Country of origin:

Germany

Description:

Three-engine military reconnaissance flying boat

Power Plant:

(Do-24K-1)

Three 662 kw (887 hp) Wright R-1820 F52 Cyclone nine-cylinder air-cooled radial engines

Specifications:

Armament:

One 7.7 mm (0.303 in) Colt Browning machine-gun in each of bow and stern turrets; one 20 mm Hispano Suiza 404 cannon in dorsal turret; provision for four 300 kg (661 lb) or twelve 50 kg (110 lb) bombs

History:

The Dornier Do-24 was a tri motor, high-wing, all-metal construction, cantilever flying boat with sponsons, the latter containing much of the fuel which was fed to gravity tanks in the wings. The hull was divided into nine watertight compartments, and the aircraft had turrets in the nose, dorsal and tail areas. Three prototypes were built, the third, the Do-24V3, being the first to fly on 3 July 1937.

On 3 August 1936 the Netherlands Ministry of Defence placed an order for six Do-24K-1 flying boats with sea-going capability, able to operate away from base for protracted periods of time, these aircraft to be for service in the Indonesian archipelago. Powered by Wright Cyclone engines, these became serials X-1 to X-6 (c/ns 761 to 766). At the same time Dornier laid down two Do-24s to be powered by 338 kw (600 hp) Junkers Jumo 205 six-cylinder two-stroke liquid-cooled diesel engines. The latter became the Do-24V1 and Do-24V2.

The first Wright-powered machine was the D0-24V3 (D-AYWI) which made its first flight at Bodensee (Lake Constance) on 3 July 1937. Following the perceived threat from Japanese forces in the Pacific to the Netherlands East Indies, the Dutch Government placed further orders for the type, the first 35 aircraft to be Do-24K-1s and the remaining 37 to be Do-24K-2s with 821 kw (1,100 hp) Wright GR-1820-G105A Cyclone engines.

The first two Dutch machines were built by Dornier at Bodensee. The last of the Do-24s to arrive in Surabaya was X-37, which was a Swiss-built machine, this being intended to be the personal aircraft of the Commander of the MLD in the East Indies. The aircraft were assigned to Aircraft Groups and replaced Dornier Wals.

Production took place in Switzerland by AG fur Dornier-Flugzeuge at Altenrhein, and in France. A manufacturing licence was acquired by the Dutch Government, the Aviolanda company building the fuselages and the De Schelde company manufacturing the wing assembly. Dutch production commenced in 1939 and 25 had been completed by the time the Netherlands was invaded by German forces on 10 May 1940. At that time 13 were on the production line and these were taken over by German forces. X-38 was then converted to make it suitable for rescue work, the turrets being removed. A number had been delivered to the East Indies but four (X-11, X-12, X-26 and X-27) were destroyed on 23 December 1941 at Davao in The Philippines by strafing Japanese fighters.

The Do-24s of the MLD (Dutch Service) were tested, dismantled, and shipped to Surabaya in the East Indies. The 34 aircraft delivered at the opening of hostilities performed the brunt of the offensive patrol work in the region until the survivors, some of which had been used for training at Morokrembangan, near Surabaya, were evacuated to Australia.

Seven were flown to Broome, WA and five (X-1, X-3, X-20, X-23 and X-28) had arrived by 2 March, 1942 but were destroyed at their moorings on 3 March 1942, along with another 18 aircraft, by strafing Japanese fighters, comprising nine Mitsubishi A6M ‘Zeros’ which attacked the aircraft moored in the harbour and aircraft at the local aerodrome. A Mitsubishi Type C5M ‘Babs’ reconnaissance aircraft accompanied the attacking aircraft. X-24 and X-36 were also flown south but ran out of fuel. The latter made a forced landing at sea after becoming lost and the tide left it stranded. The occupants walked to the beach and were rescued. Sump oil was poured over the inside of the aircraft, it was set alight and was destroyed. X-24 managed to reach Wallal in the Kimberley region on 8 March where it refuelled and flew on to Perth, WA eventually becoming A49-6 with the RAAF.

A further five were flown to Australia (X-5, X-7, X-8, X-9 and X-10) on 19 February 1942. These aircraft were taken over by the RAAF on 29 April that year as A49-1 to A49-5. One was test flown by Sqdn Ldr Bryan Monkton and on 4 June 1943 it was flown with 12 passengers and 1,179 kg (2,600 lb) of freight from Rathmines, NSW to Brisbane, QLD.

The six Do-24s which were operated by the RAAF had received considerable use in the evacuation of personnel from the Dutch East Indies and were well used by the time they arrived at Rathmines. Holes had been knocked in the hulls when they landed on lakes and rivers and the Dutch crews intended to abandon them in Australia. However, suitable aircraft were in short supply and repairs were effected at Rathmines to keep them airworthy for use in the transport role. Some had had concrete poured into the hulls to prevent water leakage.

Because of their condition, and the fact that spares were not available, restrictions were placed on the performance of the Do-24s, a max permissible speed of 305 km/h (190 mph) and a max take-off weight of 13,154 kg (29,000 lb) being applied. The last in service was A49-1 which, with A49-3, was used by No 8 Communications Unit at Kiriwina Island, PNG for search-and-rescue work, a typical flight being made on 5 February 1944 when one of the aircraft flew from Townsville, QLD to Milne Bay, PNG in 6 hrs 38 mins to carry out searches of 6 hrs 10 mins and 5 hrs 24 mins before returning to base in 5 hrs 40 mins.

The aircraft with the RAAF were: A49-1 (ex X-5 – c/n 765) which was received by No 9 Squadron in April 1942. It was allotted to Rathmines but suffered a landing accident on 16 September 1942. It was repaired by Qantas in June 1943 and saw service with No 41 Squadron, as did the other Do-24s, in the transport role. It was retired and broken up at Lake Boga, VIC in November 1944.

A49-2 (ex X-7 – c/n 767) was also received from the Netherlands East Indies in April 1942. In February 1943 it went to No 3 Operational Training Unit (OTU) at Rathmines, and was used for training Do-24 crews. It later saw service with No 41 Squadron and was also retired and broken up at Lake Boga, in November 1944.

A49-3 (ex X-8 – c/n 768) was initially with No 9 Squadron at Rathmines and later with No 41 Squadron. It was retired at Lake Boga in November 1944.

A49-4 (ex X-9 – c/n 769) had a similar history to the other aircraft.

A49-5 (ex X-10 – c/n 770) had a similar history but, whilst with No 41 Squadron at Darwin, NT, it caught fire and sank in Darwin Harbour in April 1944.

A49-6 (ex X-24 – c/n 785), as noted, was issued to the NEI Government in Australia on 6 June 1942 and was operated by Dutch crews, being used on clandestine operations. It was issued to Qantas for repairs in November 1943 and was retired at No 1 Flying Boat Repair Depot (FBRD) at Lake Boga in November 1944.

One MLD aircraft (X-22) claimed the destruction of a Japanese fighter on 13 December 1941; and another (X-32) bombed and sank the Japanese destroyer ‘Shinonome’.

Eventually the type was ordered by the German Luftwaffe, later models having the BMW-Bramo 323R-2 Fafnir radial engine. By this time the type was in production at the CAMS facility at Sartrouville in France. The type soldiered on after the war in Spain, one aircraft being fitted with Pratt & Whitney PT6A-45 turboprops, becoming the Do-24TT.  In the mid 1980s Dornier proposed the re-launch of the type with turboprops.

With the RAAF the Do-24 operated with Nos 9 and 41 (Sea Transport) Squadrons from August 1942, having been overhauled at No 1 Flying Boat Repair Depot at Lake Boga, where the armament was removed. They saw service from Townsville and Rathmines on passenger and freight runs to New Guinea. In May 1944 they were replaced by Martin Mariners. At the time they were retired the fleet had flown 1,761 hrs 42 mins. When there is a very low-tide at Roebuck Bay, Broome, the corroded remains of the Do-24s can be seen in the sand, and some relics have been recovered for a museum in Perth.

The fleet was broken up at Lake Boga and the forward fuselage of at least one was converted to a houseboat, being used on the Murray River for many years. It has been retired to a museum and placed on display at Lake Boga alongside a PBY-5A Catalina.

Other Do-24 survivors were ex-Spanish aircraft and have included: HR5-1 at the RAF Museum at Hendon in Greater London; HR5-2 at the Museo del Aire in Spain; HR5-3 with Dornier at Oberpfaffenhofen and HR5-4 also in Germany.

At one stage two Spanish aircraft were allotted US registrations, N99222 and N99225, to an operator in North Carolina but the aircraft never left Spain.

In 2004 for a period South East Asian Airlines, a German-backed commuter airline company in The Philippines, obtained the Do-24TT from a museum in Germany and placed it in service as a luxury aircraft to serve five-star resorts.