Single Engine Tank-Buster -Tractor or Pusher??

Discussion in 'Aviation' started by Piper106, Apr 1, 2013.

  1. Piper106

    Piper106 Member

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    This is a 'what-if' scenario;
    What would be the best arrangement for an air cooled single engine heavy cannon armed tank buster (and CAS) aircraft for WW2 ???.

    I feel a single heavy cannon centerline mounted is better than 2 cannon wing mounted. In the Hurrican IID and the Il-2, the wing cannon don't fire at the exact same time, their recoil introduces yaw which throws off the point of aim, something not present in a centerline mounting. Plus a single cannon mounting allows a larger more effective weapon for the same weight compared to two wing cannon.

    Most agree that an air cooled engine is a must for combat survivablity. Since there never was a high power (i.e. 1500 HP plus) inline air cooled engine, one has to chose a radial engine. Using a radial however eliminates the option of an engine mounted heavy canon ala the Yak-9T.

    In my mind, that leaves three potential arrangements;
    1. Engine mounted over the wing, tractor propeller, cannon in the nose firing thru the propeller hub, and cockpit between the weapon bay and the engine. The Itallian Piaggio P.119 (prototype only) used this arrangement. The Amerian P-39/P-63 also used this arrangement, but in place of the Allison liquid cooled engine, the proposed tank-buster would have a air cooled radial engine.
    Disadvantage: With the weapon in the extreme nose, as the heavy cannon ammo is expended, the airplane becomes tail heavy, increasing the risk of a spin.
    2. Similar to the above but with the cockpit immediately behind the propeller, and the weapon bay between the cockpit and the engine. Besides the drive shaft to the propeller, the cannon barrel would run under the cockpit to fire through the propeller hub as in the previous proposal. The aircraft profile would be somewhat similar to the 'paper only' Me 509.
    Advantage; Good pilot visibility. With the cannon closer to the center of gravity, thed is less trim change as the cannon ammo is expended. Disadvantage: Having the pilot straddle both the drive shaft and the cannon barrel results in a deep, potentially poorly aerodynamic fuselage.
    3. A pusher arrangement, with the pilot in the nose, cannon bay between the cockpit and wing, and engine again near the wing/center of gravity. Imagine air cooled versions of the (paper only) Bv P.193.01 or a scaled down Douglas XB-42. Advantage; Good pilot visiblity. As above, having the cannon near the center of gravity limits trim change as the ammo is fired off. Disadvantage: On quickly built forward airstrips, rocks thrown up from the landing gear can damage the propeller. Same bail-out hazards as all pusher designs.

    My opinion is that the Bv P.193.01 or 'mini-XB42' pusher is the best option. Depending on the producing nation it would be built around an 18 cylinder version of the BMW 801 with a belt fed BK 3.7 cannon OR a Wright R-3350 and 37 mm M9 cannon OR Bristol Centaurus / 40 mm Vickers type S gun.

    Rebuttal?? Comments???
     
  2. davebender

    davebender Well-Known Member

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  3. GregP

    GregP Well-Known Member

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    #3 GregP, Apr 1, 2013
    Last edited: Apr 2, 2013
    Give me a stock, standard Douglas Skyraider. The engine was there and the airframe was possible.

    It is the best single piston attack plane ever made ... in my opinion, of course. Others may disagree.

    If WWII is not a requirement, then I like a turboprop version of it even better. Not the Douglas A2D Skyshark, but one with a good engine, prop reduction unit, and modern avionics including an RWR. It is certainly possible, but the avionics depends on the time frame. For WWII, the stock A-1 as originally issued would have been a real bonus to the Allies and, once the ordnance was expended, the fighters would have found the A-1 to be a tough customer that maybe couldn't quite run away, but could turn and fight better than they could, and likely could outclimb the fighters, too. When light, it was a climbing fool. Light means no bombs, not no ordnance. With four 20mm cannons, the weight of fire was devastating to most targets.

    If the Skyraider dived, the fighters would be fools to follow. All the Skyraider had to do was deploy the dive brakes for 1 - 3 seconds and then retract them and make an easy kill.
     
  4. parsifal

    parsifal Well-Known Member

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    The most efficient airborne tank killers were the dedicated ground attack machines like the Ju87 and HS 129. However these aircraft were extremely vulnerable, bordering on suicidal.

    Performance gives your crews survivability, but it detracts from mission effectiveness. But the relationship (survivability versus effectiveness) is not linear. An aircraft with twice the speed of a Ju87 is not half as effeective. i dont what the number is but is not half. In any event, killing thigs by a/c is not their primary CAS effect. Its the multiplying effect that they have on friendly ground forces. Put hostile ground aircraft over an enemy ground force, and immediately you restrict their ability to manouvre, and that has a BIG effect on its combat effectiveness, way beyond anything that the aircraft may be capable of in terms of killing things

    British designs did quite well in these criteria. The Typhoon/ tempest comes to mind, as does the later Sea Fury. The much maligned Fairey firefly had a patented wing that allowed it to 'hover" above its target, whilst having a respectable straight line speed and handling characteristics as well. Ive also heard good things about the Westland Wyvern and the later gannets. These were both used as ASW aircraft, but their abilities as bomb trucks ought not be under-estimated.
     
  5. GregP

    GregP Well-Known Member

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    Performance does NOT detract from mission effectiveness. Inaccurate attack does.

    Performacne enhances aeffectiveness.
     
  6. parsifal

    parsifal Well-Known Member

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    yeah, probably a poor choice of words on my part, but surely you would agree that the faster you go, the harder it is to hit stuff, given all other issues are equal
     
  7. riacrato

    riacrato Member

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    I'd agree with Saab 21, which according to many sources has a top speed similar to the Bf 109 G (albeit much lower cruise speed) but a much larger wing area. Should have good low speed handling. Equipped with a single BK 3.7 and some machine guns it should be pretty deadly. Even if you have to switch to a lower powered engine like the Jumo 211, you should come out with decent survivability.

    Overall my preferred solution would still be: Take your most suitable fighter (considering its ability to accept armor and armament, its low speed handling and low level performance as well as its status in the lifecycle of its original figher-role) and adapt it for the role. E.g. Hurricane IV, Hawker Typhoon, FW 190 F...
     
  8. delcyros

    delcyros Well-Known Member

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  9. tomo pauk

    tomo pauk Creator of Interesting Threads

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    #9 tomo pauk, Apr 2, 2013
    Last edited: Apr 2, 2013
    If the air superiority is not a sure thing, I'll have some A-36s with Class S cannons (those from Hurricane IID), Littlejohn adapters on muzzles when available. Ditch the wing guns, so much of the cannon and ammo can be inboard. Thankyou :)
    The P-39 with such a weapon instead of the M4 cannon would be also good (we retain the HMG?), unless the M10 cannon can be installed. Yak-9T, if the enemy can not bring really fast interceptors in. For Germans, do what Soviets did - relocate the cockpit of the Bf-109 further aft (and a tad higher), so the MK-101 or 103 can fit. All 3 fighters could use dive brakes once installed.

    If the air superiority is assured, the pusher with a really big gun is a contender. The lack of defensive gun is non issue, but we might need to invent the ejection seat earlier? Molins 57mm cannon aboard? Lacking that, a variety of 37-50 mm cannons would be easy to install.
    I'd really like to see a pusher with DB 610, V-3420, Griffon, Sabre - a 400 miles tank buster (with really big guns)?

    Skyraider was a hell of an airplane, but it was not a ww2 crate.
     
  10. Shortround6

    Shortround6 Well-Known Member

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    Det cord on the gear box blows prop off :)
     
  11. GregP

    GregP Well-Known Member

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    #11 GregP, Apr 2, 2013
    Last edited: Apr 2, 2013
    Parsifal,

    I perhaps used a poor choice of words, too. Certainly there is a speed beyond which ground attack is very difficult. I have no problem if the planes can go that fast but, for ground attack, the speed should probably be no faster than 320 knots or so. So even if the attack plane can go 500 knots, it is important that it can slow down and maneuver well at 250 - 320 knots in order to get good placement of gun projectiles such as cannon shells. Even the A-10 can maneuver well at 300 knots.

    As for the Skyraider not being WWII, it first flew during WWII but was not depployed until the war ended. It was firmly rooted in WWII design, and the priority could have been changed to get it there during the war ... but the war was being won with existing equipment and the priority simply slid a bit. The prototypes were not even ordered until 6 Jul 1944. It first flew on 18 Mar 1945. If they had simply ordered it a bit sooner, it would have been a "WWII crate." Since this is a "what if" anyway, I choose to have it ordered about a year and a half sooner or so, and have the evaluation done quickly, so I'm thinking it could have been in service but the end of summer 1944, had they chosen to go that way.

    Aren't "what ifs" fun?

    A pusher with centerline armament is a nice what if, but the reliable Skyraider is a real attack plane that would be very hard to beat. Since the Skyraider is a proven commodity, get it service sooner and proceed to establish the solid reputation a bit earlier. For real hitting power, I would fall back on another real aircraft, the Beech A-38 Grizzly with a 75 mm cannon on the nose. The combination of Skyraider and Grizzlies would be one hard-hitting 1 - 2 punch.

    View attachment 229499

    Of course it isn't a single-engine variety, but would make a great addition to the Skyraider that does qualify for the thread. Both are tractor engine and are quite good at attacking ground targets without resorting to pusher configurations. I don't really know of very many successful pushers in real life. The only really successful pushers I know of are all jets (Vampire, Venom). Certainly they flew the piston Saab 21, but it wasn't exactly a world beater and was phased out in 1954. Nobody except Sweden bought it and they only built 298 in total.
     
  12. stona

    stona Well-Known Member

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    The Do 335 had a charge to blow of part of the rear end and propeller.
    It also had a rudimentary ejection seat which seems to have killed more people than it saved.
    Cheers
    Steve
     
  13. cimmex

    cimmex Member

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    I never heard that a pilot was killed by the ejector seat in a Do335. ( source?)
     
  14. stona

    stona Well-Known Member

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    Werner Altrogge was killed attempting to abandon Do 335 V2. He was struck on the head and killed by the canopy so,I suppose not exactly the ejector seat. Altrogge was one of Germany's most experienced test pilots. He had flown operationally in the Fw 189 and Ju 86 R as well as testing many of the early helicopters ( Fw C-30 autogyro,Fw 61,later the Fl 265,Fa 223,Fl 282 and Fa 330). He had joined Dornier in March 1943.

    The second attempt was made in April 1945 by Uffz. Bahlmann. He too was struck by the canopy but not incapacitated. He tried to eject but the seat failed. He then attempted to land but as he did so the seat "fired" depositing him on the runway. He was severely injured but,as far as I can tell,survived.

    The only other known attempt to use the seat was also in April 1945 by Heinz Fischer. This time neither the seat nor the tail/propeller jetisson worked. Fischer abandoned the aircraft in the usual way,missing the rear propeller,and survived.

    A 100% real world failiure rate is not good! It was a thoroughly unreliable and dangerous system. had the type been rushed into service with the system for abandoning the aircraft in that state I suspect many more would have been killed.

    Incidentally according to Smith and Creek, one US soldier was killed working on one of the Do 335s found at Oberpfaffenhofen though the reason is not known.

    Cheers

    Steve
     
  15. cimmex

    cimmex Member

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    Thanks, these stories are new to me I only read that there were some near accidents with the seat.
    cimmex
     
  16. stona

    stona Well-Known Member

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    Altrogge was killed in V2 W.Nr.230002 CP+UB. Fischer was attempting to fly V9 W.Nr. 230009 CP+UI to Switzerland on 26th April 1945 when he ran out of fuel over the Vosges mountains. I can't find my reference for Bahlmann but he must have been flying one of the several whose final fate is uncertain.
    Cheers
    Steve
     
  17. Piper106

    Piper106 Member

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    The Beech A-38 Grizzly. Yikes. It carries a lot of punch but it is a LOT of airplane. It's B-25 / A-26 size, and two R-3350 engines. Quite a demand on resources.
     
  18. Matt308

    Matt308 Glock Perfection
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    Pusher solution would have to be an airplane designed around a gun and not just a modification. I'm thinking such a large gun and short fuselage on existing airframe would have huge c-of-g issues.
     
  19. davebender

    davebender Well-Known Member

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    Not just pusher solution. Any aircraft intended for CAS should be designed that way rather then just jury rigging any available fighter aircraft.
     
  20. GregP

    GregP Well-Known Member

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    #20 GregP, Apr 2, 2013
    Last edited: Apr 2, 2013
    That's why I chose the Skyraider. I KNOW it works in the CAS role. I don't particularly like the pusher configuration either. They aren't hsitorically successful in the piston variety, but seemed to work OK as a jet.
     
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