| E 3 | |
|---|---|
 Kondor E 3a | |
| General information | |
| Type | Fighter aircraft |
| National origin | Germany |
| Manufacturer | Kondor Flugzeugwerke,Essen |
| Designer | Walter Rethel |
| Number built | c. 10 |
| History | |
| First flight | August or September 1918 |
TheKondor E 3, sometimes erroneously known asE.III, was a German single seat,monoplanefighter aircraft designed and built close to the end ofWorld War I. Though successful in the third D-type fighter competition at Aldershof in September 1918, only a few were produced, given theIdflieg designation ofKondor D.I.
The success of theparasol wingedFokker D.VIII in 1918 led several German aircraft makers to follow suit. The E 3 being Kondor's interpretation of the single-seat cantilever parasol monoplane fighter (E forEindekker in this company designation), though it was later given the service designation D.I.[1]
The E 3 had acantilever wing with a section which was centrally thick but thinned towards thewing tips. The wing was straight tapered in plan, with an unsweptleading edge, forward sweep on thetrailing edge and blunt tips. This was constructed in a novel and patented way, the wingribs protruding and the gap between them covered with strips ofveneer attached by L-shaped strips. The result was a very strong structure; Kondor claimed that the slight though clearly visible rib protrusion also improved the aerodynamics. Wing andfuselage were connected on each side by twostruts, one above the other, running from the mid- and upper forward fuselage to a common junction at the wing leading edge together with three forward-leaning struts from the fuselage close to thecockpit to the wing underside.[1]
There were two E 3 variants, differing chiefly in their engines. The original E 3 had a 108 kW (145 hp)Oberursel Ur.III eleven-cylinderrotary engine and the E 3a a 149 kW (200 hp)Goebel Goe III nine-cylinder rotary. The Oberursel had a cutaway, horseshoe-typecowling, the Goebel a complete, circular one. Behind the engine, the fuselage was flat-sided, with the single open cockpit under a large cut-out in the wing's trailing edge for enhanced visibility, tapering to the tail under shallow, rounded decking. Bothrudder andelevators werebalanced; the rudder reached down to the keel and moved within a cut-out between the elevators as thetailplane was placed on top of the fuselage. The E 3 had a fixed,conventional undercarriage, the mainwheels on a single axle with V-strut legs to the lower fuselage and cross-wire braced.[1]
Though the design process only began in July 1918, the aircraft was rapidly built and made its first flight before going toAdlershof for type testing in September and entering the Third D-type contest against some other new German fighters the following month.[1] These included theAlbatros D.XII and theAviatik D.VII, both biplanes.[2] One senior pilot there reckoned the Kondor the best machine present; it was judged as having flight characteristics only marginally less good than the recently orderedSiemens-Schuckert D.IV biplane and showed none of the high-speed parasol wing vibrations experienced with theFokker D.VIII.[1]
The higher powered E 3a probably flew for the first in October. It had a top speed of 200 km/h (120 mph; 110 kn) and a much improved rate of climb, reaching 5,000 m (16,000 ft) in 11 minutes.[1]
Confusion has reigned over the Kondor fighter designations, caused by the Idflieg during the second D-type fighter competition at Aldershof, when the two Kondor D 2 prototypes were referred to asD.I andD.II, which were unofficial and fictitious. Standard Kondor practice was a Letter followed by an Arabic numeral separated by a space. This confusion was exacerbated when the production E 3 aircraft were given the official Idflieg designationKondor D.I.[1]
After the competition, Kondor received an order for the E 3; the numbers required are uncertain but seem to have been about 100. However, the NovemberArmistice came with only a few, about 8–10, having been delivered.[1]
A few E 3s were operated after the war. One E 3a was bought by theSwiss Comte Mittelholzer for aerobatic displays.[1] Two others went to an anti-communistDutch vigilante group, along with the E 3's designer, Walter Rethel. On arrival he produced a reconnaissance aircraft, theNAVO RK-P4/220, for the group.[3]
Data from The Complete Book of Fighters[1]
General characteristics
Performance
