On 4/26/2011 7:31 PM, gotovkotzepkoi wrote:
Mark628CA;770355 Wrote:
The BonusJet's fuselage was post cured at the TsT factory to 200
degrees F. Data from the engine manufacturer PBS show the radiant heat
at various distances from the exhaust. Using the data, Bob determined
that an exhaust splitter would be necessary. PBS manufactured a
special exhaust that split the heat plume 6 degrees per side (12
degrees total). Subsequent testing with the engine at full throttle on
a 95 degree F day, using heat sensitive tape labels on the vertical
and horizontal surfaces showed a maximum temperature of 145 degrees F,
well below the 200 degrees that would subject the tail to deformation
and/or damage.

BTW, the poster that was concerned about a "bomb" on board undoubtedly
rides his bicycle or walks to the airfield if he is concerned about
travelling in a vehicle that actually carries (gasp) fuel on board.
Like every vehicle on the road. And the aircraft that tows him up.

How did you guess? Actually, I do ride my bike to the airfield. Prior to
sitting in the coffin like glider cockpit I need to get some exercise!

I'm aware of very few fuel related accidents in self-launched
sailplanes. The only one that I can recall right now was in Australia,
on the ground, with the likely cause that a fuel line was torn loose
during the engine extension. I can recall a couple canopy caused fires,
suggesting canopies may be a greater risk :^)

A jet powered self-launcher will surely carry much more fuel than the
equivalent two or four stroke engine powered self-launcher, but it's not
clear this makes it more dangerous. Owners will have to handle greater
quantities of fuel, perhaps increasing risk, but the fuel is less
volatile than gasoline, decreasing risk; however, the ignition
temperature is lower, increasing risk; and so on.

Based on our experience with automobiles fueled with diesel, and
kerosene's widespread use as a heating fuel in rural areas, I don't
think the fuel handling risk is a significant problem. Gasoline hasn't
significantly increased the accident risk in current two and four stroke
powered gliders. Overall, the promise of jet power is more reliable and
simpler operation leading to fewer accidents.

Let's keep our fingers crossed.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz