improving the 109??

[GregP]

OK, here's a link to the great fighter gun debate:

The WWII Fighter Gun Debate: Introduction

Scroll down to the bottom and click on "Gun Tables." This has been bouncing around the internet for more than 25 years. I'll stick with Q and M myself and, if anyone wants to be taken seriously in the long-ongoing debate, I'd suggest they not come up with "new" measures of effectiveness. It was tried once and the poor guy was run off the site!

But hey, maybe all the data gives someone a new place to start the debate all over again. I was into it for about 10 years when I was doing some shooting with a friend who collected and sold automatic weapons and cannons in Arizona, but I sort of lost interest when he passed away in the mid 1990's. We had some fun shooting his weapons and a few cannons.

The biggest we shot on a regular basis was a 37 mm Hotchkiss cannon mounted on a 2-wheel truck with a trailer hitch connection, but we did shoot a 75 once on a private ranch. He was a licensed dealer of automatic weapons, so it was legal for him to possess the shells. We got stopped by the police pulling the cannon out there and it took some 3 - 4 hours before they let us go, so we didn't haul that one out much after that. He was screaming at them for an hour because they wanted to see a permit for the cannon. I thought we were going to jail, but it turns out he was right, you don't need a license for a single shot gun! But you DID need a license for explosive ammunition. Interestingly, they were less concerned about the cannon shells than the machine guns in his Chevy Carryall! I kept my mouth shut and asked a few cops if they wanted a drink of water from the ice chest.

 

[wuzak]

About the thick-winged Typhoon, Hawker schemed a turbocharged variant,
(the detail drawings are in the British Kew archives) the turbo was a GE unit, that was to fit in that thick wing root).

This Typhoon was to be licence built by Bell, with the Napier Sabre like-wise US-made by Chrysler.
In the event, Bell was kept busy with the P-39s that only Stalin wanted, & for the Mopar mob, the R-3350
needed by the B-29 program took priority.

Its a pity, since if the US 9th AAF had Typhoons instead of P-47s for the invasion in 1944 they would've benefitted. .

& if Shooter can provide a single verifiable source which shows a Jadgwaffe jock was keen to go head on with
4 X 20mm Hispanos, even wing mounted such as in the Typhoon & Tempest, I'd like to see it..

You wouldn't happen to have this document?

I would be interested in seeing it if you have.

 

[wuzak]

I have often seen it stated that maybe the Merlin rotated opposite to the DB 601 / 603 / 605 in the Bf 109. Here is a DB-powered BF 109.

Note that from the point of view of the pilot, the prop rotates clockwise. Here is a Merlin-powered Spitfire.

Note that from the point of view of the pilot, the prop rotates clockwise, the same as the DB 605.

In fact, the Griffon reversed the rotation and went the other way. Here is proof of that. Here is a Griffon-powered Spitfire. Note that from the point of view of the pilot it rotates counterclockwise.

The Bf 109 does have an airfoiled vertical tail, but the main source of confusion seems to be the Hispano Buchon. The Buchon was initially developed as the Ha.1109 Tripala and was adapted for the Hispano-Suiza engine that turns opposite from the Merlin and the DB. So the Hispano Bucho has a fin airfoil that expected prop rotation opposite from the Merlin, but that is not the case with real German Bf 109s.

The Buchon was developed from the Ha.1109 Tripala. Here is the nose of an Ha.1109 with the nose of the Ha.1112 visible behind it.

Note the engine in the Ha.1109 turns the same direction as the Griffon, opposite from the DB and Merlin, and accounts for the fin airfoil on the Ha.1112 being in the wrong direction since it was assumed they would use the Hispano-Suiza engine, but actually switched to the Merlin after the Ha.1112 airframe was built.

Note the Avia S-199 with the Jumo 211 engine turned the same direction as the DB engines did. Here is a pic of one so you can see.

Thanks Greg, that explains it.

 

[wuzak]

The Tempest was an early adopter of the HUD,
having its gunsight graticule directly reflected onto its optical quality armour-glass windscreen.

Wasn't that common for all British fighters of the era?

Gyro gunsight - Wikipedia, the free encyclopedia

See the Mk II
http://www.historicflyingclothing.c...lector-gun-sight-mark-ii_13888_main_size3.jpg

 

[wuzak]

WRONG! The 109 pilot is praying that the Tempy pilot's aim is true! Because if it is, his wing guns would be zeroed at 250 yards, or ~230 meters and at 400, the bullet streams would be ~4-5 meters from his fuselage!

That is an assumption. The Tempest may have its guns "zeroed" at 250m, or having experienced this fanciful head on attack before, he would have re-zeroed his guns at a longer range.

If you doubt this draw a diagram and see for your self!

You're the one espousing this hypothesis. Why don't you do this drawing and upload it here. This forum generously allows pictures to be uploaded and attached to posts.

See the replies in red above.

I wish you would stop doing that. It;s hard to read and follow.

 

[wuzak]

http://www.spitfireperformance.com/spit109turn.gif



That chart was made, IIRC, by the RAF testing a downed 109? They used much lighter stick forces than the Germans and thus generated much lower rates of turn. Secondly, the German "Experten" as they were called routeenly claimed you were not maneuvering until the slats deployed.

Because the RAF was in the habit of testing enemy aircraft below their physical limits and thus give their own pilots incorrect information on how to combat them.

As the chart does not mention methodology, how do you know that they did not get the slats to deploy or what stick forces they used?

 

[GregP]

Hey Wayne,

I was a bit mixed up about the fin airfoil myself, and there's a good thread about it over on WIX. I KNOW our Hispano He.1112 fin is airfoiled the wrong way for the Merlin, but wasn't really aware that the Ha.1109 Tripala had that airfoil introduced to help with the Hispano-Suiza engine torque until I chanced across it in WIX. After that, you can seem to find just enough to piece the story together.

So I suppose the real "fix" would be to remove the fin and make a new one with the reverse airfoil ... maybe just flip the ribs over and make new skins ... maybe! Anyway, I'm not going to look for excuses to do more work on the Hispano! It's painted now and VERY close to being flyable. In fact, you probably COULD fly it without the lower cowl, but it has enough of a reputation when going off pavement without trying to fly one in an unairworthy condition! Not to mention being unwise and probably illegal. So, ours will have a much more Bf 109-like lower cowl and also has Aluminum wheels that we made when we broke a magnesium wheel. That was my fault.

 

[gumbyk]

Aluminum wheels that we made when we broke a magnesium wheel. That was my fault.

There was obviously a flaw in it that you uncovered

 

[GregP]

Actually, I just hit it too hard with a deadblow hammer trying to get an F-86 tire on it! I was VERY angry with myself, but we had a local school with a new 3D-measuring device volunteer to do a pair of Aluminum wheels from the surviving unit on a CNC lathe as a project! One of the guys (George Orff) on the team was already talking with them about it because the magnesium was showing signs of wear that were a bit too deep for our liking anyway. We still have the old good wheel as a spare and the cracked one as an example to new volunteers of what NOT to do.

So ,,, the Ha.1112 currently has F-86 tires on it.

 

[wuzak]

All true! But not really relevant! Re calculate for the Spit at 250 as above, but the 109 is going 300 MPH and is only 300 meters behind and has just opened fire. Then take into account the early Spits horrendous rate of roll AND the displacement of the centers of the two plane's circles due to the initial range. Then tell me the finished range, angle off and number of seconds the 109 has continuously tracked the target? This was, with one minor variation, a real live problem given to real live AF Pilots at the Colorado Springs Academy!

At 250mph TAS (~200mph IAS @ 12,000ft) the Spitfire's rate of roll was 105°/s. What was the rate of roll of the Bf 109?

http://www.wwiiaircraftperformance.org/naca868-rollchart.jpg

If the Bf 109 has closed to 300m to fire without the Spitfire manoeuvring it is safe to Assume the Spitfire pilot has been unaware of the attacking Bf 109 until that point. Which means that the Bf 109 has an immense advantage.

If the Bf 109's initial burst misses, the Spitfire will have rolled into his bank and started to turn.

So, at 12,000ft and 250mph TAS the Spitfire will do a turn of ~1,800ft at ~3G without losing altitude.

The Bf 109 at 300mph TAS can only pull ~1.8G in a turn whilst maintaining altitude, at a radius of ~3,200-3,500ft.

From the turn chart it appears that the bank angle for the Spitfire is ~70°. So it would take ~0.7s for the Spitfire to achieve the bank angle after it is initiated. As or RAF pilot is a bit asleep, assume that he takes 1s to react. So 1.7s for the plane to get to full bank angle.

Not being a pilot myself, I can only assume that the Spitfire won't fly straight and level while banking before he starts turning. Which means it won't be 1.7s before the Spitfire moves off the Bf 109's gun trajectories.

Once the Bf 109 pilot enters his turn his bullets will miss, as he cannot pull a lead while maintaining altitude. So he has to turn tighter. He can turn at the same radius as the Spitfire, pulling ~3.5g . But the problem he has now is that he is losing altitude while the Spitfire is not. And he his angle of descent is ~10°.

If he continues to try to turn with the Spitfire he is toast.

The Bf 109 in the scenario has all the advantage - he is flying faster, and the Spitfire clearly hasn't a clue he is there. He should win the battle, before the Spitfire pilot has a chance to react probably.

It is like even you have said before, most downed pilots never even saw their adversary
.

As has been mentioned earlier in the thread, the reason why Bf 109 pilots could often turn with Spitfires in the BoB was experience. Many of the Luftwaffe pilots had combat experience in Spain, Poland and France. Many of the Spitfire pilots had very little experience flying, let alone in combat.

Thus the Luftwaffe pilots could often fly their aircraft closer to the envelope than the RAF pilots. But if teh RAF pilot is equally as experienced with his plane, the Bf 109 would not prevail in a turning fight.

 

[wuzak]

Great post! I bow in aw to your Google-Foo skills! Where did you find all of this data? Also, I was under the impression the Fw-190 was 30-40 MPH faster than the Spit-V below 20K'? I ask this because was not the Spit-V the direct competitor to the Fw-190 and the Spit-IX the belated answer?
PS, I just got a Pop-Up while typing this, but it closed before I could read it. How do I find it now?

Clue - he didn't google it.

 

[GrauGeist]

My statement was true. Mono-plane Fighters in mass production, say over 1000 built, did not have LE slats except for the 109! While Handley Page put slats on lots of slow stuff, I do not remember a single fighter plane accepted into service from them during the war and certainly nothing with LE Slats. But, before you all start listing this that and the other thing, remember the part above about at least 1000 made.

Me262 - 1,430
And if you're so damned smart, you'd know this already

 

[wuzak]

It was re-hashed WW-I technology because it was designed as a Dog Fighter with high rate of turn, instead of as a "more pure" weapon like the 109 that was designed to kill WO risking the dangers of dog fighting. It was the idea, not the implementation of the design. It had beautiful Elliptical planform wings and tail surfaces. Those gave it a truly great rate of turn and great range at it's intended economy cruise speed. But they also made it very expensive to manufacture, fragile, and slower than it could have been with a much smaller Trapezoidal wing like the 109.

The Spitfire didn't have "great range at it's intended economy cruise speed" and was never intended to.

I believe that the wing planform was to accommodate the gun installation. Not for beauty and not for the turn rate.

The role of teh Spitfire was to climb quickly to altitude to intercept bombers.

 

[tyrodtom]

Every fighter Messerschmitt produced in any quantity has slats, BF 109, Bf110, Me 262, and Me410.
Even the Me163 had slots, though I don't think 1000 were produced.

The Lavochkin La5 and 7 had slats also, and meet your threshold of 1000 produced.

 

[GrapeJam]

You know, I'd really like the 109 if it didn't have the highest amount of idiotic fanboys.

 

[GregP]

That ain't Willy's fault, but understand your statement ...

 

[GrauGeist]

And as surprising as it may seem, the IJN had leading edge slats on their Nakajima C6N recon aircraft, though not a fighter and only 660 aircraft built...they were there.

So did the Italian's SM.70 (1,250) and while we're at it, I suppose we should include the Fi156 (2,900+) and there's more, like Blohm & Voss' Ha140 and so on...

 

[GrauGeist]

Its funny, I dont 'believe' in having 'favourite' machines as such ( & some people even give their bikes & cars pet names!),
but for me, there has always been something attractively 'bad boy' about the 109, even if it usually got a beat down from
the contemporary Spitfire, Mustang or Tempest.

As those still cocky jagdwaffe jocks under interrogation by USAAF G2 stated, those pilots who recognized the limitations of the 109,
still felt they had a fighting chance if they didn't push their luck too hard, like turning fights with Spits...
or duelling with 8th AAF Mustangs in the stratosphere around the cloud tops,
- but could still take on the 9th AAF JaBo P-47s - on the deck,
& with the chance of a good outcome, even in `45..

Make no mistake about it, even by April 1945, any Allied aircraft was in trouble if they encountered a skilled Luftwaffe pilot in a Bf109.
Even in the last hours of Germany's fight, Aces like Gerd Thyben shot down Allied aircraft as they were attempting to escape to an area where they could surrender - of course, Gerd did this with his Fw190 and while carrying his crew chief stowed in the luggage compartment...

As far as favorites go, the Bf109 is not one of my favorite aircraft of WWII, however, I put credit where credit is due.

 

[Milosh]

Every fighter Messerschmitt produced in any quantity has slats, BF 109, Bf110, Me 262, and Me410.
Even the Me163 had slots, though I don't think 1000 were produced.

The Lavochkin La5 and 7 had slats also, and meet your threshold of 1000 produced.

LaGG-3, La-5 and La-7 production was 22,201.

 

[stona]

Make no mistake about it, even by April 1945, any Allied aircraft was in trouble if they encountered a skilled Luftwaffe pilot in a Bf109.

Absolutely, the Bf 109 in all its forms was one of a handful of truly great aircraft of WWII.

Cheers

Steev