for <aviophile>; Sun, 1 Mar 1998 15:16:52 -0800 (PST)
Received: 1 Mar 1998 23:16:31 -0000
From: "Graham SALT" (email address removed)
To: <aviophile>
Subject: Arsenal-Delanne 10
Date: Sun, 1 Mar 1998 23:16:00 -0000
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Phew! not the easiest of 'planes to research. It appears Messrs. Green and
Swanborough are my only sources. The Salamander book entry appears to be a
truncated account of what appeared in the (much) earlier book - War Planes
of the Second World War - Fighters, Vol.1, published by Macdonalds back in
1960. I can do no better than reproduce the whole entry - paraphrasing
would be pointless, so with due acknowledgement to the maestro, here goes:-

"In 1936 M. Delanne first proposed the use of the tandem-monoplane or
Nenadovich biplane configuration for a military aircraft. The tandem
mounted wings providing a continuous slot effect were claimed to offer an
exceptional  c.g. travel and an extremely low stalling speed, and, to prove
the claims made for this configuration, the Societe Anonyme Francais de
Recherché Aeronautiques built a light tandem two seat monoplane, the
Delanne 20, powered by a 180 h.p. Regnier R6 engine. Unfortunately, this
aircraft was destroyed on its first test flight on 10th August 1938, but a
second Delanne 20 was built and successfully test-flown in March 1939.
	As the feasibility of the tandem-monoplane arrangement had now been
proven, the S.A.F.R.A. furnished, at the request of the Ministere de l'Air,
the Arsenal de l'Aeronautique at Villacoublay with full details of the
configuration, and the Arsenal commenced the construction of a unique
two-seat fighter, the Arsenal-Delanne 10. Apart from the use of slots on
the leading edge of the forward wing, the fighter followed closely the
configuration of the Delanne 20. Metal stressed-skin construction was
employed, the fighter using for the first time a technique known as
"contre-plaque-metallique"- a smooth dural skin electrically welded to
corrugated sheet. An unusual feature of the design for the period was the
fact that the wheel well doors closed once the mainwheels had been extended
in order to preserve the airflow over the lower fuselage. The pilot was
seated aft of the 132 Imp.gal. fuel tank, and the gunner, who faced
rearwards, had an exceptional field of vision. 
	The Arsenal-Delanne 10 prototype had just been completed when Villacoublay
was occupied by German forces in June, 1940, and the R.L.M. ordered the
French personnel to continue work on the machine. After protracted delays
during taxi-ing tests, and modifications to the vertical surfaces and
tailwheel, the Arsenal-Delanne 10 finally flew for the first time in
October 1941. The undercarriage was successfully retracted on the second
flight, and some fifteen test flights were made from Villacoublay during
which six hours in the air were logged. After the completion of these
trials, the fighter was ferried to a German experimental centre (Rechlin?)
for further tests, but its subsequent history is unknown."

As far as data is concerned, there appears to be some slight differences
between William green's earlier account and the Salamander book, in
particular the original figures include:
Height: 9 feet, 10 inches
Wing Area: 242.188 sq. feet (really, that precise!)
Endurance: 1.5 hours at 95% power
Service ceiling: 32,810 feet 

Graham Salt