1937-45: Doubling down on the 2-engined 'day fighters'

[SaparotRob]

I don't think of the Blenheim as a wannabe fighter. It was voluntold it was a fighter.

 

[TM06]

Italy brings a few options to the table I think are worth discussing here. Specifically the Savoia-Marchetti SM.91 and SM.92 along with the IMAM Ro.58.
The SM.91 is the worst performing of the 3 but the most heavily armed (5 x 20 mm MG 151/20 in the nose, 1 in a rear gunner) with the most range, the SM.92 slashed the armament layout (3 x 20 mm MG 151/20 and 5 x 12.7 mm Breda-SAFAT, 1 in a tail barbette) but carried a hefty bombload of 2,000 kg and was a good bit faster than the SM.91 (382 mph / 615 kph to 363 mph / 584 kph).
However I think the best option was the Ro.58. More conventional than the SM.92, same forward armament of the SM.91, solid speed (378 mph / 605 kph) and a better climb rate - all while being significantly lighter and only using DB 601's instead of the other two's DB 605's. It was even tested against a Me 410 and was judged to be largely superior.
Drop the rear gunner and replace the 601's with 605's and we have a real tough customer potentially in the range of the other top tier twins.

 

[GrauGeist]

All airforces had deadwood. It's a fact that you can't replace your entire inventory at once. The USAAF still had P-26s based at Pearl Harbor on Dec 7 1941.

Take a look at how the P-26 responded to the Japanese invasion of the Philippines in December 1941.

"Deadwood" or not, the Peashooter made an accounting of itself.

 

[Reluctant Poster]

Take a look at how the P-26 responded to the Japanese invasion of the Philippines in December 1941.

"Deadwood" or not, the Peashooter made an accounting of itself.

True. Just like the Gladiator. Deadwood was the term used by the original poster. I would think obsolescent is more appropriate.

 

[tomo pauk]

True. Just like the Gladiator. Deadwood was the term used by the original poster. I would think obsolescent is more appropriate.

When the aircraft is now 9 years old (as it was the case with P-26 taking off in late 1941), then it is probably obsolete.
When a brand new design is of dubious usability (= Defiant), or it is a repurposed aircraft of another category pressed into the role that is unsuitable for it (= fighter Blenheims), or it is of outdated layout & performance when 1st flown (Gladiator) - this is probably a deadwood.

 

[Admiral Beez]

I would have liked to have seen the IMAM Ro.57 with a pair of DB inlines.

 

[Shortround6]

When the aircraft is now 9 years old (as it was the case with P-26 taking off in late 1941), then it is probably obsolete.
When a brand new design is of dubious usability (= Defiant), or it is a repurposed aircraft of another category pressed into the role that is unsuitable for it (= fighter Blenheims), or it is of outdated layout & performance when 1st flown (Gladiator) - this is probably a deadwood.

A lot is timing.
There was little good about the Defiant. A rather untested concept didn't work out very well is the best than can be said about it.
Both the Defiant and the Gladiator were ordered/pressed into service when there were nowhere near enough 'good' fighters (Hurricanes and Spitfire) available or in the delivery queue.
A squadron of Gladiators available in early 1938 beats a squadron of Hurricanes that won't show up until 1939 IF things get worse in 1938.
The Gladiator could be built with a lot less retooling, it was ALWAYS going to be a temporary solution until production of the Hurricane and Spitfire ramped up.
Similarly the Blenheim fighter started to equip 4 squadrons in Dec 1938 (a couple of months after Munich ) and 3 more squadrons got their first Blenheim IFs in Jan 1939.
Had the shooting started in the Spring of 1939 Blenheim fighters might have done OK (not great) against Bf 110s with Jumo 210 engines
Problem was that the Blenheim fighters really didn't go to war until the Fall of 1939 and then the Spring of 1940.
And the "oh so wonderful" new fighters that were supposed to replace them were nowhere to be found.
And no improvements (none, nada, zip, zilch) were made for quite some time.
even things like just trimming the plane up a little bit.

A little sheet metal on the nose, clip a little off the wing tips, paint and sand the thing a bit better, take off the turret for fighter duties?
God forbid the British fit a better engine between 1938 and the summer of 1940 Even a little bit better.
Some of the gun packs were used on MK IV Blenheims which were heavier and had more drag with rather predictable results. But in 1940/41 the Beaufighters were needed for nightfighting and the Blenheims were shuffled off to maritime patrol/strike.

Unfortunately the availability of the Gladiator and Blenheim meant that the better planes could be kept at home while the Gladiator and Blenheim went off to defend the empire.
The Italians and Japanese did not get the memo that they were supposed use old obsolete aircraft in 1940-41-42 just to keep thing fair.

 

[GreenKnight121]

In fact, it should have been written P-38 (I should read what I'm writing ), and not for the Fokker G I because it was not a single-seat fighter but a multi-seat destroyer concept (like the Bf 110).
F-82 yes .. it would fall into that category (regardless of the two pilots). Even though the F7F is better known in its two-seater NF variants, it was designed as a single-seater.
That's why I didn't include Mosquito either.

The P-82 (only became F-82 on 11 June 1948) was a optional 2-pilot aircraft. The 2nd aircrew could be a relief pilot for very long-range missions, a radar operator for a night fighter, a camera operator for a recon version, a passenger, a trainee pilot, or the seat could be left empty altogether and still be effective in fighter missions.

 

[tomo pauk]

There was little good about the Defiant. A rather untested concept didn't work out very well is the best than can be said about it.

Second sentence is applying of numbers of layers of sugarcoating.

Had the shooting started in the Spring of 1939 Blenheim fighters might have done OK (not great) against Bf 110s with Jumo 210 engines
Problem was that the Blenheim fighters really didn't go to war until the Fall of 1939 and then the Spring of 1940.
And the "oh so wonderful" new fighters that were supposed to replace them were nowhere to be found.
And no improvements (none, nada, zip, zilch) were made for quite some time.
even things like just trimming the plane up a little bit.

A little sheet metal on the nose, clip a little off the wing tips, paint and sand the thing a bit better, take off the turret for fighter duties?

I don't think that Hurricane was ever rated as "oh so wonderful", even in late 1939/early 1940. It was Whirlwind that missed all the action of 1940.

The picture above is that of the prof-of-concept recon Blenheim, without the turret or any gun, indeed with a lot of work to even out/fill the gaps etc. Top speed of under 280 mph (= meaning that the often quoted 285/286 mph top speed of the 'normal' Blenheim was bogus) with 87 oct fuel, a bit better with 100 oct.

The only actually better 'altitude engine' than the Mercury before 1940 was Merlin; draggy Pegasus will not cut it, and less hope it is placed on Peregrine the better.

Unfortunately the availability of the Gladiator and Blenheim meant that the better planes could be kept at home while the Gladiator and Blenheim went off to defend the empire.
The Italians and Japanese did not get the memo that they were supposed use old obsolete aircraft in 1940-41-42 just to keep thing fair.

Bingo.

 

[EwenS]

Similarly the Blenheim fighter started to equip 4 squadrons in Dec 1938 (a couple of months after Munich ) and 3 more squadrons got their first Blenheim IFs in Jan 1939.
Had the shooting started in the Spring of 1939 Blenheim fighters might have done OK (not great) against Bf 110s with Jumo 210 engines
Problem was that the Blenheim fighters really didn't go to war until the Fall of 1939 and then the Spring of 1940.
And the "oh so wonderful" new fighters that were supposed to replace them were nowhere to be found.
And no improvements (none, nada, zip, zilch) were made for quite some time.
even things like just trimming the plane up a little bit.

View attachment 797767
A little sheet metal on the nose, clip a little off the wing tips, paint and sand the thing a bit better, take off the turret for fighter duties?
God forbid the British fit a better engine between 1938 and the summer of 1940 Even a little bit better.
Some of the gun packs were used on MK IV Blenheims which were heavier and had more drag with rather predictable results. But in 1940/41 the Beaufighters were needed for nightfighting and the Blenheims were shuffled off to maritime patrol/strike.

Unfortunately the availability of the Gladiator and Blenheim meant that the better planes could be kept at home while the Gladiator and Blenheim went off to defend the empire.
The Italians and Japanese did not get the memo that they were supposed use old obsolete aircraft in 1940-41-42 just to keep thing fair.

Those initial 7 squadrons that began to re-equip with the Blenheim If in Dec 1938 / Jan 1939 had been designated as two seat fighter units and had mostly been flying the Hawker Demon. What would you have preferred to go to war in in late 1938 / early 1939?

23 (Dec 1938 in place of Demons)
25 (had managed to replace its Demons in Jun 1938 with Gladiator II until Jan 1939, beginning to receive its Blenheim If in Dec 1938 and back to being a multi seater unit)
29 (Dec 1938 in place of Demons)
64 (Dec 1938 in place of Demons)

The others were Royal Auxiliary Air Force units (i.e. reserve squadrons):-
600 (Jan 1939 in place of Demons)
601 (Jan 1939. Had been flying Demons until Nov 1938 and then received single seat Gauntlets until March 1939)
604 (Jan 1939 in place of Demons)

Most of those units switched to the night fighter role after the outbreak of WW2 eventually beginning to receive Beaufighters in late 1940.

Also, the Bristol Type 142M Blenheim I airframes were about to become surplus to requirements as the Bristol Type 149 Blenheim IV was about to enter service with the bomber units. The approximately 200 Blenheim If aircraft were conversions from existing aircraft. These were also used by a number of newly formed units in late 1939/40, often alongside other types, who were awaiting the delivery of more single engined Hurricanes, Spitfires & Defiants.

By late 1939 the Blenheim IVf was also beginning to appear.

The other role that the Blenheim fighter was also able to fulfill due to its longer range was that of convoy escort, initially in Fighter Command until March 1940 when responsibility passed to Coastal Command. The first of these many squadrons formed in Oct & Dec 1939. Again a case of no where near enough Beaufighters to go around until c1942.

 

[tomo pauk]

By late 1939 the Blenheim IVf was also beginning to appear.

The other role that the Blenheim fighter was also able to fulfill due to its longer range was that of convoy escort, initially in Fighter Command until March 1940 when responsibility passed to Coastal Command.

That long range will be available to the MkIV; the MkI was with lower fuel quantity - 287 gals vs. 465 for the MkIV.
That, as well as RAF (AM) willing to pay both for Beaufighter and Whirlwind, puts into sleep the notion that a 2-engined fighter would've been curtailed in their operations in 1940 because supposedly there was lack of fuel in the UK.

 

[wjkuleck]

The Ha 41/109 family of engines was criminally under-used by the Japanese. Stick these two on a fighter size of Ki-46 already by 1941 (1942 for the 109), and there is a performer that can also carry a heavy firepower. Don't over-do the internal fuel tankage - use the drop tanks to provide the required range, while making sure that internal tanks are of the self-sealing type.

Americans - someone (Douglas? Curtiss? NAA?) make a simple fighter with two V-1710s on the wings, with the idea that two 37mm cannons are carried in the nose, as per USAAC wishes and blessings. Switch these for 6-8 HMGs, perhaps even install the turbos later - might be easier to do on a classic twin, than to retrofit that on a 1-eng

Two Allisons? Done! FM-1 Airacuda!

 

[Shortround6]

That, as well as RAF (AM) willing to pay both for Beaufighter and Whirlwind, puts into sleep the notion that a 2-engined fighter would've been curtailed in their operations in 1940 because supposedly there was lack of fuel in the UK.

I am forever baffled by the idea that twin engine fighter (with a pair of under 1000hp engines)was too expensive or used too much fuel but a single engine fighter of 2000hp was just the thing that was wanted

 

[tomo pauk]

I am forever baffled by the idea that twin engine fighter (with a pair of under 1000hp engines)was too expensive or used too much fuel but a single engine fighter of 2000hp was just the thing that was wanted

Air Ministry was paying, in 1940, for a bomber-sized day fighter that had - in an expensive way - 2800 HP and carried 550 gals of fuel.
A fighter that has a 300-350 sq ft wing, two Merlins, 4 cannons (earlier 12 .303s), is lighter by a few thousand pounds, and carries 200-300 gals of fuel seems like a bargain. Both in purchase and in usage.
It even does not fear the German fighters.

 

[Admiral Beez]

There was little good about the Defiant. A rather untested concept didn't work out very well is the best than can be said about it.

I blame the apparently successful Bristol F.2 Fighter for encouraging the idea of the twin seat, single engined fighter with strong rear armament. Though the Defiant needs a forward firing armament to complete the spec.

"While its fixed forward-firing machine gun could be used as the primary weapon, the observer could use his flexible, rear-mounted gun to provide protection from attacks from the rear. Flown in this manner, the Bristol Fighter achieved a 'remarkable' level of success and proved to be a formidable opponent for German fighters."

 

[Shortround6]

I blame the apparently successful Bristol F.2 Fighter for encouraging the idea of the twin seat, single engined fighter with strong rear armament. Though the Defiant needs a forward firing armament to complete the spec.

I blame the apparent lack of mathematical ability of the RAF planners.
Bristol F.2 Fighter.
two men + 2-3 guns.
275hp engine

Camel/SE.5A fighter
1 man + 2 guns
130-200hp engines.

Defiant
2 men +4 guns +heavy turret.
Merlin III engine.

Hurricane/Spitfire
1 man + 8 guns no turret
Merlin III engine.

F.2 Fighter with a 150-200hp engine would have been a dead duck.
Defiant with more than a token (more than 1-2 guns) forward armament would have been even more of a dead duck than the standard Defiant.

Unless....................................They could have stuffed a 1500-1600hp engine in the Defiant and added about 30-40% more wing area to keep the wing loading down.

Math ability needed is more than counting to past 12 without taking shoes and socks off.

 

[Shortround6]

Air Ministry was paying, in 1940, for a bomber-sized day fighter that had - in an expensive way - 2800 HP and carried 550 gals of fuel.
A fighter that has a 300-350 sq ft wing, two Merlins, 4 cannons (earlier 12 .303s), is lighter by a few thousand pounds, and carries 200-300 gals of fuel seems like a bargain. Both in purchase and in usage.
It even does not fear the German fighters.

Agreed.
But the Air Ministry thought the Whirlwind was too expensive while the Big Hawker fighters ( Typhoon/Tornado, either engine) would be just the thing in 1941.
Sometimes their stated reasons did not line up with reality which leads to some of the later questioning/doubts.

 

[don4331]

I blame the apparent lack of mathematical ability of the RAF planners.

They did do the math - minimum distance from Germany to UK is ~250 miles one way, more if you avoid Dutch airspace; even Bf.110 isn't able to make it to much of England on internal fuel. Defiant was reasonably successful versus bombers when single engine fighters weren't around. It also did OK against Bf.109s until they realized it could shoot back and went to head on attacks.

Yes, Defiant would have been better if it was designed around Sabre/Vulture allowing for forward firing guns and extra wing area to go with extra weight. But those engines weren't available at the time/putting them in single seat fighter is always going to be better.

 

[Zmauky]

Yes, Defiant would have been better if it was designed around Sabre/Vulture allowing for forward firing guns and extra wing area to go with extra weight. But those engines weren't available at the time/putting them in single seat fighter is always going to be better.

BP project Sabre / Centaurs

 

[don4331]

But the Air Ministry thought the Whirlwind was too expensive while the Big Hawker fighters ( Typhoon/Tornado, either engine) would be just the thing in 1941.
Sometimes their stated reasons did not line up with reality which leads to some of the later questioning/doubts.

Don't economies of scale factor into this:

Hawker has orders for 1k for F.9/37 fighter; while Westland only has order for 400 of the F.37/35 fighter. And there's probably some advantages (political?) in the Hawker conglomerate versus Westland.​

RR was saying that each Peregrine was costing as much as 2 Merlins - largely because the development/tooling cost of the Peregrine was only being spread over ~250 engines, while the same cost was being spread over >2,500 Merlins (at the time). Napier, in theory, is getting to spread its development cost over >500 planes (several other designs were looking at Sabre).​

There is also pilot training:

For single engine, you have basic training, advanced training and then type training
For twins: you have basic training, advanced training, basic twin, advanced twin and finally type training. And to muddy the water, often twin includes night and instrument training.​

The twin trainers are expensive planes (they burn 2X the fuel) and the pilots need to be proficient in flying* twin with only one engine running.​

*While really landing with only one turning.