Country of origin:

United States of America

Description:

Medium bomber and anti-submarine bomber

Power Plant:

(B-18A)

Two 746 kw (1,000 hp) Wright R-1820-53 Cyclone nine-cylinder single-row air-cooled radial engines

Specifications:

Armament:

Three 7.62 mm (0.30 in) machine-guns, one each in nose, ventral and dorsal positions; provision to carry up to 2,948 kg (6,500 lb) of bombs

History:

In 1934 the United States Army Air Corps (USAAC) sought a new bomber with twice the bomb load of the Martin B-10. Douglas Aircraft Company based in southern California submitted a design to meet the specification using the basic design of the Douglas DC-2. Designs submitted were the Boeing 299, the Martin 146 and the Douglas DB-1, each company building a private venture prototype and each prototype being tested at Wright Field, Ohio in August 1935. The Boeing 299 was built as the Boeing B-17 Flying Fortress, and the Martin 146 was produced for export. The USAAC approved production of the Douglas DB-1, an order being placed in January 1936, allotting the designation B-18 Bolo.

The Douglas B-18 prototype retained the basic Douglas DC-2 wing, tail unit and engines. However, the wingspan was increased by 1.37 m (4 ft 6 in) and was moved to the mid-wing position rather than the low-wing position. The fuselage was new, being much deeper to make provision for a crew of six, and to accommodate nose and dorsal turrets and a bomb bay. The prototype and first 133 Douglas B-18s (36-262 to 36-343; 36-431 to 36-446; 37-001 to 37-034; and 37-051) had the Wright R-1820-45 engine of 694 kw (930 hp).

In June 1937 a further contract was issued for 177 aircraft, later extended to 217 aircraft, known as the B-18A (37-458 to 37-634; 38-585 to 38-609; and 39-012 to 39-026), built at the Santa Monica facility, these mainly differing in having the bomb aimer’s position further forward and over the nose gunner’s position, and having the installation of 746 kw (1,000 hp) R-1820-53 engines. In 1940 most USAAC bomber units were equipped with the Douglas B-18 or B-18A. The 5th and 11th Bomb Groups were based on the Hawaiian Islands when Japanese forces bombed Pearl Harbour, and most were destroyed on the ground.

As production of the Boeing B-17 Fortress gained pace it replaced the Douglas B-18 and in 1942 122 B-18s were equipped with search radar and magnetic anomaly detection equipment being deployed along the United States coast on anti-submarine patrols, these aircraft becoming known as the B-18B. Twenty were delivered to the Royal Canadian Air Force (RCAF) as the Douglas Digby Mk 1, two being fitted with further anti-submarine warfare (ASW) equipment, becoming known as the B-18C.

Eventually a few were converted for use in the transport role and became known as the C-58. However, as they were replaced by the Boeing B-17 Fortress many were modified for the transport role without receiving a new designation. Eighteen were modified as the B-18AM trainer by the removal of bombing equipment; and a further 22 were modified for this role as the B-18M. Later Douglas went on to develop the B-23 Dragon from the B-18 airframe.

Four Douglas B-18s had been in service with the 19th Bomb Group at Del Monte in The Philippines as at 18 December 1941 but the following day one was destroyed and a second damaged. The latter was repaired and evacuated to Australia. It was expected to operate with the call sign VHCDX but its fate is not known.

On 26 January 1942 Air Transport Command of the USAAC was established at Amberley, QLD as part of the Allied Directorate of Air Transport (ADAT), with orders that all US transport airplanes then in Australia, and all combat airplanes flyable but unfit for combat, would be part of the Air Transport Command. At this time the war situation in the Pacific was desperate and every aircraft that could fly was being pressed into military service.

Aircraft initially attached to the unit comprised two Douglas B-18s and a Douglas C-39, these aircraft having been evacuated from The Philippines, and five Douglas C-53s which had been on board a ship heading for The Philippines but which had been diverted to Brisbane, QLD. At the time Japanese forces attacked The Philippines on 8 December 1941, there were twelve Douglas B-18s operational, this type having been ordered as a replacement for the Martin B-10. It seems only a few survived.

On 2 February 1942 the ADAT fleet comprised three Douglas B-18s (it is assumed a further B-18 reached Australia from The Philippines), three Consolidated B-24 Liberators, one Douglas C-39, one Boeing B-17C Fortress, three Beech 18s and five Douglas C-53-DOs. As time went by further aircraft were assigned to the unit as they became available, including additional transport aircraft which arrived by ship from the United States, and some acquired from the Dutch authorities, the latter being ex-KNILM aircraft evacuated from the Dutch East Indies.

By early March 1942 the number of aircraft involved meant that two squadrons could be set up, the 21st at Archerfield, QLD, and the 22nd Air Transport Squadron at Essendon, VIC. By May 1942 each of these units was known to have had a Douglas B-18 on strength, these being Model B-18-DOs. Two have been identified (Serials 36-343 – c/n 1731 – call sign VHCBB; and 37-016 – c/n 1877 – call sign VHCWB). Douglas B-18 36-343 operated with the 4th Air Depot Group, and later with the 21st Troop Carrier Squadron (TCS) from February 1942 and is believed to have used the callsign VHCCB. It was scrapped some time after October 1943.

In October 1944 the Allied Directorate of Air Transport was disbanded and operational control of RAAF transport squadrons attached to the unit was transferred to RAAF HQ. All aircraft then being operated on behalf of the Directorate by Australian civil organisations, ie Qantas, ANA, Ansett, Guinea Airways, etc, were placed under the control of the US 5298th Troop Carrier Wing. However, it would seem that by this time the B-18s had ceased to exist in Australia.

Of the three B-18s that have been mentioned above, two have been identified. It would seem they worked in the transport role during the early years of the Pacific War in this region. The ultimate fate of these aircraft is not known but, as there were only a couple, the spares supply for them would not have been great and eventually they would have become war-weary and surplus to requirements, as newer and more efficient aircraft became available. It is assumed they were eventually retired and scrapped.