It's not engine operation per-se I'm worried about. It's all of the mechanical and electronic wizardry that has to work to go along with it. Yeah, it's electic. No fuel system. No mags or plugs. Great. What happens I have a prop strike or Joe Pilot forgets to swap out the battery pack (assume that it can be swapped out) or..

If someone wants to design the capability in as an "add on" rather than as a required element, go for it. Just let me buy it without that stuff and don't charge me for it if I don't want it. Build me a robust trainer that can take the real world abuse of your typical club or FBO.

A lot of engineers love to build something that "pushes the envelope". I see it at work every single day. Yet we forget about design for maintainability or design for manufacturing.



On Friday, April 5, 2013 2:09:35 PM UTC-4, Eric Greenwell wrote:
On 4/5/2013 10:22 AM, Papa3 wrote:

I think Bob K's post just above yours says it all. We already have

wonderful XC trainers with engines - they're called Duo Discuses

(Discii). They cost a lot of money, and very few blue collar glider

training operations are going to buy one, at least here in the US.

I'm sorry, but Greg may be disconnected from the realities of a

typical club or low budget FBO. Managing a sophisticated system

like you describe? Hah! I watch what the ASK-21s, Blanik L-23s, and

2-33s go through at our operation and those nearby. We're lucky if

we can keep the 12V SLA battery charged with working connectors in

order to run the radio and electric vario :-)



The engine system Greg proposes is nothing like the ones on the Duo

Discus. It is far simpler to operate: turn on a switch and it starts

providing power in a couple seconds (no mast to raise); move the power

lever to get level flight or climb. Got your thermal? Power back, switch

off, and you are a glider again in less than 5 seconds (no propeller to

stop, no mast to put away). Compare that to managing the gasoline motor

on a Duo.



If the instructor can't manage getting the propulsion battery put on

charge, he has no business being an instructor. That part of the

operation is simple compared everything else in an instructional flight:

"Jerry, take this here battery to the clubhouse and plug it into the big

charger. Bring the one that was on the charger back with you, or you

don't fly next."



--

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

email me)