After President Franklin Roosevelt signed the Lend-Lease Act into law on March 11, 1941, outstanding British contacts were taken over under USAAF contracts. They were assigned USAAF designations and serial numbers for contractual purposes, even thought they were never intended for USAAF service.
The designation A-28-LO was assigned to the version of the Hudson that was powered by a pair of Pratt & Whitney R-1830-45s (the USAAF version of the Twin Wasp SC3-G). Serials were 41-23171/23222 (construction numbers 414-6030/6081). These aircraft were all delivered to the RAAF, where they served under the designation Hudson Mk.IVA with the serials A16-101/A16-152.
Two Pratt & Whitney R-1830-45 air-cooled radial engines, rated at 1050 hp for takeoff and 1000 hp at 11,500 feet. Performance: Maximum speed 260 mph at 12,500 feet, cruising speed 206 mph. Landing speed 68 mph. Service ceiling 26,000 feet. An altitude of 10,000 feet could be attained in 7.8 minutes. Range 1500 miles with 1400 pounds of bombs. 1800 miles maximum range. Weights: 12,810 pounds empty, 18,500 pounds gross, 20,500 pounds maximum. Dimensions: Wingspan 65 feet 6 inches, length 44 feet 4 inches, height 11 feet 10 inches, wing area 551 square feet. Armament: Two fixed, forward-firing 0.303-inch Browning machine guns mounted in the nose above the bombardier-s windows plus two 0.303-inch machine guns in a dorsal Boulton Paul power turret. Four 250-pound bombs or ten 100-pound bombs could be carried in an internal bomb bay.