Justin,

the Dornier Falke actually has quite some mysteries in it´s story, some of which are touched by the webpages quoted by Hans. To start with:

1. Dornier obviously jumped on the "parasol craze" bandwaggon started with the appearance of the Fokker E V before the end of WW I. Whether the Dornier H was the realisation of this late war project, or a new design loosely based on some design features of the D I done in 1921/22 only is not clear.

But the design was roughly contemporary with two similar all metal Parasol designs, the Junkers J 21/22 (designed as a single or twoseater, but build in some quantities as a twoseater only in Russia), and the Rohrbach Rofix (which claimed the live of Paul Baeumer).

2. Dornier themselves claim only 5 Falkes were build, with another 10 stopped when only 15 % finished. However, these aircraft had an incredible wide utilization, which makes one wonder whether there is a fault in the Dornier documents.

3. Obviously, the first Falke was flown in Duebendorf in Switzerland, on November 1, 1922, being build in Rohrschach at the Swiss side of the Lake Constance, not far from the original (German) Friedrichshafen location of Dornier, where it was designed.

4. The first Falke was powered by an original HS 300 hp engine.

5. It is not clear whether the aircraft exported to the US, tested there as the Wright WP-1 (and later ostensibly taken over by the US Navy) was the same aircraft, only reengined with a Wright H 3 (anyway only a licence build Hispano Suiza) or whether it was a new aircraft. There is a test report of a guy called Frederic H. Becker which concludes: "The aircraft was a success, teh engine was not."

6. It is usually claimed that of the 5 Falkes finished, 2 were build in Rohrschach, 3 in Marina di Pisa in Italy, where Dornier also build Wal flying boats.

7. *Amongst the countries where Dornier claimed the Falke was tested were:

- US (proven)
- Switzerland (proven)
- Italy (proven, including the seaplane version)
- Japan (proven, Dornier claims one seaplane and one landplane went there)
- Spain (questionable, but Dornier claims THREE Falkes were tested at Quatro Vientos)
- Russia (questionable, maybe a mix with the Dornier Komet/Merkur/Wal used there, but then there is your document...)

8. In addition to that, the late Bruno Lange (who, amongst others, wrote the famous "Buch der Deutschen Luftfahrttechnik") claimed "some" Falkes were sold to Chile. Lange lived in Ueberlingen, just a couple of kilometres/miles away from the Dornier archives.

9. There´s also a (most probably invalid) claim that the later Kawasaki KDA, basically a Do H fueslage married to a somewhat less advanced wing, supported by additional struts was build in a small series as the "Kawasaki type 90" - I have no idea about Japanese designs, but this series aircraft can not be found in "the usual books"

10. The crash of Rudolf Stark that you mention (and of which I have never heard) might be one with the later BMW engined Falke. There is one documented crash caused by flutter, which resulted in "the wingtips bending upward". It seems the flutter was actually a type of high speed aileron flutter, caused by the ailerons being covered with metal (only used in the later BMW version, the earlier HS version had fabric covered ailerons).

So in total: A fighter build in just 5 examples, in two locations, with at least 3 engines and 3 radiator designs, as a land and seaplane, tested in Spain (3 a/c), US (1 a/c), Italy (3 a/c), Japan (2 a/c) and Switzerland (at least 2, maybe 3 a/c), not to mention Russia and Chile - somehow there are definitely open questions in here...

If you want some more information or scans, contact me offboard.

Volker 
  

The appearance on the American market of another German all-metal
airplane of the neue Stil revealed the reasons behind the new attitude of the
Air Service. This airplane, a single-seat pursuit known as the Dornier-
Wright WP-1, was introduced to the American market in 1923 by the
Wright Aeronautical Corporation, a major military supplier of aircraft en-
gines. The WP-1 was structurally similar to the wartime Dornier DI (see
chapter two). Dornier built this airplane in Switzerland to circumvent the
Versailles treaty's prohibition against the manufacture of military aircraft in
Germany. The WP-1 had a duralumin monocoque fuselage and an inter-
nally braced monoplane wing mounted on struts above the fuselage in the
"parasol" arrangement. The wings consisted of heat-treated steel spars,
stamped duralumin ribs, and a partial duralumin covering.35
The Wright company worked hard to sell the WP-I to the Air Service. In
a letter to Maj. Gen. Mason M. Patrick, chief of the Air Service, Wright
company president Frederick Rentschler reiterated the standard arguments
in favor of metal construction. Rentschler insisted "that the airplane of the
future would be of all metal construction," arguing that metal would in-
crease "durability and reliability," and eventually reduce production costs.
Rentschler admitted that "almost prohibitive" production costs had inhib-
ited the development of metal airplanes and that it appeared "seemingly
impossible" for metal airplanes to match the performance of wood-and-
fabric types. The WP- 1, claimed Rentschler, had solved these problems. The
Wright company offered to build the WP-1 in the United States, presumably
under license from Dornier, but only if it could obtain a production order
from the Air Service.36
General Patrick instructed the Engineering Division to report on the Dor-
nier-Wright airplane. The Engineering Division did not receive the WP-1
with open arms, in sharp contrast to the embrace of the Junkers JL-6 less
than three years earlier. The intervening experience with metal construction
had cooled the enthusiasm of the army's aviation experts. Although the
McCook Field engineers acknowledged the skillful construction of the
WP-1, they reported emphatically that the Dornier design "is not the type
which is desired for service use." The division's engineers objected to both
the monocoque fuselage and the metal-covered wing. The monocoque fuse-

lage made maintenance and inspection difficult in comparison to steel-tube construction. "One has only to put this airplane [the WP-1] beside the Cur- tiss [probably the PW-8] to see that the steel frame structure with fabric covering and removable cowling offers marked advantages for a military airplane." The WP-1's gas and oil tanks, mounted internally in the fuselage, could only be accessed through the cockpit, "a decidedly poor arrangement, but one that is almost imperative in a monocoque fuselage." The metal fuse- lage covering also prevented inspection of the joints between the wing struts and the fuselage. Deterioration of this joint could cause loss of the wing during the violent maneuvers required of pursuit airplanes. The report on the WP-1 questioned the use of duralumin for any structural parts that could not be easily inspected.37 The Engineering Division also objected to the WP-I's fully cantilevered monoplane wing. It had concluded that internally braced monoplane wings were undesirable for pursuit planes. Writing for division chief McIntosh, A. H. Hobley complained of "too frequent" structural failures with this type of wing. Hobley mentioned the crashes in a recent Spanish exhibition of two monoplanes, one wood and the other metal. These accidents confirmed the army's own experience with monoplane pursuits, which included the death of an army test pilot in a Fokker monoplane due to wing flutter, and persis- tent flutter problems with the Fokker PW-5 pursuit. This distrust of the WP-1 wing proved justified when one of the wrecked Spanish monoplanes turned out to be a Dornier-Falke pursuit similar to the WP-1. This airplane crashed when the wing failed after experiencing wing flutter at full speed in level flight. This information reinforced McIntosh's recommendation against the Dornier-Wright WP-1, and led him to denounce the "reprehen- sible" behavior of foreign designers, by implication Fokker and Dornier, who failed to inform the Air Service of safety problems in airplanes being tested at McCook Field.38 The Dornier-Wright plane gave the Engineering Division the opportunity to make explicit its ideas about the proper path for the development of metal construction. The division believed that the best fuselage consisted of a rigid steel-tube structure covered with fabric aft of the metal-cowled en- gine compartment. The "most desirable" wing would have a metal frame- work, covered with fabric, "closely akin to the conventional wooden wing." Such wings could be stored uncovered and then closely inspected before being covered with fabric and placed in service. Metal wing coverings made such a procedure very difficult. A 1925 Air Service publication made the preference for fabric explicit: "It is now the policy of the Air Corps, in prac- tically all of the service types of airplanes, to insist, as far as possible, on a wooden or metal structure covered with fabric.'39 The Engineering Division's more conservative approach was reflected in the draft chapter on aircraft materials for a book titled Airplane Design. The

Go up to Top of Page

   Contents Contents  Previous Section Next FirstPrevious Page Next  

Copyright Eric Schatzberg| For information on re-use, see: http://digital.library.wisc.edu/1711.dl/Copyright

• 
• 
• 

• 

•