Twin machine guns on Allied planes

[Vic_Mouton]

Hi all

Why did it take the Allies so long to fit their aircraft with two machine guns? The advantage in firepower of the D2 and D3 over their Allied contemporaries during Bloody April must have been obvious.

VBR
Vic

[Barrett]

As noted on an earlier thread, the allies did have 2-gun fighters fairly early, but they were FE-2s, etc, followed by Nieports and SEs with one Vickers thru the prop and a Lewis on the top wing. The first allied fighter with two SYNCHRONIZED guns was the Camel, which debuted in mid-1917. Main reasons appear to be (a) weight considerations for the extra gun and ammo and (B) insufficient space in the airframe. Refer to the Sop Tripe thread for more on this. Also note that at least the 94th USAS sometimes flew its N.28s with one gun in order to improve performance.
I doubt that 2 guns gave twice the hit probability of one, but it did allow a good shooter to put more rounds into the target during the fleeting seconds available in a combat.
Having said that, the Albatros gun advantage was considered significant by RFC pilots, who sometimes referred to particuarly aggressive and troublesome insects as "twin Spandau mosquitos."

I do believe Barrett is correct on this issue.
You must consider that the military load (guns and ammo) could range in weight from 130 to almost 200 lbs for a twin gun setup. In the early stage of the war, the allied a/c simply could not take on this type of load without paying a penalty in performance.

C.Grube

[mike_baram]

Could the increased vibration of the added machine gun have been a factor, considering the limited structural strength of the earlier airframes?

[stephen]

I don't think so, Mike. Twin Vickers installments were tried on a number of planes, not just the Tripe. The SE5 was another that comes to mind, but the Hisso V8 just didn't leave enough room for belt storage or the evacuation chute. I've never read of vibration as a problem with two guns, although some overagressive later experiments with three and four guns did run into that problem.

Hey, I always thought that the reason the 94th had only one gun on their 28's in April and May was because there simply weren't enough guns available yet...? Not so?

Immelmann once tried a Fokker E-IV with three Spandaus and a 160 HP Obereusel twin row with 14 cylinders. Performance was poor and he reverted to an E-III with one Spandau and the 100 HP 9 cylinder Obereusel. He was killed in this type in June 1916.

I read that immelman tried a 3 gun Folker E-III and pronounced it a piece of *(&$&!!! that lends credance to the overarming /loss of perfomance theory

Hey! What dialect of German was that? He did not like the E-IV with three guns or one. Oblt. Student preferred the E-IV to the EIII. He flew with Fokkerstaffel der Drittearmee and later with Jasta 9. He is credited with 5 victories.

[Michael Skeet]

Keep in mind also that the Allies followed a different design philosophy than the Germans in 1916. While the Germans were developing relatively heavy single-seaters powered by large in-line engines, the Allies continued to concentrate on light-weight, maneuverable machines powered by rotaries which had much better power-to-weight ratios than the German in-lines, but which still generated only half (or so) as much power. There just wasn't the lifting capacity in machines like the Bristol Scout, Nieuport 11/16/17, or Sopwith Pup to handle an extra gun.

Incidentally, while the Camel was the first British machine to have twin synchronized guns, I believe it was preceded into service by the SPAD XIII.