On Sunday, November 2, 2014 10:22:41 AM UTC-5, kirk.stant wrote:
On Sunday, November 2, 2014 1:21:54 AM UTC-5, Paul B wrote:

Agreed, my response was an explanation why the SZD-55 driver had lower break off points than the motor / sustainers gliders, which I think Kirk was questioning.

Paul

And again, why would an FES (or jet, or even a classic "turbo") sustainer have a higher break off point than a pure glider? You would still look for lift until it became obvious that the day was over, then while setting up a pattern, fire up the sustainer and either fly away, or land - and the drag of an extended sustainer (and the workload of starting it) is nowhere near that of an SLS.

So what penalty, other than the drag of the FES system (not present in classic "turbos" or jets) does a sustainer suffer over a pure glider? Weight? Does that mean that skinny pilots should be penalized over fat (ahem, "mature") pilots? Especially in "no-ballast" contests, the difference in wingloading is more affected by the "beer ballast" that the presence or lack of a sustainer!

Kirk
LS6 "66"
Happy at my 8psf dry wingloading!
I'll have another Stag, please...

Kirk, you are simplifying things. What about a situation when the engine develops on partial power. You just don't fly away. You are quickly in very difficult situation.

When I used to fly pure sailplanes and I saved myself down to 600 feet quite safely. I would never attempt to start the engine less than 1500 feet, unless I had a really long field in front of me allowing for all kids of options. In reality since I started flying a self launcher I restart at 1500-2,000 feet depending on terrain.

Jet can also have starting issues as experience suggest. I know of at least one situation when a jet engine in a glider developed only partial power and the pilot barely got away from having a really bad day as he tried to start a bit low. I bet he will never do that again.

AK