Friday, March 14, 2008
A German Autogyro other than the FA330? The WNF 342 V3-V4 Doblhoff ?
In all of the History Channel and other rotorcraft documentaries that I have seen they credit the gyro kit FA-330 (and 336) as the only WWII German autogyro.However, upon re-reading From Autogiro to Gyroplane by Bruce Charnov, in Chapter 10 he mentions the Doblhoff machines. I have never seen these machines called anything but helicopters and are rarely mentioned at that. However, Dr. Charnov clearly states that "The rotors would be unloaded in flight, and the craft would then fly as an autogyro"..
They (Documentary writers) also completely miss the actions of the Kellet Autogiros use in England for radar calibration (where they did see action) and in Japan in anti-submarine warfare. But that does at least have some good documentation on the internet and in a few books.
As I went to look up information on the WWII machines created by Friedrich Von Doblhoff time and time again I would find brief mentions that the machines after takeoff would fly "with unloaded rotors" but NEVER in my searches are the machines called autogyros or convertaplanes. His machines are almost always referred to as helicopters. Several go so far as to say they led to the development of the Faire Rotordyne or XV-2 convertaplanes but do not label the V3 or V4 as such or as autogyros.
These same sources do not have any mention of Juan de la Cierva's work leading to the V3/V4 or the convertaplanes at all.
I think we are getting screwed once again...
The Doblhoff WNF 342 V3 and V4 are IN MY OPINION jump takeoff autogyros or at least Convertaplanes NOT Helicopters. They did NOT use powered rotors as their PRINCIPLE means of flight.
I assume there are a few original books or sources that many of the writers and historians use when talking about these aircraft and perhaps since the few original sources of material called them helicopters and not autogyros this has persisted as people (autogyro ignorant) have copied and re-written information about these machines.
Outside of Dr. Charnov I have not seen these machines discussed in the light of of autogyros or convertaplanes.
Video: (Divx codec) WNF 342 V3 http://gyrowiki.com/Video%20Library/Forms/DispForm.aspx?ID=224&Source=http%3A%2F%2Fgyrowiki%2Ecom%2FVideo%2520Library%2FForms%2FAllItems%2Easpx%3FRootFolder%3D%252FVideo%2520Library%252FWWII%2520German%2520Rotorcraft&RootFolder=%2FVideo%20Library%2FWWII%20German%20Rotorcraft
Links:"Jet Helicopter" http://www.xs4all.nl/~jqmgrdyk/jetpower/german-jetpower-p3a.htm
"Helicopter" "The tip-drive system was retained for take-off, hovering and landing only, a selective clutch enabling the engine (now a 140hp Siemens-Halske Sh.14A radial) to drive a conventional pusher propeller for forward flight while the rotor blades 'free-wheeled' in autorotative pitch. "http://wp.scn.ru/en/ww2/v/1734/2_o/0
"Helicopter" "Doblhoff used this propulsion method for his subsequent versions only for take-off and landing. In normal flight, the engine was clutched with an additional pusher propeller behaving exactly like an autogyro. Doblhoff did not manage to bring the tests to an end before the end of the war. However, his WNF-342 was the first helicopter in the world to take off by the use of jets."http://www.hubschraubermuseum.de/archives/manufacturers/doblhoff
"Helicoper" "The tip-drive system was retained for take-off, hovering and landing only, a selective clutch enabling the engine (now a 140hp Siemens-Halske Sh.14A radial) to drive a conventional pusher propeller for forward flight while the rotor blades 'free-wheeled' in autorotative pitch. "http://www.aviastar.org/helicopters_eng/doblhoff_wnf-342.php
Interestingly in later paragraphs the Air and Space Museum almost does a good job using the term convertaplane but never credit the 342 V3/4 as anything but a helicopter and no mention of the role of the autogyro in the development of these aircraft...
"Helicopter" "Doblhoff and one of his WNF-342 helicopters (v4) were brought to the U.S. by the Air Forces after World War II under "Operation Paper Clip", the program that recruited hundreds of top German technical personnel. Dr. Hohenemser had participated in successful helicopter developments at the German Flettner concern. Doblhoff's "pressure-jet rotor" concept involved piping high-pressure air from a compressor out to the rotor-blade tips, where it was mixed with fuel and burned in combustors. Thrust of the resulting hot jets thus drove rotation of the rotor."http://airandspacemuseum.org/MacsHelicopters.htm
This next link is about the V1 and V2 which were true helicopters and properly notes the V3 and V3 "behaved exactly like an autogyro" but does not go so far as to call the V3 and V4 autogyros or convertaplanes.http://www.aviastar.org/helicopters_eng/doblhoff-1.php
Just for fun here is some more FA-330 video footage:http://gyrowiki.com/Video%20Library/Forms/DispForm.aspx?ID=225&Source=http%3A%2F%2Fgyrowiki%2Ecom%2FVideo%2520Library%2FForms%2FAllItems%2Easpx%3FRootFolder%3D%252FVideo%2520Library%252FWWII%2520German%2520Rotorcraft&RootFolder=%2FVideo%20Library%2FWWII%20German%20Rotorcraft