Spitfire MK.XIV and La-7

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Soren

1st Lieutenant
6,457
25
Feb 6, 2005
Spitfire Mk.XIV


Engine: Rolls-Royce Griffon 65.
Power: 2035 hp.
Max Speed: 437 mph.
Max Range: 457 miles.
Empty Weight: 2994kg.
Max.Weight: 3856kg.
Service ceiling: 13560m.
Wing Span: 11.23m.
Wing Area: 22.48m2.
Armament: two 20mm cannons and four 7.7mm machine guns.

Lavochkin La-7


Engine: ASh-82FN.
Power: 1,850 hp.
Max speed: 422 mph.
Max range: 394 miles.
Empty Weight: 2,605kg.
Max. Weight: 3,265kg.
Service ceiling: 10,750m.
Wing Span: 9.80m.
Wing Area: 17.59m2.
Armament: three 20mm Beresin B-20 ShVak nose cannons.
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Wich one would you bet your money on in a Dogfight ?
 
There was a mock dogfight in Italy between a Spit (Mk unknown) and a Soviet (Yak ???) fighter that had flown there by a defecting pilot. The Spit got trounced.
 
They are probably both going to be turning on an equal rate, however one gets the roll-rate to its advantage.

The Speed advantage goes to the Spit.XIV though.

About armament, well I'll have to give the Spit.XIV the edge there aswell.

Climb-Rate also goes to the Spitfire.

To me the Spitfire XIV seems very much superior.
 
A hard choice. Well, acceleration would have gone to the La-7, but only slightly. Wingload would go to the Spit (but slightly, also). Durability to the La-7 thanks to the radial engine as mentioned by moskitoman (probably). Speed and climb would be on the Spit (especially) in higher altitudes. What about the weapons? The 23 mm Shvak was a great wepon, the La-7 concentrates much firepower in the nose, also. The Spit was a bigger target to aim at but probably the better energy keeper of both. I think it depends on the pilot.
 
Well strictly talking the two machines, i think the Spit XIV is very much superior.

The Spit XIV could dominate the fight, as it was faster and climbed better, and it also turned just as tightly if not tighter than the La-7 ! About roll rate, well im not sure about that one.

Armament goes to the Spit, eventhough the La-7 had great armament itself, its doesnt beat the two Hispano's and four brownings on the XIV. The XIV could actually also carry two 50.cal's instead of the four .303 Brownings.

I don't see how the La-7 could ever win the fight over the Spit XIV, if both had equally skilled pilots flying them. (Except if the La-7 jumps it from above maby)
 
Well I don´t see why the Spit should win that easy against the La-7. Because it is a soviet plane? Nono... for such a clear statement you have to proof that:
1.) The Spit turns better at all speeds and in every altitude
2.) The Spit rolls better at all speeds and in every altitude
3.) The Spit has a speed and acceleration advantage in most circumstances
4.) The Spit is superior in climb and dive under all possible circumstances
5.) The Spit can take much more damage
6.) The Spit has much more firepower
7.) The Spit has a much superior handling, esspecially at high speeds

So what? You don´t proof it, or am I wrong?
The armament of the Spit is quite a good armament, but I understand that the La-7 has a comparable, if not a better one. It has three 23 mm guns all in the nose with enough ammunition (and not two 20 mm with a few seconds ammo). That concentration works for a better gun platform (remember they once wanted the Spit to carry four of the 20mm, but they had to reduce it to two, because it wasn´t stable enough) as well as a much more devastating punch. And for the agility: Wingload speaks (slightly) for the Spit, powerload (slightly) for the smaller La-7. Who wins?
 
The 20mm's that the La-7 carried had a higher rate of fire but fired lighter projectiles at a slower velocity. (Terminal basllistics are what count though and I don't know how much the 300 yard retained velocitywas for the 20mm's that both aircraft carried.)

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-pe.html

It doesn't appear that there's any significant difference between the lethality of these two aircraft. I do, however, think there's an advantage to having three 20mm's all housed in the nose.
 
La7 below about 12,000 feet, Spitfire above about 16,000 feet, anybody's game from 12-16,000 feet.

The La7 (I assume we mean the -FNV model with 3 x B20 cannon) was tweaked for lower altitude performance, the Spitfire for higher altitude performance. The La7 defanitely outrolls the Spit at speed.

As far as guns go, they are about equal in my view. The Spitfire has a slight range advantage, and its 20mm are more devestating, but the LA has twice the volume of 20mm fire, but the Spitfire also has 2 x .50 BMGs, but the La7 guns are in the nose and are much more solidly mounted and have much less recoil (countering the Hispano velocity advantage somewhat)... who can say which is better?

At 300 yards the Hispano II velocity was about 673 m/s, about 76% of its 880 m/s initial velocity. The B-20 velocity at 300 yards was about 506 m/s, about 66% of its initial 770 m/s velocity. --- these figures are for sea level, at altitude velocity loss would be lower.

=S=

Lunatic
 
Well the Spit has low wing-loading and speed to its advantage, plus it has better allround visibility from the cockpit.

The Spit will also climbs better, with its 2035hp engine and five-bladed propeller.

The roll-rate goes to the La-7 at high speeds, but at slow-moderate speeds they are both going to be pretty equal.

The turning capability of the Spit will probably be superior to the La-7's, although it is close. The German Bf-109F-G2 series could outturn the La-7 at slow-moderate speeds (However not in sustained turns of over 360 degree's). However because of its wing-slats the La-7 will probably be at an advantage over the Spit at slow speeds.

About armament, well I'd go for the Hispano's, as they are better suited for the Fighter vs Fighter role.
 
I seriously doubt the Spit has the power advantage at low altitude. I'll try to find some climb and speed charts to compare the two planes, but I suspect the La7 was noticably faster to 10,000 feet. Also, the La7 is the more aerodynically clean design - it had a very aerodymanic cowl design and the Spit XIV is pulling two HUGE scoops (lets call them air brakes) under its wings for cooling.

While the Spit may turn a little better (debateable), the La7 was definitely more responsive at speed.

The Hispano's are the better guns for bombers, not the B-20's. The reason is that the useful range against fighters is always much shorter, and less destructive capability is required to kill a fighter than a bomber. The La7 is twice as likely to land the first 20mm hit in a mutually aware dogfight and the .50 API (or Incendiary) are effectively ball ammo against wood.

Also, that 5 bladed prop is of no real advantage at lower altitides. The whole point of the thing is that it can turn at lower speed to avoid prop-mach issues at high altitude (where mach speed is lower). Down low, all that matters is the thrust generated by the prop, and 4 blades (or even 3) can be advantagous because they interfere with each other less. If more blades were all advantage, every plane would have had an 8 bladed prop right?

=S=

Lunatic
 
yes but at the same time the 5 bladed prop must have been better than the 3 and 4s, or we wouldn't have used them, we must have used them for good reason, we're not stupid..............
 
the lancaster kicks ass said:
yes but at the same time the 5 bladed prop must have been better than the 3 and 4s, or we wouldn't have used them, we must have used them for good reason, we're not stupid..............
Click to expand...

Better for high altitudes. And even so it was somewhat questionable how much better it was.

The higher the plane goes, the lower the maximim RPM of a given diameter prop, otherwise the tip of the prop will go supersonic and create a shock wave and ruin performance (and maybe even be damaged). So you want to reduce either the RPM of the prop, or the diameter, or both. But this reduces the amount of thrust from the prop. So one solution is to add more blades. The down side of this is that the blades are closer together, which means the turbulence from one blade may interfere with the one behind it.

After lots of study, the generally accepted solution was a large four bladed prop with very wide blades - the "paddle prop", geared to a lower rpm. This gave good low altitude performance and good high altitude performance - but it required more torque to drive it - something that the merlin and griffon engines did not do so well (i.e. they had comparatively poor torque curves below peak rpm as compared to the R-2800 for example). The ability of the airframe to handle the torque was also an issue (so the plane does not rotate around the prop), and longer wider blades accentuate this.

Finally, on the Spitfire, a larger prop geared to a lower speed was not really an option, it lacked the ground clearance for such a prop.

=S=

Lunatic
 
Do you any proof for the torque claims? Naturally the R-2800 has more torque as it has more power at slightly lower rpm but it is pure hogwash to speak about torque curves as they are meanigless with constant speed props. And remember, an engine having a reduction gear ratio of .25 and 2000 hp at 4000 rpm has the same torque available from propeller shaft as does an engine with reduction gear of .5 and 2000 hp at 2000 rpm (i.e. propeller runs at 1000 rpm in both cases).

And where do you get the claim that 4-blades is the absolute best?
 
I'd say the la-7 wins at low altitude, as it was proven better than any western piston engined fighter there. The spitfire was probably better at high altitude. Same when comparing the La with German planes. By the way, isn't the plane in the picture a lavochkin la-9 ?
 
as in the late bf 109 s correct?
 
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