The first attacks by German bombing airships on the United Kingdom in the winter of 1914–15 resulted in the British Admiralty issuing a requirement for a two-seat aircraft with long endurance to attack Zeppelins by dropping incendiary Ranken darts onto the airships in the hope of igniting their gas envelopes, with an order for nine Blackburn TBs being placed in March 1915.

[2][3] Although it was intended that the TB would be powered by two 150 hp (112 kW) Smith Static radial engines, which promised low weight and good fuel consumption, these proved to be unsatisfactory, and 100 hp (75 kW) Gnome Monosoupape 9 Type B-2 had to be substituted, this allowing the first aircraft to fly in August 1915.

[4] Testing showed that the two Gnome engines gave insufficient power, with the aircraft being unable to climb above 8,000 ft (2,438 m) carrying the required three canisters of 24 1 lb (.5 kg) Ranken darts.

[2] The ninth (and final) TB was fitted with 110 hp (80 kW) Clerget engines with the hope of improving performance.

[5] Data from The British Bomber since 1914 [2]General characteristics Performance Armament