Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: earl1937 on June 12, 2014, 05:27:23 AM
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:airplane: The North American F-82 Twin Mustang was the last American piston-engine fighter ordered into production by the United States Air Force. Based on the P-51 Mustang, the F-82 was originally designed as a long-range escort fighter in World War II; however, the war ended well before the first production units were operational, so its postwar role changed to that of night-fighting. Radar-equipped F-82s were used extensively by the Air Defense Command as replacements for the Northrop P-61 Black Widow night fighter. During the Korean War, Japan-based F-82s were among the first USAF aircraft to operate over Korea. The first three North Korean aircraft destroyed by U.S. forces were shot down by F-82s, the first being a North-Korean Yak-11 downed over Gimpo Airfield by the USAF 68th Fighter Squadron
(http://i1120.photobucket.com/albums/l488/05263739/800px-27sfw-f82-bergstrom.jpg)
The Twin Mustang was developed at the end of the prop-driven fighter era and at the dawn of the jet age. Its designed role as a long-range fighter escort was eliminated by the atomic bombing of Japan and the sudden end of World War II. With the rapid draw-down of the armed forces after the war, the newly established United States Air Force had little money for new prop-driven aircraft, especially since jets, such as the Messerschmitt Me 262 and other Luftwaffe fighters, had been faster than P-51 Mustangs in the skies of Germany in late 1944. The completed airframes (less engines) of the P-82 pre-production aircraft already manufactured by North American went into storage, with an uncertain future.
However, during the 1947 Soviet Aviation Day display at Tushino Airport, a surprise appearance was put in by three four-engined long-range strategic bombers. They were early examples of the Tupolev Tu-4, which was a bolt-for-bolt copy of the Boeing B-29 Superfortress, three examples of which had been interned in the Soviet Union after having been forced to land there during bombing raids against Japan. Since the USSR was expected soon to have nuclear weapons, the appearance of the Soviet Tu-4 was a shock to U.S. military planners, since it meant that the U.S. mainland might soon be vulnerable to nuclear attack from the air.
Until jet interceptors could be developed and put into service, the Twin Mustangs already built were seen as an interim solution to SAC's fighter escort mission for its strategic bomber force and also as an all-weather air defense interceptor
The Twin Mustang had a very short operational life. About two years after its introduction to SAC, the F-82E was phased out of service in favor of the jet-powered F-84 Thunderjet for bomber escort duties beginning in 1950. Some were sent to Korea for combat, others were sent to Alaska, but most were declared surplus and were being sent to storage and ultimately reclamation in 1951. Air Defense Command's F-82Fs began to be replaced by F-94 Starfires in 1950, and by early 1951, with most being sent to the smelters, although a few Twin Mustangs remaining in ADC towing aerial targets. In the Pacific, the F-82Gs in combat were also replaced by the F-94 in late 1951 and early 1952, with the survivors being sent to Alaska after being modified to the F-82H configuration in Japan for cold-weather use.
(http://i1120.photobucket.com/albums/l488/05263739/North-American-F-82-Twin-Mustang-1.jpg)
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I heard of this plane couple times and saw pictures etc... always wondered why they did not build it more like a p-38 frame with 2 merlin engines ... and also never understood the concept of 2 pilot here, is one one them more like navigator or something ?
for sure both cant be responsible of flying the plane.
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I heard of this plane couple times and saw pictures etc... always wondered why they did not build it more like a p-38 frame with 2 merlin engines ... and also never understood the concept of 2 pilot here, is one one them more like navigator or something ?
for sure both cant be responsible of flying the plane.
"Go left!"
"No, go right!"
"It's my turn, let go of the stick!"
"No, you!"
"No, you!"
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I heard of this plane couple times and saw pictures etc... always wondered why they did not build it more like a p-38 frame with 2 merlin engines ...
Because the P-38 had a design flaw that could not be overcome beyond a bandaid fix in the dive flap. That and the P-38 didn't have a laminar wing profile like the mustang. That is my WAG. Most likely as well Lockheed had little desire in updating the P-38 with jets coming of age.
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I heard of this plane couple times and saw pictures etc... always wondered why they did not build it more like a p-38 frame with 2 merlin engines ... and also never understood the concept of 2 pilot here, is one one them more like navigator or something ?
for sure both cant be responsible of flying the plane.
:airplane: Anytime you saw one of these with both cockpits occupied, left side was command pilot, right side was radar operator! These were among the first of the "back seaters", such as was later used in the F4F "Phantom", made famous duing Vietnam and flown by one our own in this game, Puma44". There were many which were set up in the two pilot positions for traning and transition training for the single seat P-51K's, which some of the ANG outfits used. Kinda hard to land the 51K from 50 or 60 feet like a 29 or a 100 feet like the B-36.
I guess the for runner of the back seater series of aircraft were the P-38 night fighters and the P-61 Black Widow!
(http://i1120.photobucket.com/albums/l488/05263739/P-38M_Night_Fighter.jpg)
(http://i1120.photobucket.com/albums/l488/05263739/p-61inflight.jpg)
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Because the P-38 had a design flaw that could not be overcome beyond a bandaid fix in the dive flap. That and the P-38 didn't have a laminar wing profile like the mustang. That is my WAG. Most likely as well Lockheed had little desire in updating the P-38 with jets coming of age.
It's a bit unfair to refer to the "Mach tuck" problem with the 38 as a design flaw. MANY aircraft of the period were experiencing the effects of localized shock waves (typically on the upper surface of the wing) when they approached transonic speeds. In the case of the P-38 it was more pronounced because, not only did it move the CP aft, but it also reduced the downwash on the horizontal tail. But the P-47 and several other aircraft had similar problems, just to a lesser degree. At least Lockheed, to their credit, figured out what was going on and found a fix. And if it hadn't been for an RAF knucklehead in a Hurricat who couldn't tell the difference between a C-54 and a FW 200, the 8th AF P-38's would have gotten the fix they needed a whole lot sooner.
As far a laminar flow wings go, there's considerable evidence to indicate that the P-51 wing had amazingly low profile drag, even without any laminar flow reduction. In fact, testing done by the Germans on captured P-51 wings revealed that the laminar flow effect completely disappeared at Reynolds Numbers representative of real flight. Throw in typical manufacturing tolerances and surface roughness (which would "trip" the boundary layer prematurely) and there is a good chance that hardly any P-51's in service ever actually experienced the laminar flow they were designed to.
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I guess the for runner of the back seater series of aircraft were the P-38 night fighters and the P-61 Black Widow!
Beaufighter and an a/c called the Mosquito was before them.
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Beaufighter and an a/c called the Mosquito was before them.
:airplane: Although I did not specify, I was really just talking about American designed aircraft, which were designed as "night" fighters. The F-82 was equipped at different times by different radar units, mostly the (F-82F's AN/APG-28 and F-82G's SCR-720C18), units which had been used by the P-61, but it was war weary and high maintance and the 82's replaced all of them.
One the interesting side notes of the 82 was when the engineers decided on counter rotating props, the first test aircraft could not even get airborne. The counter rotating action was blanking out any lift by the center section, so 1/4 of wing was not producing lift. After re-installing props which turned, where the decending blade was on the outside of the center section, the bird jumped into the air and away they went!
Up until Burt Rutan flew around the world in his home built bird a few years ago, the F-82B held the long distance record, flying from Hawaii to New York, a little over 5,000 miles, averaging about 347 miles per hour, by a piston engine aircraft.
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I heard of this plane couple times and saw pictures etc... always wondered why they did not build it more like a p-38 frame with 2 merlin engines ... and also never understood the concept of 2 pilot here, is one one them more like navigator or something ?
for sure both cant be responsible of flying the plane.
I read the concept behind the two pilots was because the aircraft had such a long range that both pilots would take turns resting and piloting on super long range missions.
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Since the F4 Phantom was already mentioned a picture is called for. ;)
(http://i478.photobucket.com/albums/rr149/Rich46yo/aviation/f4-2_zps70b1b39d.jpg)
The fighter plane of my youth
(http://i478.photobucket.com/albums/rr149/Rich46yo/Misc/img001-b-1.jpg)
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I read the concept behind the two pilots was because the aircraft had such a long range that both pilots would take turns resting and piloting on super long range missions.
:airplane: The 82 was designed as a long range fighter escort for bombers, especially the B-29 and B-36, both of which were very long range bombers. But as things developed in the late 40's, (note the Russian copy of the B-29), the mission profile changed to one of interceptions and night fighter versions. The A, B and C versions all had dual controls in both cockpits, but some of the later models, E and G, the right seat had no flight controls, only radar consoles and radio equipment. The last 4, still on active duty, were target tow aircraft out of Eglin AFB in Fla and I think also maybe one or two at the gunnery school in Nevada. Not real positive on those numbers, but those are last ones that I heard anything about.
I have often wondered how they would have performed against the German Air Force in its hey day, considering that all six guns were center wing mounted and had no converge problems to deal with on deflection shots, which is the hardest shot to make in air combat. Be interesting to hear what you guys think about that!
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Collossus of Ker-rap... Chain Lightning... mmmm.
As for your Phantom, <yawn> yet another inferior US dogfighter...
Indeed, everything from that era was bad. Look at all the Century fighters. They're just glorified mud movers. Yet, there is a sole exception in that era of dullards. It came from a maverick firm situated in S. El Monte , or was it Pico?
(http://upload.wikimedia.org/wikipedia/commons/8/85/Northrop_F-5E_%28Tail_No._01557%29_061006-F-1234S-073.jpg)
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I read the concept behind the two pilots was because the aircraft had such a long range that both pilots would take turns resting and piloting on super long range missions.
That was also my impression. So far as I know, F-82, like the other WWII planes, had no autopilot. Hand-flying twelve hour missions in a fighter plane would tax the stamina of anyone.
- oldman
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. . . At least Lockheed, to their credit, figured out what was going on and found a fix.
Actually they didn't. The problem was solved by the same guy working on propeller mach flow problems.
I am not sure how much design work you do but in my design days we call it a design error.
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Up until Burt Rutan flew around the world in his home built bird a few years ago, the F-82B held the long distance record, flying from Hawaii to New York, a little over 5,000 miles, averaging about 347 miles per hour, by a piston engine aircraft.
The F-82 is not even listed in the records.
ANT-25 flew from From Moscow to San Jacinto, California, USA in July 1937, 11,500 km/7,100 mi
Two British Vickers Wellesley bombers which flew from Egypt to Australia in November 1938, 11,523.9 km/7,160.6 mi
http://en.wikipedia.org/wiki/Flight_distance_record
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Wondering if there was any connection between the Twin mustang and this concept from '42:
(http://www.luft46.com/mess/3bm109z.jpg)
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Actually they didn't. The problem was solved by the same guy working on propeller mach flow problems.
I am not sure how much design work you do but in my design days we call it a design error.
You're referring to John Stack at Langley who helped identify the cause of the problem.
And where would you do this illustrious design work Randy?
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That was also my impression. So far as I know, F-82, like the other WWII planes, had no autopilot. Hand-flying twelve hour missions in a fighter plane would tax the stamina of anyone.
- oldman
Why didn't it have an autopilot? There were other aircraft that had autopilots, like the C1 in the B-17. Some single engines aircraft had autopilots too; like the long range reconnaissance-bomber versions of the 109G and some G-series 190s for example. They had to sacrifice their cowl-armament to fit these electro-mechanical autopilots though.
(https://dl.dropboxusercontent.com/u/26232318/sc-500-bf-109G2-R1.jpg)
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And where would you do this illustrious design work Randy?
Designing nuclear power plants.
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Designing nuclear power plants.
You must have a lot of free time on your hands then. :)
Regarding the "design flaw", had every other contemporary fighter been designed with an all flying tail (the best known solution to the compressibility problem at the time), then I would agree that Lockheed was negligent in not designing around the problem. But the problem was barely understood in 1941, and the P-38, because of it's clean airframe, got to "take point" out on the leading edge of the problem. Without benefit of a time machine to see into the future, they and the other manufacturers did the best they could.
I agree with you that some mishaps are entirely due to design flaws. Years ago I did a lot of the stress analysis for the RCC nosecap, chin panel, and leading edge panels on the shuttle. RCC with a silicon carbide coating to prevent oxidation is amazing stuff. It's able to shrug off aerodynamic loads @ 3000 degrees F with ease. But it ain't worth a damn when you smack it with foam insulation going 400 mph at room temperature. NASA was aware of the problem and decided to ignore it. Just like the famous O-ring leakage, THAT was a design flaw, albeit one driven by bureaucratic pressure to fly no matter what.
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The F-82 is not even listed in the records.
ANT-25 flew from From Moscow to San Jacinto, California, USA in July 1937, 11,500 km/7,100 mi
Two British Vickers Wellesley bombers which flew from Egypt to Australia in November 1938, 11,523.9 km/7,160.6 mi
http://en.wikipedia.org/wiki/Flight_distance_record
:airplane: I think it was only a Air Force record and I am not sure of that, but the flight is well documented in aviation circles.
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That was also my impression. So far as I know, F-82, like the other WWII planes, had no autopilot. Hand-flying twelve hour missions in a fighter plane would tax the stamina of anyone.
- oldman
We did a 12.6 flight one hot August night. Most of it hand flown by yours truly. Lots of AR along the way, towering CUs, a very unreliable auto pilot, and a back seater with a photographic memory, great radar/computer skills, but hands that just couldn't hold the Rhino still for very long.
(http://i906.photobucket.com/albums/ac270/puma44/eedc9c75bbdb481293470438eed3e7e3_zps7c21b0d5.jpg)
(http://i906.photobucket.com/albums/ac270/puma44/F-4s/CTrtn3.jpg)
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Since the F4 Phantom was already mentioned a picture is called for. ;)
(http://i478.photobucket.com/albums/rr149/Rich46yo/aviation/f4-2_zps70b1b39d.jpg)
The fighter plane of my youth
(http://i478.photobucket.com/albums/rr149/Rich46yo/Misc/img001-b-1.jpg)
Just beautiful (the Phantom not u Rich :rofl )....by far my fav ac of all time
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We did a 12.6 flight one hot August night. Most of it hand flown by yours truly. Lots of AR along the way, towering CUs, a very unreliable auto pilot, and a back seater with a photographic memory, great radar/computer skills, but hands that just couldn't hold the Rhino still for very long.
(http://i906.photobucket.com/albums/ac270/puma44/eedc9c75bbdb481293470438eed3e7e3_zps7c21b0d5.jpg)
(http://i906.photobucket.com/albums/ac270/puma44/F-4s/CTrtn3.jpg)
I can see it now..... REO take over I need a break,12 seconds later,I dont need a break that bad! :devil
:salute
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Just beautiful (the Phantom not u Rich :rofl )....by far my fav ac of all time
:airplane: I guess everybody has seen the "Blue Angels" Navy aerobatic team by now. They were the most impressive and put on the best show when they were flying the F4F Phantoms!
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I can see it now..... REO take over I need a break,12 seconds later,I dont need a break that bad! :devil
:salute
Zackly, Morf! Except, it didn't quite take 12 seconds. The poor guy felt bad that he couldn't help out more. He just wasn't used to the pitch sensitivity of the stab at our cruise altitude.
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You must have a lot of free time on your hands then. :)
Retired.
Several new ones in the works. Built like the Japanese build theirs.
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To be sited where? I can't imagine them being permitted in the us anymore - it's impossible to permit a new refinery even, here. We're in the midst of a bit of a Luddite period here.
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To be sited where? I can't imagine them being permitted in the us anymore - it's impossible to permit a new refinery even, here. We're in the midst of a bit of a Luddite period here.
Luddite DECADES is more like it. I'm 57. I remember all the exciting technological promises of my youth. Space travel, hypersonic flight, deep sea exploration, nuclear power. Where is it? After half a century I expected a Hell of a lot more than Justin Beiber, Twitter, and an explosion in Bariatric medicine. We're not mere Luddites. We're actually going backwards.
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To be sited where? I can't imagine them being permitted in the us anymore - it's impossible to permit a new refinery even, here. We're in the midst of a bit of a Luddite period here.
http://www.nrc.gov/reactors/new-reactors/col/new-reactor-map.html (http://www.nrc.gov/reactors/new-reactors/col/new-reactor-map.html)
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(http://i888.photobucket.com/albums/ac82/mbailey166066/larry-burrows-us-air-force-f4-phantom-crew-and-ground-personnel-readying-morning-mission-at-phan-rang-airfield.jpg)
Got this pic from a squadie :aok
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http://www.nrc.gov/reactors/new-reactors/col/new-reactor-map.html (http://www.nrc.gov/reactors/new-reactors/col/new-reactor-map.html)
Of about twenty in planning, I found two (vogtle and summer) that look like they've been approved. The rest look to be suspended, deferred, or bound up in approval -eg, north Anna has been working toward approval for nine years now. That was just a quick survey. I didn't check every one of them.
All were started before the current admin came to power.
The only thing surprising: the two I found that are through the approval schedule.
I know it's kind of irrelevant to you because you design them, but, do you know if any of those approved have begun construction?
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Luddite DECADES is more like it. I'm 57. I remember all the exciting technological promises of my youth. Space travel, hypersonic flight, deep sea exploration, nuclear power. Where is it? After half a century I expected a Hell of a lot more than Justin Beiber, Twitter, and an explosion in Bariatric medicine. We're not mere Luddites. We're actually going backwards.
Understatement, my good man... Someone is standing on the brakes, and I shouldn't say who here.
My take: there's a new cautionary religion in town.
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Understatement, my good man... Someone is standing on the brakes, and I shouldn't say who here.
My take: there's a new cautionary religion in town.
There are no "new" religions, just new spins on the old ones. A different opium for the masses.
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In the ditch..............
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In the ditch..............
Yep
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There are no "new" religions, just new spins on the old ones. A different opium for the masses.
Sure, but this only means there are endless variations on how to stop things but the path forward is considerably more narrow and difficult.
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Sure, but this only means there are endless variations on how to stop things but the path forward is considerably more narrow and difficult.
Until there's some agreement on what moving "forward" actually is (and I don't see that consensus forming any time soon), then there won't be any measurable progress as you and I define it.
But hey, F-82's are really cool! Right? :)
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:furious
Understatement, my good man... Someone is standing on the brakes, and I shouldn't say who here.
My take: there's a new cautionary religion in town.
:furious Hey guys, the "O" club is what these discussion are for! Lets not forget the post about the 82's!
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:furious :furious Hey guys, the "O" club is what these discussion are for! Lets not forget the post about the 82's!
If you'll look, I attempted to do exactly that. Cool radome on the night fighter, huh? :D
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So, Earl, what was it like to fly?
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Check out the RDF antenna behind the left cockpit. Surprised it wasn't on the right behind the radar operator.
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So, Earl, what was it like to fly?
:airplane: Surprisingly, it was a "kitty kat" on the ground because of the wide spaced landing gear, 2 tail wheels and tons of power. First thing you have to get used to is that "other" ponie in the corner of your eye! Not being a trained fighter pilot, doing formation takeoffs and etc, it took me a few minutes to get to where I just ignored what was in the corner of my eye!
If I remember correctly, 3 degrees right rudder trim, although with the counter rotating props, torque and "P" factor was not a factor like in the single ponie. Thing climbed like a nothing I had ever flown, with 45 inches and 2750RPM, if I remember correctly again, 5K per min on the ROC and you better be getting ahead of this thing, if you wanted to level off at a certain altitude! Easy on just about everything you wanted to do in it! Slow rolls were very easy, as you didn't really have to do much except dance on the rudders to keep the nose on what ever you had picked out on the horizon. If you couldn't do a slow roll, plus or minus 50 feet in altitude management, you couldn't do one at all.
Off to "Pig" one, target range in the gulf, a target barge anchored 5 mile off shore, did some slow low passes to get used to the 6 guns mounted together in the center wing section. Wow! I would hate to be on the other end of that spray of .50 cals. We had the rocket trees on that bird, but no rockets, tried that later. Solid platform for gunnery of any kind!
Spins were restricted, it would go "flat" after about 3 turns, but we did all the other stall stuff, power on, gear and flaps out, it would just nod its head, level out and start flying again. Hammerheads were a joy, easy with two throttles to work with. Accelerated stalls were a blast, because it would snap into a spin before you could blink a eye, but a little opposite throttle and rudder and she just flew right off.
Landings were easy, again the wide gear. Used 200IAS and a 360 degree overhead approach, bleeding speed to 100IAS over the fence, and try to roll level just as you crossed the end of the runway. It was very sable in all flight attitudes, so a novice like me didn't have much trouble with it. Had about 5.5 hours in it I think. Lost all my flight logs and etc in house fire in 88, but I think that was about right.
It was a great aircraft, just got to the war 2 years to late. I don't think any every saw any action of any kind until the Korean thing!
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Just beautiful (the Phantom not u Rich :rofl )....by far my fav ac of all time
I used to worship that fighter and we watched them like they were our own children.
The F4s in that theater were also tasked with "special weapon delivery" and we didnt play any games keeping them secure. With the terrorism of the era, probably worse then, we secured those babies 24/7. I think the Phantom is a beautiful airplane.
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I know it's kind of irrelevant to you because you design them, but, do you know if any of those approved have begun construction?
I worked at the sites in both construction and startup of two of the older units here in GA. Yes construction is underway.
Here is the company promo
http://www.southerncompany.com/what-doing/energy-innovation/nuclear-energy/pdfs/vogtle-nuclear-brochure.pdf (http://www.southerncompany.com/what-doing/energy-innovation/nuclear-energy/pdfs/vogtle-nuclear-brochure.pdf)
Lets not take anymore space from Earl's thread. My bad.
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:airplane: Surprisingly, it was a "kitty kat" on the ground because of the wide spaced landing gear, 2 tail wheels and tons of power. First thing you have to get used to is that "other" ponie in the corner of your eye! Not being a trained fighter pilot, doing formation takeoffs and etc, it took me a few minutes to get to where I just ignored what was in the corner of my eye!
If I remember correctly, 3 degrees right rudder trim, although with the counter rotating props, torque and "P" factor was not a factor like in the single ponie. Thing climbed like a nothing I had ever flown, with 45 inches and 2750RPM, if I remember correctly again, 5K per min on the ROC and you better be getting ahead of this thing, if you wanted to level off at a certain altitude! Easy on just about everything you wanted to do in it! Slow rolls were very easy, as you didn't really have to do much except dance on the rudders to keep the nose on what ever you had picked out on the horizon. If you couldn't do a slow roll, plus or minus 50 feet in altitude management, you couldn't do one at all.
Off to "Pig" one, target range in the gulf, a target barge anchored 5 mile off shore, did some slow low passes to get used to the 6 guns mounted together in the center wing section. Wow! I would hate to be on the other end of that spray of .50 cals. We had the rocket trees on that bird, but no rockets, tried that later. Solid platform for gunnery of any kind!
Spins were restricted, it would go "flat" after about 3 turns, but we did all the other stall stuff, power on, gear and flaps out, it would just nod its head, level out and start flying again. Hammerheads were a joy, easy with two throttles to work with. Accelerated stalls were a blast, because it would snap into a spin before you could blink a eye, but a little opposite throttle and rudder and she just flew right off.
Landings were easy, again the wide gear. Used 200IAS and a 360 degree overhead approach, bleeding speed to 100IAS over the fence, and try to roll level just as you crossed the end of the runway. It was very sable in all flight attitudes, so a novice like me didn't have much trouble with it. Had about 5.5 hours in it I think. Lost all my flight logs and etc in house fire in 88, but I think that was about right.
It was a great aircraft, just got to the war 2 years to late. I don't think any every saw any action of any kind until the Korean thing!
How was it with an engine out? Any significant difference with the left or right engine out?
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Lets not take anymore space from Earl's thread. My bad.
Yeah, I think the three of us owe Earl an apology for nearly derailing his thread. Now if we can just get the Phantom Admiration Society to follow suit. ;)
Earl, were you serious about the 5000 fpm climb rate on the Twin Mustang? That's outstanding.
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Yeah, I think the three of us owe Earl an apology for nearly derailing his thread. Now if we can just get the Phantom Admiration Society to follow suit. ;)
Earl, were you serious about the 5000 fpm climb rate on the Twin Mustang? That's outstanding.
The Phantom Admiration Society has moved to another thread.
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Yeah, I think the three of us owe Earl an apology for nearly derailing his thread. Now if we can just get the Phantom Admiration Society to follow suit. ;)
Earl, were you serious about the 5000 fpm climb rate on the Twin Mustang? That's outstanding.
:airplane: I can't remember guys, I just know it climbed like a rocket, with no ords or anything but guns. It flat outclimbed anything I was ever in!
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How was it with an engine out? Any significant difference with the left or right engine out?
:airplane: A handful to say the least! If you are going to have shut one down or lose it, better make the right one the choice, if you have one, cause if the left goes, now you have twice the normal effect of torque and "P" factor. All I ever had thrown at me was 12 inches MP, which is zero thrust for that bird and 3 touch and goes later, the man said let out of here before you kill me! LOL!
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:rofl
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The Phantom Admiration Society has moved to another thread.
+1. Sorry Earl :cheers:
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If you'll look, I attempted to do exactly that. Cool radome on the night fighter, huh? :D
Yep, and I said nothing, but nodded silently in agreement.
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Earl, were you serious about the 5000 fpm climb rate on the Twin Mustang? That's outstanding.
Look into the climb rate of the P-38K. Standing start at the runway threshold to 20K feet in 5 minutes flat.
Also remember that the P-38K had a 3 blade version of that propellor that improved further with the 4 blade version.
From an article on the P-38K :
Flight tests were conducted from late February through the end of April 1943. Performance was better than hoped for. Maximum speed at critical altitude (29,600 ft) was 432 mph (Military Power). At 40,000 feet, the "K" zipped along at a speed that was 40 mph faster than the current production P-38J could attain at this same height. Maximum speed in War Emergency Power, at critical altitude, was expected to exceed 450 mph. The increase in ceiling was just as remarkable. Flown to 45,000 ft on an extremely hot and humid day, Lockheed engineers predicted a "standard day" service ceiling in excess of 48,000 ft! Improvement of the cowling fit and the elimination of the heavy coat of paint would have gained even more performance. Due to the added efficiency of the new propellers, range was expected to increase by 10 to 15 %. Lockheed appeared to have a world-beater on their hands.
The plane, now designated the P-38K-1-LO was flown to Elgin Field for evaluation by the USAAF. Flown against the P-51B and the P-47D, this Lightning proved to be vastly superior to both in every category of measured performance. What astounded the evaluation team was the incredible rate of climb demonstrated by the P-38K. From a standing start on the runway, the aircraft could take off and climb to 20,000 feet in 5 minutes flat! The "K", fully loaded, had an initial rate of climb of 4,800 fpm in Military Power. In War Emergency Power, over 5,000 fpm was predicted.
Note when the plane was built and tested.
Also of note, the P-82 was powered not by Packard Merlin engines, but by G series Allison V-1710 engines. The G series was the updated version of the F series in the P-38. The G series had additional counterweights on the crankshaft for improved durability, and a higher RPM redline, as well as improved crank driven superchargers. The rare V-1710F-15 engines found in the P-38K were rated at 1875HP each. Had the turbocharger and tune from the V1710F-15 engines been used on the G series, around 2500HP was possible, even at 35K feet. The V1710G-6 series was rated at 2250HP @ 101" of boost @ 3200 RPM. Throw on a General Electric B-33 turbocharger and intercooler system as found on the P-38J and later, and you have an easy 2500HP, and the capability to produce sea level HP at over 30K feet.
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There was only one P-38K-1-LO built. :x
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There was only one P-38K-1-LO built. :x
And a I bet you Steve McQueen bought it. Probably keeps it stabled with his Porsche 917K. :D
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There was only one P-38K-1-LO built. :x
Actually, there was a mule built from a P-38E test plane, and then a P-38G service test airframe was built.
http://www.456fis.org/P-38K.htm (http://www.456fis.org/P-38K.htm)
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"
Also of note, the P-82 was powered not by Packard Merlin engines, but by G series Allison V-1710 engines."
Actually the first 20 were built with Packard Merlin 1650-23/25. The XP 82 with these engines with 1380 Hp Take Off power and 1500 Hp at MP and 1810 Hp WEP, 19,100 GW with full 600 gallons internal fuel hit 468 mph at 22K, climbed to 25K in 6.4 minutes.
The AAF jammed the Allison 1710-143/145 into the rest of the produced P/F-82s and it never achieved the same WEP ratings as the Packard Merlin. According to Schmued the Allison folks would never respond to the need for backfire screens at high boost and the problem was so severe that manifold pressure was limited to 60" in that engine. Schmued remained pissed off at Allison until the day he passed.
Source "Mustang Designer" by Ray Wagner.
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An article by Warren E. Thomson in International Air Power Review (Vol. 3) sheds a different light on the engines powering the F-82G: "Over the years, a gross misconception has arisen regarding the horsepower developed by the huge Allison engines in the F-82G models. In many periodicals, it has been stated that these 12-cylinder engines developed 1,600 hp, but this is incorrect. This figure was true of the early, lighter-weight models, but for the all-weather versions, laden with radar gear and added equipment, 1,600 hp would hardly be sufficient to get the aircraft off the ground.
Lieutenant Colonel John Sharp shed some light on the powerplants of his G models. 'The 1,600-hp engines that are currently published on the F-82 stats pertain only to the early day fighter models, which were significantly lighter. After World War II, the all-weather version was built and it was much heavier. These engines did not have enough power. Even the vaunted Rolls-Royce Merlin could not satisfy the power requirements. Finally, the giant 2,250-hp Allisons, originally designed for the P-51H, were installed - and with the counter-rotating props, it was a dream to fly!'"
Lieutenant Colonel Sharp continues in Mustangs International Fall 2013: "The twin Mustang flew like no other fighter. It far surpassed the performance of the P-51 and P-38. Anyone who flew the P-38 knew the comfort of flying the counter-rotating propellers --- no torque, no trim changes during maneuvers, etc. The big drawback to the P-38, however, was that the props rotated "out" creating a terrible torque problem and trim change during single-engine operation. The F-82 props rotated "in" causing the torque or "P" factor if you prefer, to work to LIFT the dead side. We could feather one of these engines at high speed with little or no trim change. We flew the F-82 with a stick instead of a wheel, which made it more comfortable and far more maneuverable. The massive ailerons extended almost the length of the outer wing panel and were hydraulically operated with a 17-to-1 boost ratio. Talk about power steering -- you could aileron roll this thing so fast it would snap your head, and to the pilot, he was rolling on a point. The other airplane on the other side seemed to roll around him in an arc."
Sharp continues: "And power ! That was something else. Two big left- and right-hand Allison engines pushing out 2,250 hp each with constant supercharged power to max altitude. They say these engines were designed to take 145-in of mercury on takeoff using 145-octane gas and water injection. We never did this so we don't know for sure. We flew them dry without water injection and were limited to 75-in MP but that still gave us one heck of a rate of climb. Aerobatics in the Twin Mustang were unreal. The aircraft was almost totally unrestricted even with the pressurized radar pickle installed. Yes, sir, this airplane with a top speed of 475-mph+ flat out-topped them all."
Sounds like a pretty good aircraft to me. In the ground attack role, they could replace the radar pod with a gun pod containing 8 .50 caliber guns with 400 rds. each to go along with the 6 already in the wing for a total of 14 .50 caliber guns. What firepower! This was never used as far as I know, but what a gun platform it would have been. The F-82 in my opinion got lost in the shadow of the jet age and never reached its full potential but not because it was underpowered unless Colonel Sharp and Warren Thompson are blowing smoke.
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Colonel Sharp's statements raise some huge red flags. He said the P-82 rolled around the pilot, the other aircraft arcing. The P-82 would have rolled around its longitudinal axis (the center-line of the plane). Then he states that the allison engine could pull 145 in/mg with 145 octane gas, but that they were limited to 75 in/mg.
So basically one erroneous statement and one bogus statement.
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Colonel Sharp's statements raise some huge red flags. He said the P-82 rolled around the pilot, the other aircraft arcing. The P-82 would have rolled around its longitudinal axis (the center-line of the plane). Then he states that the allison engine could pull 145 in/mg with 145 octane gas, but that they were limited to 75 in/mg.
So basically one erroneous statement and one bogus statement.
:airplane: Good points Dave~ another one of his mistakes was the direction of rotation of props, they did not turn in as he claims, because when they tried that, it created so much drag, it could not get airborne. The left engine had a "gear" box in it in the final fix, to turn that prop to the left and the right engine to the right!
As far as climb speed, I once made the statement, 5,000 feet per minute, but I am not sure, but with 40% fuel and no ords, the top number on the ROC indicator was 4 and I saw it pegged several times. Even with 2 250 lb practice bombs and 10 rockets, 1 tree of 5 on left wing and 1 tree of 5 on right wing, it would still do between 2500 and 3,000 feet per minute. Of course you have to take density altitude into consideration as that has a drastic effect on climb performance. In winter time, it would climb like a rocket, but in summer, not so good.
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Colonel Sharp's statements raise some huge red flags. He said the P-82 rolled around the pilot, the other aircraft arcing. The P-82 would have rolled around its longitudinal axis (the center-line of the plane). Then he states that the allison engine could pull 145 in/mg with 145 octane gas, but that they were limited to 75 in/mg.
So basically one erroneous statement and one bogus statement.
The important thing to take from Colonel Sharp's account is that he said the other airplane on the other side SEEMED to roll around him in an arc, not that it actually did. We all know as I'm sure he does that airplanes roll around their longitudinal axis. I think he was trying to stress the rolling prowess of the P-82 with its 17 to 1 boost ratio in the ailerons and the pilot rolling on a point and snapping the pilot's head etc. I take the statement to be akin to a plane "turning on a dime" which we all know to be impossible as well. As far as the engine limitations go, all aircraft engines "could" pull a certain amount of power but all were certainly limited to some degree. The fact that he says it was a 475+ mph airplane is impressive to me. The 75-in. pulled is still more than the 60-in. quoted in a previous post and that would make a big difference in performance, all things being equal.
:airplane: Good points Dave~ another one of his mistakes was the direction of rotation of props, they did not turn in as he claims, because when they tried that, it created so much drag, it could not get airborne. The left engine had a "gear" box in it in the final fix, to turn that prop to the left and the right engine to the right!
At this very moment, they are working on restoring a P-82 back to flying condition and they describe the powerplant as follows: "Two Packard-built Rolls Royce V-1650-23-25 Merlins; 1,860 hp each, counter rotating. After first flight, props turned inboard. Left engine - right-hand rotation. Right engine - left-hand rotation." Here is the website if you want to check it out: http://xp-82twinmustangproject.blogspot.com/p/facts-at-glance.html I find it hard to believe they have the engine rotation wrong. Also, any picture I have seen of the P-82 and the pitch direction of the propellers show inward rotation being the only possible way to have the plane move forward. I'm fairly certain they turned inward, not outward. I'll have to agree with Colonel Sharp on this one.
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Actually they didn't. The problem was solved by the same guy working on propeller mach flow problems.
I am not sure how much design work you do but in my design days we call it a design error.
It's a design error if there was data showing that high Mach behavior would be unsatisfactory. There was no such data when the P-38 was designed (1938), and aircraft design teams really didn't have a good grasp of localized transonic behavior until the late 1940s.
I can't think of a single WWII fighter that didn't experience Mach tuck when dived well beyond critical Mach. The P-38 experienced it at a lower air speed due to the outer wing profile selected (inner wing had a higher critical Mach than the outer).
Later P-47s incorporated dive recovery flaps. So did the F7F and F8F. In the P-38L, deploying the recovery flaps resulted in a 3g hands-off pull-out.
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The important thing to take from Colonel Sharp's account is that he said the other airplane on the other side SEEMED to roll around him in an arc, not that it actually did. We all know as I'm sure he does that airplanes roll around their longitudinal axis. I think he was trying to stress the rolling prowess of the P-82 with its 17 to 1 boost ratio in the ailerons and the pilot rolling on a point and snapping the pilot's head etc. I take the statement to be akin to a plane "turning on a dime" which we all know to be impossible as well. As far as the engine limitations go, all aircraft engines "could" pull a certain amount of power but all were certainly limited to some degree. The fact that he says it was a 475+ mph airplane is impressive to me. The 75-in. pulled is still more than the 60-in. quoted in a previous post and that would make a big difference in performance, all things being equal.
At this very moment, they are working on restoring a P-82 back to flying condition and they describe the powerplant as follows: "Two Packard-built Rolls Royce V-1650-23-25 Merlins; 1,860 hp each, counter rotating. After first flight, props turned inboard. Left engine - right-hand rotation. Right engine - left-hand rotation." Here is the website if you want to check it out: http://xp-82twinmustangproject.blogspot.com/p/facts-at-glance.html I find it hard to believe they have the engine rotation wrong. Also, any picture I have seen of the P-82 and the pitch direction of the propellers show inward rotation being the only possible way to have the plane move forward. I'm fairly certain they turned inward, not outward. I'll have to agree with Colonel Sharp on this one.
:airplane: You are right I guess, I am relying on a 80 year old mind, about something that occurred 57 years ago. I tried to research that a little and all I could come up with was some info on wiki as follows:The XP-82 was to be powered by two Packard-built Rolls-Royce V-1650 Merlin engines. Initially, the left engine was a V-1650-23 with a gear reduction box to allow the left propeller to turn opposite to the right propeller, which was driven by the more conventional V-1650-25. In this arrangement both propellers would turn upward as they approached the center wing, which in theory would have allowed better single-engine control. This proved not to be the case when the aircraft refused to become airborne during its first flight attempt. After a month of work North American engineers finally discovered that rotating the propellers to meet in the center on their upward turn created sufficient drag to cancel out all lift from the center wing section, one quarter of the aircraft's total wing surface area. The engines and propellers were then exchanged, with their rotation meeting on the downward turn,
It sounds as though the right was turning right and left was turning left, according to this, but not sure of their info creditability. I just do remember that when you reduced power to 12 inches, (zero thust) on the left engine, you had your hands full and a lot of right rudder to keep it straight, but with the right reduced, and the left doing the work, it wasn't much problem to keep it straight. Again, I am relying on an old mind and I could have those backwards.
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I can't think of a single WWII fighter that didn't experience Mach tuck when dived well beyond critical Mach. The P-38 experienced it at a lower air speed due to the outer wing profile selected (inner wing had a higher critical Mach than the outer).
The P-51 with the NAA/NACA 45-100 seemed to have far less adverse CMac due to the Max T/C at 45% rather than 25%+- for virtually every other fighter. The primary issue was the Yaw build up in the dive that took a boosted rudder tab, then reverse boost to 'incent' the pilot to get out of the dive. I don't know about the P-63 experience..