Wing mounted Lewis gun.

[EricGoedkoop]

The SE5 was rather narrow through the fuse - I don't believe there was room for two Vickers with ammo boxes and and feed/discharge chutes.

I might be wrong . . .

[EdStevens]

I don't think that's it. They experimented with a triple Lewis gun mount inside the cockpit angled to fire up at 45 degrees, so there must have been room for a couple of Vickers. I wonder if it wasn't more to do with the fact that the S.E.5 was one of the first with the Constantinesco interrupter mechanism, and perhaps they didn't trust it enough to do away with the proven external Lewis. Later when they produced the S.E.5a, they just kept things the same (we are talking Royal Aircraft Factory here, after all -- okay, that was mean).

And I have no idea how they tried to synchronize not one but three Lewis guns with the propeller, so don't ask.

[EricGoedkoop]

Well, whaddaya know . . . . . . I did a little looking and the Wylam drawings of the SE5a show a twin Vickers installation, with empty belt boxes tucked underneath the ammo boxes and a central empty shell chute that branches to both guns. I'm way out of my element here, but he's got the ammo feeding into the outboard side of each gun - is that kosher? I'm a complete dunce on guns, but doesn't the ammo only feed in one direction?

[Romani]

From what I heard, in addition to the installation difficulties in the narrow fuselage, and the added complication of having to install "left-handed" Vickers, there was a shortage of Vickers MGs in 1916, hence why all allied fighters until the Camel and Spad XIII had just one MG.

Also, the advantage in firepower of the Lewis is much reduced by the fact that most pilots would fire several failed bursts before getting close enough or accurate enough to hit the target. So they would find themselves with an empty Lewis by the time they got a good opportunity. If the pilot held its fire with the Lewis until he was sure to get a sure target, then the Lewis is a bit of overkill, since if you aim well enough, a single MG suffices.

It's my guess that it would take a good pilot to make most effective use of the Lewis, so the average pilot would be better off with the twin MGs of the Camel, particularly if the theory that the syncronizing gear of it gave a superior ROF over German guns.

On the other hand, the SE5a was more stable and easier to maneuver into a good firing position, so it balances out.

[Tripehound]

There's evidently still a lot to be "discovered" about the over-wing Lewis favored by the British. After reliable synchronizing gear became available the French went to the Vickers gun on the Nieuports, but the British kept the over-wing Lewis. Ball supposedly liked it because he could get underneath a two-seater, into its blind spot, and blast it. The SE5 Lewis was supposed to be for that purpose, aside from also being locked to fire forward. The separation of the guns made little difference. The a/c was hauled out to the butts and the guns were aligned to the Aldis sight, generally set to converge at about 100 yards or so, distance according to pilot preference.

The Specification that resulted in the Snipe asked two Vickers and an over-wing Lewis. RNAS Camels dropped one Vickers and added one or two over-wing Lewis guns. The F2B sometimes mounted an over-wing Lewis, and some night fighters on Home Defence had two, fixed to fire upward at an angle. These were combined with the observers' two, fired parallel to the fixed over-wing guns. The Dolphin had the fixed-at-an-upward-angle Lewis guns (regarded as useless) reduced to one, or removed entirely. Late in the War, 87 Squadron had a Lewis gun fixed on each side just inboard of the middle interplane struts and sighted to the Aldis.

[TonyWilliams]

Some extracts from 'Flying Guns – World War 1: Development of Aircraft Guns, Ammunition and Installations 1914-32':

"Later on, incendiaries became available in .303 in (7.7 mm) calibre, although concerns that this ammunition might contravene international agreements prohibiting munitions which might cause unnecessary suffering held up their use until 1916, and even then they were restricted to home defence applications. They tended to be used with top-wing mounted Lewis guns for several reasons; it was initially felt dangerous to fire explosive/incendiary bullets through the propeller disk in case the synchronisation malfunctioned, there was also the risk of "cook off" of the sensitive projectiles in the closed-bolt Vickers, and the usual Foster mounting enabled the Lewis to be pulled down so that it could fire straight up – a major advantage when trying to catch Zeppelins."

and

"Aircraft used for the night defence of England were characteristically equipped with the top-wing Lewis guns, as well as or instead of the usual synchronised Vickers, right to the end of the war. Apart from the advantages already given, the muzzle flash of the Vickers tended to spoil the pilots' night vision; not a problem with the top-wing mounting. The night-fighter version of the Sopwith Camel had both Vickers guns removed in favour of two top-wing mounted Lewis guns on Foster mountings, with the cockpit moved to the rear. Later on, flash hiders were developed for the Vickers guns."

and

"The gun armament of naval aircraft did not vary significantly from that of landplanes, although RNAS fighters differed from the RFC's. The RNAS chose the Sopwith Pup to succeed the Baby as its fighter, but replaced the Vickers gun with a top-wing Lewis, possibly to save weight in order to enable the little planes to climb fast and high enough to tackle the Zeppelins, but also so the gun could be aimed vertically to attack from below. For the same reason, the navalised Sopwith Camel lost one of its synchronised Vickers in favour of a top-wing Lewis."

Tony Williams: Military gun and ammunition website and discussion forum

[EricGoedkoop]

Originally Posted by Tripehound

Ball supposedly liked it because he could get underneath a two-seater, into its blind spot, and blast it. The SE5 Lewis was supposed to be for that purpose, aside from also being locked to fire forward. . . .

. . . some night fighters on Home Defence had two, fixed to fire upward at an angle. . . .

. . . The Dolphin had the fixed-at-an-upward-angle Lewis guns (regarded as useless)

The "Comic" home defense night-fighters would have most often found themselves climbing to intercept an enemy, probably either a Zeppelin or Gotha. The upward-angled guns would've made it a bit easier to hit a target that was above you and that you were straining your machine to reach, although aiming them must've been a bit of an art. As odd as it looks at first, the arrangement makes a lot of sense. Ball's method of firing up into the belly of a two-seater was also used by D.VII pilots later in the war, except in that case the aeroplane's performance allowed the pilot to hang the whole crate on its nose long enough to rip up the other guy. I've often wondered if the Dolphin was armed to the teeth with these things in mind, but the Lewis became "useless" as the plane's other attributes suited it so well to high-altitude missions where it wasn't climbing to meet the enemy.

Then again, I've also wondered if the angled Lewis were intended to give a Dolphin driver the edge in a turning fight, especially when there was a good chance his opponent could turn tighter than he could. Following your enemy into a tight turn and losing altitude, the Lewis guns might have been able to take a piece out of him after he was out of the Vickers' line of fire.

Either way, the pilots obviously didn't think very much of them.

[TomVrille]

References: The S.E.5 File, 1996, and Aeroplanes of the Royal Arircraft Factory, 1999

The original armament proposed for the S.E.5 was a single Lewis gun rigged to fire through the hollow propeller shaft of a geared engine. Although the S.E.5 airframe was designed around the direct drive 150-hp Hispano-Suiza V8 engine, this choice of armament appears to assume availability of the 200-hp geared 'Hisso' by the beginning of serial production. Low reliability of the existing mechanical interrupter systems precluded consideration of firing through the propeller arc. Initial prototypes were built with the 150-hp engine which was incompatible with the planned armament system, requiring an alternative armament approach. The choice fell to a semi-sumerged Vickers gun using the newly developed Constantinesco hydraulic synchronizer. The combination of the Vickers gun and an overwing Lewis gun in a Foster mount appeared in late December of 1916. Albert Ball, who took part in the earliest flight trials of the S.E.5, may have been influential in adding the Lewis gun. As with most newly developed systems, the Constantinesco gear had numerous bugs that had to be worked out. At one point, Ball removed the complete Vickers gun installation from his aircraft, and replaced it with a second Lewis gun firing downward through the cockpit floor, ostensibly to reduce weight. This bizarre scheme was short-lived. It does not appear that any serious consideration was given to the the original armament plan once the 200-hp engines became available, probably because it was recognized that the days of the single gun scout were fast fading into history.

[Dan_San_Abbott]

Gentlemen:
In a conversation with Paul Winslow , flew S.E.5a machine with No.56 Squadron, S,E,5a (RAF) said the first time he tried to change the drum, the slip stream wrenched his shoulder and he lost the drum. After that experience he never changed a drum. When the Ammounition was expended from the Lewis gun, that was it. The Vickers and the Lewis guns to converge at 150 yards. An order by General Hugh Trenchard.
Blue skies,
Dan-San

[EricGoedkoop]

Originally Posted by TomVrille

At one point, Ball removed the complete Vickers gun installation from his aircraft,

So which was it? Did he pull the Vickers or the Lewis? Both?