AviationDiscuss Single-engined pusher planes: any role for those? in the World War II - Aviation forums; Hi, Elmas,
It would not be too difficult for designers to allocate a space for fuel tank & ammo just ...
It would not be too difficult for designers to allocate a space for fuel tank & ammo just above the CoG (a fuel tank being, say, 1 meter long) and then allocate space for engine just aft the fuel tank? So, the engine is half a meter away from CoG at the nearest point that way.
My FAI ( Fédération Aéronautique Internationale) license to be able to compete in aeromodelling competitions was released in 1965 when I was thirteen.....No kits and much less ready made airplane models in those times, you had only to design and built your own........
And I would not to say that, fortysix years after, now I'm PhD in Structural Engineering and I teach that at the University.
Is that enough to know what CG and MAC are? Did I pass the examination? I don't know, I hope so.
Well you did pass but you miss the point....
Originally Posted by Elmas
And I do remain of my idea: in a piston pusher fighter most of the permanent weight (engine and propeller) remains always aft of the CG, while most of the consumables must of necessity be located ahead of the CG. What you are going to do: to place all the consumables around the CG and to add a little bit of ballast in the nose of the plane to compensate for the weight of the engine and propeller?
Depending on how much weight were're talking about and where its located, yes - and you may have to limit the amont of consumables if it causes the aircraft to go out of its CG/ MAC range, something calculated during the design stage. That's where the length (arm) of the fuselage comes into play
Originally Posted by Elmas
Thence the dangerous attitude of these planes to be nose-up at landing: all the designers of piston pusher figthers tried (more or less unsuccesfully) to solve this fact.
As I read somewhere in this Forum "one thing is a test pilot, another a 20 years old boy with one hundred hours" ..... almost all the Air Forces tried pushers in the '30s, here the Italian prototipe SS 4, that crashed in 1939, killing her pilot
but fortunately refused to use on a large scale what were going to be "widow makers".
There were plenty of safe pusher aircraft developed and even in today's world there are dozen of homebuilt designs that are safer than traditional tractor designs. How about this one, From Italy no less and its a great plane!
I said that a piston pusher fighter was (almost) completely useless for an Air Force of WWII era.
Every good aeroplane is the result of many compromises: and with a pusher figher a good one was never found, even with his performances in terms of speed and concentration of armament, for all ( or, better, some of) the difficult design problems I tried to explain.
I said that a piston pusher fighter was (almost) completely useless for an Air Force of WWII era.
Every good aeroplane is the result of many compromises: and with a pusher figher a good one was never found, even with his performances in terms of speed and concentration of armament, for all ( or, better, some of) the difficult design problems I tried to explain.
Cheers
Nicely summed up Elmas.
Maybe that's why the design was left on the drawing board so's to speak.
Cheers
John
My favourits are the work of Dr Richard Vogt the BV.208.3
The aircraft is not really tailess, I believe the term is 'semi-tailess'. This configuration was extensively tested by NASA and found not to have the flutter issues that were feared. In anycase Blohm and Voss had tested the layout on a modified Skoda-Kauba V-6
The advantage of the split tail (on wing tip outrigger booms) is that the pusher prop does not have to draw in disturbed air from tail surfaces.
The advantages of the configuration are obvious: outstanding forward visibillity, heavy concentrated fire power, including outsize guns for anti-tank work or standoff attacks and the possibillity of in flight refueling.
Assuming local air control, I think ground attack and bomber interceptor would be the best roles for a pusher to play. (Wasn't that the original question?) Engine in the rear theoretically protected by everything infront of it and the (assumed) low mounted wings (from ground fire) and all the armament concentrated in the nose. A tight cone of fire. There, that's my 2 cents.
“The entrance to the cockpit of this aircraft is most difficult. It should have been made impossible.” — Flight Journal magazine, April 2000, regards the XF10F-1, Grumman's first attempt at a swing wing fighter.
What role could assume a single-engined plane in pusher configuration (eg. Saab 21 was such a plane), and do that better than a 'classis' design? Throw in your propositions for a good pusher, too
Are we only talking about prop jobs? (Seeing as the J-21 was both a prop and jet in different models one could get confused.) Because all jets are pushers, they don't suck their way along! Though I may think a majority of them do actually suck. LOL
“The entrance to the cockpit of this aircraft is most difficult. It should have been made impossible.” — Flight Journal magazine, April 2000, regards the XF10F-1, Grumman's first attempt at a swing wing fighter.
"The first of three J 21 prototypes flew on 30 July 1943 flown by SAAB test pilot Claes Smith. During the takeoff, the wrong flap setting resulted in the prototype running into a fence at the end of the runway, damaging one of the landing gears. The subsequent test flight ended with a successful landing on the undamaged undercarriage units.[4]
A total of 54 J 21A-1 fighters constructed at the main plant in Trollhättan were delivered from December 1945, followed by 124 and 119 examples respectively of the J 21A-2 with revised armament and the J 21A-3 fighter-bomber. Utilized mainly in the bomber role, the limitation of the design led to a proposed front-engine replacement, the J 23."
"In March 1941 Saab was given the task to design a better fighter than the Seversky Republic P-35:s and Reggiane 2000:s we had been able to buy. (The Mitsubishi Zero had also been considered.) This resulted in the twin-boom pusher J 21 (which hardly was a fighter, but became a passable ground attack aircraft). This was a technological risk, with ejection seat and all, so a more conventional fall-back design with the same engine was needed. In December 1941 the fall-back design was cancelled, as it was considerably less manoueverable than the J 21. Both designs were to use the same engine, DB 603, and interestingly the J 23 was to have an ejection seat too! "
"The J 21A-1s were all retired at the beginning of 1949. It was never a success as a fighter, but those designated A 21 (A = Attack, ground attack) or even B 21 (B = Bomb) made good service. They had the same armament as the fighter version, but also provision for carrying rockets and bombs with a bomb aiming sight, as well as two RATO bottles."
The same old story: a poor fighter or interceptor becomes a"passable" ground attack aeroplane......
"The first of three J 21 prototypes flew on 30 July 1943 flown by SAAB test pilot Claes Smith. During the takeoff, the wrong flap setting resulted in the prototype running into a fence at the end of the runway, damaging one of the landing gears. The subsequent test flight ended with a successful landing on the undamaged undercarriage units.[4]
A total of 54 J 21A-1 fighters constructed at the main plant in Trollhättan were delivered from December 1945, followed by 124 and 119 examples respectively of the J 21A-2 with revised armament and the J 21A-3 fighter-bomber. Utilized mainly in the bomber role, the limitation of the design led to a proposed front-engine replacement, the J 23."
"In March 1941 Saab was given the task to design a better fighter than the Seversky Republic P-35:s and Reggiane 2000:s we had been able to buy. (The Mitsubishi Zero had also been considered.) This resulted in the twin-boom pusher J 21 (which hardly was a fighter, but became a passable ground attack aircraft). This was a technological risk, with ejection seat and all, so a more conventional fall-back design with the same engine was needed. In December 1941 the fall-back design was cancelled, as it was considerably less manoueverable than the J 21. Both designs were to use the same engine, DB 603, and interestingly the J 23 was to have an ejection seat too! "
"The J 21A-1s were all retired at the beginning of 1949. It was never a success as a fighter, but those designated A 21 (A = Attack, ground attack) or even B 21 (B = Bomb) made good service. They had the same armament as the fighter version, but also provision for carrying rockets and bombs with a bomb aiming sight, as well as two RATO bottles."
The same old story: a poor fighter or interceptor becomes a"passable" ground attack aeroplane......
It is recognized that this airframe design by far wasn't a record beater but it was utilized for several years by the SAF. Additionally the same airframe was converted into a jet. The basic design, considered poor did serve into the 1950s as the jet version was retired in 1956.
which hardly was a fighter, but became a passable ground attack aircraft
such a comment smells as being an opinion, rather than a fact.
Then:
Utilized mainly in the bomber role, the limitation of the design led to a proposed front-engine replacement, the J 23
What was a limitation?
In December 1941 the fall-back design was cancelled, as it was considerably less manoueverable than the J 21. Both designs were to use the same engine, DB 603, and interestingly the J 23 was to have an ejection seat too!
So the fall-back design was canceled, not the pusher. And, then, DB-603 engines???
"The J 21A-1s were all retired at the beginning of 1949. It was never a success as a fighter, but those designated A 21 (A = Attack, ground attack) or even B 21 (B = Bomb) made good service. They had the same armament as the fighter version, but also provision for carrying rockets and bombs with a bomb aiming sight, as well as two RATO bottles."
How good/bad the combat record was for J-21, so we can judge the success?
Further, J-21 used the engine that was sub-standard for 1945 and on (under 1500 HP). Asking from such a plane to compete vs. what war-winning countries were fielding then would be too much.
"At any rate, the successful development and operation service of the Saab 21 series provided the nation of Sweden with an indigenous design that was quite capable in the tasks assigned to it. The platform served its purpose for a time and offered up much-needed experience in the field of aircraft engineering that would serve the country well in the coming decades, producing further stellar home-grown designs in the form of the Tunnen, Draken, Viggen and - ultimately - the Gripen."
..................
offered up much-needed experience in the field of aircraft engineering that would serve the country well in the coming decades, producing further stellar home-grown designs in the form of the Tunnen, Draken, Viggen and - ultimately - the Gripen."
Seems to be differences of opinion there........
That were all jets, not piston pusher fighters.
A jet is a completely different thing than a piston propeller pusher : put a Napier Sabre with a Rotol propeller instead of a Goblin in a Vampire, and I will see if you can make it fly.......
The fact that, initially designed as a fighter, the J21 was very soon declassed to ground attack, and that the Sweden Air Force bougth and used Mustangs as fighters
ending the production of J21 " Originally 484 were ordered, but with the purchase of Mustang the number was reduced to 422, but in the end only 298 were made. (Same site)".
tells many things about how the Swedish Air Force considered the J21 as a fighter.
Originally Posted by Elmas
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