Aircraft Spead and the interecept...

[Apollo11]

Hi all,

ORIGINAL: Mr.Frag

Interestingly enough the US did gradually abandon the wing mounted weapons in post-WWII aircraft and favored centerline mounted instead for its fighters...

Jet engines are not normally monster sized Radial's stuck on the front of the plane [;)]

It tends to leave a lot more room including space for mounting things like Radar.

Yes of course!

But wings were not that thin until 1960's (and unable to support wing mounted armament) - the US aircraft designers nonetheless started to see wisdom of putting armament on centerline after WWII...

BTW, the P-38 was one of the few (or perhaps the only one) centerline armed US fighters in WWII and that (in addition to German experience) must have heavily influenced decision to switch armament from wings to fuselage.


Leo "Apollo11"

[hithere]

I love you guys (gals)

[Brady]

"BTW, the P-38 was one of the few (or perhaps the only one) centerline armed US fighters in WWII and that (in addition to German experience) must have heavily influenced decision to switch armament from wings to fuselage."

P-61, Mossie, Beaufighter,Bregoute 693,Ki-45, Ki-102,Pe-2...ect, their were many aircraft that had centerline gun packages, prety much every country in WW2 had planes that had most all of their guns as close to the centerline as posable, this was the ideal posation for guns, and it was universaly understood to be so.

[tigercub]

JUST THE FACTS WHEN IT COMES TO FIGHTERS
THE FIGHTER THAT SHOT THE DOWN THE MOST PLANES IN ALL HISTORY IS THE ME109!!! OVER 20,000 KILLS JG52 HAD 10,000 ALONE!
MAY HAVE NOT BEEN THE BEST PISTON ENGINE FIGHTER OF WW2{ME109K14 455MPH![;)]} BUT IT DID HAVE
THE BEST PILOTS FLYING THEM FOR A LONG PART OF THE WAR UNTILL THEY WERE KILLED.
JUST A NOTE NOT MANY OF GERMANYS TOP PILOTS FEW THE FW190
LEFT TO THE NEW BOYS EASYER TA FLY
LEARNING IN A 109 WAS NOT THAT MUCH FUN BUT WHEN YOU MASTERED IT LOOK OUT!!

[CynicAl]

Thank you, Cubby, for that insightful and relevant post. Toward the left-hand edge of your keyboard there should be a 'CapsLock' button; as a courtesy to your fellow posters, please locate it and familiarize yourself with its use. Or (more to the point) its non-use.

Brady, did you happen to note another similarity among the aircraft types you just listed? Something pertaining to number of engines, perhaps? [:D] That said, there were US single-engined fighters during WW2 which featured guns firing through the prop. The F2A, P-36, P-39, and P-40B and C (but no later models!) all mounted guns in the nose, as did the initial prototypes of the P-47 and F4U. All early-war types (or prototypes), and their replacements (or developed versions, for the P-40, P-47, and F4U) moved either the guns or the engines out on the wings. That's a pretty strong trend - doesn't it make you wonder whether there might have been a reason for it?

Leo, I don't think it was the "wisdom" of centerline-mounted armament that US designers suddenly grasped at the dawn of the jet age, so much as the practicality. The limited space available in the nose of a single-engined fighter has already been brought up; this was further aggravated by the popularity of radial engines in the US aero industry, which absolutely ruled out anything firing through the propeller hub. So the question is, then, would you rather have two guns (probably still .50") in the "ideal" location in the nose, or six to eight guns in a slightly less ideal - but still serviceable - location out on the wings?

[Brady]

Cynical: Their were several reasions for putting the guns in the wings but it was by no means considered ideal, ever, Germany Italy, Japan,Russia, all had late war fighter desings, single engined ones that featured gun packages that fired through the prop, as close to centerline as posable. One down side to placing the US 50 cal or the Brithish Hispano close to the centerline in British and American aircraft were the sizes of these weapons, both were very large, also the US 50 Cal was not an espichaly fast firing weapon, at least not compared to it's contempoarys, so mounting it to fire through the prop would incure the 8-10% reduction in firpower, plus prove problem matic from a designe standpoint. the wing guns worked to be shure, but again this was by no means idea.

[Apollo11]

Hi all,

ORIGINAL: CynicAl

Leo, I don't think it was the "wisdom" of centerline-mounted armament that US designers suddenly grasped at the dawn of the jet age, so much as the practicality. The limited space available in the nose of a single-engined fighter has already been brought up; this was further aggravated by the popularity of radial engines in the US aero industry, which absolutely ruled out anything firing through the propeller hub. So the question is, then, would you rather have two guns (probably still .50") in the "ideal" location in the nose, or six to eight guns in a slightly less ideal - but still serviceable - location out on the wings?

Hmmm... let's just use the Me-109 for example...

The late war Me-109 was sporting 2x 13 mm (i.e. .50 caliber) machine guns over the engine cowl and 1x gun inside engine shaft.

Since Me-109 used liquid cooled engine (Daimler Benz) how is that so much different in design from P-51 and its liquid cooled engine (Merlin derivative)?


Leo "Apollo11"

[Brady]

Appolo, the 13mm MG 131, was a very diferent gun than a US 50 Cal, much smaller lighter and in all respects a much better aircraft weapon, much easer to fit into that space.

[Apollo11]

Hi all,

ORIGINAL: Brady

Appolo, the 13mm MG 131, was a very diferent gun than a US 50 Cal, much smaller lighter and in all respects a much better aircraft weapon, much easer to fit into that space.

Of course...

BTW I used it only for caliber comparision (and not of whole weapon)...


Leo "Apollo11"

[Brady]

CC, it is amsing how diferent the guns and ammo can be for similar calibers.

[freeboy]

just think of a 30 06 rifle verses a 300 winchester magnum, or win mag. Same projectile, HUGE velocity difference. Large downrange dropoff on power 30 06 vs winmag... or the German hi velocity 75 used by the panther tank.

[Jonny_B]

[8D][font="Times New Roman"][/font]

Anybody:

I notice reading the screenshots on the Witp Web Page under the title.
Plane and Weapons database
The following:

A6M2 has I believe an endurance of 380 (hard to read)
A6M3
A6M5
>
>
A7M2 has an endurance of 240

According to the database, the Zero’s endurance deceases with each new model.
I thought that this increase as the range decreased on naval zeros.

Somebody know the answer and why?

[Mr.Frag]

You getting endurance confused with perhaps durability? [&:]

[Jonny_B]

[:D][font="Times New Roman"][/font]

Mr. Frag:

Endurance is the relationship to distance, thanks for the correction.

[mdiehl]

just think of a 30 06 rifle verses a 300 winchester magnum, or win mag. Same projectile, HUGE velocity difference. Large downrange dropoff on power 30 06 vs winmag... or the German hi velocity 75 used by the panther tank.

Actually that is largely incorrect. The downrange performance (energy and bullet drop at ranges in excess of 250 yards) is where the two begin to equal out. The big difference between the .300 wm and the .30-06 is in the first couple hundred yards.

There was a very good article on this point in a recent issue of The American Hunter. The author was basically making the argument that going to a 300 wm from a .30-06 was a substantial gain in recoil energy for almost no gain in long range performance.

If you want a real contrast compare the .308 to the .300wm.

[mdiehl]

edit. letting that one drop.

[freeboy]

Ok look at the data again.. downrange at the same grain of projectile.. do the math yourself if this is unclear.. a 180 grain bullet shot faster is going to drop reletively slower.. the same 180 grain projectile fired slower drops reletivly quicker.. they actually drop at the same speed but the difference is in downrange dropage, how far downrange for each inch of drop.
ok?

[freeboy]

mdiel... the auther of the said article probably is correct in that one kicks much harder, and if you us a big difference in grains say 220 vs 150 maybe less noticable difference, but again what would you be hunting? What issue, I'd like to read it

[mdiehl]

IIRC the author standrdized on a 180 grain bullet. If you look at the 300 yard drop the difference between a .30-06 and .300 wm is not all that great. I think it has all to do with the fact that the higher velocity round loses velocity faster for a given ballistic coefficient.

Anyhow, just to mess around I ran the Remington comparison assuming the same bullet (180 grain pspb) with a .30-06 and .300 wm. In each case the top row is the .30-06 and the bottom is the .300 wm. The results are:

Velocity (fps) at muzzle 100 200 300 400 500
Premier Core-Lokt Ultra 180 PSP CLU 2700 2480 2270 2070 1882 1704
Premier Core-Lokt Ultra 180 PSP CLU 2960 2727 2505 2294 2093 1903

Energy (ft-lbs) at muzzle 100 200 300 400 500
Premier Core-Lokt Ultra 180 PSP CLU 2913 2457 2059 1713 1415 1161
Premier Core-Lokt Ultra 180 PSP CLU 3501 2971 2508 2103 1751 1448

Trajectory (bullet drop/gain inches) at m 150 200 250 300 400 500
Premier Core-Lokt Ultra 180 PSP CLU 2.1 1.8 zero -3.5 -8.9 -25.8 -52.7
Premier Core-Lokt Ultra 180 PSP CLU 2.7 3.1 2.2 zero -3.8 -16.4 -37

You can see from the chart that the .300 wm is ahead of the .30-06 the whole way in terms of drop but not very different in terms of energy-on-target after 300 yards. So.. I guess whether you think a cartridge is "better" depends on what you want. For a k-e round trying to kill an airplane I think energy would be what you'd care about as long as the general ballistic trajectory was acceptable above a certain limit (I regard the 30mm trajectories in WW2 aircraft as largely unacceptable unless your target is big, slow, and not too agile so that you can get in close). On the other hand, a sniper would want the round with the flattest trajectory.

What issue, I'd like to read it

I'll look it up for you tonight. The presumed target was any North American ungulate.

[freeboy]

ok.. so if downrange damage is what we want, how far do you think a plane hits another in a dogfight? Not those lumbering b17/24 flying streight and flat, but a turning val or helldiver after its dropped its load? 150 meters? more ? less?
above comparison shows the difference in traj well.. if you are hunting over 250 yard shots, not uncommon in the west.. the win mag shines do to flat tragectory...

thanks for the above info... do you remember what issue of A H?