Do-24K

After the first order for six Do24K-1's by the MLD, the Dutch ministry of defense decided, because of the Japanese threats in the Indonesian archipelos, to change the order to 72 airplanes. Starting with the 37th the new Do24K-2 was to be introduced, differing from the Do24K-1 largely by the Wright Cyclone GR-1820-G105A delivering 1100 hp. The Dutch government however had one demand, that the aircraft were to be produced in The Netherlands under lincense. August 21st 1936 the neccesary contracts were signed. The lincense production rights were sold seperately and for every Do24 build an extra som of money had to be paid to Dornier-Metallbauten G.m.b.H..
The main aircraft facotury's in The Netherlands, Fokker and Koolhoven, were not involved in the production because they did not have the machines, technicians or experience to work with all metal airplanes. The only two factory's that were capable of building all metal airplanes and that had the time and people were De Koninklijke Maatschappij 'De Schelde' in Vlissingen ('Flushing') and Maatschappij voor Vliegtuigbouw NV 'Aviolanda' in Papendrecht. The latter one is special because the company structure was set up in the same way as was with Dornier.
Managers of the Aviolanda were H.A. Burgerhout and P.A. van de Velde, both having a good relationship with Claude Dornier. The scientific department was under the management of Mr. Routnay, a Hungarian with an Austrian engineering-certificate (in 1943 he was forced by the political circumstances to leave the factory and return to Hungary). D. Vlot was in charge of the general technical management.
Actually Aviolanda was a shipbuilding company, but in those days it was not so strange that these kind of company's started making sea-going airplanes. In England Harland & Wolff in Belfast, in Germany Blohm und Voss in Hamburg and in France Penhoet in Saint Nazaire all did the same. Because the Dutch navy demanded at least 4 new planes per month and Aviolanda was not able to handle this quantity (yet) it was decided to include De Schelde in the production process, handing them the building of the complete wing (including engines and struts) and the fueltanks, while Aviolanda handled the remainder of the aircraft and the final assembly.
It was however seven years ago that Aviolanda stopped building metal airplanes. The factory was idealy located near water and the productioncapacity was there, but only a handful of the skilled labourers from the former period remained. That's why new personel was needed and the people already with the factory were sent on a course of working with metal. The realisation of the productionline thus needed some time and that was one thing the Dutch MLD did not have. That's why it was decided to place an inbetween order which was to build by Aero-Metall A.G.. July 22nd 1937 an order was placed for 12 Do24K-1's (to become X-7 upto X-18), followed on May 30th 1938 by another 6 (to become X-19 upto X-24) and January 13th 1939 for 5 Do24K-1's (to become X-25 upto X-29) and one Do24K-2 (X-37). Then also the specifications for the Do24K-2 were complete and not only the engines were changed but the plane also received bigger fueltanks for expanded range.
The first order for the X-1 upto the X-6, which were build by Dornier, started late 1937. Around that time the name of the factory had changed to Dornier-Werke G.m.b.H.. The X-1 (V3) and X-2 (V4) were build on the German side of the Bodensee where the factory was located, while the remainder was to be build at Altenrhein. Parts were manufactured at Rickenbach (tail), Lowenthal (wings and engine gondolas) en Ravensburg (stubs). The X-1 upto X-3 were transported directly to the Dutch East Indies and the remainder was first flown to Aviolanda to be euipped with Dutch requirements and to be flight-checked. The Dutch equipment concisted of the Gunturrets and the application of the Dutch insignia. During the flight from the Bodensee to Aviolanda the Do24's were painted with the German registration D-AYWI which was painted on with waterpaint. The first Do24K-1 to arrive at Aviolanda was the X-4 on March 18th 1938. The X-4 was flown by Dornier pilot Erich Gundermann and Dutch Naval pilot J.W.F. Backer.
The armament of the first 12 Do24K-1's consisted of three Alkan gunturrets, each equipped with a Colt-Browning 7,9 mm machinegun. Starting with the X-13 the middle gunturret was equipped with a 20 mm Hispano-Suiza type 404 cannon.
Aviolanda/De Schelde received the first order for 18 Do24K-1's (X-30 upto X-36) and X-38 upto X-48) on February 10th 1938. The last of this series was to be delivered in June 1940. In the meantime the Aviolanda factory was getting useful knowlegde of the Do24 through the flight-checks of the Dornier build examples.
Follow-on orders to Aviolanda followed on June 16th 1939 for 13 (X-49 upto X-61) and March 12th 1940 for 12 (X-62 upto X-73), bringing the total Dutch required production to 43. These last orders were for the new model Do24K-2. The use of the Do24K-1 in the Dutch East Indies saw the structural weakness in the tail, which caused a few cracks in the stabilo. All Do24K-1's were modified and this also was one of the improvements in the new Do24K-2, which also had a bigger range than the previous version.
The first Aviolanda Do24K-1, the X-30, was started on June 15th 1938 and was finished exactly one year later. This one had to be ready on February 1st for it's first flight but delays were caused by lack of information and faulty information supplied by Dornier. De Schelde also had these problems and thus a production delay of two and a halve months was the result. November 23rd the fifth cooperatively build Do24K-1 was handed over to the MLD. Despite the efforts of both the factory's the productiondelay rose to four and a halve months. Main causes for the rise in the delay was the draft of personel from the factory's for military duty and the stagnating foreign delivery of raw materials. The technical management of the licenseproduction in the Netherlands was in the hands of Oberingineur Otto Stellmann, who earlier was involved in the production of the Dornier Wal flyingboat by Aviolanda. Stellmann remained in this function even during the war.
The Aviolanda Do24K's were testflown by officer-pilot 2nd class H. Schaper. After acceptation by the MLD the plane was dismantled and brought to Rotterdam by ship, from Rotterdam the Do24 was shipped to the Dutch East Indies.
Only seven Do24K-1's were delivered when the war broke out for The Netherlands on May 10th 1940. The Germans captured the Aviolanda factory intact and found over 13 Do24K-2's in several stages of building. The stockrooms were filled with material for another 16 examples. for at least 11 planes there were Wright Cyclones available. That same month Stellmann returned to Aviolanda and ordered the X-38 and X-39, which were almost ready, to be completed. The interest came from the German Seenotdienst (sea rescue) who had long waited for a chance to check out the so-called X-boot. The fighting forces of the Luftwaffe had first choice in equipment and the Seenotdienst had to do with aging Heinkel He59's. They saw their chance for a new rescueplane, the captured Do24K-2.
June 1940 Flugkapitan Karl Born, commander of Seenotflugkommando I at Norderney, together with reprisentatives of Dornier and factory pilot Erich Gundermann came to Aviolanda at Papendrecht to see the X-38 in own person. Born was happy that he was to get the Do24's, it meant a massiv leap forward for the Seenotdienst. As fast as possible the X-38 was brought to E-Stelle Travemünde by LZA pilots(Luftzeugambt). During the flight the plane still wore the colors of the Dutch MLD but the insignia were replaced by the German insignia and the registration D-AFBT. The gunturrets were removed because the pilots of the Seenotdienst were under the impression that they were protected by the red cross on the fuselage. Other small changes were made to the X-38 to make it more suitable for rescue missions and July 19th 1940 the former X-38, now completely white with great red crosses on the fuselage was delivered to Seenotkommando I (4/Seenotstaffel). Because the Seenotdienst was a civilian organisation the plane got a civil registration, D-AEAV. Why it did not retain the registration D-AFBT is not known.
Delivery of the former X-38 meant the start of a new model, the Do24N-1.

Production of the Do24K-1

Do24K-1

Inside the Do24K-1

Do24K-2

Do24K