets' better survivability rateas the issue of "damage tolerance" was. I doubt that your claim is errant in terms of the water-cooled engine being likely more susceptable to damage from ground fire, but the numbers you present are not solely dependent upon the factor of "damage tolerance". Brooks It should be possible to compare the loss rate of the A36 (ground attack version of the P51 in WW2) with the loss rate of the P47 in WW2 to extrapolate the possible loss rate of a hypothetical F47 of the Korean war. In this way we could compare this hypothetical F47 radial with the above Jets. |
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Subject: Survivability in Combat
From: "The Enlightenment" Date: 12/8/03 3:29 AM Pacific Standard Time Message-id: ggZAb.44513$aT.5240@news-ser It should be possible to compare the loss rate of the A36 (ground attack version of the P51 in WW2) with the loss rate of the P47 in WW2 to extrapolate the possible loss rate of a hypothetical F47 of the Korean war. In this way we could compare this hypothetical F47 radial with the above Jets. Now that would be interesting. But leave out the P-51. It didn't have radials. Regards, Arthur Kramer 344th BG 494th BS England, France, Belgium, Holland, Germany Visit my WW II B-26 website at: http://www.coastcomp.com/artkramer |
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Ed Rasimus wrote in message . ..
On Sun, 7 Dec 2003 16:56:41 +0000, "Paul J. Adam" wrote: In message , ArtKramr writes Let's take two planes going on low level support missions. They will have to fly through heavy ground fire including small arms fire. One plane is equipped with a radial engine,. let's say an R-2800. The other with a jet engine. Which plane would have a better chance of survival inder these conditions?. Opinions? My gut feeling is the jet, if only because it's faster and spends less time being shot at (and the higher deflection makes it harder to hit). Also, jet aircraft can be pretty tough; stories around about them surviving assorted insults (going as far as F-105s flying with destroyed engines, using the afterburner as a sort-of-ramjet) so the survivability between a jet and a radial recip isn't as pronounced. After all, either aircraft is equally at risk from hits to pilot, control surfaces, fuel tanks et cetera... superior survivability of the engine is a factor, but not the only one (vice the use of P-51s rather than P-47s in Korea) Seems to me that you need to define a lot of additional parameters before you can reduce the discussion to whether a radial is more survivable than a jet. If you say same speed, same profile, same airframe, same tactics, same thrust(power) to weight, same performance, then I'd go to the radial engine as being one that sustains a bit more insult. But, we've not added the factor (significant in my mind) about the volatility of AvGas over JP-4 (JP-8). Wet wing airplane taking a hit in the fuel tanks? Not pretty. But, if you let your jet go faster, pull more G, maneuver more aggressively, build a tactics package that suppresses the defenses, etc. then you come up with the undebatable conclusion that the jet does better. Have I ever mentioned that FAST is better? I can feel a Lawndart versus Warthog debate comming on. Douglas Skyraiders seem to have fullfilled niche missions well into the Jet age. By the end of the second world war the Japanese (J7W1 Shinden), USA (Curtiss XP-55 Ascender) and Germans were all testing pusher piston engined aircraft that might have managed 500-520mph and likely 577mph with development. Here is one of the German projections: DO P.247 Max. Speed: 835 km/h (519 mph) http://www.luft46.com/dornier/dop247.html With transonic swept tip "scimatar" shaped propellors: Dornier Do P.252 Max. Speed 930 km/h 577 mph. http://www.luft46.com/dornier/dop252.html So Mach 0.88 was conceivable for a piston engined propellor aircraft with a modest amount of development no more than jet development. Mach 0.88 is Enough to take on early Sabres and Mig 15s! If it had not of been for the development of the Jet engine the two stroke super charged and turbo supercharged engine probably would have attracted development and replaced the petrol piston engine. This type of diesel (eg Napier Nomad) is lighter and more fuel efficient than a petrol engine and runs of diesel and jet fuel to boot. With effort some one could have fielded a Mach 0.88 gasoline or diesel fighter to take on Sabres, Meteors and Mig 15s during the Korean war on close to even terms and probably with a lot more range. The B47D with turbo-prop was once tested at 597mph. In general its was probably not worth diverting the engineering resources into becuase the only gain: fuel efficiency could be circumvented by just flying higher and the speed of sound was the ultimate limit. |
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Speed is life.
"ArtKramr" wrote in message ... Let's take two planes going on low level support missions. They will have to fly through heavy ground fire including small arms fire. One plane is equipped with a radial engine,. let's say an R-2800. The other with a jet engine. Which plane would have a better chance of survival inder these conditions?. Opinions? Regards, Arthur Kramer 344th BG 494th BS England, France, Belgium, Holland, Germany Visit my WW II B-26 website at: http://www.coastcomp.com/artkramer |
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Subject: Survivability in Combat
From: "Leslie Swartz" Date: 12/6/03 8:02 PM Pacific Standard Time Message-id: Speed is life. But no gaurantees. Witness all those suiperfast planes lost in battle while going superfast. Regards, Arthur Kramer 344th BG 494th BS England, France, Belgium, Holland, Germany Visit my WW II B-26 website at: http://www.coastcomp.com/artkramer |
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