A-series aircraft were armed with two 7.92 mm (.312 in)
MG 17 machine guns and two 20 mm MG 151/20 cannons in the nose and delivered as the
Me 410 A-1 light bomber. The
Me 410 A-2 heavy fighter was cancelled because the dual 30 mm (1.18 in) MK 103 cannon mount, also available for the later
Me 410 B-2 subtype as the
Umrüst-Bausatz /U1 factory kit available by 1944, was not ready in time. The Me 410 A featured a bomb bay for carrying bombs. Though by fitting conversion kits, this could be used for other equipment. Initially, three
Umrüst-Bausätze (factory conversion kits) were available: the
U1 which contained cameras for photo-reconnaissance, the
U2 with two 20 mm MG 151/20 cannon with 250 rounds-per-gun for the heavy fighter. And the
U4 with a 50 mm (2 in)
Bordkanone,
BK-5 cannon with 22 rounds (21 rounds to load and 1 extra round in the breech). The purpose of this was to convert either an Me 410 A or B-series aircraft into a bomber destroyer. The Me 410 A-3 entered service in small numbers in early 1944 and equipped three long-range reconnaissance squadrons, usually grouped larger, three or four-squadron (one
Gruppe on the
Western Front and the other two on the
Eastern Front). The
Me 410 B-series was similar to the A-series but replaced the pair of 7.92 mm (.312 in) MG 17s with 13 mm (.51 in)
MG 131 machine guns. The originally planned 1,900 hp (1,400 kW) DB 603G engine had been cancelled in early 1944, so all Me 410 Bs used DB 603A or DB 603AA engines. The DB 603G would have increased the maximum speed to and cruising speed to , although the weight increased once again. The versions were the same as with the A-series, the
Me 410 B-1 and
Me 410 B-3 filling the same roles as the earlier A-1 and A-3 versions, also with the option of using the same
Umrüst-Bausätze factory conversion kits as the A-series. Several experimental models were also developed. The
Me 410 B-5 added shackles under the fuselage to carry a
torpedo, and removed the MG 131s in the nose to make room for the
FuG 200 Hohentwiel 550 MHz UHF-band
maritime patrol radar. The bomb bay was not used in this version in order to make room for a fuel tank, and the rearward-firing remote
turrets were replaced by another fuel tank for long-range missions. The
Me 410 B-6 was a similar anti-shipping conversion, but intended for the short-range coastal defence role only. For this mission, it did not use a torpedo, and was instead a simple modification of the B-1 with the FuG 200 radar. The
Me 410 B-7/B-8 were updated B-3 reconnaissance models that were never actually built. The
Me 410 C was a high-altitude version drawn up in early 1944, with two new wing designs that increased
span to . The larger wings allowed the gear to retract directly to the rear. A new universal engine mount would allow for the use of any of the
DB 603JZ or
BMW 801J
turbocharged engines or the
Jumo 213E two-stage mechanically
supercharged engines, driving a new four-blade
propeller with very wide blades. The BMW 801
radials were air-cooled and the DB 603 and Jumo 213 used an annular
radiator, all
Kraftei (
power-egg) engine "modules" onto an airframe for ease of installation and field maintenance, so the normal under-wing radiators were removed. None were ever built, as Me 410 production was cancelled before the engines matured. The
Me 410 D was a simpler upgrade to the B-series to improve altitude performance than the C-series. It would be powered by the DB 603JZ engines, and had a revised forward fuselage to increase the field of view of the pilot and reduce drag. It also replaced portions of the outer wing panels with ones made of wood to conserve
strategic materials. Several were built, but like many other attempts at wood construction by the German aviation industry late in World War II, the loss of the Goldschmitt
Tego film factory in
Wuppertal, in a
Royal Air Force night bombing raid, meant the acidic replacement adhesives available were too corrosive to the materials being bonded, and the wooden portions tended to fail. Production was eventually cancelled to concentrate on
Bf 109Gs in August 1944, after 1,160 Me 410s had been built, the month after the
Jägernotprogramm had gone into effect. == Operators ==