After the end of the Second World War the Dutch Marineluchtvaartdienst (MLD) had on its inventory the Consolidated Vultee PBY-5 Catalina amphibious flying boat. For a possible replacement for this ageing type, Claudius Dornier was contacted by MLD at his Madrid office. Here he had a small team available for design and consultancy work. The Dornier team drew up for the MLD a number of projects for a twin-engine amphibian, known as DoP312, DoP318 and DoP320. Possible power plants were the big radial engines of around 2500 hp available from the USA and the UK.

Dornier not only saw possibilities for a new armed military patrol flying boat, but also for a flying boat for car and passenger transport. Dornier, having no production capacities at that moment, was not a very illogical choice since Dornier had designed before the war a highly successful flying boat for the MLD: the Do-24. This type was licence-built in the Netherlands by Aviolanda at Papendrecht. Also a possible new military amphibian flying boat should have been built by Aviolanda!

Dornier Do-28 model

The Dutch Institute for Aircraft development N.I.V. received in 1953 from Claudius Dornier for evaluation a ‘Strictly Confidential’ information package including 15 detailed blueprint drawings and reports with technical data. Dornier had already  designated the new amphibian as Do-28! The package contained a business card from Claudius Dornier himself  ‘mit besten Empfehlungen’ (with best recommendations)!

N.I.V. no longer exists today, but the Do-28 information package was fortunately not lost. It was part of the large Fokker Engineering archive that was temporary based at Nieuw Vennep. All Fokker-related material has now been transferred to the Aviodrome Theme Park Museum archives. Since it was not directly Fokker-related, the Do-28 package was initially selected as waste paper material, but luckily it was saved from shredding by ex-Fokker employee and Aviodrome volunteer Gerrit Russchenberg.

The blueprints are presented here as Pdf’s and show the following:

-Scan4529: DoP318/5-02 with detailed layout drawings of  side view, top- and front view and cross sections. Project showed a twin-fin ocean patrol version with guns and an internal bomb bay

-Scan4530: DoP318/5-03 with detailed side views and cross sections for an unarmed freighter version.

-Scan4531: DoP318/5-07 with a detailed 3-view drawing with exact dimensions of the armed ocean patrol version.

-Scan4532: DoP320/2-01with  detailed 3-view drawings of a single-fin armed ocean patrol version.

-Scan4533: DoP329/2-03 with side and top view and cross section layout drawings

-Scan4534: DoP312/8-03 was a flying boat intended as a (most likely civil) car ferry. The blueprints shows not only the plane, but also the entry and exit ramp!

-Scan4536: DoP318/5-09 was a passenger version with a capacity of 40. It was intended as a civil transport plane to replace older flying boats like the Short Solent and Sandringham.

-Scan4537: DoP318/5-12 was a special version for ‘Seenotdienst’ (sea rescue work)

-Scan4538: DoP318/5-13 troop carrier version

-Scan4539: DoP318/5-15 military transport version with capacity to transport a cannon and  military vehicles

-Scan4540: DoP318/5-14 shows cargo load distribution for the transport version

-Scan4541: DoP318/5-16 military medical transport plane

-Scan4542: DoP320/2-02 shows layout detail drawing of side, top and cross section view of the single-fin armed patrol version

-Scan4543: DoP320/2/05 shows layout details of the various versions

The photos show the DoP318 in model form. Note the extra fuselage sponsons in the top view!

Eventually the Do-28 amphibian/flying boat  project never progressed further than in model form. The MLD finally selected the Martin  PBM-5A Mariner as a new armed patrol amphibian.. The Mariner showed a remarkable resemblance with the DoP318 with grossly the same dimensions, weights and performances. Because of its poor single engine performances their reputation was not all to good and after a number of fatal crashes the type was soon grounded and eventually all Mariners were scrapped.

So ended the story of the flying boat at the MLD!

After Dornier had resumed aircraft production at their Oberpfaffenhofen works, the designation Do-28 was used again for the twin-engine small STOL transport plane Skyservant.

Nico Braas

Note- High-detail pdf’s of the original drawings can be provided upon request