No Spitfire?

[XBe02Drvr]

Higher CLmax are associated with lower Lift/Drag ratios (ie higher drag/lift) leading to an eventual reduction in speed but this may take a turn to manifest.

So to reduce this engineer talk down to peasantspeak, you're saying the thicker Defiant wing suffers less L/D loss with increasing G than the thinner Spitfire wing, but total drag will be greater, causing faster airspeed decay in a combat turn? And I'm guessing the thicker wing will have more user-friendly behavior in an accelerated stall, aiding pilot confidence in pushing the envelope. This can be decisive in a turning fight. Pull your lead and get your shot before you bleed too much energy.

 

[PAT303]

For what it's worth, even the standard Defiant (with turret)

• could out-turn a Spitfire
• had 1.65 times the range of a Spitfire (575 miles vs. 950 miles)
• had a better view than the Hurricane

I think if Britain was panicking with no Spitfire, it's possible Boulton-Paul could have produced something worthwhile.

Your turretless Defiant will would only survive 2 minutes longer in a dog fight than the actual Defiant did.

 

[Koopernic]

So to reduce this engineer talk down to peasantspeak, you're saying the thicker Defiant wing suffers less L/D loss with increasing G than the thinner Spitfire wing, but total drag will be greater, causing faster airspeed decay in a combat turn? And I'm guessing the thicker wing will have more user-friendly behavior in an accelerated stall, aiding pilot confidence in pushing the envelope. This can be decisive in a turning fight. Pull your lead and get your shot before you bleed too much energy.

1 The Coefficient of Lift of the Spitfire Wing and the Defiant Wing will be about the same for the same angle of attack but the Spitfire wing will stall earlier at a lower angle of attack.

2 The L/D ratio of the Spitfire Wing Section per unit area and the Defiant Wing per unit area will be about the same for the same angle of attack however after the Spitfire wing has stalled the Defiant wing can keep going however the L/D ratio is now worse than when the Spitfire had stalled and keeps getting worse as alpha increases. The defiant makes up for its higher wing loading by a higher CLmax but the price is a inferior L/D ratio at high angles which eventually can slow the aircraft down. The price for the Spitfire is the big wings extra weight, which apparently wasn't much, Super marine worked hard here to keep wing structural weight down, kept the undercarriage attachment away from wings.

So the Defiant L/D ratio is likely worse than the Spitfires but only at angles beyond which the Spitfire wing has stalled. However the Spitfire doesn't have to use such high alpha because its wing is so big.

The thicker wing of the Defiant has more zero lift drag coefficient per unit area but because the wing is smaller it is probably less or the same drag.

Ultimately the Spitfire performance came from the efficiency (high L/D) of its wing at generating large amounts of lift in high g manoeuvres without lots of induced drag. It also came from an acceptable zero lift drag coefficient due to the thin wing that didn't build up compressibility drag.

However the Defiant may be able to generate significantly more lift than the Spitfire, only at the expense of drag. How this pans out in a situation is probably pilot dependant.

 

[Koopernic]

Your turretless Defiant will would only survive 2 minutes longer in a dog fight than the actual Defiant did.

If its 2000lbs heavier imagine
1 The weight of the turret and its systems removed, the weight of the gunner removed
2 The weight of any material used to provide space for the turret removed and the weight of any material used to reinforce the structure.
3 The undercarriage reduced in weight. All sorts of compounding effect, even reduced wing spar.

 

[PAT303]

If its 2000lbs heavier imagine
1 The weight of the turret and its systems removed, the weight of the gunner removed
2 The weight of any material used to provide space for the turret removed and the weight of any material used to reinforce the structure.
3 The undercarriage reduced in weight. All sorts of compounding effect, even reduced wing spar.

And after all that you end up with a plane that has less performance than a Hurricane, the old saying applies, you can't make a silk purse out of a sows ear.

 

[Greyman]

Based on flight trials of the turretless K8310, Boulton Paul figured their P.94 (Merlin XX) would be 30 mph faster than the Hurricane II.

 

[Koopernic]

Based on flight trials of the turretless K8310, Boulton Paul figured their P.94 (Merlin XX) would be 30 mph faster than the Hurricane II.

Boulton Paul P.94
The first attempt to turn the Defiant into a single seat fighter came in 1940, when the original Defiant prototype, K8310, had its turret removed and a mock-up of four fixed forward firing guns installed. The modified Defiant was estimated to have superior performance to contemporary marks of the Hurricane, but to be behind the Spitfire. It might have entered production if there had been a shortage of Spitfires and Hurricanes, but fighter production kept up with demand during the crucial months of 1940.

Boulton Paul P.94 - Destination's Journey
The first Defiant prototype had not been fitted with a turret at first and had an impressive top speed. In 1940, Boulton Paul removed the turret from the prototype as a demonstrator for a fixed-gun fighter based on Defiant components. The armament offered was either 12 .303 inches Browning machine guns (six per wing) or four 20 millimetres Hispano cannon in place of eight of the Brownings. The guns could be depressed for ground attack. By that time, the RAF had sufficient quantities of Hawker Hurricanes and Supermarine Spitfiresand did not require a new single-seat fighter. With a calculated top speed of about 360 miles per hour (580 km/h) at 21,700 feet (6,600 m) the P.94 was almost as fast as a contemporary Spitfire although less manoeuvrable.

From Tony Buttler's 'British Secret Projects, Fighters and Bombers 1935-1950.

Prototype Defiant K8310 eventually had its turret removed and in August 1940 was flown as an unarmed flying demonstrator for a fixed-gun version called P.94, which was intended for rapid production using many complete Defiant components. The P94 had the turret replaced by 12 0.303" MG disposed in each side of the wing centre section in nests of six – 4 20mm cannon replacing 8 of the 0.303" in two nests of two each were an alternative while the MG could also be depressed 17 degrees for ground attack work. P.94 had a 1,100hp Merlin XX, which offered a maximum speed of 360mph at 21.700ft, a sea level climb of 3,250ft.min and would get to 25,000ft in 8.1 minutes. To allow the type to act as a long range fighter two 30-gallon auxiliary tanks could be carried and in production the aircraft would use standard Defiant jigs. The P94 was never ordered but Boulton Paul also proposed to convert the now single seat Defiant prototype into a 4 cannon fighter demonstrator. The Air Ministry's rejection of this idea was recorded at a company board meeting on 26th September 1940.

 

[Shortround6]

From reading an account of the report, not the actual report, the Defiant seems to used a descending spiral turn in order to maintain speed. Account doesn't give rate of descent, which could have varied. It doesn't say that the Defiant actually out turned the Spitfire. Just that the Defiant gunner used up his gun camera film in 5 minutes and the Spitfire didn't use any film.
Now if the Spitfire, in a conventional turning fight, attempted to out turn the Defiant and set up a deflection shot it would position itself right in the Defiant's field of fire. Trying to make a wider turn but fly faster and then pull in to attack from "below" might not have been possible due to the relative speeds and rates of turn. Likewise trying to get below or above the banked Defiant may well have put the Spitfire in the gunners sights.
I believe the fight started at 20,000ft but it does not say when (altitude) the Spitfire gave up.
We don't know how hard the Spitfire pilot was trying to a avoid being caught on film.

 

[XBe02Drvr]

So build a Spitfiant with a Spitfire wing and a Defiant fuselage, armed fore and aft. Bite Adolf in the ass and kick him in the face. Problem solved!

 

[PAT303]

It's impressive that the Defiant with that thick wing and weighed down with 12 brownings could hit 360mph with 75hp less horsepower than the same era Hurri or Spit.

 

[PAT303]

From reading an account of the report, not the actual report, the Defiant seems to used a descending spiral turn in order to maintain speed. Account doesn't give rate of descent, which could have varied. It doesn't say that the Defiant actually out turned the Spitfire. Just that the Defiant gunner used up his gun camera film in 5 minutes and the Spitfire didn't use any film.
Now if the Spitfire, in a conventional turning fight, attempted to out turn the Defiant and set up a deflection shot it would position itself right in the Defiant's field of fire. Trying to make a wider turn but fly faster and then pull in to attack from "below" might not have been possible due to the relative speeds and rates of turn. Likewise trying to get below or above the banked Defiant may well have put the Spitfire in the gunners sights.
I believe the fight started at 20,000ft but it does not say when (altitude) the Spitfire gave up.
We don't know how hard the Spitfire pilot was trying to a avoid being caught on film.

In an actual fight a fighter is not going to fluff around with all those turns, the pilot is going to bore in and B&Z the Defiant into the ground. Reports like that just appear to make the situation suit the agenda not real life.

 

[Greyman]

It's impressive that the Defiant with that thick wing and weighed down with 12 brownings could hit 360mph with 75hp less horsepower than the same era Hurri or Spit.

The P.94 isn't a Defiant (or wouldn't have been a Defiant, I should say).

 

[pbehn]

But with no Spitfires what is Castle Bromwich tooled up to make?
change overs take time,

N.A. only tooled up a certain amount,
Production of the Mustang for the first year was

1941
Aug.........2
Sept........6
Oct.........25
Nov.......37
Dec........68
1942
Jan.........84
Feb........84
Mar.......52
April.....86
May......84
June.....84
July......76
Aug.....24

large scale production requires more resources.

To have numbers (hundreds) of aircraft available in 1941 is going to require making a decision on the airframe before 1940.
The US had 3 possible contenders. The Hawk 75/P-36/P-40, The Seversky P-35/P-43 and the Brewster Buffalo. (F4F isn't finalized until late 1939 or early 1940)

TBH I was only thinking of having numbers in 1942 with large numbers in 1943, that historically is what the Spitfire MkIX did.

 

[pbehn]

Ok...game on.



The Spitfire was a far more efficient and effective fighter. From actual Battle of Britain statistics, the 19 Spitfire squadrons made claims of 521 kills compared to 655 claims for the 30 Hurricane squadrons. That's 27.4 claims per Spitfire squadron versus 21.2 per Hurricane squadron. Now, I'm assuming that actual kills were proportionate to claims, but that's not a big stretch given that we're talking about a single battle and the same forces engaged. Therefore, if you have no Spitfires, you'd need an additional 6 squadrons of Hurricanes (ontop of the 19 "Spitfire" squadrons that would have been Hurricane-equipped) just to inflict the same number of casualties on the Luftwaffe. Given the Fighter Command pilot shortage in 1940, it's interesting to ponder where those extra squadrons would come from?

The Spitfire had a claim/loss ratio of 1.8:1 compared to the Hurricane's of 1.34:1. Swapping those Spitfires for Hurricanes means your front line wastage rate is significantly higher. And that's before we consider whether the Hurricane's ratio would remain the same without Spitfires (theoretically) tangling with the Me109s so the Hurricanes could take on the bombers. Yes, I know it was never that simple but the fact remains that the Spitfire could more than hold its own against the Me109E whereas the Hurricane really couldn't. And that's 1940 not 1942. Again, not only do we have to find 6 additional fighter squadrons but we have to replace a greater number of pilot losses due to the lower kill-loss ratio of the all-Hurricane force (and that assumes a constant 1.34:1 claim/loss ratio - the wastage problem for both pilots and aircraft is compounded if an all-Hurricane force has a lower ratio than that).

We're also assuming that the war would continue on the path it pursued without the Spitfire. That's a pretty big assumption to make. If Fighter Command can't generate those extra 6 Hurricane squadrons to achieve the same level of claims, then the Luftwaffe can count on 10% fewer casualties during the Battle of Britain...and perhaps many more given the relative effectiveness of Spitfire compared to the Hurricane. Again, would Hurricanes have maintained a 1.34:1 claim/loss ratio without the Spitfires, or an equally capable alternative, as part of the mix? The Me109F was coming into service in the late summer of 1940, with the Fw190 a year later, both well before your 1942 timeline. Both easily outmatched the Hurricane. With fewer losses and greater success against an all-Hurricane Fighter Command, who's to say the Luftwaffe won't continue to press on with the Battle of Britain into 1941?

As others have noted, photo recce is a key role that the Spitfire performed. Are we now expecting unarmed Hurricanes to fulfill that role as well? Slower, operating at lower altitude...they'd be dogmeat against the defences in Western Europe in the period when the early Spitfires were operating (mid-1940 thru the end of 1941).




Except that the US never agreed to licence manufacturing for anything of significance (the Canadian Car Foundry-produced Goblins are a notable exception...except (pun intended) that the Goblin was worthless operationally). There has to be a reason for that. Also, to avoid the scenario above where Fighter Command has to find 6 additional Hurricane squadrons just to maintain pace with the real-world BoB figures, there would need to be a higher-performing fighter in the stable in the early 1939 timeframe. Again, there is NO WAY the US is going to enable licence production of a state-of-the-art fighter in 1938. You can say "there's no reason" but history shows that the US doesn't export jobs to anyone unless it absolutely has to...and in 1938, the US didn't have to. You keep pointing to the late-1941 timeframe but, as shown above, the only way we can effectively assume that the war proceeds as it did with the Spitfire is to have a more efficient fighter than the Hurricane fighting alongside it during the BoB...which means we need that aircraft in service in late 1938.

With respect, it is a what if, and a topic of discussion. All what you say is true. However I was looking at a different opinion on how not having the Spitfire would affect the UK. If you consider your front line fighter is not that good and you have nothing else the only solution is more of them. The statistics in the BoB are (as I have already said) based on the numbers. If you produce more of perhaps the most easily produced front line fighter of the era then you get different statistics (I would argue). It was known that the Hurricane was inferior, I don't argue that it wasn't, but huge resources were put into the Spitfire (which is now outside the discussion). The Typhoon and Tornado, the Defiant and the Whirlwind. The what if is "No Spitfire" I am just proposing that with just hurricanes and nothing expended on anything else the RAF would have so many Hurricanes the BoB would not really have taken place, Goering couldn't dream of defeating it in weeks or even months. Similarly on Malta the problem was it wasn't properly defended to start with, if there were a hundred Hurricanes on Malta and not a few Gladiators it wouldn't have become the most bombed place on earth at that time.

 

[pbehn]

The Spitfire MkV was rushed into service because the Hurricane was so outclassed, like I have posted already, if the Hurricane could hold it's own the interim model Spits would not have been made, instead of converting MkII airframes to MkV then MkIX's we would have had the MkIII, with clipped wings, retractable tail wheel, internal glass, cleaner aerodynamics, increased internal fuel and two speed Merlin it was 50+mph faster than anything else in the Allied inventory in 1940-41 and more than capable of handing both the 109 and 190 at any altitude, not only that Supermarine would have followed that development path and the RAF would move to the MkVIII and MkXIV as front line aircraft. The Hurricane hampered the RAF just as much as it helped by causing the less capable Spitfire marks to be rushed into production, even during the BoB the Hurri was fitted with Merlin XX's while the Spit ran the XII just to try and make it slightly less obsolete.

I agree, but the what if is that there is no Spitfire. Much of the immediate problems faced in 1940 were due to there being a Spitfire in the first place. Use the dispersed factory that the government arranged to produce Spitfires around Southampton and the West Bromwich factory to Hawkers to produce Hurricanes and you have a huge number of Hurricanes. As I have also said, offensive operations are a different matter but UK offensive operations in 1941 were mainly a waste of pilots over France.

 

[pbehn]

So build a Spitfiant with a Spitfire wing and a Defiant fuselage, armed fore and aft. Bite Adolf in the ass and kick him in the face. Problem solved!

It reminds me of the argument that Sir Walter increased life expectancy when he introduced tobacco to the UK, well it was 45 years at the time and is now 75, conclusive proof to all the anti-smoking lobby. (there may be other factors but they don't matter a dime).

 

[ThomasP]

I say again that we really need a rating that says "that's funny and I agree".

 

[SaparotRob]

Could use an "Insightful" too.

 

[The Basket]

Peace time then yeah Hurricane all the way and wait for the Typhoon Tornado Tempest Teasmaid Toothbrush Trumpet Trombone to come along.

I see no issue with this.

I wonder if Hawker maybe gave the 2000bhp fighters the good old flannel so the Spitfire would seem a overpriced luxury.

Nah...military contractors never over hype their gear.

 

[Koopernic]

The P.94 isn't a Defiant (or wouldn't have been a Defiant, I should say).

View attachment 617287

It looks like P94 was Defiant forward of the engine firewall, used the Defiant wing and wing box, used the Defiant empennage. The Radiators and oil coolers are the same.
The differences seems to begin after of the upper part of the fuselage rearward of the windshield near the cockpit canopy area to about the beginning of the tail. I'd say 80% of the tooling and jigs would be Defiant and certainly all of the expensive stuff.

It's impressive that the Defiant with that thick wing and weighed down with 12 browning could hit 360mph with 75hp less horsepower than the same era Hurri or Spit.

The Hurricane used an American Clark-Y air foil. This was a German Gottingen air foil with the bottom chopped of and flattened. It literally was flat. Very easy to make. It was very thick, over 20% and because it was flattened at the bottom there was a very curved upper surface. However the Defiant used an Modified NACA air foil more advanced than the Clark-Y and more symmetrical. It would have had less drag and less effected by shock drag. It would have been better than Hurricane by far.

The drag characteristics of a wing do not just depend on the Thickness/Chord ratio but the point of maxim thickness and the amount of camber (distortion from symmetrical) and the Modified NACA were clearly far better than Clark-Y. Less zero lift drag, less shock drag

The Defiant had a modified NACA to me the wing root looks like 4418 ie 2% camber at 40% thickness and 18% thick.
NACA 4 digit airfoil generator (NACA 4418 AIRFOIL) (airfoiltools.com)


Hence that the P.94 could have done 360mph on a Merlin XX, 20mph faster than a Hurricane, is very believable. Its a far more streamlined aircraft.

It's also obvious that had Bolton and Paul been given a specification for a single seat fighter from the beginning they could have come up with something as good as Spitfire.

Note that the P.94 had plenty of room in the wings for 4 Hispanos, no bulges needed.