Additional F and HF variants

[Lythronax]

I think it would help flesh out the Spit IX module to include some of the other sub-variants, namely the F Mk IX (Merlin 61 and 63) and the HF Mk IX (Merlin 70). Additionally, I think an overhaul of the current LF variant would be very nice. There are currently a whole lot of 3d/visual issues and inaccuracies and as sold is a bit of a hodgepodge of features with a whole bunch of anachronisms. I'm thinking of doing a bug report on this.

A proper F Mk IX (and even an early LF) without the Aero-Vee filtered intake would be more appropriate for 1943 scenarios such as the Beware Beware! campaign.

Furthermore, a "late" version of the LF with gyro sight and perhaps the E wing would feel more appropriate for the D-Day/Normandy timeframe.

I'd happily pay for an upgraded and expanded V2 of the Spit IX module like the redone A-10 and Black Shark!

F Mk IX with early intake, early wheels/undercarriage, no Rebecca aerial, early mirror, metal propeller and removed outer .303 MGs.

 

 

[Skewgear]

Our current Spitfire seems to be modelling an early (late 1942) production line conversion of a Mk.VB, hence duplicating things like the wobble pump and electric fuel pump.

I have a feeling the F.IX performance wasn't that much different from the LF.IX except at lower altitudes where the LF's Merlin 66 had had the supercharger impeller cropped and its gear ratios adjusted for greater power output below 10,000ft. This gave the M66 a lower full throttle height than the M61 in the F.IX but an otherwise similar performance profile.

In theory all that would need doing to create a late production F.IX in DCS is adjusting the engine and associated flight model parameters of our current LF.IX, no 3D model changes or major work.

Normandy didn't have that many E wing Spitfires until the very end of the campaign as it progressed past Paris and into the Low Countries and Germany proper. If ED was to model an E wing Spitfire then for the effort involved (new 3D model, new damage model, flight dynamics changes with the different parasitic drag characteristics of the E wing from removing the outer .303" guns and adding the inboard .50" guns) you may as well go the whole hog and model a full Mk.XVIe as if it was fuelled with 130 grade, giving 25lbs boost.

I'd really like the option of an E wing but having read up on what it involves after suggesting it myself a while ago, it's far more work than it might seem given how similar they are in reality.

What are the 3D inaccuracies you mention?

[Art-J]

Our Spit is a hodgepodge of features because it's modelled mostly (albeit not solely) after MH434, which is a retrofit hodgepodge in itself. That was discussed ad nauseam back in '17 when module was released, so even though one can create a new bug report, I wouldn't count on any major changes being made.

Cockpit textures and materials are the most outdated aspect at the moment (compared to remaining ED warbirds, which have 2018 cockpits or newer), but we know a new pit is coming (who knows, maybe we'll get it with 2.9?), so let's wait and see how it turns out.

[Lythronax]

vor 13 Stunden schrieb Skewgear:

Our current Spitfire seems to be modelling an early (late 1942) production line conversion of a Mk.VB, hence duplicating things like the wobble pump and electric fuel pump.

I have a feeling the F.IX performance wasn't that much different from the LF.IX except at lower altitudes where the LF's Merlin 66 had had the supercharger impeller cropped and its gear ratios adjusted for greater power output below 10,000ft. This gave the M66 a lower full throttle height than the M61 in the F.IX but an otherwise similar performance profile.

In theory all that would need doing to create a late production F.IX in DCS is adjusting the engine and associated flight model parameters of our current LF.IX, no 3D model changes or major work.

Normandy didn't have that many E wing Spitfires until the very end of the campaign as it progressed past Paris and into the Low Countries and Germany proper. If ED was to model an E wing Spitfire then for the effort involved (new 3D model, new damage model, flight dynamics changes with the different parasitic drag characteristics of the E wing from removing the outer .303" guns and adding the inboard .50" guns) you may as well go the whole hog and model a full Mk.XVIe as if it was fuelled with 130 grade, giving 25lbs boost.

I'd really like the option of an E wing but having read up on what it involves after suggesting it myself a while ago, it's far more work than it might seem given how similar they are in reality.

What are the 3D inaccuracies you mention?

The Merlin 61, 63 of the F and 70 of the HF are rated for higher altitudes in both supercharger gears (can hold rated power up to 30k feet in the case of the 70) and thus reach their top speeds at a higher altitude. Thanks to this their top speeds are actually higher than the LF's, though they are slower lower down. The Merlin 61 also has a lower propeller reduction gear ratio due to its origins as a bomber engine (.42:1 vs .477:1) thus the early Fs had some different characteristics in the climb.

"In theory all that would need doing to create a late production F.IX in DCS is adjusting the engine and associated flight model parameters of our current LF.IX, no 3D model changes or major work." - Not so. A lot of 3D work would have to be done. The late F IX with the Merlin 63 of 1943 vintage would lack the outer cannon stub, use the early short air intake, have the fuel cooling port in the port wing root, different undercarriage/wheels (and other features which I'll detail in a list below which also apply to the F IX). That's not to mention the work required in the cockpit to bring it to standard. For example, the F IX used the Mk V throttle quadrant and slow running cutout controls which are completely different to the LF.

Unfortunately if the current DCS LF IX were replicating a late 1942 conversion, it would not be an LF. They did not appear until the spring of 1943. The fact is, the current model is a bit of a mess. I'm sure the flight model is fine but the 3d model, inside and out (incl. many of the features in the cockpit) are incorrect. The "classic" LF Mk IX really came into being in November/December 1943 - by this time the Aero-Vee tropical intake was being introduced, the slim feed motor blister for the cannon was standard, as were the late elevators, beam approach aerial, late IFF aerial, booster pump, and other features. For our LF IX which seems to represent (or ought to) an early 1944 LF Mk IXc in ADGB and 2TAF service, the following features are inaccurate:

1. Wing fuel tank cap on the ammunition bay; this is a post-war "warbird feature"- this is however just on the texture mapping and can be removed fairly easily

2. Over-wing wheel well blister and reinforcing strake; late/postwar feature related to a change in angle of the wheel axle (from 8 degrees to 4) when operating off of tarmac; should be completely smooth surface above the wheel wells, in-sim axle angle is correct 8 degrees however

Spoiler

3. Scissor link undercarriage; very late/postwar modification - oddly enough, the model has the correct gear leg fairings and bay without the extra cutout for the links; should be straight spline type

4. 5-spoke wheels; common in 1942 and Mk V conversions but by 1943/44 a four-spoke wheel was the standard, sometimes with a hubcap

5. Recognition light behind the aerial mast; this was deleted in 1943 and should be absent by the time the Aero-Vee filter was introduced

Spoiler

6. Missing gun camera in starboard wing root - the original port wing installation was deleted in lieu of the fuel cooler in the F Mk IXs - the LF lacked this cooler, but when the gun camera later returned on the F (and LF) it was decided to standardise on a starboard wing installation - it is correct that early LF's lacked the camera but probably by late 1943 and definitely by the time of D-Day it should have returned*

Spoiler

7. Missing IFF aerial under the starboard wing

8. Missing drop tank deflection hooks

Spoiler

null

9. Both wobble AND booster pump; should be either or - early ones had the wobble pump, later the booster pump; ours should probably have singly the booster pump

10. Missing beam approach aerial and associated cockpit control (this is a variable feature as some had them, some didn't)

11. Missing remote contactor control in cockpit**

Spoiler

12. Headrest; this is a Mk V feature not present on Mk IXs

13. Erroneous radiator flap control; this was a feature of the PR Mk XI and is a common "warbird" modification in modern times, is however anachronistic and should be in fact the "Camera Master" switch; only the test button should be present*

Spoiler

14. Missing generator failure light

15. Missing the interconnected prop and throttle control; this was standard in the Mk IX by the time of the Normandy campaign and was one of the other features differentiating it and the F Mk XVI, which wasn't set up for it

16. Missing gun camera exposure control on port wall*

Spoiler

There are some geometric issues with the external and internal 3d models, be they missing features or outright incorrect:

17. Cannon fairings incorrect shape; in-sim they taper immediately from the root, when they should have a straight channel, then a second tapering piece which attaches to it (this tapered fairing is the same piece as used on the outboard cannon in the four-cannon configuration, the E wing, and even the single cannon on the Mk VB). I remember originally the model had the later cigar-shaped fairing; this would have actually been fine for 1944 but it was changed in 2017 and in doing so it's now inaccurate. Additionally, the plug for the outer cannon casting is completely flat, when it should be somewhat rounded

Spoiler

 

18. Cockpit windscreen piece currently replicates the version from the pressurised Mk VII, which had a greater number of bolts and seatings for them in the windscreen casting

Spoiler

Mk XVI

19. The windscreen framework is missing bolts; these appear however to be included in the Spitfire cockpit update that's upcoming, judging by the Normandy 2 trailer

Spoiler

 

20. The outer wing panels appear to be a little too thick in section; it's hard to get a photo demonstrating this but it's something I've noticed since the module first came out in 2016

21. Front of tail fin and fairing very angular and awkward; should be a more graceful curve

22. Profile of the bottom of the rudder is slightly incorrect

Spoiler

23. Edge of gunsight mounting casting is round; should be cut square

*These only apply if the gun camera is mounted, which it should be for the Normandy time period

**This applies when the wobble pump isn't fitted, which should be correct for the Normandy time period

Here are a few photos demonstrating the state of F Mk IXs throughout late 1943 and throughout 1944 - the appropriate time period for the module.

Here's an early Castle Bromwich LF Mk IX (before MH434 was built).

I really don't think a hodgepodge of features is the way to go, I feel an early and late LF variant set would be more appropriate - and that's not even mentioning potential F or HF variants and their differences!

Edited October 12, 2023 by Lythronax

[71st_AH Rob]

On 10/12/2023 at 4:49 PM, Lythronax said:

23. Edge of gunsight mounting casting is round; should be cut square

That is some great and very detailed work.  I agree with almost everything and it is the same as my research when it overlaps except the above.   I believe that by the time we are looking at, the gunsight should be the Ferranti Gyroscopic Gun Sight G.G.S. Mk.IID.   By the end of may nearly all if not all operational squadrons equipped with the Mk IX should have been converted to the new sight. 

Here you can see a Mk IX on either the 4th or 5th of June receiving it's invasion stripes, it is equipped with the G.G.S. Mk.IID.

 

As for our DCS Mk IX, it appears to be based on a survivor that has had lots of replacement parts or it is a Mk V that was converted at the factory when it went for a major over-hall into a Mk IX or when it served in another airforce post 1946 or by a private owner out of necessity.

 

 

[Lythronax]

Am 14.10.2023 um 04:53 schrieb 71st_AH Rob:

That is some great and very detailed work.  I agree with almost everything and it is the same as my research when it overlaps except the above.   I believe that by the time we are looking at, the gunsight should be the Ferranti Gyroscopic Gun Sight G.G.S. Mk.IID.   By the end of may nearly all if not all operational squadrons equipped with the Mk IX should have been converted to the new sight. 

Here you can see a Mk IX on either the 4th or 5th of June receiving it's invasion stripes, it is equipped with the G.G.S. Mk.IID.

 

As for our DCS Mk IX, it appears to be based on a survivor that has had lots of replacement parts or it is a Mk V that was converted at the factory when it went for a major over-hall into a Mk IX or when it served in another airforce post 1946 or by a private owner out of necessity.

 

 

AFAIK, the E wing Spits had priority for the GGS, which never became ubiquitous. The .303 armed Spits were seen as better for rookie pilots with worse aim, as there was a greater chance of hitting something with that volume of fire. The Barr and Stroud sight was still in use till the end of the war!

 

It seems the in-sim Spit is based on MH434 (going by the default livery) which is a total mess of features due to its postwar overhaul for Danish service.

[Lythronax]

Here's a curious photo! Two Spit IXs of No.453 RAAF around the time of D-Day at RAF Ford. The one in the foreground has an Aero-Vee filter, spokeless wheels and the GGS; the one in the background is clearly a much earlier Spit as it has 5-spoke wheels and, most curiously of all, no filter! I wish I had the serial numbers.

To further clarify, the Aero-Vee filter was in fact not a retrospective modification, aside from cases where the aircraft in question had sustained damage to its original intake!

Edited October 17, 2023 by Lythronax

[Skewgear]

I can give you a list of serial numbers for 453 Sqn during June 1944 if you like. Nearest aircraft is possibly MK260, you can see the letter K, and that machine was lost on 6th July 1944 after sustaining blast damage during a strafing run.

Furthest one could be L, I, H or U. That looks like a sqn ldr's pennant on the fuel tank, so whichever aircraft 453's CO flew most often is the likely candidate.

I'm unconvinced everything was as black and white as you say it was with regard to individual aircraft mod states. There was at least one ex-Mk.Ia airframe in frontline squadron service after upgrade to VB standard (X4272, even scored a kill after D Day!) and other than receiving B wings with the hard points for bomb, upgraded radio and other role specific equipment, I would bet that had a lot of Mk.I specific features tucked away in it.

Many 2TAF sqns couldn't accurately describe the very aircraft they were flying. In going through the ORBs for the three months after D Day I've seen mentions of the IXA, IXB, IXC, LF. IX, IXE (on a sqn whose Y appendices record expenditure of .303", not .50") and other variations. Doubtless the airfield CTOs and servicing commandos had precise records at the airframe level but those are long gone.

I cannot imagine anyone caring about the number of spokes on a wheel in frontline service unless the wheel had failed. Different story, naturally, for a contractor or RAF Maintenance Unit charged with bringing a machine up to a given mod state before issue.

One of the Air Historical Branch narratives about RAF logistics mentions that some MUs were receiving factory fresh Spitfires built to the latest mod state, only to strip some of those mods out because the latest orders hadn't reached them and their duty was to issue aircraft at whatever the last authorised mod state was.

When I get home I'll dig out the references as this stuff is important.

[Skewgear]

(edit - 453 did record airframe serial numbers on the final page of the monthly RAF Form 541) What I compiled for the PO archives for mission bort code creation purposes is this (edit, which turns out to be mostly wrong!), although I couldn't tell you now what the sources were or whether the serial/letter reconciliation are 100% authentic:

Serial	Fate	Date	Location	Letter
NH557	Hit by ground fire belly landed in front lines Bemmel and overturned	27/09/44	Bemmel	G
NH462				P
MK618	Shot down by flak	24/07/44	Villers Bocage	F
MK575				D
MK566	Hit by flak and crashlanded nr Montford [Bernay]		Montford [Bernay]	L

If you google it there are other 453 Sqn serial numbers out there. Possibly the master Spitfire production list (linked from RAFCommands and other sites) has some serial number allocations to 453 Sqn.

Sqn Ldr Donald Smith appears to have most often flown an aircraft whose letter is given in the Form 541 for June 1944 as "?" so either nobody knew what the CO was flying or possibly 453 had a Spitfire IX on charge with no code letter or an actual question mark on the side. With disproportionate effort, it's possible in theory to figure out that aircraft's identity.

 

Aircraft mod states. AP 3397, 'Maintenance' at this link: https://www.raf.mod.uk/our-organisation/units/air-historical-branch/second-world-war-thematic-studies1/

Actual document title is "THE DEVELOPMENT OF ROYAL AIR FORCE MAINTENANCE, SEPTEMBER 1939 TO MAY 1945". No.41 Group was the formation which received new RAF aircraft from the manufacturers and repaired or overhauled aircraft from contractors. Page 124:
 

Quote

No. 41 Group Modification Policy

The modification policy of the Group confined the basic responsibility for the incorporation of modifications to Class I , and Class II only. No aircraft were issued for flying purposes with any Class I modifications outstanding, but in the case of Class II modifications this was sometimes permitted when the necessary parts were not available. Modifications of a lower class were not incorporated except under specific instructions.

Command modifications were not normally embodied by No. 41 Group units except under special arrangements with the Group H.Q., and there was no obligation to remove such modifications, when fitted, before reissue.

 

and page 125, seems I misremembered the work on mod embodiments at MUs. Some were receiving aircraft with all required frontline equipment fitted and ready to go, stripping the equipment off and then refitting it!
 

Quote

 

Aircraft Received Complete from Contractors and Held Ready for Issue

By l6 September 1943 certain types of aircraft were being received from contractors to an equipment and modification standard which enabled them to be issued direct to users, where such vacancies existed in their establishments. It was therefore decided to allot all such aircraft to units for temporary storage only so that they would be ready for reissue at once should requirements suddenly materialise. Previously these aircraft had been prepared according to the full Directorate of Repair and Maintenance instructions for preparation, which in addition to placing them unserviceable also entailed duplication of much of the work already carried out at contractors. On arrival they were therefore brought on charge in the normal way, given a between-flight inspection and any defects found or reported on the pilots' ' snag ' report rectified. Any missing equipment was replaced and the aircraft were then picketed out and given a 'daily' inspection at least once every seven days. If they had not flown for 72 hours before they were required for issue they were given an air test, and if this was satisfactory were reported as ready for issue.

 

 

Edited October 31, 2023 by Skewgear

[Lythronax]

Am 17.10.2023 um 18:33 schrieb Skewgear:

I'm unconvinced everything was as black and white as you say it was with regard to individual aircraft mod states. There was at least one ex-Mk.Ia airframe in frontline squadron service after upgrade to VB standard (X4272, even scored a kill after D Day!) and other than receiving B wings with the hard points for bomb, upgraded radio and other role specific equipment, I would bet that had a lot of Mk.I specific features tucked away in it.

Obviously it wasn't so cut and dry and could be quite fluid, but I don't really think it's a fair excuse for the 3d model to be so full of anachronisms and errors. I hope that if ever the external model is to get a refresh that at least the basic errors like the wing bulges, cannon fairing shape, undercarriage legs, missing features, etc. can be rectified, especially if it's only ever going to be a 1944 +18lbs LF IX.

In other news, the new cockpit that got released today is a whole lot nicer - the windscreen bolts are now in place! That's one thing off the list.

[Art-J]

I'd say let them tackle the incorrectly marked 2.9 boost gauge first, so that it actually shows what boost we're really pulling. Followed by fixing inop P8 compass. These are going to affect our flight ops more than external rivet-counting bits mentioned above  .

[NineLine]

On 10/12/2023 at 1:49 PM, Lythronax said:

The Merlin 61, 63 of the F and 70 of the HF are rated for higher altitudes in both supercharger gears (can hold rated power up to 30k feet in the case of the 70) and thus reach their top speeds at a higher altitude. Thanks to this their top speeds are actually higher than the LF's, though they are slower lower down. The Merlin 61 also has a lower propeller reduction gear ratio due to its origins as a bomber engine (.42:1 vs .477:1) thus the early Fs had some different characteristics in the climb.

"In theory all that would need doing to create a late production F.IX in DCS is adjusting the engine and associated flight model parameters of our current LF.IX, no 3D model changes or major work." - Not so. A lot of 3D work would have to be done. The late F IX with the Merlin 63 of 1943 vintage would lack the outer cannon stub, use the early short air intake, have the fuel cooling port in the port wing root, different undercarriage/wheels (and other features which I'll detail in a list below which also apply to the F IX). That's not to mention the work required in the cockpit to bring it to standard. For example, the F IX used the Mk V throttle quadrant and slow running cutout controls which are completely different to the LF.

Unfortunately if the current DCS LF IX were replicating a late 1942 conversion, it would not be an LF. They did not appear until the spring of 1943. The fact is, the current model is a bit of a mess. I'm sure the flight model is fine but the 3d model, inside and out (incl. many of the features in the cockpit) are incorrect. The "classic" LF Mk IX really came into being in November/December 1943 - by this time the Aero-Vee tropical intake was being introduced, the slim feed motor blister for the cannon was standard, as were the late elevators, beam approach aerial, late IFF aerial, booster pump, and other features. For our LF IX which seems to represent (or ought to) an early 1944 LF Mk IXc in ADGB and 2TAF service, the following features are inaccurate:

1. Wing fuel tank cap on the ammunition bay; this is a post-war "warbird feature"- this is however just on the texture mapping and can be removed fairly easily

2. Over-wing wheel well blister and reinforcing strake; late/postwar feature related to a change in angle of the wheel axle (from 8 degrees to 4) when operating off of tarmac; should be completely smooth surface above the wheel wells, in-sim axle angle is correct 8 degrees however

  Hide contents

3. Scissor link undercarriage; very late/postwar modification - oddly enough, the model has the correct gear leg fairings and bay without the extra cutout for the links; should be straight spline type

4. 5-spoke wheels; common in 1942 and Mk V conversions but by 1943/44 a four-spoke wheel was the standard, sometimes with a hubcap

5. Recognition light behind the aerial mast; this was deleted in 1943 and should be absent by the time the Aero-Vee filter was introduced

  Reveal hidden contents

6. Missing gun camera in starboard wing root - the original port wing installation was deleted in lieu of the fuel cooler in the F Mk IXs - the LF lacked this cooler, but when the gun camera later returned on the F (and LF) it was decided to standardise on a starboard wing installation - it is correct that early LF's lacked the camera but probably by late 1943 and definitely by the time of D-Day it should have returned*

  Reveal hidden contents

7. Missing IFF aerial under the starboard wing

8. Missing drop tank deflection hooks

  Reveal hidden contents

null

9. Both wobble AND booster pump; should be either or - early ones had the wobble pump, later the booster pump; ours should probably have singly the booster pump

10. Missing beam approach aerial and associated cockpit control (this is a variable feature as some had them, some didn't)

11. Missing remote contactor control in cockpit**

  Reveal hidden contents

12. Headrest; this is a Mk V feature not present on Mk IXs

13. Erroneous radiator flap control; this was a feature of the PR Mk XI and is a common "warbird" modification in modern times, is however anachronistic and should be in fact the "Camera Master" switch; only the test button should be present*

  Reveal hidden contents

14. Missing generator failure light

15. Missing the interconnected prop and throttle control; this was standard in the Mk IX by the time of the Normandy campaign and was one of the other features differentiating it and the F Mk XVI, which wasn't set up for it

16. Missing gun camera exposure control on port wall*

  Reveal hidden contents

There are some geometric issues with the external and internal 3d models, be they missing features or outright incorrect:

17. Cannon fairings incorrect shape; in-sim they taper immediately from the root, when they should have a straight channel, then a second tapering piece which attaches to it (this tapered fairing is the same piece as used on the outboard cannon in the four-cannon configuration, the E wing, and even the single cannon on the Mk VB). I remember originally the model had the later cigar-shaped fairing; this would have actually been fine for 1944 but it was changed in 2017 and in doing so it's now inaccurate. Additionally, the plug for the outer cannon casting is completely flat, when it should be somewhat rounded

  Reveal hidden contents

 

18. Cockpit windscreen piece currently replicates the version from the pressurised Mk VII, which had a greater number of bolts and seatings for them in the windscreen casting

  Reveal hidden contents

Mk XVI

19. The windscreen framework is missing bolts; these appear however to be included in the Spitfire cockpit update that's upcoming, judging by the Normandy 2 trailer

  Reveal hidden contents

 

20. The outer wing panels appear to be a little too thick in section; it's hard to get a photo demonstrating this but it's something I've noticed since the module first came out in 2016

21. Front of tail fin and fairing very angular and awkward; should be a more graceful curve

22. Profile of the bottom of the rudder is slightly incorrect

  Reveal hidden contents

23. Edge of gunsight mounting casting is round; should be cut square

*These only apply if the gun camera is mounted, which it should be for the Normandy time period

**This applies when the wobble pump isn't fitted, which should be correct for the Normandy time period

Here are a few photos demonstrating the state of F Mk IXs throughout late 1943 and throughout 1944 - the appropriate time period for the module.

Here's an early Castle Bromwich LF Mk IX (before MH434 was built).

I really don't think a hodgepodge of features is the way to go, I feel an early and late LF variant set would be more appropriate - and that's not even mentioning potential F or HF variants and their differences!

 

Thank you for the detailed description and effort, I will discuss with Nick and the team about what we can do on these.

 

On 10/21/2023 at 1:37 AM, Art-J said:

I'd say let them tackle the incorrectly marked 2.9 boost gauge first, so that it actually shows what boost we're really pulling. Followed by fixing inop P8 compass. These are going to affect our flight ops more than external rivet-counting bits mentioned above  .

Yes, that one is... bad. it is already reported internally, but I have elevated it. Thanks. 

[Lythronax]

vor 3 Stunden schrieb NineLine:

Thank you for the detailed description and effort, I will discuss with Nick and the team about what we can do on these.

Thank you so much! I wish I had all the documentation apropos modification lists/classes etc. to hand at current, but I trust you guys already have it all somewhere.

[Skewgear]

On the point about cannon blanking stubs not being rounded enough, here is one of the most famous photos of a Spitfire IX of all time.

[71st_AH Rob]

6 minutes ago, Skewgear said:

On the point about cannon blanking stubs not being rounded enough, here is one of the most famous photos of a Spitfire IX of all time.

That's a Mk IXe and it is tape over the .50 cal gun port, not the same as the blank on the second empty cannon/.50 cal port on a Mk IXc.

[Skewgear]

3 minutes ago, 71st_AH Rob said:

That's a Mk IXe and it is tape over the .50 cal gun port, not the same as the blank on the second empty cannon/.50 cal port on a Mk IXc.

Without having the engineering drawings to hand (!), by eye the gunport plug looks to be about the same diameter as for the cannon barrel fairing. I'd be surprised if the two were different diameters requiring two differently shaped items.

For what it's worth, the original caption says: "Wing Commander J E Johnson, leader of No. 144 (Canadian) Wing RAF, rests on the the wing of his Supermarine Spitfire Mark IX with his Labrador retriever Sally, between sorties at B2/Bazenville, Normandy."

144 Wg had three sqns, 441, 442 and 443. No. 443 Sqn RCAF's Form 541 for June 1944 says Johnson was flying with them, but only gives the aircraft type as "Spitfire IX". 442's says "Spitfire" (no mark number) and 441's says "Spitfire L.F.". Cross-referencing a handful of 441's serial numbers from the .txt Spitfire production list on the internet shows the type only as "Spitfire LFIX" with no suffix. All are Castle Bromwich aircraft, MKnnn, delivered in the first few months of 1944.

Some random website selling a model of Johnson's Spitfire says: "MK392, the Spitfire Johnson flew with 144 Wing has now been identified as being originally produced as a Spitfire IXc. In June 1944, Johnson had an MU modify the airplane by changing the gun positions, which was not difficult since MK392 used the large teardrop-shaped “universal gun cover.”

Seems that the items pictured could have been local mods by this MU or whoever rearmed Johnson's aircraft with .50s, but my point is that we cannot baldly state that what's modelled in game at the moment is 100% wrong.

[Lythronax]

vor 23 Stunden schrieb Skewgear:

Without having the engineering drawings to hand (!), by eye the gunport plug looks to be about the same diameter as for the cannon barrel fairing. I'd be surprised if the two were different diameters requiring two differently shaped items.

For what it's worth, the original caption says: "Wing Commander J E Johnson, leader of No. 144 (Canadian) Wing RAF, rests on the the wing of his Supermarine Spitfire Mark IX with his Labrador retriever Sally, between sorties at B2/Bazenville, Normandy."

144 Wg had three sqns, 441, 442 and 443. No. 443 Sqn RCAF's Form 541 for June 1944 says Johnson was flying with them, but only gives the aircraft type as "Spitfire IX". 442's says "Spitfire" (no mark number) and 441's says "Spitfire L.F.". Cross-referencing a handful of 441's serial numbers from the .txt Spitfire production list on the internet shows the type only as "Spitfire LFIX" with no suffix. All are Castle Bromwich aircraft, MKnnn, delivered in the first few months of 1944.

Some random website selling a model of Johnson's Spitfire says: "MK392, the Spitfire Johnson flew with 144 Wing has now been identified as being originally produced as a Spitfire IXc. In June 1944, Johnson had an MU modify the airplane by changing the gun positions, which was not difficult since MK392 used the large teardrop-shaped “universal gun cover.”

Seems that the items pictured could have been local mods by this MU or whoever rearmed Johnson's aircraft with .50s, but my point is that we cannot baldly state that what's modelled in game at the moment is 100% wrong.

E wing Spits often used a wooden plug inside the MG port shaped to fit the cannon "chimney pot", often with tape over it too as can be seen in the photo. Aside from cases where the outboard cannon was removed in Mk VCs, which were often flat as in-sim, the plug for the superfluous cannon port was made in-factory and the shape/material depended on time of manufacture. Most however were a half-dome shape as I've demonstrated. Late Mk VII and VIIIs had a more pointed variant as seen below, whereas some also had clear pieces as recognition lights were fitted in the outboard cannon bay.

 

The quality isn't fantastic but here is a later Supermarine arrangement for the Mk VII/VIII with the solid "Blanking Cap" outboard:

 

Here is the late C wing for the Mk VC and IX before the outer cannon port was reintroduced in December (?) 1943 (to facilitate easy conversion in-field to E wing configuration when enough kits were ready):

 

and here is the Mk IXe wing setup; the inboard/50 cal chimney port and blast tube are all one piece:

[Skewgear]

Fantastic information, can't do much better than that. Looks like there were at least 3 different types of cannon/MG plug depending on time period and wing type: the rounded spitzer bullet nose; the semi-rounded flat face one in the diagrams above; and the almost flat plate taped into place as seen on Johnson's IXE (or was it a C converted to E armament spec?)

[Doughguy]

This might be simply due to the manufacturer of guns/cannons etc. And what was spare in parts.

Parts change over time. B17 crews e.g. wore sheep leather jackets at first, later then dropping these, as they were too expensive.

[71st_AH Rob]

https://en.m.wikipedia.org/wiki/Johnnie_Johnson_(RAF_officer)#/media/File%3AWing_Commander_James_E_'johnny'_Johnson_at_Bazenville_Landing_Ground%2C_Normandy%2C_31_July_1944_TR2145.jpg

This is almost certainly taken on the same day, I can't remember what the article was about that this photo shoot was staged for but you can see that it is most definitely a Mk IX.  There is nothing definitive that can distinguish it as a c or e wing however, the term e wing had not been adopted yet when this picture was taken, the e was about the armament. 

If you look closely enough at the yellow leading edge on the starboard wing there are two dark marks which could be gun ports for the .303s. 

As for the inner ports, the plugs are clearly red and flat which would denote a port that had a live weapon not an empty bay. If it was an empty bay they would just reuse the rounded rubber plug that would have been in the the outer bays before.

The universal wing (c wing) could accommodate two 20mm Hispano and either four .303, or four 20mm Hispano or two 20mm Hispano and two .50 cal.

I have read in several places that 2TAF converted all of its Spitfire squadrons to e type armament by the end of July 44.  I have not seen any primary sources however.  I think the devil will be in the logistics and research will reveal.50 cal ammo allocation to 2TAF squadrons.

I believe that these famous photos show Johnson in late July '44 with his Mk IX equipped with 2 x Hispano and 2 x .50cal. 

If it was four Hispano you would see them protruding, if it was two Hispano and four .303 there would be no need to move the cannon to the outside bays and put a red plug on the empty ports. 

[Lythronax]

vor einer Stunde schrieb 71st_AH Rob:

https://en.m.wikipedia.org/wiki/Johnnie_Johnson_(RAF_officer)#/media/File%3AWing_Commander_James_E_'johnny'_Johnson_at_Bazenville_Landing_Ground%2C_Normandy%2C_31_July_1944_TR2145.jpg

This is almost certainly taken on the same day, I can't remember what the article was about that this photo shoot was staged for but you can see that it is most definitely a Mk IX.  There is nothing definitive that can distinguish it as a c or e wing however, the term e wing had not been adopted yet when this picture was taken, the e was about the armament. 

If you look closely enough at the yellow leading edge on the starboard wing there are two dark marks which could be gun ports for the .303s. 

As for the inner ports, the plugs are clearly red and flat which would denote a port that had a live weapon not an empty bay. If it was an empty bay they would just reuse the rounded rubber plug that would have been in the the outer bays before.

The universal wing (c wing) could accommodate two 20mm Hispano and either four .303, or four 20mm Hispano or two 20mm Hispano and two .50 cal.

I have read in several places that 2TAF converted all of its Spitfire squadrons to e type armament by the end of July 44.  I have not seen any primary sources however.  I think the devil will be in the logistics and research will reveal.50 cal ammo allocation to 2TAF squadrons.

I believe that these famous photos show Johnson in late July '44 with his Mk IX equipped with 2 x Hispano and 2 x .50cal. 

If it was four Hispano you would see them protruding, if it was two Hispano and four .303 there would be no need to move the cannon to the outside bays and put a red plug on the empty ports. 

Very clearly a Mk IXe - most likely a standard LF IX converted to E wing status, as was very common in the run-up to D-Day.

 

The E wing conversions maintained the blast tubes and gun ports for the .303 guns, so they still had to be covered over with tape.

 

In any event, the Mk IX was not capable of mounting four cannon, due to the cannon heating plumbing running through the outer cannon bay, and aside from one prototype no Mk IX was ever so equipped. For the E wing the gun heating system was rearranged, but still precluded the fitment of four cannon. The Mk IX "Universal wing" is in fact not universal at all, and "Mk IXc" was never a designation that was used officially.

[71st_AH Rob]

10 hours ago, Lythronax said:

The E wing conversions maintained the blast tubes and gun ports for the .303 guns, so they still had to be covered over with tape.

 

In any event, the Mk IX was not capable of mounting four cannon, due to the cannon heating plumbing running through the outer cannon bay, and aside from one prototype no Mk IX was ever so equipped. For the E wing the gun heating system was rearranged, but still precluded the fitment of four cannon. The Mk IX "Universal wing" is in fact not universal at all, and "Mk IXc" was never a designation that was used officially.

The e wing kept the .303 gun bays but did not have the gun ports in the leading edge, nor the ejection ports for spent casings.  In all other ways they were the same as the c wing and could mount 2 x 20mm Hispano in each wing or 1 x 20mm Hispano and 1 x .50 cal the same as the c wing.

IWM Duxford released a timely video on the subject that I just saw this evening

~11:00 in they talk about a Vc with two 20mm Hispano in each wing.

[Lythronax]

vor 11 Stunden schrieb 71st_AH Rob:

The e wing kept the .303 gun bays but did not have the gun ports in the leading edge, nor the ejection ports for spent casings.  In all other ways they were the same as the c wing and could mount 2 x 20mm Hispano in each wing or 1 x 20mm Hispano and 1 x .50 cal the same as the c wing.

Yes I am well aware of this. My point is that the limited number of E wing conversions from standard Mk IXs retained the bays, blast tubes and gun ports for the 303s, which had to be blanked off. Hence why Johnson's Mk IXe in the photos has tape over the 303 gun ports.

And yes, the Mk Vc could carry two cannon per wing, but as I've stated before the Mk IX could not for reasons already mentioned. Nor the standard Mk IX or Mk IXe variants could carry two cannon. It was for a very short time intended that it could use the eight .303 fitment as was also provided for in the Mk Vc but this was never even trialled let alone used in combat.

To clarify further, there is no "Mk IXc", only Mk IX and IXe. As all Mk IXs were originally built with the same wing and armament a suffix wasn't used till the E wing was introduced. The prefixes F, LF, HF etc. came into use in March and April of 1943. The Mk IX wing is not a "C" wing in the sense of the Mk Vc in that it is not universal. Mod 683 was eventually embodied in late 1943 and officially standardised armament on the Mk IX (and Vc for that matter) exclusively to 2x 20mm and 4x .303s., although some squadrons removed two or all four of the Brownings in service to reduce weight. The removal of the outer cannon stub and use of slimline feed motor blister began in April of 1943, though this modification was cancelled in November with the future introduction of the E wing in mind, to easier facilitate conversion to that configuration.

[Skewgear]

On 10/17/2023 at 3:57 AM, Lythronax said:

Here's a curious photo! Two Spit IXs of No.453 RAAF around the time of D-Day at RAF Ford. The one in the foreground has an Aero-Vee filter, spokeless wheels and the GGS; the one in the background is clearly a much earlier Spit as it has 5-spoke wheels and, most curiously of all, no filter! I wish I had the serial numbers.

To further clarify, the Aero-Vee filter was in fact not a retrospective modification, aside from cases where the aircraft in question had sustained damage to its original intake!

Just stumbled across a historical snippet which means there's a complete answer available.

453 Sqn recorded their aircraft serial numbers at the end of each month's Form 541, reconciling letter to serial number.

At the end of May 1944 (i.e. a week or two before the photo above) these were:

A	MH443
B	MJ789
D	MK575
E	MK288
F	MH418
G	MH355
H	MK355
J	MH487
K	MK260
L	NH244
M	MJ333
N	MJ779
P	MH454
R	NH208
S	MK618
T	MK285
U	MK284
V	NH274
Z	MK421
?	MK379

K in the photo above is therefore MK260. A Castle Bromwich LF.IX, taken on charge by 9 Maintenance Unit from the factory on 2nd February 1944.

The background Spitfire is clearly not coded ? which was the CO's personal marking; apparently he went through six such machines coded ? according to https://www.britmodeller.com/forums/index.php?/topic/235017530-spitfire-mkixc-bs227-fuu/page/2/#comment-3605666

Judging by the part of the code letter visible on the background machine it must be one of these four, 453 having no FU-I:

FU-L MK566 - Castle Bromwich LF.IX taken on charge by 39MU on 1st March 1944

FU-H MK355 - Castle Bromwich LF.IX taken on charge at 9MU on 4th February 1944

FU-U MK284 - Castle Bromwich LF.IX taken on charge at 6MU on 2nd February 1944

FU-J MH487 - Castle Bromwich LF.IX taken on charge at 33MU on 17th August 1943

MH487 was previously the CO's personal mount in April, being coded ? during that month before the delivery of MK379 in June which took on the ? code letter. Combining this with what looks like a squadron leader's pennant and a piece of unique nose art in the photo, I am fairly sure that the Spitfire in the background is MH487.

With MH487 being the older aircraft, it seems likely to me it may well have been fitted with ex-Mk.V components of no critical importance on the production line.

Incidentally, MH487 was destroyed in a crash recorded as so: "Crashed Coombe Hill W of Eastbourne on ferry flight 13-6-44 FSgt DG Saunders (RAAF)+"

[Lythronax]

vor 44 Minuten schrieb Skewgear:

I am fairly sure that the Spitfire in the background is MH487.

MH487 makes a lot of sense! As a contemporary of MH415 and 434, it would have been constructed with the early air intake, which it still has in the photo.

(MH434 in March 1944 at Hornchurch with No.222)

 

Edited October 31, 2023 by Lythronax