The Hudson was originally built to the order of the British government as a military conversion of the L.14 transport. The first Hudson flew on 10 December 1938. Production lasted from 1939 until June 1943, thousands being built and delivered to the British, Australian, New Zealand, Canadian, Netherlands, Chinese and US forces.

Six versions of the Hudson were delivered to the British government, the majority of which arrived by air across the Atlantic. The Hudson I was powered by two 745.2kW Wright GR-1820-G102A Cyclone engines driving Hamilton-Standard two-position propellers. It first entered service with Coastal Command, RAF in mid-1939. The Hudson II was similar to the Mk I but had Hamilton-Standard Hydromatic constant-speed propellers fitted.

The Hudson III represented the first major revision, having 894kW GR-1820-G205A Cyclone engines with Hydromatic propellers and a retractable rear-firing ventral gun position. Large numbers of the Hudson III were delivered to the RAF under Lease-Lend (resulting in the use of the USAAF designation A-29) with 894kW Wright R-1820-87 Cyclone engines. Like earlier Hudsons, the Mk III was basically a maritime-patrol bomber and reconnaissance aircraft, but A-29A were fitted with benches for troop carrying. A-29/29A were also used by the USAAF and by the US Navy (as PBO-1).

Powered by two Pratt & Whitney R-1830-SC3G Twin Wasp engines, the Hudson IV was produced for the RAAF, but a small batch was diverted to the RAF. These had the ventral gun removed but received a D/F loop aerial in a transparent blister. The Hudson V for the RAF had R-1830-S3G4G engines driving Hamilton-Standard two-position propellers and a retractable ventral gun (as fitted to the Mk III). The final version was the Hudson VI (designated A-28 by the USAAF) which was convertible to troop transport or cargo carrier with the turret removed.

After withdrawal from combatant service with the RAF, USAAF and US Navy, the Hudson continued to be used for miscellaneous duties, including transport, air/sea rescue, training, target-towing, etc. As a trainer for air gunners, the USAAF operated a special version with a Martin dorsal turret as the AT-18.

The Hudson III was the first aeroplane to be fitted to carry the British-developed Mk I airborne lifeboat. This lifeboat was first used operationally in May 1943 by an RAF air/sea-rescue squadron to rescue the crew of a downed bomber in the North Sea.

3-View

A three-view drawing (756 x 936)