Jet turbine reliability

Originally Posted by Dan Marotta

That's what I thought.

On 6/2/2015 7:47 PM, wrote:
They are MODEL engines and are not "man rated" by the FAA. There are several YT vids showing how they are built and assembled. Watch these and then determine if you ever want to put your "skin on the line" using one. By comparison, the Williams FJ-44 is a small TURBOFAN originally built to power US cruise missiles. It had to demonstrate extreme reliability before it was FAA certified and man rated for use on very light business jets. Not to mention it was originally designed to stringent military specs. Bottom line again, these are model TURBOJET engines. Never put your safety/life in a position where their reliability matters.

--
Dan Marotta

No Dan, the TJ42 turbine used in the JS1 Revelation has been developed from scratch specifically for the sailplane market. They have never been used in anything but sailplanes and comprehensive testing has been completed for certification. I have had the privilege of visiting the factory in Northern Germany and was very impressed with the dedicated plant and the professionalism of the staff.

Brett

That was Brett that wrote about the FJ-44, not me.

On 6/3/2015 2:57 PM, Brett wrote:
Dan Marotta;904892 Wrote:
That's what I thought.

On 6/2/2015 7:47 PM, wrote:-
They are MODEL engines and are not "man rated" by the FAA. There are
several YT vids showing how they are built and assembled. Watch these
and then determine if you ever want to put your "skin on the line" using
one. By comparison, the Williams FJ-44 is a small TURBOFAN originally
built to power US cruise missiles. It had to demonstrate extreme
reliability before it was FAA certified and man rated for use on very
light business jets. Not to mention it was originally designed to
stringent military specs. Bottom line again, these are model TURBOJET
engines. Never put your safety/life in a position where their
reliability matters.-

--
Dan Marotta
No Dan, the TJ42 turbine used in the JS1 Revelation has been developed
from scratch specifically for the sailplane market. They have never been
used in anything but sailplanes and comprehensive testing has been
completed for certification. I have had the privilege of visiting the
factory in Northern Germany and was very impressed with the dedicated
plant and the professionalism of the staff.

Brett





--
Dan Marotta

I would expect the QA on these units to be better than that of the typical model turbine. You'll be much less likely to run into a dud here. What is the retail price of this 420N turbine with ECU?

"They are MODEL engines and are not "man rated" by the FAA. There are several YT vids showing how they are built and assembled."

A very inappropriate comparison. It's akin to comparing an experimental aircraft with a certified, high capacity transport category aircraft.

The Williams has undergone destructive testing, blade containment testing, is certified for flight into known icing, use on ground, use in rain etc etc.

Using M&D's engine as an example, it has no accessory gearbox so no lubrication; you add extra oil to the fuel like a 2-stroke. It has no electrical system thus no self-sustaining fuel delivery nor command and control. Both of those functions are powered by the battery so it's essential to leave a battery untouched 'for Justin'. It's not approved for ground operation other than maintenance nor for flight in rain. It's a simple, elegant, low weight, low drag thrust source for sustaining. A 'getcha home jet' with only the operating principle as a similarity with Williams and other certified products. And thanks heavens for that! It would be too large, too heavy and too *EXPENSIVE* otherwise.

CJ

Chris is exactly right. The HPH Shark Jet uses a industrial
powerplant with over 700 made for UAV / Drone use, so maturity is
high. Field reliability is very good with minimal issues... Normally a
"one-off" re-tuning exercise. You mix turbine oil with JET A1 and
this total-loss approach avoids the needs for a separate lubrication
system. Drag on deployment is not noticable at all. The Engine
management is achieved with a FADEC controller which leaves you
with a single 'Throttle' knob on the panel. HPH have been shipping
the Shark Jet for over 5 years now and into the UK Market (where I
live) for about three years. With "Double-digit" Shark Jets in the UK
I have never had to remove a Jet powerplant yet....

At 05:47 04 June 2015, wrote:
"They are MODEL engines and are not "man rated" by the FAA.
There are
seve=
ral YT vids showing how they are built and assembled."

A very inappropriate comparison. It's akin to comparing an
experimental
air=
craft with a certified, high capacity transport category
aircraft.=20

The Williams has undergone destructive testing, blade
containment testing,
=
is certified for flight into known icing, use on ground, use in rain
etc
et=
c.

Using M&D's engine as an example, it has no accessory gearbox
so no
lubrica=
tion; you add extra oil to the fuel like a 2-stroke. It has no
electrical
s=
ystem thus no self-sustaining fuel delivery nor command and
control. Both
=
of those functions are powered by the battery so it's essential to
leave a
=
battery untouched 'for Justin'. It's not approved for ground
operation
oth=
er than maintenance nor for flight in rain. It's a simple, elegant,
low
wei=
ght, low drag thrust source for sustaining. A 'getcha home jet'
with only
t=
he operating principle as a similarity with Williams and other
certified
pr=
oducts. And thanks heavens for that! It would be too large, too
heavy and
=
too *EXPENSIVE* otherwise.

CJ