DCS: Spitfire Mk LF IXc Discussion

[Friedrich-4B]

Good man, we'll make a spitfire pilot out of you yet.

 

The next step is a handlebar moustache.

 

Either a Spitfire pilot or an evil, chopper wielding gang leader

 

[bongodriver]

How about fusing it neatly into an evil Spitfire wielding Squadron leader :thumbup:

[Kurfürst]

It depends, some models armaments... The MK V Hispano cannon had to be cocked on the ground by hand, because of them getting rid of the Cock camber.. The .303 Brownings were a type of automatic loading...

 

Thanks. So if I understand right, the Hispano cannon had no possibility to reload/recycle in the air in case of say, a jam or a forgetful ground crew...?

[bongodriver]

Thanks. So if I understand right, the Hispano cannon had no possibility to reload/recycle in the air in case of say, a jam or a forgetful ground crew...?

 

Sounds about right, I don't think the Hispano differed wildly from any other wing mounted armament.

[DD_Fenrir]

Hold up chaps; I've got a copy of 'The Guns of the Royal Air Force, 1939-1945' by Graham Wallace (ISBN-10: 0718303628); I'll dig it out and see if there's any conformation in that.

[Friedrich-4B]

Sounds about right, I don't think the Hispano differed wildly from any other wing mounted armament.

 

AFAIK the MG 151s in the wing gondolas on some Bf 109Fs, Gs and Ks could not be re-cocked, nor could Fw 190 wing guns so, no, the Hispanos in the Spitfire were not unique or unusual in that respect.

[Yob]

Thanks. So if I understand right, the Hispano cannon had no possibility to reload/recycle in the air in case of say, a jam or a forgetful ground crew...?

 

Correct, :thumbup:

[Kurfürst]

Sounds about right, I don't think the Hispano differed wildly from any other wing mounted armament.

 

Indeed, I guess there is just not enough space for complex piping in space restrained wing installations. I wonder if there is some detailed manual for the Spitfire describing the sub systems, like board weapons (the pilot manuals we all know are very basic in this regard), as in the case of German aircraft manuals, which have many parts dedicated to each subsystem like fuel system, guns, bombs etc...?

[MiloMorai]

Indeed, I guess there is just not enough space for complex piping in space restrained wing installations. I wonder if there is some detailed manual for the Spitfire describing the sub systems, like board weapons (the pilot manuals we all know are very basic in this regard), as in the case of German aircraft manuals, which have many parts dedicated to each subsystem like fuel system, guns, bombs etc...?

 

Complex piping?

 

Of coarse there are manuals for the sub systems, they do have to be maintained.

[Friedrich-4B]

Indeed, I guess there is just not enough space for complex piping in space restrained wing installations.

How complex does one want the piping to be? Every extra, complex piece of equipment that's installed increases weight and requires extra maintenance. Generally speaking the Hispanos and Brownings were reliable enough to be mounted in the wings, and didn't jam often enough to warrant extra equipment. If a ground crew was unreliable enough to forget to cock the weapons I would suggest they would be unreliable enough to forget how to set any unjamming/recocking equipment as well - no unit would tolerate klutzy ground crews for long!

 

I wonder if there is some detailed manual for the Spitfire describing the sub systems, like board weapons (the pilot manuals we all know are very basic in this regard), as in the case of German aircraft manuals, which have many parts dedicated to each subsystem like fuel system, guns, bombs etc...?

 

It would be very surprising if there weren't detailed manuals for the Spitfire's sub-systems, although they don't seem to be as readily available as those of the Bf 109 or Fw 190: I would guess that whereas the German manuals were often captured and stored for future reference because of their technical interest, many of the RAF's manuals were routinely destroyed post-war as the aircraft became obsolete.

 

I have found a Spitfire VIII Technical manual...http://ep.yimg.com/ca/I/yhst-92316622267239_2264_225158537

Edited March 2, 2014 by Friedrich-4/B

[NineLine]

I believe ED has alot of the detailed tech manuals for the Spit, I know we found alot on the guns and such already, you are right though, they dont seem to be as readily available on the net...

[NineLine]

Interesting picture...

 

[MiloMorai]

A 132 Sqd Spitfire.

[westr]

Interesting picture...

 

 

That's a great picture!

[WildBillKelsoe]

Spitfire FTW!! go Yo-Yo!!!

[Friedrich-4B]

Two more bombed-up Spitfires, plus some interesting information in the captions (from Polish Wings 15: Supermarine Spitfire IX 1944-1946 ):

[Kurfürst]

The following is a rather interesting article by the well known gun expert Anthony G Williams on the Hispano:

 

The Hispano (technically the Hispano-Suiza HS 404) was designed and developed at the French arm of the European Hispano-Suiza company in the mid 1930s. A firing demonstration of a prototype to British officers in Paris in 1936 banished all thought of the Oerlikon; the Hispano was similar in size and weight, slightly more powerful and fired nearly twice as fast. Unfortunately, the processes of obtaining approval to buy the gun, setting up a subsidiary Hispano factory at Grantham (the British Manufacturing And Research Company, or BMARCO), redrawing the gun to imperial rather than metric units, testing and debugging the prototypes, then fitting them into aircraft and debugging the installations, all took too long for the cannon to achieve anything in the Battle of Britain.

 

A key problem was that the Hispano was designed for engine mounting, which meant that it would be bolted to a rigid crankcase. An aircraft wing is nowhere near as rigid, and this caused problems with all wing mountings, which had to be fine-tuned to achieve reliable gun functioning. In the initial Spitfire installation, which did see brief use in the Battle, matters were made worse by mounting the guns on their side in order to bury as much as possible of the bulky drum magazine within the wing thickness. The Hispano took a marked dislike to its unfamiliar environment and jammed as often as it fired. Much modification was needed to both the gun and the mountings before acceptable reliability was achieved. Even so, the stoppage rate by 1944 was still three times that of the US .50 Browning. A major improvement was the replacement in 1941 of the original 60-round drum by a belt feed.

 

Work was also needed to the ammunition, as it was found that the fuze of the standard explosive shells was too sensitive, causing them to burst on the aircraft skin rather than within the structure where they would do most damage, and plain steel practice shells often proved more effective. By 1941 both a delayed-action fuze and an explosive with added incendiary filling had been developed, but the practice rounds remained in use alongside the HEIs until they were replaced by a new semi-armour piercing round (SAPI) which was essentially an HE shell filled with an incendiary compound and capped with a hard steel tip instead of a fuze. From 1942 on, the standard Hispano loading became 50% HEI, 50% SAPI.

 

Compared with other Second World War 20 mm aircraft cannon, the Hispano was a powerful and effective gun, but only averagely fast-firing and unusually long and heavy. Its weaknesses were addressed in the late-war Mk V, shortened, lightened and speeded-up from 600 to 750 rpm. Here you can compare the size of the .303 Browning with the .50 Browning, the short-barrelled Mk V Hispano and the standard Mk II.

 

The Hispano Mk V could lay claim to being the best aircraft gun of the war, but this mainly saw action in the Hawker Tempest. What became the standard RAF armament of four Hispanos was also probably the best all-round fighter armament of the war, weighing more or less the same as the standard American armament of six .50" Brownings but being about twice as destructive.

 

Tony also noted that in actual practice, the gun was only load only 90 rounds instead of the nominal 120. This was quite common practice btw by armorers to reduce jamming probability.

 

Some practical firing trials were also made in 1942 to acquire information of the rate of stoppages when firing the cannon. Tony reports on that as the following:

http://www.quarry.nildram.co.uk/US404.htm

 

 

In 'Guns of the Royal Air Force 1939-1945' by G.F. Wallace - who was there - there is an account of British tests of the British and US Hispanos which took place early in 1942. The British were unhappy with initial supplies of the American-made guns: "there were frequent misfeeds and lightly struck cap stoppages, and the life of several small components was very short" so a comparative test between one British and three American guns was set up. The intention was to fire 5,000 rounds from each gun without replacing any components.

 

"The British gun fired the full programme but the performance of the American guns was so bad that in each case the trial had to be abandoned before the 5,000 rounds had been fired." The British gun experienced 19 stoppages in firing 5,012 rounds. The American guns experienced 67 stoppages out of 4,092, 97 out of 3,705 and 94 out of 2,610 respectively. Incidentally, Wallace states that the US guns were "beautifully made and better finished than our own" and expressed surprise that although lightly struck caps were a major source of stoppages, even more frequent were mis-feeds.

 

As well as lifespan - apparantly a breach lock crack could be expected anywhere between 1500-2000 rounds.

 

 

At the suggestion of Capt. E. R. S. Adams of the British Air Mission, two guns each from International Harvester, Oldsmobile, and Bendix were shipped to England for the purpose of competitive aerial tests with the Mark II. Representatives of the Army Ordnance Department were present to observe the 2,000-round tests which were held during July and August 1943.

 

Two British Mark II's were mounted in the left wing of a Hurricane fighter with two AN-M2's made by Oldsmobile and International Harvester in the right wing. Combat flying, dives, G-loading, straight-away, etc., were simulated. One stoppage was attributed to the Oldsmobile gun. The International Harvester weapon had no stoppages but a cracked breech-block was noticed at the completion of the trial. Each Mark II had one sear failure and one of them had a cracked breech lock after 1,400 rounds. The Bendix guns were fired on the ground in competition with the British-made guns and made a creditable showing.

 

In reporting the findings of the test, Mr. Hansen, of the British Ministry of Aircraft Production, declared: "American guns are as good as British guns and are acceptable for service use".

 

There is an inconsistency here. As will be seen below, the performance of the American Hispanos remained unsatisfactory throughout the war, yet the British expressed no concerns and were obviously happy with their guns. There would seem to be only two possible explanations; either the British tolerance of unreliability was considerably greater than the American, or the American guns had been assembled from selected components and thereby performed better than average.

[bongodriver]

I guess it was predictable that K would be going down this sort of road, time to let go old boy, with or without Hispano stoppages the Nazis lost WWII and no matter how hard you try to influence flight simulation games it won't change history.

[9.JG27 DavidRed]

still interesting and possibly usefull information for a flight sim nevertheless...

although i doubt that Ilya will ever read the forum

Edited March 3, 2014 by 9./JG27 DavidRed

[Friedrich-4B]

The following is a rather interesting article by the well known gun expert Anthony G Williams on the Hispano:

 

The Hispano (technically the Hispano-Suiza HS 404) was designed and developed at the French arm of the European Hispano-Suiza company in the mid 1930s. A firing demonstration of a prototype to British officers in Paris in 1936 banished all thought of the Oerlikon; the Hispano was similar in size and weight, slightly more powerful and fired nearly twice as fast. Unfortunately, the processes of obtaining approval to buy the gun, setting up a subsidiary Hispano factory at Grantham (the British Manufacturing And Research Company, or BMARCO), redrawing the gun to imperial rather than metric units, testing and debugging the prototypes, then fitting them into aircraft and debugging the installations, all took too long for the cannon to achieve anything in the Battle of Britain.

 

A key problem was that the Hispano was designed for engine mounting, which meant that it would be bolted to a rigid crankcase. An aircraft wing is nowhere near as rigid, and this caused problems with all wing mountings, which had to be fine-tuned to achieve reliable gun functioning. In the initial Spitfire installation, which did see brief use in the Battle, matters were made worse by mounting the guns on their side in order to bury as much as possible of the bulky drum magazine within the wing thickness. The Hispano took a marked dislike to its unfamiliar environment and jammed as often as it fired. Much modification was needed to both the gun and the mountings before acceptable reliability was achieved. Even so, the stoppage rate by 1944 was still three times that of the US .50 Browning. A major improvement was the replacement in 1941 of the original 60-round drum by a belt feed.

 

Work was also needed to the ammunition, as it was found that the fuze of the standard explosive shells was too sensitive, causing them to burst on the aircraft skin rather than within the structure where they would do most damage, and plain steel practice shells often proved more effective. By 1941 both a delayed-action fuze and an explosive with added incendiary filling had been developed, but the practice rounds remained in use alongside the HEIs until they were replaced by a new semi-armour piercing round (SAPI) which was essentially an HE shell filled with an incendiary compound and capped with a hard steel tip instead of a fuze. From 1942 on, the standard Hispano loading became 50% HEI, 50% SAPI.

 

Compared with other Second World War 20 mm aircraft cannon, the Hispano was a powerful and effective gun, but only averagely fast-firing and unusually long and heavy. Its weaknesses were addressed in the late-war Mk V, shortened, lightened and speeded-up from 600 to 750 rpm. Here you can compare the size of the .303 Browning with the .50 Browning, the short-barrelled Mk V Hispano and the standard Mk II.

 

The Hispano Mk V could lay claim to being the best aircraft gun of the war, but this mainly saw action in the Hawker Tempest. What became the standard RAF armament of four Hispanos was also probably the best all-round fighter armament of the war, weighing more or less the same as the standard American armament of six .50" Brownings but being about twice as destructive.

 

Tony also noted that in actual practice, the gun was only load only 90 rounds instead of the nominal 120. This was quite common practice btw by armorers to reduce jamming probability.

 

Some practical firing trials were also made in 1942 to acquire information of the rate of stoppages when firing the cannon. Tony reports on that as the following:

http://www.quarry.nildram.co.uk/US404.htm

 

 

In 'Guns of the Royal Air Force 1939-1945' by G.F. Wallace - who was there - there is an account of British tests of the British and US Hispanos which took place early in 1942. The British were unhappy with initial supplies of the American-made guns: "there were frequent misfeeds and lightly struck cap stoppages, and the life of several small components was very short" so a comparative test between one British and three American guns was set up. The intention was to fire 5,000 rounds from each gun without replacing any components.

 

"The British gun fired the full programme but the performance of the American guns was so bad that in each case the trial had to be abandoned before the 5,000 rounds had been fired." The British gun experienced 19 stoppages in firing 5,012 rounds. The American guns experienced 67 stoppages out of 4,092, 97 out of 3,705 and 94 out of 2,610 respectively. Incidentally, Wallace states that the US guns were "beautifully made and better finished than our own" and expressed surprise that although lightly struck caps were a major source of stoppages, even more frequent were mis-feeds.

 

As well as lifespan - apparantly a breach lock crack could be expected anywhere between 1500-2000 rounds.

 

 

At the suggestion of Capt. E. R. S. Adams of the British Air Mission, two guns each from International Harvester, Oldsmobile, and Bendix were shipped to England for the purpose of competitive aerial tests with the Mark II. Representatives of the Army Ordnance Department were present to observe the 2,000-round tests which were held during July and August 1943.

 

Two British Mark II's were mounted in the left wing of a Hurricane fighter with two AN-M2's made by Oldsmobile and International Harvester in the right wing. Combat flying, dives, G-loading, straight-away, etc., were simulated. One stoppage was attributed to the Oldsmobile gun. The International Harvester weapon had no stoppages but a cracked breech-block was noticed at the completion of the trial. Each Mark II had one sear failure and one of them had a cracked breech lock after 1,400 rounds. The Bendix guns were fired on the ground in competition with the British-made guns and made a creditable showing.

 

In reporting the findings of the test, Mr. Hansen, of the British Ministry of Aircraft Production, declared: "American guns are as good as British guns and are acceptable for service use".

 

There is an inconsistency here. As will be seen below, the performance of the American Hispanos remained unsatisfactory throughout the war, yet the British expressed no concerns and were obviously happy with their guns. There would seem to be only two possible explanations; either the British tolerance of unreliability was considerably greater than the American, or the American guns had been assembled from selected components and thereby performed better than average.

 

While this is all very interesting and has, no doubt, been raised by Kurfurst because of his deep and abiding interest in all things British, it neither gives us concrete evidence of the relative failure rates of the 20 mm Hispano in service in Spitfires of 2 TAF in 1944, nor does it give any indication of what primary source documents were used. According to the firing trials mentioned later, there were 19 stoppages out of 5,012 rounds, or a failure rate of .0039%.

 

According to Shores and Thomas 2nd Tactical Air Force Volume 4, 13,500,000 Hispano rounds were fired by 2 TAF with an average failure rate of 1 in 1,562, 50% of which were feed failures and nothing to do with the weapon (page 606): that equals 0.001562% failure rate, or 0.000781% attributed to the Hispano.

 

The material on the American weapons is interesting, but a bit of a red herring because no American Hispanos were ever used in RAF service - Kurfurst forgot to quote Wallace on the matter:

 

Wallace states that although thousands of American-made Hispanos were supplied under Lease-Lend to the UK, none was ever installed in RAF aircraft. Some were modified for use as AA guns by shortening the chamber and fitting triple-wire recoil springs, but these non-standard guns were never used in operations.

 

As Sith has mentioned, ED has a lot of information on the Spitfire's guns, so there is probably a clear understanding of their failure rates and combat effectiveness.

Edited March 4, 2014 by Friedrich-4/B

[NineLine]

As Sith has mentioned, ED has a lot of information on the Spitfire's guns, so there is probably a clear understanding of their failure rates and combat effectiveness.

 

yeah, I have no idea how failures will be handled, or if they will be handled, and by no means do I want you guys to stop sharing, but yes, make sure if you take the effort to share, share the sources, and/or links to original documents, etc...

[Kurfürst]

Further interesting details from Hispano firing trials. The highlights:

 

- API (SAPI) rounds of the Hispano were rather insensitive, they have required considerable structure to function properly (i.e. armored fuel tanks). When hitting 6 s.w.g. plates, 50% of them fucntioned; when hitting less than that, they did not function.

- HEIT rounds had a tendency to blow up and damage the gun recoil reducer mechanism of the gun. There has been also production defects with the driving bands, resulting in abnormal ballistics. Either of that happened in one of 15 rounds fired.

[Friedrich-4B]

Further interesting details from Hispano firing trials. The highlights:

 

- API (SAPI) rounds of the Hispano were rather insensitive, they have required considerable structure to function properly (i.e. armored fuel tanks). When hitting 6 s.w.g. plates, 50% of them fucntioned; when hitting less than that, they did not function.

- HEIT rounds had a tendency to blow up and damage the gun recoil reducer mechanism of the gun. There has been also production defects with the driving bands, resulting in abnormal ballistics. Either of that happened in one of 15 rounds fired.

 

The reason firing trials were usually held was to assess the effectiveness of the weapon and ammo; there's no reason to assume that the ammunition was not improved as a result of the trials.

 

The excerpt of the report is neither dated, nor is there any indication as to what it recommended, nor does it say what improvements were made; thus, while mildly interesting in themselves, the trials results are not necessarily indicative of how the ammunition and weapons performed over Europe in 1944. For instance, there is no evidence of how the 1 in 15 failure rate of HE/IT rounds noted in the report translated into the 1 in 1,562 overall failure rate in 13,500,000 rounds of all types expended by 2 TAF.

Edited March 4, 2014 by Friedrich-4/B
Grammatical tweaks

[MiloMorai]

However did the Spitfire ever manage to shoot down all those Bf109s with such defective ammo?

[Friedrich-4B]

Not forgetting that by mid-1944 a high proportion of 2 TAF Spitfires were fitted with the Mk II Gyro gunsight: according to Price Late Marque (sic!) Spitfire Aces 1942-45 the gunsight doubled gunnery effectiveness, with pilots able to hit evading aircraft at ranges of 600 yards + and deflection angles of 50°.

 

 

Edited March 4, 2014 by Friedrich-4/B
add Price