Spitfire IX Armament

[Squire]

4 Hispanos were all Mustang IAs not A-36s.

"Indeed you are right that the Mk IX was basically a reworked Mk V structure, however you forget that the Mk IX was much heavier, and the tires/undercarriage could not support the extra weight of the Merlin 60 series AND the extra Hispanos."

Well thats odd because there were Spit VIIIs with 4 x 20mm and they are almost identical to a IX (merlin 60). They could easily have 4 x 20mm on the Spit IX E, but the RAF chose not to arm them so. It was an operational decision, not a design problem. By definition the "E" wing could mount 4 x 20mm, it was designed for just that, as an option. The other option was 2 x 20mm and 2 x .50 caliber. It also had a bomb rack.

Should the IX E in AH have it? No. Why? Because it was not so armed. Thats my opinion, but the "it couldnt mount them" stuff is not correct.

[VO101_Isegrim]

Originally posted by Nashwan
The Spitfire IX could also carry a 500 lb bomb on the centreline, and later 2 250 lb bombs under the wings as well, so the extra weight of the cannon was hardly that much of an issue.

Never seen any primary reference mentioning that 500 lbs + 2 x 250 lbs configuration. The Spitfire`s IX/XVI manual of 1946 (that`s quite late) only lists the following:

Add: Checked Mk XIV`s manual, the same types are listed.

1 x 500 lbs AN/M 58
or
1 x 500 lbs AN/M 64
or
1 x 500 lbs AN/M 76
or
1 x 500 lbs SAP bomb
or
1 x 65 lbs nickel bomb Mk II
or
1 x 10 lbs practice bomb

Could you please list the reference to the 500 + 2x250 lbs config carried at the same time, not as alternate loadouts ?


Other than that, in every publication I have seen that deals why the 4x20mm config was never fitted to Mk IXs the problem with the increased weight is mentioned. If that was not true, I don`t see why no single subtype until the wing`s redesign employed the 4 cannon config again.

[VO101_Isegrim]

Originally posted by Squire

Well thats odd because there were Spit VIIIs with 4 x 20mm and they are almost identical to a IX (merlin 60). They could easily have 4 x 20mm on the Spit IX E, but the RAF chose not to arm them so.
It was an operational decision, not a design problem. By definition the "E" wing could mount 4 x 20mm, it was designed for just that, as an option.
 

I don`t see why you find that odd. The Mk VIII was a new airframe, different from the Mk IX, being 300 lbs heavier in the same config, period. The E or C wing could carry the cannons, there was enough space for that, another thing is that the u/c couldn`t cope with carrying such a burden on every mission if weight is not decreased by other means. It`s just not as easy as "they could have mounted it, no problem at all". Saying they could is what all easy. They had a slightly modified Mk V airframe, that was designed to cope with 6500 lbs takeoff weight. When they made slight modifications to accept the much heavier two stage Merlins, they had 7400 lbs at their hand. Adding another extra 250 lbs w/o redesigning the tires, strenghtening the undercarriage was simply not an option, especially on a plane that was meant to be an "interim solution". As for the "RAF just didn`t want to add 4 cannons"... hmm... they wanted that in 1941-43 with the Mk V, and they wanted that 1945+ with the Mk 2x series. I just wonder why the different thinking only in regardwith the Mk IXs, which are hastily converted old airframes designed for MUCH less weight..

[MiloMorai]

Spifire, The History pg 309

"Later loadings could consist of 2 x 250lb wing, plus 1 x 500lb fuselage bomb, no overload fuel or rear tank, auw 9059lb; or 2 x 250lb wing bombs plus 90gal overload tank, no rear fuel, auw 9250lb; or 1 x170gal overload tank only, auw 9500lb"

normal TO weight for the IXE, 7181.5lb

A 1946 manual??? After the defeat of Nazi Germany all a/c had their loads reduced.

tare weights

XIII - 5806lb
IXE - 5816lb

max permisable weights

VC - 7300lb
VIII - 8000lb
IXE - 9500lb
XVI - 9500lb

tires

VC - Dunlop IJ 12, 13, or 17
VIII - Dunlop IK 13 or 17
XVI - Dunlop IJ 13 or 17, or IK 13 or 17
XIV - Dunlop IK 13 or 17

[VO101_Isegrim]

A 1946 manual??? After the defeat of Nazi Germany all a/c had their loads reduced.

I wouldn`t swore on that, especially as the 1944 Mk XIV manual says the same loadout, ie. 500 lbs bombs, it rather seems like your own hypothesis born in the spite of events... Not really something to be trusted over a primary source! Still, I would like to see some source or at least a photo of a 500+2x250lbs config. I wouldn`t be surprised if the Spitfire book would be in error, it confronts the manual itself, not to mention they are dead wrong in the normal TO weight which they claim for the IXE, 7181.5lb, and is simply wrong, see :



Also:

2......Weight Summary.


*Load 1. 2.  
'TARE' Weight (including 5 standard ballast weights of 17.5 lb. in tail 5749 5719  
Service load 1008 798  
Fuel 85 gallons @ 7.2 lb./gall. 612 612  
Oil 8.5 gallons @ 9.0 lb./gall. 76  76  
Flying weight 7445 7205  


See 7445 lbs as Flying weight for IX, not mentioning that the E was even heavier if there were .50s installed...

[Nashwan]

How about TB232, a Spit XVI (which was a IX with a Packard built engine) tested with 2 250 lbs bombs, 1 90 gallon drop tank (in excess of 650 lbs, and therefore heavier than a 500lb bomb) AND a rear fuselage fuel tank?

How about MJ823, tested with 2 250 lb bombs and 90 gallon drop tank? AUW with 2 250 lbs and 90 gallon tank 8,435 lbs. "All trials satisfactory"

Remember Isegrim, your initial claim was

however you forget that the Mk IX was much heavier, and the tires/undercarriage could not support the extra weight of the Merlin 60 series AND the extra Hispanos.

You claimed the extra 240 lbs of Hispanos would be too much for the Spit IX, whereas it carried 500 lbs of bombs, or 600 lbs of drop tanks routinely, and later in the war 1,000 lbs of bombs or 500 lbs of bombs and 650 lbs of fuel.

As to pictures, try p75 of Osprey's "late mark spitfire aces" which shows a Spit Ix of 132 squadron being bombed up with 2 250lbs and 1 500 lb. P 76 shows a Spit IX of 74 squadron with two rockets (weight 80 lbs each) and a 500 lbs bomb. Note both these aircraft have "E" armament, which weighed 110 lbs more than the standard "B" armament anyway.

[FUNKED1]

The fifties on the Spits IX were mounted in the empty inner twenty bays.

[Squire]

"I don`t see why you find that odd. The Mk VIII was a new airframe, different from the Mk IX, being 300 lbs heavier in the same config, period."

Same "C" or "E" wing, and 300 lbs is not big # for a/c that have loaded weights of 7500 lbs. You make it sound like the IX could barely lurch airborne under its huge weight.

"The E or C wing could carry the cannons, there was enough space for that, another thing is that the u/c couldn`t cope with carrying such a burden on every mission if weight is not decreased by other means. "

There is no source that states that, thats just conjecture. Thats like saying it had to have wing guns removed to perform a fighter-bomber mission.

"It`s just not as easy as "they could have mounted it, no problem at all". Saying they could is what all easy."

Well, sorry, talk to Supermarine, they built it. It could carry 4 cannons.

"They had a slightly modified Mk V airframe, that was designed to cope with 6500 lbs takeoff weight. When they made slight modifications to accept the much heavier two stage Merlins, they had 7400 lbs at their hand. Adding another extra 250 lbs w/o redesigning the tires, strenghtening the undercarriage was simply not an option, especially on a plane that was meant to be an "interim solution"."

Again, what does the undercarriage have to do with the price of tea in Bejing? Give a source that states there was any problem with the undercarriage and a 4 x 20mm mount???

 "As for the "RAF just didn`t want to add 4 cannons"... hmm... they wanted that in 1941-43 with the Mk V"

Some Mk VCs  had 4 x 20mm cannon...if they wanted that as a standard option, it was no problem. They chose not to. The Spitfire VIII could also have 4 x 20mm and they chose not to, the Spitfire XIV could have it and they chose not to. Why? I dont know, ask the RAF. It was probably a decision based on production, the need for the heavier armament, cost, ect. for whatever reason they decided to go with mounting the browning .50 in the second cannon port instead of a 20mm.

If they wanted 4 x 20mm so bad why did the XIV not have it with a 2000hp RR Griffon engine then? was it too heavy for it too?

Interim solution. Again, what does that have to do with anything? Do you think the P-51, 109 or 190 went through WW2 as the designers originally envisioned them? I can tell you none of them did.

[Guppy35]

Some of you guys are making this way too tough.

The Spit Vc did carry 4 cannon armament.  The bunch launched off the USS Wasp for Malta in April of 42 all had 4 cannon.

But because of the weight penalty etc, most if not all had one set of cannon removed once on Malta.  Often times they were left in the outboard cannon bay too like the E wing later.  

To paraphrase someone's sig, "if you can't hit the enemy plane with 2 cannon, you aren't going to hit it with 4"

Were 4 cannon Spit Vc used in combat?  Yep, in the ground attack role late in the war in Italy for one, while with 2 Squadron SAAF.  One 500 pound bomb, 4 20mm cannon.  But this was for ground attack and not air to air.  Once again the impact on turning ability etc was the difference.

Keep in mind, that a number of pilots had the outboard 303s removed and relied only on the 2 20mm cannon as they felt like it made them faster and turn better.

Image is of a flight of 2 Squadron SAAF Spit Vcs late in the war over the Adriatic.  All 4 cannon Spits.

I can post images of Spit IX with 4 cannon including one of the converted Spit Vcs very early in 42, and Spit VIII if anyone wants as well as the mock up for a 6 cannon armament that was test flown in the first Griffon Spit IV in 1942.

So it's all about performance, not whether the Spit Vc, IX or VIII could carry the armament.

Ask those cannon boot 109 pilots how they liked to dogfight with one of those birds vs one without them.  I kinda doubt they'd take the heavier plane and armament over the better performer

Dan/Slack

[Squire]

I think in the end it was a case of #1 some weight would be saved, and #2  4 x 20mm was not deemed as needed, so they went with the .50 in the outer port as the definitive armament.

[Guppy35]

What the heck.  One of the first converted Spit Vcs to IX in early 1942.

Note the 4 cannon armament.  

Once again, rarely used.  No we don't need it in AH

Dan/Slack

[MiloMorai]

Originally posted by VO101_Isegrim

I wouldn`t be surprised if the Spitfire book would be in error, it confronts the manual itself, not to mention they are dead wrong in the normal TO weight which they claim for the IXE, 7181.5lb, and is simply wrong,

Well it is not first, or last, time a typo will be made. Notice on the num pad that the 1 and 4 are next to each other.

One should not include pilot weight as that weight can vary by 50-70lb. Spitfire IX with Merlin 66 engine(JL165) had a TO weight of 7400 lbs(2 x 20mm, 4 x .303"). What prop was fitted has also to be considered(Dural or Rotol) in the weight.


OBW, we all miss you over at Ubi Ise, especially Gibbage.

........

Nashwan, notice the MkVIII with 4 long barrel cannons on pg 79 that was photographed in April 1944. How much did those beer barrels weigh?

[Cobra412]

Many later versions of the Spitfire Mk. IX's used the "E" configuration.  With that being a said yes they were capable of a 2x 20mm MkII and 2x12.7mm(.50) Browning configuration or a 4x 20 mm MkII configuration.

 How many actually flew with this configuration would be a better question and as of right now I've only found a few pictures with the 4x 20mm configuration.  One of those pictures was a formation of 3, 2 aircraft being the old style canopies and 4x 20mm and the other being the newer bubble style canopy and a 4x 20mm configuration.

Is there anything out there that states also the reason that not all were not fitted with 4x 20mm's?  Also is there anything that says specifically about this configuration and that it's armament effectiveness wasn't enough to out weigh the performance decrease if there was one?  Anyone got a link to every Spitfire Mk. IX squadron and there typical loadout configurations?  I'd assume it'd be a production issue of the MkII when it comes to why they didn't retrofit all Mk. IX's with this config.  Mass production of the Browning from the U.S might have something to do with it too.  I'd prefer the 4x20 over the 2x2 anyday.  Cause when it comes down to it and all you got left is .50's your looking for the next available exit.  Having the extra cannon rounds would come in handy to finish off that last pesky fighter so you don't have to bob and weave all the way home.

I myself can see many reason for having the 4x 20mm configuration even as an A/A config.  One being during the BoB with so many bomber waves coming in the higher lethality of a 4x20mm compared to a 2x2 config would definately be a bonus.  The second thing would be even though the rate of fire was slower on the 20mm than the .50 it'd only take a few hits to disable an enemy aircraft and the high rate of fire of the .50 would be a mute point.  Plus a loadout of 480 cannon rounds isn't to shabby.

[Guppy35]

Cobra,

The photo of the three Spits you refer to are two Spit 21s and a Spit 22 with the bubble canopy.  The Spit 21 saw very limited action with 91 Squadron just before the end of the war.  The 22 didn't see WW2 service.  The 21,22,24 had a completely different wing design and were Spits in name only.

They DID NOT use the 4 cannon wing with the IX in any numbers or total squadron service.  The ONLY squadron I can definately say used 4 Cannon Spit Vcs in squadron strength is 2 Squadron SAAF late in the war as an air to ground support aircraft in Italy.

The weight gain was far more detrimental in an A to A environment then the extra set of cannon was worth.  As I said earlier a number of pilots got rid of their 303s and relied totally on the 2 cannon as they figured if they couldn't hit with the cannon the 303s were pointless.  The loss of that weight improved speed and turning ability in the pilot's eyes.

Trust me I love Spits but there is no reason to push for a 4 cannon Spit.  A clipped wing, late war LFIXE or LFXVIE yes, but not 4 cannons

Dan/Slack

[Karnak]

The Spitfire definately carried two 250lbers and one 500lber.

Funked (IIRC) posted a document from one of the Polish squadrons in the RAF that showed the armament for each mission and most of them carried that loadout.

Furthermore there are many photos of Spits bombed up in said fashion.

What we are actually missing (if it were an E winged Spitfire) is the option for four rockets.  I do have a photo of that.