Country of origin:

United States of America

Description:

Light single-engine commercial transport

Power Plant:

One 548 kw (735 hp) Wright SR-1820-F2 Cyclone nine-cylinder air-cooled radial engine

Specifications:

History:

The Northrop Delta 1-D was produced in 1935 as an eight passenger derivative of the Northrop Gamma 2-D of 1933.  The Delta was an advanced airliner for its time and used the same wing and undercarriage as the Gamma but was fitted with a larger fuselage to accommodate the passengers. The prototype Model 1-A (NC-12292) was to become the first of 15 examples delivered to Transcontinental & Western Air in 1933 but in the event was the only one delivered. An example (XA-BED – ex X-236Y) was supplied to Aerovias Centrales, a subsidiary of Pan American Airways, and it operated from Los Angeles to Mexico City but was lost in service. Two were supplied to A B Transport in Sweden and these had Pratt & Whitney Hornet 660 engines. Production took place at the Northrop facility at Inglewood, California.

In the 1930s a manufacturing licence was acquired by Canadian Vickers Ltd in Montreal to build the type for the Canadian Department of National Defence, which had chosen the type for photo-survey work. Three were obtained by the Department in 1936 as the Delta Mk I (serials 667 to 669), being able to be fitted with wheels, skis or floats. A further four were obtained in 1937 (serials 670 to 673) as the Mk II; and a further 13 Mk IIs were later obtained (serials 674 to 677, and 682 to 690).  Two engines were available, the 548 kw (735 hp) Wright SR-1820-F2 Cyclone, and the more powerful SR-1820-F52 rated at 578 kw (775 hp) at 2,100 rpm at (5,800 ft) driving a Hamilton Standard propeller.

Construction of the fuselage was semi-monocoque with transverse dural rings covering with metal sheet. The cabin was well sound-proofed and accommodation for up to eight passengers was provided. The executive variant had seating for four or five and a toilet was installed to the rear. The baggage compartment was 0.70 m³ (25 cub ft) to the rear of the cabin and under a divan along the fuselage 16 kg (35 lb) could be carried. The wings were cantilever of multi-cellular construction and covered with metal sheet, the wing being designed to carry a large share of the load.  Fuel was carried in six separate fuel tanks.

Northrop production continued at the same time and examples were exported all around the world. Two, a 1D-1 (c/n 38 – ex NC14241) and a 1D-4 (c/n 41 – ex NC14266), were shipped from New York in January 1937 to the Republic Forces in Spain but the ship, the SS Cantabrico, and the aircraft, were captured by Nationalist Forces and put into service. Another (c/n 39 – ex NC14242, F-AQAQ) was to become G-AEKR in the United Kingdom but ended up in Iraq and became YI-OSF.  Another (c/n 10 – ex NC13759) went to Mexico; and a couple were impressed by the USAAF.

One example of the Delta has seen some service in this region. This machine, a Model 1-D (c/n 42 – ex NR14267), was used alongside an Aeronca K (NC18888 – later VH-ACK) on skis by the Lincoln Ellsworth Expedition to the South Pole in 1938-1939. Following return to Australia, his exploration ship, the Wyatt Earp, was purchased by the Australian Government. The Delta and the Aeronca were brought ashore and the former was bought by the Australian Civil Aviation Board in August 1940 as VH-ADR.

This Delta was owned by George Harding and had flown across the Atlantic Ocean with the Lincoln Ellsworth Expedition. It was placed in storage and as the RAAF needed light transport it was flown from Sydney to Essendon, VIC where it was compleely overhauled and, as noted, registered to the Department of Civil Aviation.

Subsequently it operated to test radio and navigtion equipment, being stored in a hangar accompanied by the Fokker F.VII/3m VH-USU.  It was taken over by the Allied Air Forces Directorate of Air Teansport and flown to Galeton in the Indian Ocean.  It later returned to Australia and was impressed by the RAAF as A66-1 and operated from Laverton, VIC. It was used to fly air crew to Woomera for a period of 10 months until the tailwheel collapsed on take-off in September 1943 extensively damaging the aircraft. Spares were not available and the aircraft was converted to components.

The Delta saw service with the department checking navigational aids until December 1942 when it was impressed by the RAAF (A61-1) and used as a communications aircraft, being issued to No 35 Squadron at Laverton, VIC. For a period it was hangared alongside Charles Kingsford Smiths Fokker F.III/3m in a hangar.  It was then taken over by the Allied Air Force Directorate of Air Transport and flown to Galeton in the Indian Ocean. It later returned to Australia.

In July 1943 it was transferred to No 34 Squadron.  It spent sometime ferrying aircrew. However, on 30 September 1943 it swung on take-off at Nowra, NSW causing the collapse of the tail wheel strut and was damaged beyond repair. Ansett Airways sought use of the aircrat at one stage. It went to No 2 Central Recovery Depot on 25 July 1944 but was dismantled and scrapped in 1944.