Fulmar in 1941/42/43: feasible and/or plausible upgrades?

[FLYBOYJ]

what is seldom discussed is the 2nd crewman, often called the radio operator, as part of his equipment had a radio receiver that could find a signal transmitted from the carrier and home in on it, guiding the plane back to the carrier. He was NOT a 'navigator'. The British homing system was 'supposed' to be not interceptable by the enemy and give away the carriers location like a normal "homing system".

AKA an ADF...

 

[RCAFson]

Another way of looking at potential performance increases is to look at the 13 mph increase in Fulmar II performance, from SL to 6800ft by increasing the boost from 9.75lb/3000rpm to 12lb/3000rpm. At 12000ft the FulmarII/Merlin 30 was down to about 7-8lb of boost at 3000rpm and was putting out maybe 1100hp and it could still make 260mph. With a Merlin 45/16lb boost we are adding another 400hp at 12000ft and this must give a substantially higher performance.

 

[Shortround6]

AKA an ADF...

Yes but what you could do with 1937-40 technology is not what you could do with 1943-45 technology

I think the description of the British system has been post here at some point (or a link) but apparently it took a dedicated operator in the early form.

 

[RCAFson]

This is from the Historical Office of the Aeronautica Militare (in Italian, sorry).

It wouldn't be the first time that an official history was wrong, but you'll have to take up the accuracy of Mediterranean Air War with authors, Shores, Massimello and Guest.

 

[FLYBOYJ]

Another way of looking at potential performance increases is to look at the 13 mph increase in Fulmar II performance, from SL to 6800ft by increasing the boost from 9.75lb/3000rpm to 12lb/3000rpm. At 12000ft the FulmarII/Merlin 30 was down to about 7-8lb of boost at 3000rpm and was putting out maybe 1100hp and it could still make 260mph. With a Merlin 45/16lb boost we are adding another 400hp at 12000ft and this must give a substantially higher performance.

And what's being done to the structure to support that extra 400hp? When you bolt on hp you're going to pay somewhere else. You're still talking a fighter that could barely make 300 mph, had for the most part an unnecessary extra crewman and for the most part was obsolete by 1942. I think the Marlet was the better choice until Seafires became available. The Fulmar had its moments, but it was cast into the sunset at the right time.

 

[Shortround6]

Another way of looking at potential performance increases is to look at the 13 mph increase in Fulmar II performance, from SL to 6800ft by increasing the boost from 9.75lb/3000rpm to 12lb/3000rpm. At 12000ft the FulmarII/Merlin 30 was down to about 7-8lb of boost at 3000rpm and was putting out maybe 1100hp and it could still make 260mph. With a Merlin 45/16lb boost we are adding another 400hp at 12000ft and this must give a substantially higher performance.

Yep, it gets you to about 288-290mph.

The power needed goes up according to the cube law. going from 1100 to 1500hp gets you about a 10.8-11% increase in speed. Starting with a 260mph airplane gets you 28-30mph( assuming NO INCREASE IN DRAG).

If you start with a 350mph plane the same 10.8-11% increase in speed gets you 38-39mph increase in speed.

 

[Greyman]

These numbers are wrong for the Fulmar. Numerous sources (including the pilot's notes) state 155 Gals of internal fuel and a 60 gal DT. Defiant I was later modded to carry 162 gals, but this was not on production Defiant Is.

Good catch. Typo fixed.

Original Defiant I performance and handling tests give 104 gallons (A&AEE, Jul '40 - data sheet date is Aug '41)

Hello, Greyman, would it be possible to take a more compete look at the data sheets?

Not especially handy at the moment, was there something specific you needed or just needed to take a look at the overall data?

 

[RCAFson]

And what's being done to the structure to support that extra 400hp? When you bolt on hp you're going to pay somewhere else. You're still talking a fighter that could barely make 300 mph, had for the most part an unnecessary extra crewman and for the most part was obsolete by 1942. I think the Marlet was the better choice until Seafires became available. The Fulmar had its moments, but it was cast into the sunset at the right time.

The Spitfire V had no major problems ( apparently there was some local strengthening of the engine mounts) in accepting the power increases from the Merlin 45 and I doubt that the Fulmar would either. I have posted the performance graphs for the Martlet IV and it would probably trail a Fulmar/M45 in every category:

http://www.ww2aircraft.net/forum/at...-f4f-4-under-10-000-ft-f4f4b_fulmar_speed.jpg
http://www.ww2aircraft.net/forum/at...us-f4f-4-under-10-000-ft-f4f_fulmar_climb.jpg

and it's margin of performance over the Fulmar II wasn't all that much under 12000ft or so.

 

[FLYBOYJ]

The power needed goes up according to the cube law. going from 1100 to 1500hp gets you about a 10.8-11% increase in speed. Starting with a 260mph airplane gets you 28-30mph( assuming NO INCREASE IN DRAG).

And weight AND assuming the extra power (torque) can be coordinated with a propeller...

 

[FLYBOYJ]

The Spitfire V had no major problems ( apparently there was some local strengthening of the engine mounts) in accepting the power increases from the Merlin 45 and I doubt that the Fulmar would either. I have posted the performance graphs for the Martlet IV and it would probably trail a Fulmar/M45 in every category:

http://www.ww2aircraft.net/forum/at...-f4f-4-under-10-000-ft-f4f4b_fulmar_speed.jpg
http://www.ww2aircraft.net/forum/at...us-f4f-4-under-10-000-ft-f4f_fulmar_climb.jpg

and it's margin of performance over the Fulmar II wasn't all that much under 12000ft or so.

Read Shortround's prior post. This "assumption" is speaking in terms of a perfect world matching airframe/ engine/ propeller with minimal changes in weight and drag.

 

[Dogwalker]

It wouldn't be the first time that an official history was wrong, but you'll have...

Curiously the Aeronautica Militare report is consistent whit that of Andrew Thomas' "Royal Navy Aces of World War 2" (two SM.79 shot down, one during the attack on the Ark Royal, one alone). I don't think the survival of Marini could be seriously doubted. Given that, I do not think it's up to me to take further actions.

 

[tomo pauk]

...
Not especially handy at the moment, was there something specific you needed or just needed to take a look at the overall data?

I'd like to take a look at technical data re. ww2 types, but anytime you can post the data sheets is good time

 

[fastmongrel]

Yes but what you could do with 1937-40 technology is not what you could do with 1943-45 technology

I think the description of the British system has been post here at some point (or a link) but apparently it took a dedicated operator in the early form.

I posted a link about the Homing Beacon
http://www.ww2aircraft.net/forum/aviation/rn-carrier-homing-beacon-35429.html

 

[wuzak]

And what's being done to the structure to support that extra 400hp? When you bolt on hp you're going to pay somewhere else. You're still talking a fighter that could barely make 300 mph, had for the most part an unnecessary extra crewman and for the most part was obsolete by 1942. I think the Marlet was the better choice until Seafires became available. The Fulmar had its moments, but it was cast into the sunset at the right time.

Right. How nice it would have been in Seafire development had started when the FAA requested it - ie in 1938 or so.

 

[wuzak]

With all these Merlin 45s going to Fulmars and Hurricanes I guess the RAF gets the Spitfire III (Merlin XX) instead of the "interim" Spitfire V? If that's the case I don't think the RAF would complain.

The Spitfire III would also make a good base for a Seafire.

 

[fastmongrel]

Right. How nice it would have been in Seafire development had started when the FAA requested it - ie in 1938 or so.

Does anyone know how this original 1938 Seafire would have looked. Would it have been a similar job to the Seafire MkIII.

 

[wuzak]

The matter of a seaborne Spitfire was raised again in November 1939 when the Air Ministry allowed a Commander Ermen to fly a Spitfire I. After his first flight in R6718 Ermen learned that Joseph Smith, Chief Designer at Supermarine had been instructed to fit an "A-frame" arrestor hook on a Spitfire and that this had flown on 16 October; a drawing of this aircraft had been shown to the FAA on 27 October. After further discussions Supermarine submitted a drawing of a Spitfire with folding wings and an arrestor hook. In this case the wings were designed with a fold just outboard of the undercarriage bays; the outer wings would swivel and fold backwards, parallel with the fuselage. On 29 February 1940 the Admiralty asked the Air Ministry to sanction the production of 50 folding wing Spitfires, with the first deliveries to start in July.

Supermarine Seafire - Wikipedia, the free encyclopedia

So Supermarine's initial navalisation proposal was different to what the Seafire III would turn out to be.

 

[wuzak]

The idea for Fairey to develop the Seafire was rejected in 1938.

The Supermarine proposal of late 1939 was still 2 years ahead of the eventual development of the Seafire.

 

[RCAFson]

Curiously the Aeronautica Militare report is consistent whit that of Andrew Thomas' "Royal Navy Aces of World War 2" (two SM.79 shot down, one during the attack on the Ark Royal, one alone). I don't think the survival of Marini could be seriously doubted. Given that, I do not think it's up to me to take further actions.

Upon re-reading Shores, I noticed that Marini was not killed, but was rescued along with his crew: "...Marini had to crash land in the sea near Galite Island..." The crews of the other 3 SM-79s were all lost and I failed to note that Marini and his crew are listed as being rescued. The initial combat between the Fulmars and the first wave of SM-79s involved 5 Sm-79s, 15 CR-42s and 8 Fulmars, with the Fulmars being bounced as they intercepted the SM-79s.

 

[RCAFson]

With all these Merlin 45s going to Fulmars and Hurricanes I guess the RAF gets the Spitfire III (Merlin XX) instead of the "interim" Spitfire V? If that's the case I don't think the RAF would complain.

The Spitfire III would also make a good base for a Seafire.

Fulmar production peaked at 25/month.