Jet-A or kerosene are the only approved fuels. The
microjets use a small portion of the fuel to lubricate
the bearings, thereby eliminating oil pumps, reservoirs,
seals, etc. Jet-A and kerosene are better lubricants
than gasoline.

The jet engine pylon can be retracted while airborne.
After shutdown, the engines cool to a safe temperature
in about 30 seconds. I have video footage of the retraction,
but it's not on any of the short clips on the website.

Bob C




At 18:06 17 November 2005,
wrote:
Bob,
In all of the great videos I've seen of you and the
jet-powered Silent,
I never saw you retract the engines in the air. Is
it impossible
because of temperature? Or is it just a coincidence
?
Thanks
Uri

wrote:
Bob, my question is about approved types of fuel.

In the jet aircraft I fly, occasion use of av-gas
is approved; however,
some aircraft have a limitation in their Flight Manuals
as to how many
gallons of av-gas is allowable before a hot-section
inspection becomes
mandated. Av-gas (100% or mixed) is useable in these
aircraft for a
couple of reasons: as an emergency return-to-home
fuel, and as a way to
control microbal growth in the fuel systems, particularly
in tropical
environments.

The downsides of using av-gas in turbine engines are
that it burns
hotter and deposits lead on the turbine blades (does
the micro jet
engine use turbine blades and a containment ring?).
The Lead deposits
reduce the engine's efficiency, and the higher exhaust
gas temperatures
simply reduce the life of the components.

But when the chips are down, av-gas can be used...in
jet-powered
airplanes. Thus my question: Can the micro-jet engine
use av-gas?

Raul Boerner