DCS: Spitfire Mk LF IXc Discussion

[Crumpp]

I am going to show some more docs as soon as they are arranged, processed and sorted... but the reading was very interesting, though I was very short in time.

Anyway, the feelings and opinions of different pilots could be very different. For example, as I asked Erich about 109G stability he said that he did not find it unpleasant, though Rusian test pilots mentioned the instability as disadvantage of 109G (though I-16 had even worse instability or was neutral having worse damping due to its short fuselage). Possibly, it was done not to praise German plane...

 

 

Additionally, pilots complied to unwanted reaction during landing and taxiing because of this bobweight.

 

Which is exactly why the NACA adopted a Stability and Control standard!

 

I love the RAE report on the Spitfire Mk IX fuselage tanks for this very reason. It really highlights the engineers dilemma. One pilot says the aircraft is absolutely not suitable for formation flying and the next few days, Jeffery Quill comes back and says the aircraft is fine for formation flying!

 

:thumbup:

Edited November 17, 2015 by Crumpp

[Crumpp]

Yo-Yo says:

Additionally, pilots complied to unwanted reaction during landing and taxiing because of this bobweight.

 

I imagine that they would have complained. There is a danger if the pilot suddenly letting go of the stick in a maneuver as well as PIO on a bounced landing with inertial weights. The weight will act in the opposite manner the designer intends.

 

I would look for them to added weight forward of the hinge line on the elevator or increase the cable tension/friction. I would be interested in knowing what they did to increase the stick force per G limit on the Mk IX.

[Friedrich-4B]

Is something being confused somewhere?

 

Just clearing up a myth that Merlin 66 pistons regularly failed after 7 1/2 to 50 hours of running at high boost.

 

That is why some folks think the operational limits published in the POH are just a big joke to fool the pilots going into combat.

 

It demonstrates that the Merlin wasn't made of glass and stops some folks from believing that Merlins should automatically self-destruct after 5 minutes and 5 seconds running at +18 lbs boost during combat.

[klem]

Is this a confirmation that the Spitfire IX we will be getting is an early Mark?

 

Oh well, another early 1944 Allied airplane to 'fly' against late 1944 Luftwaffe airplanes.

 

I don't understand the question. It is a MkIXb.

 

It would appear to be modelled after OFMC's MH434 as illustrated in the pre-releases and to which ED may well have access as it is at Duxford where their associates The Fighter Collection are based (and whose pilot(s) tested their P-51D modelling for them).

 

It would of course have been nice to get the MkIXe with 20mm cannons and 0.5 m/gs....... but we ain't. And anyway the IXe had the Merlin 66 too.

[MiloMorai]

MH434 was delivered to 222 Squadron 13 August 1943.

 

to 84GSU 15 June 1944

to ROS 7 July 1944

 

MH434 was built to the 9th Spitfire order of which the last a/c of that order was delivered to 46MU 29 April 1944.

[Cripple]

Omg... please don't turn this thread in to a CoG debate too. :(

 

It was my understanding that the mkIX was very similar to the mkV, essentially being an up-engined mkV airframe with a few wee tweeks. I believe early models were even converted from mkVs on the production line, before dedicated production of the mkIX got up to speed.

 

Certainly, if you read the manuals for the mkIX (AP 1565J&L?), they refer back to the mkV manuals (AP 1565E) - with Section 2, the flying and handling info, being a placeholder that says "same as a mkV" (image attached).

 

I'm not going back through this thread, but I am sure I read she's going to have the Merlin 66 too. That should even the playing field nicely...:D

[Friedrich-4B]

I don't understand the question. It is a MkIXb.

 

It would appear to be modelled after OFMC's MH434 as illustrated in the pre-releases and to which ED may well have access as it is at Duxford where their associates The Fighter Collection are based (and whose pilot(s) tested their P-51D modelling for them).

 

It would of course have been nice to get the MkIXe with 20mm cannons and 0.5 m/gs....... but we ain't. And anyway the IXe had the Merlin 66 too.

 

Actually, DCS is modelling a Spitfire L.F. Mk. IXC with the Merlin 66 - Mk IXb was simply an unofficial designation given to the L.F Mk. IX by the RAF's pilots when it first entered service. (Hopefully, if ED has access to The Fighter Collection's pilots, it will lay to rest any myths about the "longitudinal instability" of the Mk IX so beloved of certain members of this forum.)

 

Maybe we'll get an option for a IXE wing, seeing as so many L.F Mk. IXEs were operational by D-Day.

[Kurfürst]

Just clearing up a myth that Merlin 66 pistons regularly failed after 7 1/2 to 50 hours of running at high boost.

 

Oh but they did. You posted the evidence yourself.

 

 

Reliability with continous operating conditions of 18 lbs/in boost and 3000 rpm

 

Ring gumming after

Test (1) 9 1/2 hours

Test (2) 7 1/2 hours

Test (3) 21 1/2 hours

Test (4) 20 hours

Test (5) 50 hours

 

From the avarage of 5 tested engines at +18 boost, the statistical avarage is 21.7 hours of operation before piston ring gumming and piston failure would occur - in as little as 7 1/2 hours or as much as 50 hours.

By that time however, failures of the crankase "in many main bearing panels" was a statistical certainity to occur, so in brief, the Merlin 66 bearings and pistons would simply fall apart after about 20 hours worth of maximum allowable load.

Edited November 17, 2015 by Kurfürst

[Kurfürst]

Is this a confirmation that the Spitfire IX we will be getting is an early Mark?

 

Define early. The Mark IX LF with Merlin 66 did not see mass operational deployment until spring 1944, when Squadrons began to swtich to it from the Mk V en masse.

 

Oh well, another early 1944 Allied airplane to 'fly' against late 1944 Luftwaffe airplanes.

 

The early 1944 Spitfire would be the Mk V, actually. The Mk IX LF at +18 lbs became by far the most numerous Spitfire Mark in most 1944, after it replaced the Mk V and it kept facing the latest German birds that the Luftwaffe fielded quickly and in large numbers - D9 and K4 production totals (ca 3500) easily matched Mark IXs available to the British, since about a thousend of the cc 4000 built were shipped to the Soviet Union (who kept them back from the fronline for high altitude air defense tasks). So I do not see whats wrong with the choice of having the Nine instead of the early 1944 Spitfire Mk Vs.

Edited November 17, 2015 by Kurfürst

[Crumpp]

From the avarage of 5 tested engines at +18 boost, the statistical avarage is 21.7 hours of operation before piston ring gumming and piston failure would occur - in as little as 7 1/2 hours or as much as 50 hours.

By that time however, failures of the crankase "in many main bearing panels" was a statistical certainity to occur, so in brief, the Merlin 66 bearings and pistons would simply fall apart after about 20 hours worth of maximum allowable load.

 

Which is nothing special for World War II fighter aircraft engine development. The results of these engineering investigations can be seen in every Pilot Operating Instructions limitations for the Merlin 66/Packard 266/ V-1650-7 engine flown during World War II.

 

5 minute limitation at War Emergency Power...

 

That time must be reported, logged, and the engine inspected at each use before being returned to service.

 

Practically the same as every other engine using an extremely over-boosted power setting during the war.

[Friedrich-4B]

Oh but they did. You posted the evidence yourself.

Reliability with continous operating conditions of 18 lbs/in boost and 3000 rpm

 

Ring gumming after

Test (1) 9 1/2 hours

Test (2) 7 1/2 hours

Test (3) 21 1/2 hours

Test (4) 20 hours

Test (5) 50 hours

 

From the avarage of 5 tested engines at +18 boost, the statistical avarage is 21.7 hours of operation before piston ring gumming and piston failure would occur - in as little as 7 1/2 hours or as much as 50 hours.

By that time however, failures of the crankase "in many main bearing panels" was a statistical certainity to occur, so in brief, the Merlin 66 bearings and pistons would simply fall apart after about 20 hours worth of maximum allowable load.

 

:lol: What a shame Kurfurst didn't read all of the cited material properly, instead of conveniently overlooking Harvey-Bailey's comments and favouring just five tests, carried out using two Merlin 66s.

 

Once again; the tests favoured by Kurfurst were carried out from mid-1942 to early 1943 and, as Harvey-Bailey noted, the problems with the Merlin 66s pistons (and with the crankcase) were systematically resolved by Rolls-Royce as they arose.

Edited November 17, 2015 by Friedrich-4/B
Small punctuation correction

[NineLine]

:lol: What a shame Kurfurst didn't read all of the material properly, instead of conveniently overlooking Harvey-Bailey's comments and favouring just five tests, carried out using two Merlin 66s.

 

Once again, the tests were carried out from mid-1942 to early 1943 and, as Harvey-Bailey noted, the problems with the Merlin 66s pistons (and with the crankcase) were systematically resolved by Rolls-Royce as they arose.

 

Its a shame this keeps coming up... aside from destroying the engine from abuse during a flight (over boosting, over heating, whatever), the lifespan of the 66 really isnt going to be an issue for anyone until the tie the engine/aircraft to our accounts, and track how many hours we fly it, and make you guys repurchase when you crash and destroy your aircraft :P

[Crumpp]

Its a shame this keeps coming up... aside from destroying the engine from abuse during a flight (over boosting, over heating, whatever), the lifespan of the 66 really isnt going to be an issue for anyone until the tie the engine/aircraft to our accounts, and track how many hours we fly it, and make you guys repurchase when you crash and destroy your aircraft :P

 

:megalol:

[MiloMorai]

Which is nothing special for World War II fighter aircraft engine development. The results of these engineering investigations can be seen in every Pilot Operating Instructions limitations for the Merlin 66/Packard 266/ V-1650-7 engine flown during World War II.

 

5 minute limitation at War Emergency Power...

 

And when the engine went to 25lb boost from 18lb boost, the engine still had a 5 minute limit.:music_whistling:

[Crumpp]

And when the engine went to 25lb boost from 18lb boost, the engine still had a 5 minute limit.

 

And there were also appropriate design changes that allowed to run at 25 lbs boost for 5 minutes.

 

:music_whistling:

[MiloMorai]

Define early. The Mark IX LF with Merlin 66 did not see mass operational deployment until spring 1944, when Squadrons began to swtich to it from the Mk V en masse.

 

The early 1944 Spitfire would be the Mk V, actually. The Mk IX LF at +18 lbs became by far the most numerous Spitfire Mark in most 1944, after it replaced the Mk V and it kept facing the latest German birds that the Luftwaffe fielded quickly and in large numbers - D9 and K4 production totals (ca 3500) easily matched Mark IXs available to the British, since about a thousend of the cc 4000 built were shipped to the Soviet Union (who kept them back from the fronline for high altitude air defense tasks). So I do not see whats wrong with the choice of having the Nine instead of the early 1944 Spitfire Mk Vs.

 

You forgot about the re-engined Mk XVI which takes care of those IXs sent to the SU.

 

PK312-PL499 - 800

last a/c delivered 30-6-44 (1st half of 1944)

 

NH series, 600 delivered by June 1944

 

Your own research has:

 

December 1943

Mk IXs:

 

RAF : No. 19, 32, 43, 64, 65, 66, 72, 74, 93, 111, 131, 132, 152, 165, 222 , 237, 241, 249, 602, 682. Total : 20 Squadrons.

 

Allied : No. 302, 306, 308, 310, 312, 315, 326, 341, 350. Total: 9 Squadrons

Commonwealth : No. 401, 411, 412, 421, Total: 4 Squadrons

RAAF : No. 451, 453, 457. Total: 3 Squadrons

RNZAF : No. 485, 501. Total: 3 Squadrons.

 

Grand total : 39 Sqn x 20 (not 12 as you stated) = 780

 

Granted all would not be LF XIs.

 

You can go on all you want about total production of K-4s and D-9s but,

 

End Nov 366 D-9s produced

End Nov 529 K-4s produced

 

only 236 K-4s were 'on hand' in operational units in the late Fall/Autumn of 1944.

[Friedrich-4B]

Define early. The Mark IX LF with Merlin 66 did not see mass operational deployment until spring 1944, when Squadrons began to swtich to it from the Mk V en masse. The early 1944 Spitfire would be the Mk V, actually.

 

Correction; Starting from August 1943 for the first operational deployments of the L.F Mk. IX, beginning with MH350, MH708, & etc etc etc.

 

What Kurfurst counts as Mk V British-based squadrons in early 1944 were mostly squadrons of 2 TAF that had been using Mk IXs operationally in 1943, then were "rested" while flying Mk Vs on rear-echelon airfields pending re-equipment with new L.F Mk. IXs, or Tempests, Typhoons or Mustang IIIs. The first so-called en masse operational deployments of the L.F. Mk. IX occurred in January-February 1944, after several squadrons had re-equipped.

 

On November 15 1943, for example, 2 TAF had 17 Spitfire Mk. IX squadrons and 5 Spitfire V units; most of the latter were "resting" prior to re-equipping with L.F Mk IXs or other aircraft types:

 

 

an early 1944 example of the rotational process, where squadrons were rested after operations and traded Mk IXs for Mk Vs, while 2 squadrons using Mk Vs were brought up to operational strength using IXs; with the addition of 453(RAAF) Sqn. plus the three Czech squadrons of 134 Airfield, the relative Spitfire IX vs V strength remained about the same:

 

 

Thus, Kurfurst's assertion that Mk Vs were the Spitfires of early 1944 is completely wrong, particularly in the frontline units of 2 TAF. (Albeit, he may be right when counting operational and non-operational squadrons combined.)

 

The Mk IX LF at +18 lbs became by far the most numerous Spitfire Mark in most 1944. So I do not see whats wrong with the choice of having the Nine.

 

:thumbup: 2 TAF on June 5 1944:

 

 

The only units using Mk Vs were 6 Air Spotting squadrons of the RAF, FAA and USN.

 

(all pages from 2nd Tactical Airforce Volume One: Spartan to Normandy June 1943 to June 1944 Christopher Shores and Chris Thomas)

Edited November 18, 2015 by Friedrich-4/B
Spelling

[Kurfürst]

Thus, Kurfurst's assertion that Mk Vs were the Spitfires of early 1944 is completely wrong, particularly in the frontline units of 2 TAF. (Albeit, he may be right when counting operational and non-operational squadrons world-wide.)

 

The Air Ministry disagrees with this notion. Force as of 1st January 1944:

 

Spitfire V - 24 Squadrons

Spitfire VII - 2 Squadrons

Spitfire IXF - 11 Squadrons

Spitfire IXHF - none

Spitfire IXLF - 9 Squadrons

Spitfire XII - 2 Squadrons

Spitfire XIV - none, one Squadron (610) re-equipping

[Friedrich-4B]

The Air Ministry disagrees with this notion. Force as of 1st January 1944:

 

Spitfire V - 24 Squadrons

Spitfire VII - 2 Squadrons

Spitfire IXF - 11 Squadrons

Spitfire IXHF - none

Spitfire IXLF - 9 Squadrons

Spitfire XII - 2 Squadrons

Spitfire XIV - none, one Squadron (610) re-equipping

 

First question is So What? What does it "prove" that the RAF chose to use the Spitfire V as a transition aircraft to allow RAF squadrons to rest and re-equip on rear-echelon airfields? What it does show is that the RAF was using its available resources to the maximum.

 

As it is, Kurfurst should read what I wrote:

 

What Kurfurst counts as Mk V British-based squadrons in early 1944 were mostly squadrons of 2 TAF that had been using Mk IXs operationally in 1943, then were "rested" while flying Mk Vs on rear-echelon airfields pending re-equipment with new L.F Mk. IXs, or Tempests, Typhoons or Mustang IIIs....Thus, Kurfurst's assertion that Mk Vs were the Spitfires of early 1944 is completely wrong, particularly in the frontline units of 2 TAF. (Albeit, he may be right when counting operational and non-operational squadrons combined.)

 

Thus, the majority of the Spitfire Vs in Britain were transitional aircraft only, being rotated from one squadron to the next as the frontline Spitfire IX units were rested and re-equipped over the winter of 1943-44 (at a time when front line operations were limited by winter weather). Another problem with Kurfurst's 'point' (what ever it is) is that the list doesn't show whether any of the the squadrons listed as Spitfire V units already had some Spitfire IXs on strength as of Jan 1 1944.

 

Here's a more accurate picture:

 

 

Anyway, the apparent strength of the Spitfire V vs IX population in January 1944 has little to do with the DCS Spitfire L.F. Mk IX of D-Day and later. :smilewink:

Edited November 18, 2015 by Friedrich-4/B

[Ala13_ManOWar]

Anyway, the apparent strength of the Spitfire V vs IX population in January 1944 has little to do with the DCS Spitfire L.F. Mk IX of D-Day and later.

Yeah, I don't get what's the whole point of this soooo long discussion... :huh: We don't have the module yet... :shocking:

 

S!

[Kurfürst]

First question is So What? What does it "prove" that the RAF chose to use the Spitfire V as a transition aircraft to allow RAF squadrons to rest and re-equip on rear-echelon airfields? What it does show is that the RAF was using its available resources to the maximum.

 

"transitional aircraft", "rear echelon only" :lol: . So if we believe that explanation, the vast majority RAF Spitfire Squadrons between 1941 and 1944 were doing what, transitional rear echelon duties...? That's just silly, yet you seem to believe in this odd twist of operational reality that can be clearly seen to be untrue by the actual operational documents, and I doubt any of that would change if its gets re-painted in MS Paint.

 

As to answer your question, the aforementioned Air Ministry document shows and it proves irrefutably that the RAF Spitfire Squadrons were mostly equipped with the Mark V for the better part of the war. No 'explanation' is needed, the numbers are there for all to see.

 

Whether using the (by then, rather obsolate) available Mark V resources to the maximum an intentional choice (if so, outright crazy) decision or out of necessity because the Mk IX L.F. wasn't produced in sufficient numbers for the better part of 1943 (as it was the case) and/or because its Merlin 66 was still trouble plagued for the better part of 1943 at its increased boost and was too prone for failure to permit wider operational use (as it was the case) is, in the end a matter of historical interest and debate, but doesn't change a bit on the basic fact that the IX L.F. was simply wasn't an operational reality until 1944 for all practical purposes. By the the time it seen operational service that worth speaking of it was on the edge of becoming obsolete itself, since the fighters introduced parallel with it had become very considerably faster.

 

As it is, Kurfurst should read what I wrote:

 

I am not particularly interested in reading historical fantasies and 'explanations' of similar nature - it is the historical reality that is found in the actual operational documents that interests me.

[GrapeJam]

Even the vast majority of 109s at the end of the war were still G6s.:music_whistling:

[Kurfürst]

Even the vast majority of 109s at the end of the war were still G6s.:music_whistling:

 

Actually, as of 31 January 1945, there were 71 G-6s, 431 medium altitude G-14s, 619 high altitude G-10/G-14AS and 314 K-4s in 1st line service.

[Solty]

I am not particularly interested in reading historical fantasies and 'explanations' of similar nature - it is the historical reality that is found in the actual operational documents that interests me.

 

Why do you even participate if you do not read what other's say. Your attitude is horrible and I give you negative for that.:mad:

 

Now I am not a Spitfire enthusiast, so I may know way less, but Spit Mk IX was beeing produced since 1942 with various modifications along the way. So I would imagine that it has been the main Mk in production for 1943.

 

Our game is set in late 1944 Europe with Bf109K4 and Fw190D9 around, so that is very late 1944. So... naturally I would expect Spitfire MkIX LF with Merlin 66 and 25lbs boost as it will keep the Spit both competetive against those "wunderwaffe" and historically accurate as this setting was used by the RAF for many Spitfires in service.

 

I don't think Spitfire MkV is in any way relevant for the time period of DCS.

[MiloMorai]

Actually, as of 31 January 1945, there were 71 G-6s, 431 medium altitude G-14s, 619 high altitude G-10/G-14AS and 314 K-4s in 1st line service.

 

Reference source required.