Can we make a slightly smaller Fulmar as an improved carrier fighter? (1 Viewer)

[nuuumannn]

Ewen is right, modifiying the Fulmar design is going to require a clean sheet design, which, as Shortround said - and I agree with him, may or may not produce the requirements for a naval fighter that the FAA needed. What it needed, what it wanted and what it actually received were not the same thing. The Fulmar was at best a compromise, an interim solution borne of the frustrating period when the Air Ministry specified that FAA aircraft do more than one, often disparate job, with middling results that ended up with the FAA receiving aircraft that were not really what was needed. The Fulmar was a stopgap right from the start, it was designed to get put into service as quickly as possible, so to circumvent the whole idea of conceiving a whole new naval fighter from scratch, which is what we are doing, Lobelle decided on modelling the aircraft of an existing design. The time factor is the essential thing here, not necessarily its capabilities. Let's not forget that once the Admiralty regained control of the FAA in 1939 it made a raft of changes to existing specifications, including for the Fulmar replacement. The takeaway was that the naval fighter the Admiralty wanted turned out to be the Firebrand, whose specification was for a naval fighter interceptor (not a late, overly heavy torpedo fighter as it became). To fulfil the time aspects of the Fulmar's specification, the use of an existing design would have to be considered, therefore there is no harm in using either the Defiant or Hurricane as a basis, but is it what the FAA needs?

It isn't, The FAA needed a modern naval fighter-interceptor that would, like the Spitfire, have good performance to match existing and future enemy fighter performance, and service longevity and yet meet all the criteria for carrier operations. Modifying the Hurricane or the Defiant would not do that because the designs do not have enough shelf life and were not capable of the performance of advanced fighters entering service in mid to late 1940. The Admiralty wanted a naval Spitfire and in 1939 investigated such an option with Joe Smith of Supermarine's help. This was going to be very different to the Seafires that the navy eventually received in 1942 as it was going to be purpose-designed from the ground up as a naval fighter. This was really the only option if the navy wanted an advanced, thoroughly modern fighter by 1940, when the Fulmar starts entering service. Building a modified Fulmar is going to give the FAA another fighter it is going to have to supplement in time with US-built aircraft and which would still lead the navy to continue to pursue the Spitfire option.

 

[Admiral Beez]

Ewen is right, modifiying the Fulmar design is going to require a clean sheet design,

There's always the Gloster F5/34. Sluggish, but faster than a Fulmar and doesn't press Rolls Royce.

 

[Wild_Bill_Kelso]

Easy, just put Soviet engines in the planes
Merlins didn't room/space for a hub mounted gun. you have to used the right spacing on the reduction gears in addition to not filling up the space between the cylinder banks with stuff like intake manifolds and you need to leave space at the back for the supercharger and any other bits and bobs.
View attachment 742843

View attachment 742845
Early speed testing may have been done without ejector exhausts, not the ones fitted were that great. May have used different prop and other changes.

As a reality check try the P-40F with the same engine. Boscombe Down got 354mph out of one of them, kitted out for service (drop tank fittings and slots for bomb racks,etc) and while a lot heavier it used a a wing about 2 ft shorter, a bit less area, a lot thinner (15% at the root).
The P-40F was only about 25mph faster than a 12 gun Hurricane.

Yeah but one test at Boscombe Downe isn't the last word, (it was done at an overload weight at 8,910 lbs, and the speed was calculated according to some formula) and that isn't the actual reality for the P-40F - it made 370 mph at 20,000 ft as I've pointed out several times before....

 

[Wild_Bill_Kelso]

Ewen is right, modifiying the Fulmar design is going to require a clean sheet design, which, as Shortround said - and I agree with him, may or may not produce the requirements for a naval fighter that the FAA needed. What it needed, what it wanted and what it actually received were not the same thing. The Fulmar was at best a compromise, an interim solution borne of the frustrating period when the Air Ministry specified that FAA aircraft do more than one, often disparate job, with middling results that ended up with the FAA receiving aircraft that were not really what was needed. The Fulmar was a stopgap right from the start, it was designed to get put into service as quickly as possible, so to circumvent the whole idea of conceiving a whole new naval fighter from scratch, which is what we are doing, Lobelle decided on modelling the aircraft of an existing design. The time factor is the essential thing here, not necessarily its capabilities. Let's not forget that once the Admiralty regained control of the FAA in 1939 it made a raft of changes to existing specifications, including for the Fulmar replacement. The takeaway was that the naval fighter the Admiralty wanted turned out to be the Firebrand, whose specification was for a naval fighter interceptor (not a late, overly heavy torpedo fighter as it became). To fulfil the time aspects of the Fulmar's specification, the use of an existing design would have to be considered, therefore there is no harm in using either the Defiant or Hurricane as a basis, but is it what the FAA needs?

It isn't, The FAA needed a modern naval fighter-interceptor that would, like the Spitfire, have good performance to match existing and future enemy fighter performance, and service longevity and yet meet all the criteria for carrier operations. Modifying the Hurricane or the Defiant would not do that because the designs do not have enough shelf life and were not capable of the performance of advanced fighters entering service in mid to late 1940. The Admiralty wanted a naval Spitfire and in 1938 investigated such an option with Joe Smith of Supermarine's help. This was going to be very different to the Seafires that the navy eventually received in 1942 as it was going to be purpose-designed from the ground up as a naval fighter. This was really the only option if the navy wanted an advanced, thoroughly modern fighter by 1940, when the Fulmar starts entering service. Building a modified Fulmar is going to give the FAA another fighter it is going to have to supplement in time with US-built aircraft and which would still lead the navy to continue to pursue the Spitfire option.

They could build an 'as-is' Fulmar, and then also build a single seat fighter with decent range and performance, without needing a Griffon or some other bigger engine, which could have gotten into service a year or more before the Firefly did... and be better than the Firefly was in the fighter role.

 

[Wild_Bill_Kelso]

There's always the Gloster F5/34. Sluggish, but faster than a Fulmar and doesn't press Rolls Royce.

I like the F.5/34 a lot, and I don't think it was sluggish considering it had an 840 hp engine. If you could fit an 1,100 hp engine you might have something quite nice. Radial engines have some advantages for naval aircraft as well.

I don't know how much fuel it carried though. But it's not a tiny aircraft, there is room in it for fuel.

 

[Shortround6]

even if we don't quite follow the path the RAF and RN took if we want to replace the Fulmar we need to have good understanding of what it did and what it did not do.
this helps.

Fairey Fulmar - Flying to the Limit: Testing World War II Single-engined Fighter Aircraft

Fairey Fulmar - British Fighters - Flying to the Limit: Testing World War II Single-engined Fighter Aircraft - by Peter Caygill

erenow.org

The Fulmar used a 342 sq ft wing, It could weigh up to 10,200lbs in MK II version. Normal loaded weight was about 500lbs lower. This gives a wing loading of about 28.4lbs at normal gross weight. For a 250sq ft wing this means gross weight of 7090lbs IF the stalling speed is the same (different wings will stall a bit different)
Just for context, the Martlet I was 6811 lb max and the Martlet II was 7255lbs. There is a little room to play with.

From the website listed above. Stall speed with flaps and gear down 61mph IAS and 4 mph higher with gun muzzles unsealed. weight is not given.
There are several paragraphs about landing and low speed handling.

They also tested it using 100 octane fuel, due the low altitude engine any performance difference disappeared by 10,000ft.

the range has been given by others and that was with the 155 imp gal of internal fuel, The Fulmar II with the 60 gal ventral tank was good for 1100miles at 140 IAS at 5,000ft.
Ammo for the Fulmar seems to go from 500rpg to 800rpg (?)

The problem with "simple" substitutes is that they may not be able to do the Fulmars job/s.
yes we can plane that goes faster and climbs better but...........what radius or endurance are we willing to accept?
How much trigger time on the guns?

How much of an increase in landing speed?

how many fewer "fighter" planes on the carrier because we need more long range recon planes (stupid combination requirement but there you are) or you get fewer "strike" aircraft.

 

[Admiral Beez]

How much of an increase in landing speed?

Few British-made single engine monoplane carrier fighters landed with as little drama as the Fulmar.


View: https://m.youtube.com/watch?v=26u-mZElfkw&pp=ygUgRmFpcmV5IGZ1bG1hciBsYW5kaW5nIG9uIGNhcnJpZXI%3D

We don't want to lose that advantage by significantly increasing landing and stall speed.

 

[Shortround6]

I like the F.5/34 a lot, and I don't think it was sluggish considering it had an 840 hp engine. If you could fit an 1,100 hp engine you might have something quite nice. Radial engines have some advantages for naval aircraft as well.

I don't know how much fuel it carried though. But it's not a tiny aircraft, there is room in it for fuel.

Wiki says that the empty weight is 4,190lbs, all up is 5400lb, this is the same as "The British Fighter since 1912"

payload is 1210lbs.'

Payload for Hurricane L-2026, report dated June 12th 1940 was 1650lbs, with fixed military load, service load, fuel and oil.
What is the F.5/34 not carrying?
600lbs of fuel
..68lbs of oil
200lbs of pilot.

You have 442lbs left for guns, ammo, radio, landing flares, etc,

Heck, a Gloster Gladiator carried a 1370lb payload.

Something smells and it is not the oil on the exhaust pipes.

 

[Wild_Bill_Kelso]

even if we don't quite follow the path the RAF and RN took if we want to replace the Fulmar we need to have good understanding of what it did and what it did not do.
this helps.

Fairey Fulmar - Flying to the Limit: Testing World War II Single-engined Fighter Aircraft

Fairey Fulmar - British Fighters - Flying to the Limit: Testing World War II Single-engined Fighter Aircraft - by Peter Caygill

erenow.org

The Fulmar used a 342 sq ft wing, It could weigh up to 10,200lbs in MK II version. Normal loaded weight was about 500lbs lower. This gives a wing loading of about 28.4lbs at normal gross weight. For a 250sq ft wing this means gross weight of 7090lbs IF the stalling speed is the same (different wings will stall a bit different)
Just for context, the Martlet I was 6811 lb max and the Martlet II was 7255lbs. There is a little room to play with.

From the website listed above. Stall speed with flaps and gear down 61mph IAS and 4 mph higher with gun muzzles unsealed. weight is not given.
There are several paragraphs about landing and low speed handling.

They also tested it using 100 octane fuel, due the low altitude engine any performance difference disappeared by 10,000ft.

the range has been given by others and that was with the 155 imp gal of internal fuel, The Fulmar II with the 60 gal ventral tank was good for 1100miles at 140 IAS at 5,000ft.
Ammo for the Fulmar seems to go from 500rpg to 800rpg (?)

The problem with "simple" substitutes is that they may not be able to do the Fulmars job/s.

Well, i think the biggest problem was at the spec level, i.e. that the Fulmar had too many jobs and it was only good at some of them. As an armed scout / pathfinder and even probably as a light bomber and ASW plane, it's fine. As a fighter not so much. That's why I'd say keep the Fulmar, and make a "Lite Fulmar" or another fighter with similar range but better performance. You don't need 800 rounds per gun either. Or 8 guns necessarily.

yes we can plane that goes faster and climbs better but...........what radius or endurance are we willing to accept?

I think that part can be done. All I really need is about as much endurance as a Wildcat though more would be better of course.

How much trigger time on the guns?

Doesn't need 800 rounds that's for sure. Especially considering a Fulmar couldn't catch some of the bombers it was supposed to deal with.

How much of an increase in landing speed?

Just keep the wing loading reasonable and deploy flaps

how many fewer "fighter" planes on the carrier because we need more long range recon planes (stupid combination requirement but there you are) or you get fewer "strike" aircraft.

Yeah I think one or two recon planes is fine, plus some fighters and dive bombers or torpedo bombers. We'll fix those next...

 

[nuuumannn]

They could build an 'as-is' Fulmar, and then also build a single seat fighter with decent range and performance, without needing a Griffon or some other bigger engine, which could have gotten into service a year or more before the Firefly did... and be better than the Firefly was in the fighter role.

That's what the Firebrand was meant to be, the naval fighter-interceptor, as the Fulmar was only ever meant to be an interim. The Firefly specification was re-issued in parallel to the single-seat fighter-interceptor specification in 1940. This took place once the Admiralty regained control of the FAA because the previous specifications issued to replace the Fulmar were flawed and the navy ditched them in favor of something more akin to what it needed.

The thing is, when do you want to start doing this stuff? At the time the Fulmar specification was released in 1938? As I said, the Admiralty got Supermarine to investigate building a naval Spitfire a year later. You still would need to start sooner rather than later, so you need to decide, do you want to invest in the next-generation advanced fighter interceptor at the time the interim specification is released that will fulfill your needs and not require replacement in the next couple of years? Or do you want to waste time building an interim slimmer, lighter Fulmar that will become obsolescent within a few years, knowing you should have invested the effort to do something better?

I know what I'd do. Invest in a better, longer-lasting design that anticipates future fighters. Harder to do, but a Spitfire derivative designed by Smith would have been more suitable than a design based on an aeroplane that will become obsolescent within a few years. By the end of 1940 those first-generation all-metal fighters, the Spitfire I, the Hurricane I, the Fulmar I, the Defiant I and early model Bf 109s up to and including the E-models were verging on becoming, if not already obsolete. The Spitfire and Bf 109 survived through constant reinvention. The Fulmar hung in there through the lack of a feasible alternative. If there had been one, then there would not have been those attempts to produce a mediocre interim naval fighter, like the Miles M.20, or the Sea Hurricane, or the first generation Seafires...

 

[Admiral Beez]

Wiki says that the empty weight is 4,190lbs, all up is 5400lb, this is the same as "The British Fighter since 1912"

payload is 1210lbs.'

Payload for Hurricane L-2026, report dated June 12th 1940 was 1650lbs, with fixed military load, service load, fuel and oil.
What is the F.5/34 not carrying?
600lbs of fuel
..68lbs of oil
200lbs of pilot.

You have 442lbs left for guns, ammo, radio, landing flares, etc,

Heck, a Gloster Gladiator carried a 1370lb payload.

Something smells and it is not the oil on the exhaust pipes.

Given that it didn't get past an under-engined prototype, I think there's a lot about the capabilities and specifications of the hypothetical production F5/34 that we just don't know.

 

[Shortround6]

Doesn't need 800 rounds that's for sure. Especially considering a Fulmar couldn't catch some of the bombers it was supposed to deal with.

Maybe 800 rounds is too much. But 600 rounds of .303 gives about the same trigger time as 400 rounds of .50 cal. What did the four gun Wildcats have for ammo
The Fulmars often could stay in the air for over 4 hours and make multiple intercepts before having to land to refuel/rearm. Granted a faster plane might have been able to do more intercepts in the same time frame. A plane on the deck refueling/rearming isn't intercepting anybody.

BTW .303 ammo is around 6.66lbs per hundred (for easy figuring) while .50 cal ammo is 30lbs per hundred.

Just keep the wing loading reasonable and deploy flaps

Fulmar had flaps, just not as large/advanced as later planes.

The other thing with carrier landings is that the arresting gear has to be up to the job. Usually rated as how much weight impacting at what speed. There were periodic up grades to handle heavier and faster aircraft as the war went on. Just because they could land an Avenger in 1943 does not mean they could land somewhat lighter planes at similar speeds in 1940/41

Yeah I think one or two recon planes is fine, plus some fighters and dive bombers or torpedo bombers. We'll fix those next.

You need a lot more than 2 planes of given type unless you can guarantee 100% reliably/availably. You also want several recon planes in the air at once, 140 mph plane trying to sweep a zone 200 miles wide (100 miles each side of the ship/taskforce path?) And if you want near 100% coverage the relieve planes have to fly out to patrol sectors before the patrolling planes leave the patrol area for the trip back to the carrier.

 

[nuuumannn]

that the Fulmar had too many jobs and it was only good at some of them. As an armed scout / pathfinder and even probably as a light bomber and ASW plane, it's fine. As a fighter not so much.

Correct. A good reason not to continue with the specification in 1938. Tell Fairey the Fulmar is not being accepted and if he wants work then he'll have to build Sea Spitfires to Smith's design under licence (obviously this can only happen with a lot of things being different in real life, like the Admiralty taking charge of aircraft development from the Air Ministry and that body not saying Spitfire development is for the RAF only. It is a what-if after all). And if Fairey doesn't, then Blackburn will do it, and tell Blackburn forthwith it will ONLY build other firms' designs under licence. There will be NO naval fighter specification issued to it (again, in light of fore-knowledge that the Firebrand is going to be a disaster and not fulfil the future specification for a naval fighter interceptor).

 

[Shortround6]

Given that it didn't get past an under-engined prototype, I think there's a lot about the capabilities and specifications of the hypothetical production F5/34 that we just don't know.

True, but we have two problems looking through retrospectroscope.
There was no good way forward, at least with a British engine, and the US engine may have been doubtful.
The plane was not combat capable in the sense of even spring/summer of 1940.

The bright ray of sleeve valve performance shinning down in 1937/39 turned in a dim glimmer in late 1939/early 1940.
Whatever they were promising in 1937/38 when they were fitting 840hp/14,000ft Mercury's turned into 880hp/15,500ft by the end of 1939 Perseus engines. You also had an engine that weighed 10% more.
Leaves the Pegasus which is already over subscribed.
And the Taurus...............enough said.

US has the R-1820, maybe you can get more of the engines used the Buffalo
R-1830 weighs over 400lbs more than the Mercury.

how much protection?

 

[nuuumannn]

The bright ray of sleeve valve performance shinning down in 1937/39 turned in a dim glimmer in late 1939/early 1940.

One great alternative timeline what-if is that Bristol does not pursue troublesome and complicated sleeve valves and concentrate its knowledge and experience on producing a 2,000 hp four-poppet valve-headed twin-row radial for British aircraft that's ready for service for 1940. A missed opportunity as the firm had the know-how and experience.

 

[SaparotRob]

US has the R-1820, maybe you can get more of the engines used the Buffalo

Just get a better vendor than Brewster used.
And I do mean used.

 

[RCAFson]

Correct. A good reason not to continue with the specification in 1938. Tell Fairey the Fulmar is not being accepted and if he wants work then he'll have to build Sea Spitfires to Smith's design under licence (obviously this can only happen with a lot of things being different in real life, like the Admiralty taking charge of aircraft development from the Air Ministry and that body not saying Spitfire development is for the RAF only. It is a what-if after all). And if Fairey doesn't, then Blackburn will do it, and tell Blackburn forthwith it will ONLY build other firms' designs under licence. There will be NO naval fighter specification issued to it (again, in light of fore-knowledge that the Firebrand is going to be a disaster and not fulfil the future specification for a naval fighter interceptor).

The proposal for a folding wing Seafire was made in ~mid 1939, (Morgan and Shacklady p506, and Buttler p169), when the Fulmar was only months away from production vs two years for the proposed Seafire. The best way to boost Fulmar speed and climb performance would be giving it a Merlin X/XX.

 

[Wild_Bill_Kelso]

That's what the Firebrand was meant to be, the naval fighter-interceptor, as the Fulmar was only ever meant to be an interim. The Firefly specification was re-issued in parallel to the single-seat fighter-interceptor specification in 1940. This took place once the Admiralty regained control of the FAA because the previous specifications issued to replace the Fulmar were flawed and the navy ditched them in favor of something more akin to what it needed.

The thing is, when do you want to start doing this stuff? At the time the Fulmar specification was released in 1938? As I said, the Admiralty got Supermarine to investigate building a naval Spitfire that year. You still would need to start sooner rather than later, so you need to decide, do you want to invest in the next-generation advanced fighter interceptor at the time the interim specification is released that will fulfill your needs and not require replacement in the next couple of years? Or do you want to waste time building an interim slimmer, lighter Fulmar that will become obsolescent within a few years, knowing you should have invested the effort to do something better?

I know what I'd do. Invest in a better, longer-lasting design that anticipates future fighters. Harder to do, but a Spitfire derivative designed by Smith would have been more suitable than a design based on an aeroplane that will become obsolescent within a few years. By the end of 1940 those first-generation all-metal fighters, the Spitfire I, the Hurricane I, the Fulmar I, the Defiant I and early model Bf 109s up to and including the E-models were verging on becoming, if not already obsolete. The Spitfire and Bf 109 survived through constant reinvention. The Fulmar hung in there through the lack of a feasible alternative. If there had been one, then there would not have been those attempts to produce a mediocre interim naval fighter, like the Miles M.20, or the Sea Hurricane, or the first generation Seafires...

I really dont' want an interceptor, and despite claims to the contrary, the Spitfire made a terrible naval fighter. A naval fighter shouldn't be an interceptor, it needs to have endurance to fly long CAP missions, and it needs to have the range to escort bombers to their strikes.

The Fulmar was doomed by the spec, there is no way to make a two seat naval fighter that will be viable, which is why it was less than mediocre - it couldn't catch a Ju 88 to save it's life. It would be hard pressed to catch a lot of Japanese bombers too.

 

[Wild_Bill_Kelso]

Maybe 800 rounds is too much. But 600 rounds of .303 gives about the same trigger time as 400 rounds of .50 cal. What did the four gun Wildcats have for ammo
The Fulmars often could stay in the air for over 4 hours and make multiple intercepts before having to land to refuel/rearm. Granted a faster plane might have been able to do more intercepts in the same time frame. A plane on the deck refueling/rearming isn't intercepting anybody.

BTW .303 ammo is around 6.66lbs per hundred (for easy figuring) while .50 cal ammo is 30lbs per hundred.

Fulmar had flaps, just not as large/advanced as later planes.
View attachment 742905
The other thing with carrier landings is that the arresting gear has to be up to the job. Usually rated as how much weight impacting at what speed. There were periodic up grades to handle heavier and faster aircraft as the war went on. Just because they could land an Avenger in 1943 does not mean they could land somewhat lighter planes at similar speeds in 1940/41

You need a lot more than 2 planes of given type unless you can guarantee 100% reliably/availably. You also want several recon planes in the air at once, 140 mph plane trying to sweep a zone 200 miles wide (100 miles each side of the ship/taskforce path?) And if you want near 100% coverage the relieve planes have to fly out to patrol sectors before the patrolling planes leave the patrol area for the trip back to the carrier.

If you have long range fighters and bombers, you aren't only relying on the 'special' recon / pathfinder planes obviously because they can fly recon too. The Japanese had their C6, the US navy in the 60s and 70s had the Vigilante and a variety of recon types. It's not like I invented the concept.

 

[Wild_Bill_Kelso]

Correct. A good reason not to continue with the specification in 1938. Tell Fairey the Fulmar is not being accepted and if he wants work then he'll have to build Sea Spitfires to Smith's design under licence (obviously this can only happen with a lot of things being different in real life, like the Admiralty taking charge of aircraft development from the Air Ministry and that body not saying Spitfire development is for the RAF only. It is a what-if after all). And if Fairey doesn't, then Blackburn will do it, and tell Blackburn forthwith it will ONLY build other firms' designs under licence. There will be NO naval fighter specification issued to it (again, in light of fore-knowledge that the Firebrand is going to be a disaster and not fulfil the future specification for a naval fighter interceptor).

Sea Spitfire is not going to be a successful naval fighter (Seafire was mediocre at best)