Jet turbine reliability

At 20:47 06 July 2015, Ramy wrote:
There was a recent landout of a brand new JS1 in the middle of nowhere
near
Hobbs during the contest due to jet failure. Multiple attempts were made
to
start it.
So much for jet reliability. Apparently can't trust them either.
I heard of at least 3 landouts of motorgliders recently.
Hopefully electric motors will be more reliable.

Ramy

It would be interesting to know why that jet didn't start and also whether

it had been run in the air or on the ground before the task that day.
The
jet glider pilots I have spoken to don't seem to routinely do test runs but
I
can imagine simple problems that could be found - e.g. airlock in the fuel

line after trailering. The JS1 jet overhaul interval is going to be based
on
number of starts rather than hours so perhaps that is a disincentive. In
22 years I never intentionally took a 2 stroke turbo cross-country without

doing a test run before starting the task. I occasionally uncovered
starting
problems that were easily fixed back on the ground. Any time the turbo
didn't start there was always a straightforward reason for it. At least
the
jets can be started on the ground for a few seconds so a problem could be
found found before taking a launch rather than afterwards.

John Galloway