Fw-190 Dora-9 vs P-51D Mustang

[stona]

The Spitfire canopy evolved just like the rest of the aircraft. As far as the view from the cockpit goes, it is worth remembering that the first 'low back' Spitfires didn't appear in production until 1944.
Cheers
Steve

 

[drgondog]

I understand that a US liaison officer was the one who pushed for the bubble canopy on US fighters after seeing it on the Typhoon.

"A problem encountered with the Merlin-powered P-51B/C Version
was the poor view from the cockpit, particularly towards the rear. The
'Malcolm Hood' fitted to the P-51B/C was an early attempt to correct
this deficiency. However, a more lasting solution was sought. In January
1943, Col. Mark Bradley had been sent to England and saw how the new
'bubble' or 'teardrop' canopy had given Spitfire and Typhoon pilots an
unobstructed 360-degree vision. He returned to Wright Field in June and
began exploring the possibility of incorporating bubble canopies on
USAAF fighters.

Republic Aviation installed a bubble canopy on the P-47D
Thunderbolt in record time and Bradley flew it to Inglewood to
demonstrate its features. Following discussions with the British, and after
examination of the clear—blown 'teardrop' canopies of Spitfires and
Typhoons, NAA secured an agreement with the Army to test a similar
canopy on a Mustang in order to improve the pilot's View from the
cockpit.

P-51B-1-NA (43-12101) was selected to be modified as the test
vehicle for the new bubble canopy."

Ref:
Mustang: Thoroughbred Stallion of the Air
By Steve Pace

Unfortunately, Bradley was either a little foggy on the details or he didn't realize that the 106-xxxxx drawings were complete for the Production D and that 43-12102 had already installed the prototype bubble canopy. Steve made several errors in his collection but the Bradley tale came from Bradley - not NAA. He also claimed to have flown the first 85 gallon tank but Chilton holds that distinction.

 

[pbehn]

When the Spitfire was first seen in public, it didn't have a bulged canopy.
The prototype is shown above, complete with original canopy, 2-blade prop, and tail skid. No stealth at all!.

That is a proper prototype, it looks like I just made the worlds worst Spitfire replica and propped it up on a beer crate for a photo.

When I said "seen in public" I meant at an air show where the worlds designers could see it.

 

[davparlr]

Somethings are relative, 20 mph to a 320 mph fighter is a bigger difference than 20mph to a 420 mph fighter. And in some cases it is the acceleration rather than the actual speed that allows the separation. I doubt that any piston engine fighter pilot decided to depart a fight while flying at top speed. He may well have been at full throttle but you are not at top speed even if banked let alone turning. If a 340mph fighter decides to "run" while doing 280-290mph with a 320 mph fighter behind him (also doing 280-290mph) but not in firing position the 340mph fighter may have better acceleration and be able to hit 320mph before the slower fighter does and then keep accelerating. What this looks like to the pilots involved may be a bit different than the actual physics. or even the actual top speeds of the planes.

I have to disagree here a bit. Delta airspeed is an absolute function, not a relative one. A car that is going 60 mph sees a car going by 80, will say that car car is really going fast. A plane fly 400 mph sees a plane going by at 420 could say the same thing since the distance the 80 mph car over the 60 mph car in say one minute, will be the same as the 420 mph plane will have over the 400 mph plane in same minute. Separation rate of the two examples are based on the same value, 20 mph. What you say about the acceleration rate is true. Two planes in a turning fight, one is capable 400 mph top speed and the other 420 mph, the 420 mph plane is in the lead and decides to roll out and run counting on his top speed for separation. Unfortunately, for the lead aircraft, even though he can out accelerate the chasing plane he is likely not going to be able to out accelerate the rounds coming his way before he can get out of range, which is exactly a repeat what you have said.

 

[davparlr]

Bubble canopy technology seems to have been an evolutionary design. Both the Zero and Fw 190 had pretty close to 360 degree viewing whereas most fighters at the start of the war had poor aft viewing, like Bf 109.

 

[Milosh]

There was also a problem in forming full blown canopies in the beginning without imperfections that would cause vision problems.

 

[Shortround6]

It took a while to make large one piece blown canopies. Why it took so long to get "bubbles" made up of multi panels is a bit harder to understand.

first flight Oct 1938
while the Tornado

solid rear for what reason?

Grumman XF5F but the F6F and even the F7F didn't follow.
P-38 and P-39?

However there may have been a drag penalty with some of these early canopies??

 

[pbehn]

The Miles M20 had a sort of bubble canopy in 1940.

Of course there is no way to tell how optically perfect it was. As I understand it a bubble canopy cannot have perfect optics, but then flat glass only has when looking straight through it. My point was that the British (Spitfire and whirlwind) Germans (Fw190) and Japanese (zero) were moving in that direction while the brand new designs in USA were still birdcage type.

I have no idea what Hawkers were up to the Typhoon was probably worse than the Hurricane to start with.

 

[eagledad]

Hi Eagledad,

I'll be sure to read that one since I have often heard about the fantastic rolling capability of the Fw 190 radial aircraft. particularly when they first came out and were such a surprise to the RAF. I figured the switch to the inline might affect pitch rate, but I didn't think it should affect roll rate by much. Perhaps that is incorrect. Everything I HAVE read indicates the Fw 190 D-9 was a good one, in every sense of the word.

Thanks! It will make a good read, I'm sure. And I can't disagree with it since I wasn't there.

Edit: Well. that certainly doesn't bear out what I said above, does it? I wonder if the example they flew was representative. It obviously had some issues, and may not have been entirely in good working order. I would THINK the D-9 to be better than that report indicated, but have no proof of same as I don't read German. Since the report was of flying a captured D-9 with some obvious difficulties, I'd not want to claim the conclusions as typical of the type without other corroboration.

What's even funnier is that report contradicts every other flight report of the radial units. They were supposed to stall with little to no warning and this D-9 gives plenty of warning. Something is fishy here ...

Steve Hinton flew Paul Allen's Fw 190 restoration and said the feel of the aircraft was first rate. That is, it was immediately apparent he was in a first-rate fighter that flew considerably differently from a Flugwerk replica (which he has also flown). He didn't explore the flight envelope very much as the test card was all about making sure it was airworthy, not about performance. That particular aircraft is BMW 801-powered.

Greg;

I also thought that the D-9 had a similar roll rate as the A. The only way I can see a P-38J out roll a FW-190 would be if the Lightning was equipped with powered ailerons, the speed was almost 350 true, and we are talking steady state roll, not "slam bang" (ie quick roll one direction followed but a hard reversal the other direction,)

.

I have included a chart comparing the P-38L, P-51B, and FW-190A roll rates, by Lockheed via Dr.Carlo Kopp.

Eagledad

 

[CORSNING]

1938 / 1939 Nakajima Ki.27

 

[Peter Gunn]

Unfortunately, Bradley was either a little foggy on the details or he didn't realize that the 106-xxxxx drawings were complete for the Production D and that 43-12102 had already installed the prototype bubble canopy. Steve made several errors in his collection but the Bradley tale came from Bradley - not NAA. He also claimed to have flown the first 85 gallon tank but Chilton holds that distinction.

Another question if you don't mind, re Mustang stability with the 85 gallon tank, did stability issues stem from the lack of baffles in the tank or just the fact that it added all that weight where it did.

And, if it was a tank without baffles did they ever try it with baffles? I think I've read that postwar some of the 85 gallon tanks were removed to increase stability, yes or no?

Thanks as always.

 

[drgondog]

Another question if you don't mind, re Mustang stability with the 85 gallon tank, did stability issues stem from the lack of baffles in the tank or just the fact that it added all that weight where it did.

And, if it was a tank without baffles did they ever try it with baffles? I think I've read that postwar some of the 85 gallon tanks were removed to increase stability, yes or no?

Thanks as always.

The lack of baffles was noticeable but not sure that it was destabilizing. That said, the 85 gallon tank received two lateral baffles following a December 22, 1943 Test report. The lack of longitudinal baffles were not deemed important.

I have not heard that AAF/USAF removed the 85 gallon tank. For example, It was very important in Korea for sufficient range of FB ops out of Japan. Removal is a no-brainer for Warbird community. That said, the P-51B Berlin Express re-installed the tank and plumbing to make the cross-Atlantic trip to Duxford yesterday.

 

[Peter Gunn]

Many thanks, always happy to learn more about the Mustang. I try not to be a fanboy about it but it's my favorite from WWII and I think one of the most beautiful (and impressive) aircraft to ever take wing.

Also I got my signals crossed and transposed the removal of the fuselage tank by warbird owners with AAF/USAF postwar, my bad. I really should be fully awake when I post.

 

[GregP]

Not sure liking a plane makes you a fanboy. I usually attribute that more to the guys who credit their pet aircraft with abilities beyond what it really had. Perhaps that is not the literal internet definition?
.
Unfortunately, I like ALL WWII fighters! Regardless of side or country. And I assume they were all pretty decent when they were selected for production. Almost everyone who produced a fighter looked at the world competition before buying it

The P-26 Peashooter, while obsolete in WWII, looked pretty decent in 1932! By 1936 (Curtiss Hawk, Bf 109, and Spitfire time), it didn't. It just happened to be a time of rapid engine and airframe development.

I have also heard maybe 50+ WWII pilots way top speed was almost meaningless in a fight. None said it was meaningless when running away, just that it was in a fight. Perhaps what they were saying is, "If you weren't trying to escape, top speed was not all that important." Maybe most in here can see that as absolutely true. It's just that, in a fight, it can turn from a fight to escape in a heartbeat, and you have little control over when that happens some of the time.

 

[pbehn]

I have also heard maybe 50+ WWII pilots way top speed was almost meaningless in a fight. None said it was meaningless when running away, just that it was in a fight. Perhaps what they were saying is, "If you weren't trying to escape, top speed was not all that important." Maybe most in here can see that as absolutely true. It's just that, in a fight, it can turn from a fight to escape in a heartbeat, and you have little control over when that happens some of the time.

I have read of Hurricane pilots being unnerved when in combat in France with Bf 109s because while they could stay in combat they couldnt break it off. By the same token I read of a Tempest pilot who didnt fancy taking on a flight of Fw190s just pushing the throttles through the wire gate to use max boost and leave the problem behind.

 

[GregP]

Heard of them, too. Never been one of them, so I only have anecdotal evidence and combat reports.

Seems that if you were attacking, top speed wasn't all that important. If you were trying to avoid contact, it was. Altogether, I'd say it has importance, but I'm not sure where it fits in. I'd bet it is different for each fighter pilot, but don;t really know.

 

[airminded88]

I'd say that top speed is also critical at an offensive capacity for when the pursued aircraft tries to disengage a fight and put distance between it and its pursuer, it is a superior speed that will become the dominant factor for the pursuing fighter.

 

[GregP]

Not too sure. As long as you were in range, it didn't matter if he was extending. It mattered if you could shoot before he got out of range (WW2). If he was running, you could bet he wasn't going to be overly aggressive in the immediate future. That says nothing about his friends, though.

Today, top doesn't matter at all, except to GET there. ALL the missiles are faster than the aircraft! And all dogfights are at speeds lower than top speed.

Biff could chime in here.

 

[stona]

In the 1930s the Air Ministry and RAF concentrated on developing two properties of their fighters' performance. Those were speed and firepower. Both the Hurricane and Spitfire were direct results of the Air Ministry's high speed research programme. I find the arguments that maximum speed was somehow unimportant unconvincing. Both aircraft look the way they do because the merging of various specifications (including F.35/35 which was specifically for an experimental 'High Speed Aircraft'). It's why they are monoplanes, why they have retractable undercarriage etc., etc. Everyone developing fighters was seeking to produce certain types to be as fast as was technically possible at the time and the Air Ministry was acutely aware of developments in Germany. The Air Ministry was aware that RAF fighters generally sacrificed performance for other operational factors, and that this might no longer be tenable. As the Director of Technical Development (Cave) wrote:

"We receive from A. I. [Air Intelligence] reports of high speed claimed for fighters built abroad. As our new Fighter Specifications F.7/30, F.5/33 and F.22/33 all sacrifice performance for other operational requirements the situation may arise shortly that our fastest fighter is very much slower than some foreign fighters."

A situation which was clearly not acceptable. The ever increasing speed of bombers was also a concern, as was the need to develop a sufficiently faster fighter to be able to effect an interception.

Cheers

Steve

 

[drgondog]

Top speed is a function of Power Available vs Power Required. Although a 20 mph difference (or 40) may not be perceived as important in a fight, Acceleration and Climb are important and those are directly related to 'excess power'

So, if a P-51B-1 and Bf 109G6 at 25K are zipping along at the 109's max Power/top speed of say 390mph, the 109G6 is way behind the 51B-1 in Energy available when the 51 pilot moves from MP to WEP.

Top Speed as a metric is as stated above, but it IS a reflection of 'what's left in the tank' when comparing relative performance.