09/30/2012. Remarks by Johan Visschedijk: "The Bf 110 D, which entered service in the spring of 1940 with
V.(Z)/LG 1, was a specialized long-range fighter variant.

The pre-production Bf 110 D-0 had beneath the fuselage a large 277.4 gal (1,050 l) 'Dackelbauch' (Dachshund belly) non-jettisonable fuel tank, that took the form of a huge ventral 'blister' covered by a fairing constructed of plywood and fabric. It discarded the twin MG FF cannon of the Bf 110 C, but provision being made for two drop-tanks of varying size.

The production Bf 110 D-1/R1 did not have the under-fuselage tank, due to the considerable aerodynamic penalty imposed by the belly fairing, but was equipped with two 237.75 gal (900 l) underwing drop tanks, and reverted to the MG FF cannon armament. The Bf 110 D-1/R2 was similar but equipped with two ETC 500 shackles for 1,102 lb (500 kg) bombs, and the Bf 110 D-1/U1 was a night fighter with provision for an infra-red sensing device (Spanner Anlage) in the nose. Used in conjunction with a 'Q Rohr' sighting screen, the device proved too sensitive and was abandoned.

The Bf 110 D-2 was a fighter-bomber with two ETC 500 shackles, while rear armament increased to two MG 17 machine guns. The Bf 110 D-2/Trop had tropical equipment and the Bf 110 D-3 could carry both bombs and drop tanks simultaneously."