On Monday, August 26, 2013 10:38:05 AM UTC-7, Andrew wrote:
I found this website with an interesting commentary on motor

gliders.



http://www.trb.8m.com/index.html





Real has some important insights about the issues of flying MGs, but has reached a couple of very wrong conclusions.

First:

"The more complicated the motor the more dangerous. SLS is more problem than a sustainers, which in turns is more than an electric."

An self-launcher just has a larger motor than a sustainer; the complexity is very comparable. SLS will be heavier, which increases wing loading, but the start sequence is pretty much the same. In fact, I was surprised at the issue of getting all of the petal blades deployed - this is definitely not an issue with an SLS. Electrics are the clear winners on simplicity, but they are also the clear losers on range, which, flying 1000 k tasks over Nevada, is a big issue for me.

"Flying a motor glider could force you to more land out then having a pure glider."

If this actually happens, you are doing something seriously wrong. In Real's case this is his mystifying decision to carry ONLY 4 l of fuel. Fuel translates directly to range. If he had carried a full fuel tank he probably would not have had any landouts. The 13 l tank capacity only adds another 15 lbs of weight - this will have a negligible affect on wing loading (less than 2%).

The circumstances that give pure gliders a SLIGHT edge over MGs so emphasized by Real happens very rarely in reality. It happened to me a couple of times in 16 years. One was in a contest that had a weak day. I ended up landing at an airport (to get a landing card signed) and self-retrieved. Another pure glider also landed at the same airport. After I launched, a bystander asked the other pilot if he also was going to do the same thing! Not a single MG made it around that day w/o restarting, but pure gliders did (albeit by doing numerous low saves). I concluded that MGs were at a definite disadvantage in contests and stopped flying them.

Personally, I will only own an SLS (we don't have a tow plane here!). Pure glider owners must look at the short list of commercial operators and a few of the larger clubs if they want to tour the country - I only have to find an airport (of which there are 1000s)!