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

[RCAFson]

I see the S.P.O.O.S.E.S.* is back in full session.

Please note that what ever boost level you can get out of a Merlin 45 or XX series engine is for about 5 minutes only. The 30 minute climb ratings and the max cruise ratings didn't change.

Merlin 30 was good for 1260hp at 8750ft. the only way you are going to get a Fulmar to 310mph at 10,000ft is with a large rocket strapped to it.

* Silk Purse Out Of Sow's Ear Society.

The Merlin 30 was rated at 1360hp at 6000ft @ 3000rpm with 12lb boost and FTH with ram was 6800ft = 268 mph TAS in the single test result we have access to. . The Merlin 45 was rated at 1515hp at 11000ft @ 3000rpm with 16lb boost. It follows from this, that a Fulmar with a Merlin 45 producing 1360hp at ~12000ft (with ram) = a TAS of ~290 mph but at 16lb boost it would be developing 155 extra HP at 12000 which should provide another ~20 mph for ~310mph TAS. The Merlin 45's climb rating was at 9lb boost but it could maintain 9lb boost for another ~6000ft higher altitude which would more than compensate for the slightly reduced climb rate at lower altitude.

The data for a Merlin XX would be similar.

 

[Shortround6]

155hp does not get you anywere near 20mph faster.

IF 1360hp did get you to 290mph in the Fulmar the cube law says you need about 1660hp to make 310mph.

The reality check is the Firefly, while heavier it was a actually a smaller airplane, slightly less wing span and area and several feet shorter fuselage. It used the Griffon IIB engine which was also used in the Spitfire XII. 1490hp at 14,000ft (?)and the FireFly I could do 316mph at 14,000ft.

Apparently the the MK XII Spitfire was a waste of time. Just crank the boost on the old Merlin 45 to 16lbs and away you go.

 

[wuzak]

I think improving the Fulmar is a bit of a lost cause; it was too slow, slow in the climb and slow in level speed. What the FAA really needed was a good single-seat fighter, they just didn't realise it when the Fulmar was conceived (hindsight is wonderful).

Like I said, Fairey should have been tasked with developing the Seafire. From 1938, like the Admiralty asked.

They could hav eeven made modifications to boost range.

 

[wuzak]

The Fulmar had far more range and endurance than a Seafire and a lot more firepower (750rpg or 38secs or 1000 rpg or 50sec firing time) than a Seafire, especially a hypothetical Mk1 with 8 x .303 with 330rpg. Overall a Fulmar would probably score more kills per sortie than a Seafire I, given the typical opposition, especially with an upgraded engine plus the Fulmar would have a much lower operational loss rate per sortie. The Seafire could better handle enemy SE fighters but that wasn't really a major problem for the FAA anyways.

How often were Fulmars fully loaded with ammo? How often did they expend fully their ammo load?

Seafire I would be 40-50mph faster than your theoretical Fulmar. It will climb better. Turn better. Developed parallel to the Spitfire it could have its range issue (ie tankage) addressed.

Why would the Fulmar have a lower operating loss per sortie? Because of the undercarriage?

 

[RCAFson]

How often were Fulmars fully loaded with ammo? How often did they expend fully their ammo load?

Seafire I would be 40-50mph faster than your theoretical Fulmar. It will climb better. Turn better. Developed parallel to the Spitfire it could have its range issue (ie tankage) addressed.

Why would the Fulmar have a lower operating loss per sortie? Because of the undercarriage?

Fulmars expended their ammo fully on a number of occasions.

When would this mythical Seafire appear and what would the FAA do in the interim?

The Seafire's historical fuel capacity wasn't significantly increased until the postwar Seafire 47 so asking for more capacity sooner is really stretching what was possible, especially without the Griffon to provide the needed power.

The whole point of giving the Fulmar extra ammo and fuel was to maximize it's time in the air and minimize the number of landing cycles, so compared to the Seafire the Fulmar can stay in the air twice as long and doesn't need to be rearmed as often, all of which combined with the stronger LG makes for a much lower operational loss rate. Additionally the Fulmar's combat and patrol potential is enhanced due to the extra set of eyes and a separate radio operator.

 

[RCAFson]

155hp does not get you anywere near 20mph faster.

IF 1360hp did get you to 290mph in the Fulmar the cube law says you need about 1660hp to make 310mph.

The reality check is the Firefly, while heavier it was a actually a smaller airplane, slightly less wing span and area and several feet shorter fuselage. It used the Griffon IIB engine which was also used in the Spitfire XII. 1490hp at 14,000ft (?)and the FireFly I could do 316mph at 14,000ft.

Apparently the the MK XII Spitfire was a waste of time. Just crank the boost on the old Merlin 45 to 16lbs and away you go.

If you give an aircraft the same power, but at a higher FTH, then the aircraft will go faster because there's less drag at higher altitudes and then add even more power and it goes faster yet. The Hurricane gained ~30 mph (295 to 325) with a ~250hp increase at 10,000 ft so I would expect something similar for the Fulmar at 12,000ft.

The Firefly was much heavier than the Fulmar and the frontal profile suggests that it probably had the same or even greater frontal area and we are giving our Merlin powered Fulmar another 25hp and asking less of it terms of speed. The Firefly's Griffon was low altitude rated and gave it far more power down low (1735hp TO rating) which it needed for CV TO because of it's extra weight and higher wing loading.

The Spitfire XII had a maximum speed in M.S. supercharger gear of 375 mph at 4,600 ft and in F.S. supercharger gear, 389 mph at 12,800 ft with 1630 hp versus 369 at 13,000 ft for the V (Merlin 45 at 16lb and 1515hp) but the Griffon IIB powered XII could do 397 mph at 17800ft with only 1495hp so increasing FTH by 5000ft on the XII gave another 8 mph even with 135hp less.

In any event 310mph is a just a guesstimate but even 305 mph would have given the Fulmar a big boost in performance.

 

[Shortround6]

But you don't need the Griffon engine, just crank those Merlin 45s up to 16lbs of boost.

That is what you keep saying.

I actually like the Fulmar but there are limits as to what you can reasonably do with it and Fairey themselves were ready to move on in the summer of 1940.

The Best thing that could come of improving the Fulmar is the delay or cancellation of the Barracuda which would lower England's insults to the atmosphere a considerable amount

 

[RCAFson]

But you don't need the Griffon engine, just crank those Merlin 45s up to 16lbs of boost.

That is what you keep saying.

No, you keep saying it, and I keep patiently explaining that the two speed Griffon VI has a lot more power at low altitude and medium altitude. However the XII and Griffon IIB was actually slightly slower than the V at the V's 16lb FTH because at that altitude the Merlin 45 had slightly more HP.

I actually like the Fulmar but there are limits as to what you can reasonably do with it and Fairey themselves were ready to move on in the summer of 1940.

The Best thing that could come of improving the Fulmar is the delay or cancellation of the Barracuda which would lower England's insults to the atmosphere a considerable amount

There are limits to what can be done with it, but adding another few hundred HP via improved Merlins is not asking a lot. Historically, the Fulmar got caught in a squeeze where Fairey had to drop it to start production of the Firefly.

The Albacore was dropped to start production of the Barracuda, which was the Allies most advanced carrier strike aircraft when it went into production given the Avenger's inability to divebomb and it's less than efficient torpedo, and given the SB2C-1's numerous teething problems. It's a pity the USN didn't produce the Barracuda in the USA as per the RN's request.

 

[RCAFson]

duplicate post.

 

[nuuumannn]

The long range/long endurance scout/patrol fighter concept was a good one, IMHO and the Fulmar has the kill stats to back it up.

The majority of the Fulmar's kills were made in the Mediterranean, where its range was not a significant issue, but its weakenesses were plainly highlighted, when countering Italian and LW raids against Malta, bases in N/Africa and Allied shipping. The Fulmar was a competent aeroplane and served the FAA well; but it was clearly inadequate as a fighter against modern opposition. The service made the most out of all the equipment it had, however, in many, if not most cases when the opposition were operating superior equipment, in the early war years. This was largely because of the calibre of FAA personnel. The following quote gives an impression of what FAA crews were up against in the Mediterranean in their Fulmars; this is 806 Sqn's Robert Henley;

"I recall a fairly massive raid of Ju 87s and Ju 88s, with all available fighters scrambled - some four Fulmars - and we just flew around uncontrolled, shooting at anything that came within range. The poor old Fulmar had problems gaining height and speed against the Ju 88. My aircraft was hit, I think to my embarrasment, by a Ju 87, which stopped my engine some miles south-east of Hal Far." Henley was credited with a Ju 88 on that day.

 

[RCAFson]

This is a summary of a post that I made awhile back:

On May 08 1941 Fulmars from Ark Royal and Formidable engaged both the Luftwaffe and Reggia Aeronautica:

RA losses:

4 x SM79
2 x CR42

Luftwaffe losses:
1 x Ju-88
4 x He-111
2 x Me-110 (crash landed due to battle damage)
1 x Me110 damaged
1 x Ju-87 (confirmed by Fulmar gun camera but not noted in Luftwaffe records)
1 x Ju87 damaged

FAA:

2 x Fulmar (one from bomber defensive fire)
2 X Fulmar crash landed on CVs
1X Fulmar crashed due to weather (not combat related)
6 x Fulmars damaged

Data from Shores, Mediterranean Air War, 1940-1945: Volume One: North Africa, June 1940-January 1942, p182-185

So the Fulmars engaged Me-110s and CR-42s while racking up another impressive kill-loss ratio. Give the poor Fulmar another few hundred horses under the hood, and they'd do even better, or so you'd think.

 

[wuzak]

So, this is one of the beasts the Fulmar engaged?

Impressive.

As to Bf 110s, surely if they nailed the throttle the Fulmars would be left trailing in their wake? Even with Merlin 45s at +16psi boost (the ones obviously not being used for Hurricanes).

 

[wuzak]

No, you keep saying it, and I keep patiently explaining that the two speed Griffon VI has a lot more power at low altitude and medium altitude. However the XII and Griffon IIB was actually slightly slower than the V at the V's 16lb FTH because at that altitude the Merlin 45 had slightly more HP.

I would say that at the Spitfire V's full throttle height on +16psi boost (13,000ft) that the Griffon II was around its gear change point. Either side of that the XII is markedly superior to the V in level speed.

 

[wuzak]

When would this mythical Seafire appear and what would the FAA do in the interim?

The FAA wanted a Seafire from 1938, apparently.

The Spitfire was in production, although it not going as quickly as desired.

First pass navalisation could be done quite quickly (add hook, beef up landing gear, folding wing). Using Fairey's production facilities, it should be in production before 1940 - I would hope.

Second pass would be adding tankage to increase range.

Third pass would be adding the Griffon (like the Spitfire XII). This could happen late 1942/early 1943 - and a couple of years ahead of when it was done for the Seafire XV.

 

[RCAFson]

So, this is one of the beasts the Fulmar engaged?

As to Bf 110s, surely if they nailed the throttle the Fulmars would be left trailing in their wake? Even with Merlin 45s at +16psi boost (the ones obviously not being used for Hurricanes).

Yet the Cr-42 was nominally faster than the Fulmar and could be expected to out climb and out turn it as well. Improving Fulmar Performance surely must improve it's chances even more.

Yes, if the Bf-110s and Cr-42s bugged out they could probably escape but given their mission that wasn't an acceptable option and again better Fulmar performance would only improve it's kill ratio.

 

[Dogwalker]

This is a summary of a post that I made awhile back:

On May 08 1941 Fulmars from Ark Royal and Formidable engaged both the Luftwaffe and Reggia Aeronautica:

For completeness, it was not an open sky encounter. It was an attack on a British convoy of five merchants, two carriers, two cruisers and nine destroyers (Operation Tiger). Due to bad wheater, that the British were taking advantage of, to avoid the chase of the Axis forces, the action of the Regia Aeronautica could begun only at 13:45, a time particularly unfavorable for torpedo bombers, who usually preferred to strike at dawn or dusk, to take advantage of the sun.
Italian records registered two (of six present) SM79 torpedo-bombers lost (Lt. Cappa and Cpt. Boetto), the first credited to the ships' defensive fire, and three Cr.42 for various reasons. In the action was shot down, by a Cr.42, the Fulmar of Lt. Rupert Tillard (Commander of the 808 squadron, fighter ace with 6.5 victories) and Lt. Mark Somerville, observer. Three other Fulmars were also damaged.

Don't know for the Germans, who attacked later, but I tend to believe that, even in this case, the fighters were responsible only for a part of the losses.

 

[Dogwalker]

It's worth to say that, in may 1941, the Fulmars, on the Ark Royal, had just replaced the Blackburn Skuas, so they were, strange as it may seem, the newest aircrafts that operated that day.

 

[Dogwalker]

This is the same encounter, in "Royal Navy Aces of World War 2"

"As the fighters approached the force of 16 (!) S.79s, they were in turn bounced by escorting Fiat CR.42s, and Tillard, attempting to dogfight with the nimble biplanes, was shot down and killed, along with his observer, Lt. Somerville. Lt. Ted Taylour's aricraft was also hit, and his TAG badly wounded. As the bombers pressed on to the carrier, the first Fulmars from 807 NAS arrived, Lt "Buster" Hallet waded in, hitting one of the Savoias, but his fighter was in turn struck by return fire, and he was in turn forced to ditch. Battle of Britain Ace, Billy Gardner, also attacked the same S.79 as Hallet, which duly disintegrated under the weight of his final burst, thus opening the squadron's account.
Two hours later ,another section of 808 NAS, led by Lt. Ronnie Hay (who had claimed his fifth victory the previous month), shot down an S.79 off Galita Island (!). ... .
Just before dusk another raid approached, ... , the intruders were 28 Ju 87s escorted by 6 Bf 110s. The airborne section of 807 SAS went for the escort, whilst the remaining Fulmar from both squadrons attacked the dive-bombers. Lt Taylour, of 808 NAS, downed one of the Stukas before being hit, forcing him to limp back to Ark Royal with his starboard undercarriage dangling.
the other section also enjoyed success, whit Jimmie Gardner destroyng two Ju 87s. However, his fighter was also badly hit, and he too crashed on Ark Royal's deck upon his return to the ship."

The He 111 and Ju 88 claimed that day were described as unescorted aircrafts, intercepted by Fulmars of the 803 and 806 NAS, of the Mediterranean fleet (Formidable carrier), in three different actions, much east than the main one.

 

[tomo pauk]

I'll again call the Merlin 30 as 'Merlin 20 series with low supercharger gear only ', for the sake of comparison. The Hurricane IIC was making ~305 mph on low gear, ~325 on high gear, all at +9 psi boost. That's 7% increase in speed. 280 mph increased for 7% gives 300 mph, for the 'Fulmar III' (the hypothetical with Merlin 20 series).

 

[nuuumannn]

Let's be realistic; even a small increase in speed isn't going to make anything but a negligible difference to the Fulmar's combat capability (no one's doubting the kills made in it, but the Med was swarming with enemy aircraft). The Fulmar can be described as being the Boulton Paul Defiant of the FAA - without any derogatory connotations. Both were well designed and finely finished machines, which were easy to fly, but the concepts they were designed to were flawed in the face of modern combat scenarios. Another thing they both had in common was that there were very few of them in operation at any one time, facing overwhelmingly superior numbers of enemy aircraft. After a less than impressive innings as a day fighter (for which it was not designed - it was a bomber destroyer, not for fighter v fighter combat) The Defiant redeemed itself as a night fighter, but the fundamental problem with both types was that they were too slow, even after refitting with more powerful engines. This meant that both were always going to be replaced by better performing types. Both were also somewhat larger and heavier than their single-seat opposition.

Comparing the two, the Fulmar I was larger, heavier (9,800 lb loaded weight), had a shorter range (800 miles) and lower ceiling (26,000 ft) and was slower (280 mph, 1,200 ft/min rate of climb) than the Defiant I (8,240 lb AUW) (950 miles) (31,000 ft) (304 mph, 1,900 ft/min).

Fulmar figures from Fairey Aircraft since 1915; H.A.Taylor, Defiant figures from The Defiant File; Alec Brew.