spitfire mk xiv (14)

[RTHolmes]

I know almost nothing about the 109s ... you'll have to ask a luftie.


btw I found the XIV's theme tune:
http://www.youtube.com/watch?v=BonCLU297hM

[Shuckins]

The difference between the Spit XIV and earlier models in terms of handling has little to do, in my opinion, with the shifting of the cg.  It boils down to differences in wing-loading between the various models which all shared a common wing planform.  Looking at three of the more well known Spitfire models shows that the differences in dry weight were stark:

Spit V..........5065 lbs.
Spit IX.........5610 lbs.
Spit XIV.......8385 lbs.

Thus, the Spit XIV is 2775 lbs. heavier than the Spit V.  That's more than a ton and a half.  If I'm doing the math correctly, that's a 60% increase in dry weight from 1941 to 1944.  The Spit XIV gained quite a bit in speed and altitude performance but yielded much of its ballerina-like flying qualities.  At low to medium speeds the Spit V and 109F would eat it alive.

[Karnak]

Shuckins,

You sure those numbers are correct?  Earlier in the thread it was stated that the Spitfire Mk XIV's maximum takeoff weight was 8,500lbs.  If its dry weight was 8,385lbs that doesn't leave much margin for fuel, oil, crew, ammo or drop tanks, only 115lbs for all of that.

[Shuckins]

Karnak....you're correct.  I've got books on this stuff at the house....but I was using an online source during a break at work...and I didn't notice that that source did not have a dry weight for the XIV.  The figure I quoted for it I inadvertently pulled off of the line beside the one for dry weight, and thus erroneously used the loaded weight.

So...the actual figures should be:

Spit V..........5065 lbs.
Spit IX.........5610 lbs.
Spit XIV.......6600 lbs.

And the increase in dry weight from Spit V to Spit XIV should be 1535 lbs.  That's  3/4s of a ton, or about a 25% increase.

[nrshida]

I give up. Can't reason out why it would bounce. Don't have enough detailed knowledge. Yet.

[JOACH1M]

I give up. Can't reason out why it would bounce. Don't have enough detailed knowledge. Yet.

Bigger tail, huge wing area is the reason it bounce around.

[Karnak]

Bigger tail, huge wing area is the reason it bounce around.

That doesn't make sense.  The horizontal stabilizes are the same as on the Mk VIII as are the wings.


Why to the Spitfire need significant increase in the size of the vertical stabilizer while the Bf109K-4 gets by fine on the same dinky little vertical stabilizer the Bf109E had?

[PR3D4TOR]

Why does any aircraft "bounce"?

[JOACH1M]

That doesn't make sense.  The horizontal stabilizes are the same as on the Mk VIII as are the wings.


Why to the Spitfire need significant increase in the size of the vertical stabilizer while the Bf109K-4 gets by fine on the same dinky little vertical stabilizer the Bf109E had?

Is the nose longer on the spit14? Making the center of balance different from other spits?

[PR3D4TOR]

Anyone tried some dead stick aerobatics to see if it "bounces" with the engine off. If it does then it has nothing to do with torque or HP, and is some sort of dynamic stability problem.

[nrshida]

What do you think about this issue Karnak?

[Karnak]

What do you think about this issue Karnak?

I'm not the one to ask, to be honest.  I simply don't have the background in mathematics to really assist.

[Denniss]

I agree, but why doesn't the Bf109 suffer the same trait for a parallel development?

Continuous evolution instead of revolution regarding the engine, the DB 605 delivered more mover but gained little weight and still turned in the same direction. CoG was not really changed much from G to K-Series.

[SouthLanda]

Lusche, I tried what you said, however included drop tanks.
Spit14 -
15k 4 min
25k 7 min
30k 9 min
WEP 0-10k and 17-27k

Bf109K
15k 4 min
25k 7 min
30k 10 min
WEP 0-30k

I'd suggest that the Spit 14 would be superior from about 25k. Below that, its an even match up.
The 109K has full power to 22k and then the single stage supercharge struggles to provide enough boost.
The spit 14 has a supercharging issue between between 17k and 23k at normal boost. However above that, you have very good power through 30+k

[Lusche]

Lusche, I tried what you said, however included drop tanks.

That's a somewhat unfair comparison. The small slipper DT on the spit brigns it toabout the 109's fuel endurance without DT, while adding DT to the 109 gives it a big increase in both endurance and drag.
See my chart on both 100% no DT in the "unperk 14" thread in Wishlist Forum.