Js3 jet catastrophic failure.

On 09/07/2018 02:11 AM, David Salmon wrote:
At 16:58 06 September 2018, John Seaborn A8 wrote:
Good information on the pump. Can you expand on this a bit? What voltages
a=
re needed on the pump for a normal start on the M&D Jet? What makes sense
f=
or tuning based on fuel, jet vs. diesel? What is the best way to monitor
th=
e voltage to the pump under power?

I've been reading this long long thread, as I'm on a gliding holiday and
the weather could be better.
Something not mentioned, pertinent, but not to the reliability problem, is
noise. May not matter too much in the wide open spaces, but can be a bit
anti-social in the UK. We had a Shark jet fly from our club, and it could
be heard at 2 to 3 times the distance of a Solo engine. I have flown a bT
for 11 years, it has never failed to start, except for human error. Of
course one day it might fail, so advice given in this thread is good.
As to winch launching, which I have survived for over 50 years and into 5
figures, taking off with a wing on the ground is only for those with
suicidal tendencies. I have witnessed the result.
Look at the simulated videos on the BGA web site, under Safe Winch
Launching. No need to re-invent the wheel.
Dave


I mentioned both the noise and the fuel consumption. Seen two jets run
out of fuel on self-retrieves, even though neither had done a sef-launch.

And yes winching starting with a wing down is a terrible idea. Our club
had a two-place Grob drop a wing during launch, pilot didn't release in
time, and bent the fuselage in half.