lMG 08 A lightened air-cooled version of the original water-cooled rectangular pattern-receiver MG 08 infantry automatic ordnance, the
lMG 08, was developed by the Spandau arsenal as a rigidly mounted aircraft machine gun and went into production in 1915, in single-gun mounts, for use on the E.I through the E.III production versions of the
Fokker Eindecker. A lower case letter "L" beginning the prefix meant
luftgekühlt (air-cooled) rather than
Luft (air). The lMG 08s were later used in pairs by the time of the introduction of the
Fokker D.III and
Albatros D.I biplane fighters in 1916, as fixed and synchronized cowling guns firing through the propeller. The
Parabellum MG14 built by DWM was a lighter (22 lbs) and quite different, air-cooled Maxim system gun with a very high rate of fire (600-700 rounds/min). It was introduced in 1915, and was, but not without serious problems on occasion (as noted by
Otto Parschau), prototyped on
Parschau's own A.16/15 Fokker A.III "green machine" monoplane with the Fokker
Stangensteuerung gun synchronizer, received back with the synchronized Parabellum by Parschau on May 30, 1915 and first used in quantity as the synchronized forward-firing armament on the five examples of the Fokker M.5K/MG
Eindecker production prototype aircraft, and soon afterwards served as a flexible aircraft observer's gun for rear defense. '
Fokker E.IV, May 1916 - these guns have the "over-lightened" cooling jackets that caused fragility problems. These use the standard (for aviation) "two hole" ammunition belt and triggering assembly included below the gun. The initial model of the air-cooled "Spandau" lMG 08 front-firing cowling machine guns had lost the stocks, grips, and bipods of the infantry MG 08s to adapt it to a fixed, forward-firing mount forward of an aircraft's cockpit, with gun synchronization allowing safe firing through a spinning propeller's arc. The 105 mm diameter cylindrical sheet metal water jacket used for the infantry's MG 08, an important support member for the barrel, was initially over-lightened with cooling slots, with fourteen rows of such slots completely surrounding and running the whole length of the jacket's circumferential sheetmetal. These alternated between seven rows of nine "oblong" slots, alternating with seven more intervening rows of eight slots and twin round holes fore and aft of the slots apiece. Because of the important physical reinforcement provided by the cooling jacket on the MG 08 series of guns, the excessive slotting of the initial model of the air-cooled lMG 08 — amounting to slightly over 50% of the total area of the cylindrical cooling jacket's original circumferential sheetmetal — rendered the gun as too fragile, to the point of making it impossible to fit the
muzzle booster that the water-cooled infantry MG 08 guns could be fitted with. The later models of lMG 08 air-cooled machine gun variously "tweaked" the amount of slotting of the barrel by reducing the amount of sheet metal removed from it in minor ways through at least two or three trial formats, and eventually in the final versions produced, had the slotting omitted at the extreme ends of the cooling jacket's cylindrical member, with a 13 cm wide area of solid sheet metal at the breech end, and a 5 cm wide solid area at the muzzle end, giving the resultant gun much more rigidity. The lMG 08 also retained unchanged the rectangular rear receiver and breech assembly of the water-cooled MG 08 infantry weapon.
LMG 08/15 Later, the MG 08's receiver would be lightened by being "stepped down" at its upper-rear and lower-forward corners as the more refined and lighter weight
LMG 08/15 version was developed, using the same airframe mounting geometry as the earlier ordnance to allow interchangeability between the earlier lMG 08 and later LMG 08/15 models, with the still well-perforated cooling jacket reduced to a 92.5 mm diameter. Spandau Arsenal began producing the LMG08/15 in May 1916. The LMG 08/15 was introduced in 1917. The lMG 08 and LMG 08/15 guns were always used on fixed-wing aircraft, as fixed forward-aimed synchronized firing ordnance initially in single mounts for Germany's 1915-16 era Fokker Eindecker and
Halberstadt D.II "scout" single-seat fighters, and by 1916 in dual mounts, first appearing on the mass-produced examples of Robert Thelen's Albatros D.I and
D.II fighters in late 1916, and singly on German "
C-class" armed two-seat observation aircraft for synchronized forward-firing armament. The usual ammunition load for fighters was for longer, 500 round, belts, one for each gun. A device, occasionally fitted to the rear surface of the later LMG 08/15's receiver backplate, told the pilot how much ammunition was left to fire. Later on a significant upgrade to the gun's aerial usability was the fitting of the Klingstrom device on the right side of the receiver, which allowed the gun to be cocked and loaded with one hand from the cockpit. Various cocking/charging handle styles evolved with a simplified distinctive long handled cocking/charging device finally becoming preferred late in the war. LMG 08/15's used the 30mm "two hole" ammunition belts of the flexible Parabellum MG14 machine gun rather than the wider "three hole" belts of the MG 08/15 water-cooled infantry weapon. It is possible that these belts were used as they were a bit lighter and less bulky than the wider "three hole" ground gun belts and certainly made for standardization which would have been easier for the armorers and in addition allowed for smaller and lighter "tubes" or "chutes" that guided the empty belts into storage containers in the aircraft after firing. It is a common misconception that the tubes or chutes coming out of the fixed mounted aviation LMG 08/15 fixed guns were for expended cartridge cases. In actuality these attachments were for guiding the empty cartridge belts into a container inside the fuselage of the aircraft so that the belts would not interfere with the operation of the aircraft. As the entire MG 08
Spandau family of German machine guns ejected their empty cartridge cases forward through a round hole in the receiver's lower forward surface, immediately under the aft end of the barrel's cylindrical cooling-jacket (as can be clearly seen on many videos), these cartridge cases were guided out of the aircraft (except on Martin Kreutzer-designed Fokker biplane fighter aircraft, and the Fokker fighters designed by Kreutzer's successor
Reinhold Platz) through tubes from under the barrel to the bottom of the fuselage. With Fokker designed aircraft following the Eindecker, the cartridge cases were ejected without tubes from the receiver hole directly into open trays that guided the tumbling cartridge cases backward and sideways onto the sloped fuselage decking, which then streamed down past the cockpit on either side. These trays are clearly visible in photographs but have rarely been recognized for their purpose.
Hermann Göring, who flew both the
Fokker Dr.I and
Fokker D.VII was so annoyed with the case tumbling out in front of him that he had deflectors made on his aircraft to ensure the empty cartridge cases did not find their way into his cockpit. On photographs of Göring's aircraft these plates, seen only on his aircraft, are very prevalent and have even been recognized in scale models of his aircraft copying his particular planes, but even then most historians have failed to recognize their purpose. Both empty belt guides and trays were attached directly to the machine guns rather than to the aircraft. In the famous film showing Australian officers handling the LMG 08/15s from Baron von Richthofen's crashed triplane, the Fokker type belt tubes/chutes and empty cartridge trays can be clearly seen still attached to the guns. More than 23,000 examples of the LMG 08/15 and an unknown number of the lMG 08 were produced during World War I. == Chinese derivative ==