Jaroslaw,

thanks for the link. Would you be able to provide a translation of the
text on this site? I am just curious about the strangely bent pipes in
front of the pulse jet engines. Does the text make any reference as to
why they have this shape? Looking at a German V-1 pulse jet at the
Dayton Airforce Museum, it doesn't look anything like that.

Thanks,
Ulrich Neumann
Libelle 'GM'

All right Ulrich

The answers for your questions you can find from links of Bill Higdon, so
let me just provide some simple translation from this site.

"The second prototype of SZD-9 "Bocian" was equipped with 4 tiny pulse jet
engines, developed by PhD Eng. Stanislaw Wojcicki at the Institute of
Aviation. MSc Eng. J. Sandauer guided redevelopment of the glider. The work
scope included rebuilding of the wing - airbrakes were removed, wing
ferrules were strengthened and elastic engines suspensions were installed
(due to pulsejet engine generates vibrations that can lead to construction
damage). In order to prevent heat defects (pulsejet engine heats up to very
high temperatures) bottom part of wings were covered with asbestos and
duralumin sheets. Also non-flammable paintings of bottom part of wings, rear
part of fuselage and tail were implemented.



Electrical, air (compressed air necessary for start-up) and fuel system of
engines let pilot to start them up in pairs during flight. Necessary
pressure for fuel system was supplied from nitrogen cylinder placed together
with fuel tank in adapted trunk.



Engines were built of heat-resisting metal sheets. Nominal thrust was about
10 kgf each (weight 6 kg), fuel consumption about 8 liters of gasoline per
hour. Ignition has been started after pressure generation in chamber and
mixture firing with spark from ignition plug. The ignition plug has been
turned off during engine operation. Also additional air supply was not
necessary. Fuel supply system needed pressure within the range of 2.8-3 atm.



Due to poor thrust the glider was not able for self-launching. MSc Eng. J.
Bojanowski and Eng. S. Makaruk have carried out the flight tests.



Further design works of implementation biggest pulsejet engines (total
thrust 80 kgf) have been going on in order to enable self-launching.
Unfortunately technical data and further lot of the glider are unknown for
author."

Two old photos below pulse jet engine scheme.
Left:
"Twin pulse jet engine below the wing. Take off and landing damage
prevention metal bow can be seen."
Right:
"Fuel control system - fuel pipes and valves can be seen."

Maybe there are some mistakes but I hope it could be understandable.
If you prefer German version here is link:
http://www.piotrp.de/SZYBOWCE/dbopuls.htm

Best Regards
Jaroslaw Zaczek