Eidgenössische Konstruktions Werke

multi-role combat aircraft

EKW C-3603

MeierMotors Aircraftsales

by MeierMotors GmbH

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Achim Meier

achim@meiermotors.com

Phone: +49 7634 503797

EKW C-36

There are not many Swiss aircraft designs, but the C-36 is regarded as one of the outstanding Swiss constructions. EKW, i.e. the federal design workshops (Eidgenoessische Konstruktions Werkstaetten), was a merger of various Swiss state-owned enterprises. The aim of the conglomerate was to make the Swiss defense independent from imports. Already from 1915 it was attempted to make Switzerland independently from the import of aircraft. One of these construction bureaus was settled in Thun. Here werebuilt lorries, coaches and fieldkitchens. From 1918, the aircraft production began. As chiefconstructor acted August Haefeli. In addition to the inhouse developements, the employees also workedwith licensed productions, such as the Fokker CV-E. Later the aircraft production has been outsourced to Emmen, Thun works were increasingly engaged with the production of artillery, and armored cars. 1943, in Emmen was founded the Federal airplane factory (Eidgenoessische Flugzeugwerke). So far as the history of the "EKW" .

Dealing with the history of the EKW C-36, the facility "Dornier Altenrhein" pops up as one of the production plants. The so-called "Dornier Works Altenrhein AG" was an operating company, which was financed by the "Dornier aircraft AG" ( Do-Flug AG). The origin of this construct is closely linked with the famous Großflugboot Dornier Do-X. Claude Dornier founded in the year 1926 the “Dornier Metallbauten GmbH” and in the same time the former German Reich founded the “Do-Flug AG”. The purpose of the AG was the financing of the Do-X project and the provision of the construction plants along with equipment. As the Do-X program expired in 1933, the “Do-Flug AG”was disbanded, but the “Dornier Works Altenrhein” remained and were organizationally appended to "Dornier Metallbauten GmbH", and later in 1938 to the “Dornier Works Friedrichshafen”.In Altenrhein, up to the beginning of the Second World War, Dornier aircraft were built. During the war, the work was under state supervision and should only produce civilian goods, or just run Swiss government procurement.

Here the circle closes, one of these government procurement was precisely the EKW C-36.

The history of EKW-C-36

Already in 1934 developed the EKW "department flight" a two-seater combat aircraft. The crew sat in tandem configuration. The plane with conventional tailplane had a non-tractable landing gear and was motorized with a 12-cylinder V-engine Hispano-Suiza HS-77-12 Ycrs wich provided around 860 hp. This construction was given the name C-3600.

From spin-test with a Dewoitine D-27 one recognized however, that a twin-ruddered tailplane as mounted on the Messerschmitt Bf110 and Potez 63, the preference to be given to. An interesting aspect of this is, that the Swiss Air Force had decided at that time a procurement of these two combat aircraft to the replacement of the obsolete fleet. The C-3600 never came out of the project stadium.The successing construction with twin-ruddered-tailplane was called C-3601 vanished in the drawer, the decision in favor of the Messerschmitt Bf110 had fallen.

The procurement of the required modern military airplane failed,however due to the political developments in Germany, also as analternative, the Potez 63 failed. The government remembered the EKW C-36 engeneering design and gave order for the construction of a prototype. The with K&W Thun created prototype C-3601 received the immatriculation number C-1.

Whilest a ferry flight en route to Duebendorf evaluationcenter the plane crashed by wing fluttering loosing the ailerons. Immediately a second prototype, the C-3602 (immatriculation C-2) was buildt, but this time motorized with the 1.000 hp Hispano-Suiza HS-51-12Y. The flight testing was completed successfully. In July 1940 the Swiss government decided the procurement of the C-36, but with some changes, so the plane should be fitted with a retractable landing gear to increase the topspeed. For replacement of the obsolete C-35, EKW received the order to finish a 100 series. This order was in October increased by a further batch of 43 planes, another 100 plane-order was set in July 1941. However, it remained at the end of 1948 by 160 units produced.

The production of these, now designated as the C-3603, aircraft began in 1942, in the works F&W Emmen, DoFlug Altenrhein and also in Stans in the Pilatus AG. The first series was the so-called pre-production with 10 units (C-401 - C-410/WkNr 181-190). Again, some wing fluttering happened. EKW solved the problem by capping the elliptical wingtips and with a new balancing of the ailerons thefluttering was stopped. This capping reduced the wingspan from 15.1 m to 13.7 m.

Here on of those EKW C-3603-1 in socalled neutrality livery patroulling over the Swiss alps.

This upgraded Series was built as C-3603-1. This C-36 version was assigned until 1952 to the reconnaissance and ground-support units. This series also includes the aircraft presented here. In all probability the aircraft was built with “DoFlug AG” in Altenrhein.

Technical data

C-3603-1 / serial 327 / immatriculation C-547

Delivered to the Swiss Fliegertruppen at 22.03.1944

•wingspan 13,71m•length 10,23 m•height 3,29 m•empty weight 2.272 Kg, load capacity 1.680 Kg, Mtow 3.952 Kg (military use) •powerplant Hispano-Suiza HS-51 12Y, 1.000Hp (licence production by SLM Winterthur –even serial numbers/ Saurer AG – odd serial numbers) •3-bladed propeller, automatic pitch for constant speed, diameter 3,25m•Vmax 476 km/h in 4.800m ceiling (military use))•Max.climrate 10,4 m/s – time for climbing to 5.000m : 8 minutes (military use) •Range 680 km

The C-36 as target tug

1946 the Fliegertruppen gained experience with the C-36 as target towing aircraft. For this purpose, 20 aircraft were converted in the Farner + Grunder works Grenchen to target tugs as a substitute for the obsolete Fokker CV-E. For the new role the aircraft received a towing winch.

In the year 1953, a further batch of 40 units for target-towing purposes were converted. The conversion with an improved winch was carried out in the F+WEmmen. To this batch belonged also the serial number 327.

„The Alpine Anteater“

At the end of the 1960s the Hispano-Suiza engines of the target tugs showed overaging and they made it to the search for a replacement. All reference samples such as North American T-28, Rockwell OV-10 Bronco, Fairey Gannett were either too expensive or too time-consuming in the conversion. It was therefore summarily decided, to equip well-preserved C-3603-1 airframes with a turboprop. The Swiss Airforce procured used Avco-Lycoming T-53-L7A turboprops (Helicopter engines from USAAF-surplus inventories) and upgraded 1968 the immatriculation number C-502 with.

Since the turboprop engine in the comparison with the V-12 was a very light (252 Kg) one, the C-36 requires a 1.8 m long nose for holding the right CG (center of gravity), a third tailfin like the Lockheed Super-Constellation and the well known yellow-black striped painting.

The " Alpine-Ant -Eater" was born and test flown by the Swiss Airforces.

A batch of 23 conversions were approved, including the serial number 327.

On 12.09.1971 the at F+W Emmen converted aircraft were deliveredto the troops. Now the type designation was C-3605, the

immatriculation number C-547 was flown with Zielfliegerkorps ZFK5.

Second life

14 years later the phasing out of the C-3605 fleet took place. On 12th December 1987 were 18 no longer airworthy C-3605 Lodrino offered for auction. The C-547 had 1,904 hours at this time on the clock and has been auctioned for 10,000.00 Swiss francs to

the Swiss entrepreneur Max Daetwyler.

In 1990 Max Daetwyler gave order to the “Ju-Air” for dismantling the C-3605 and reconversion to C-3603-1 standard with an original Hispano-Suiza engine. The engine has been overhauled by the “Naef-Flugmotoren AG” on zero-hours, the restoration and conversion of the airframe was made with “Ju-Air” at Duebendorf . After over 3,400 hours work C-3603-1 / C-547 with the serial number 327 made its maidenflight on 02 September 1991 in Zuerich/Kloten.

The civil registration was HB-RBI.

This is the end of the history

of C-547.... for the time being...

The very rare aircraft is the only airworthy C-3603-1 with Hispano-Suiza HS-51 12y engine worldwide. It is now under restoration with the MeierMotors aircraft restoration shop Eschbach, on the former NATO-airfield Bremgarten (EDTG).

So, this masterpiece of Swiss technic history will fly again.

EKW C-3603-1 D-FRBI

engine tests and first flight after overhaul

August 2013, maidenflight after overhaul; Achim Meier at the controls

EKW C-3603-1 D-FRBI

engine tests and first flight after overhaul

EKW C-3603-1 D-FRBI

engine tests and first flight after overhaul

EKW C-3603-1 D-FRBI

Data

Airframe: 794 hours TTSN, 72 SMOH

Engine: Hispano Suiza 12Y51, 72 SMOH by NAEF Switzerland

Propeller: Escher Wyss EW190 72h SMOH

Avionics: Becker AR3201 PM1200 Intercom

Annual: Due August 2014Spares:

Parts For 2 project aircraft:

• 1 x HISPANO SUIZA engine, swiss military overhaul

• 1 x Propeller, overhauled by Hoffmann Propeller• 4 x Wings, Main-Ldg-Gears and Wheels included

• 2 x Fuselage "empty"

• 1 x Horizontal, complete with verticals

• 2 x engine-mounts (new built)• 1 x Box with all Fuselage internals, controls and instruments

• 1 x Box with a set of new overhauled Main-Ldg-Gears

The MeierMotors Team & EKW C-36

By MDorst Webdesign November2013