JoblinTheGoblin
Airman
- 61
- May 13, 2023
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
Which brings up a third dimension of combat - endurance.If your opponent is much faster you have to shoot him down to escape, he can go home anytime he likes.
How much structural strengthening would that require and how would the extra weight affect performance?If the A6M zero had changed the engine to the 1,900 hp Ha-45, it would have been an awesome fighter. With this much power, the top speed would have been in 400+MPH, additional armor could have been fitted, and some heavier armament, making the A6M a truly dangerous opponent.
Without a drastic redesign, more power would just exacerbate this problem. Best to do what Mitsubishi actually did and focus on a new fighter.
All fighters had control problems as speeds got higher, both the Spit and 109 suffered from it during the BoB as pilots pushed their planes to the limit.Would reducing aileron size have helped the hypothetical newer, higher-powered model? My understanding is that the A6M's poor control-response at high speed was due to the large control surfaces. Am I misunderstanding something?
All fighters had control problems as speeds got higher, both the Spit and 109 suffered from it during the BoB as pilots pushed their planes to the limit.
The MkVIII was not Griffon powered it had the 2 stage Merlin. The XII had the 1 stage Griffon. The XII actually weighed less than the VIII.Hey Thumpalumpacus,
Reducing the aileron area would help at high speeds to a degree (how much I do not know) as would modifying the mechanism. At the very least it would allow greater roll rates at higher speeds, but it would also reduce the roll rates at slower speeds. The A6M3 (with clipped wings and smaller ailerons) was supposed to have reasonable roll control upto about 350 mph, and could still roll slowly at VNE.
Fitting a 1900 BHP engine (if practical) would allow a significant increase in speed, though how much would be dependent on what altitude the new engine could produce that horsepower at. If the new engine produced that kind of HP at 13,780 ft (the rated altitude of the original Sakei 12 at 950 BHP) or higher, then you are correct the A6MX could reach ~400 mph+ (at an altitude above ~17,000 ft with RAM?), assuming no significant increase in drag. Not sure what the Mach effects would be at that speed.
Another significant increase in performance would be in climb. With that much excess power the ROC would go up to ~5000 ft/min (I think) assuming a climb power of 1500 BHP (~80% of 1900 BHP). Operational ceiling (ROC of 500 ft/min) would be over 40,000 ft?
Excess power to that level would also allow the A6MX to out turn (sustained) any propjob that saw combat during the war, at speeds upto about 350 mph (I think). This is all assuming a weight increase of ~500 lbs over the A6M2's TOGW of about 5550 lbs with full DT. At 6050 lbs TOGW the wing loading of the A6MX would be about the same as the early Spitfire and Hurricane at ~25 lbs/ft2. Using the A6M3's wing the A6MX's wing loading would go up a bit more, but it would still be relatively low compared to pretty much all the mid- to late-war Allied fighters. Obviously, if you add armour and SSFT the empty weight would increase even more, but if you use the A6MX as an interceptor and local area fighter (ie don't worry about the very long range capability) you could limit the TOGWmax and/or maneuver weight by not putting as much fuel in the plane - say 120 USgal internal instead of the original 141 USgal, plus the 87 USgal DT? Or take-off with full internal fuel but no DT (592 lbs with fuel)? Only straight flying and gentle maneuvers until the DT is empty or dropped?
As mentioned above by Greg Boeser the airframe would have to be strengthened significantly to handle the increased bending and torsional forces. And I doubt anything less than a 5-blade propeller of the same diameter could absorb the increased power. In the WWII period the maximum effective HP that the props could absorb was in the 5-6 BHP per blade per ft2 of the propeller disc. So if you keep the same Ø9' 6" for the propeller, you would end up with ~5.36 BHP/blade-ft2 for a 5-blade prop, which is a reasonable prop disc load. With a 4-blade prop you end up with ~6.7 HP/blade-ft2 - maybe a German 4-blade broad chord type prop could absorb that?
NOTE: The reason I used a basic increase of 500 lbs for the TOGW is that that is what occurred when the Spitfire jumped from the Merlin powered Mk V to the Griffon powered Mk VIII/XII. I realize this weight increase may be a significant underestimate, but I figure it is a good starting point.
Sorry but it is still incorrect. The Mk VIII and IX weighted the the same, about 600 lb more the the single stage Merlin powered Mk V. The single stage Griffon powered XII weighed about 100 Lb less than the VIII or IX. The 2 stage Griffon powered MkXIV weighted aboutOoops!Thank you for the correction Reluctant Poster. I have corrected my post to Spitfire Mk IX and Mk XII.
That worksOoops again.(It is 0810 in the morning here and I have not gone to bed yet.)
Okay, edited it again and changed it to Spitfire Mk V and Mk XII?