The DH.18 was a single-engined biplane, powered by a Napier Lion engine with wooden two-bay, wire-braced wings, and a forward fuselage clad in plywood.

[1] The first DH.18 was delivered to Aircraft Transport and Travel for use on the Croydon-Paris service, but was wrecked in a forced landing shortly after takeoff from Croydon on 16 August 1920.

In March 1921, the British government granted temporary subsidies for airline services,[3] with the Air Council purchasing a number of modern commercial aircraft for leasing to approved firms.

One aircraft, G-EAWO, was transferred to Daimler Airway for operation on the Croydon-Paris route until the de Havilland DH.34s which it had on order could be delivered.

However, on 4 April 1922, two days after Daimler commenced operations with the aircraft, it collided with a Farman Goliath over Northern France,[2] 62 mi (100 km) north of Paris, killing seven people, the first midair collision between airliners.