On Thursday, April 9, 2020 at 8:21:00 PM UTC+2, Eric Greenwell wrote:
Magnus wrote on 4/8/2020 7:11 AM:
Hi experienced glider pilots,

I am a newly retired ex glider pilot that is updating my license and want to do some serious soaring and distance flights in Europe now that I have plenty of time. I live in Lausanne (member of Montricher gliding club) and as well member in Landskrona gliding club in Sweden as well where I spend most of my summers.
I have come down to the following alternatives for a private purchase:

- LAK 17C Front Electric Self starter, 18m, 22kW, 10.32 m2 wing surface, MTOW 600kg and CS-22 certification

- GP-15 Jetta, retractable motor, 15m, 25kW, 7.78 m2 wing surface, MTOW 470kg, UL/EcoLight certification

Both ships are flapped, take water ballast, Vne= 275km/h, wing loading between 37 - 57kg/m2, L/D around 50 and has a base price of apps. 100kEuro

GP15 seems to be a more modern glider with safety cockpit, ballistic rescue system and steerable tail wheel but LAK seems to be a more stable company with longer experience.

This is a nice problem to have but I would very much like your input as I have a one time opportunity to get my dream machine and I want to get it right.

Where do you find the information about the LAK 17C? I can not find any, not even
on the LAK site.

My dream is for a smaller, lighter, simpler self-launcher, but with the same
performance as my ASH26E. I considered the miniLak, AS34, and the GP15. The
miniLak did not have enough wing loading, L/D, and powered range for the
Nevada/Utah area I often fly in, and the AS34 was just as big and heavy as the
ASH26E. So, I have ordered a GP15 for delivery next year, as it promises the best
compromise. It will be a few months, maybe longer, before we know if it begins to
fulfill it's promise.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Hi Eric,
Thanks very much for your Guide to Self-Launching...
Your dream is the same as mine and I am curious how you came to the decision with all your experience behind you. Have you tested it? GP15 looks really good on paper but is unproven so far. I also met Sebastian Kawa last year after his almost crash landing with his GP14 when the electrical motor did not start. He has written an article about it in Soaring International December issue. I would really need some pilot feedback from testing it before I would dare to order one.
The LAK17FES was first officially shown at the Aero Show last year but the information is limited as LAK is waiting for the CS-22 certification. I will send you a data sheet separately by mail. It is heavier (but also 18m) and the motor is not as strong as for GP15 so it needs 350m on asphalt and 400-500m on grass to get airborne (without water ballast), which is a handicap. he battery is also smaller compared to GP15 if you choose the Jettas 8.1 kW alternative. The front vs the pylon mounted propeller can be discussed but the front mounted seems simpler with less risk for failure (less moving parts).
I really wish you all the best with the GP15 choice and look forward to your experiences.