On 4/5/2015 6:29 PM, son_of_flubber wrote:
Branching from a thread where FES related comments are not welcome...

On Sunday, April 5, 2015 at 7:55:55 PM UTC-4, jfitch wrote:

I do not own a sustainer, rather a motorglider (ASH26e) but some of the
experience is relevant. 1) If you are looking at any auxiliary engine as
a safety device, I think you will eventually be disappointed if not
injured. 2) An engine significantly increases the pilot workload at just
the moment you would like it to be reduced, that is when low and looking
for lift or a landing site. 3) An engine increases maintenance for a
glider by around 2x or maybe more. These are realities that must be
considered along with any perceived benefit

1)I thought that FES (like other sustaining auxillary sources of thrust)
reduced the possibility of landouts and that FES therefore reduced the risk
of damage/injury related to landouts.

2)I thought the 'throw one switch' of FES added little to pilot workload

3)I thought that FES was lower maintenance compared to other auxiliary
engine options.

If I thought wrong, I should stop daydreaming about getting a FES some
day.

I've never owned or even flown an auxiliary-powered glider, but have watched
with considerable interest as the various flavors of them came on the scene.
In a nutshell, agree with jfitch's first-hand-experienced assessment above.

Pretty much all the operator-assisted flavors of crunches had occurred within
a few years of the PIK-20E coming to the U.S. "way back when;" most (all?) of
these had to do with Joe PIC flying as if the engine would help him avoid a
landout...the "iron thermal save." Understandably seductive idea..."not a
chance" in practical terms.

Subsequent flavors of "internal combustion engine on a retractable stick"
self-launchers have evolved considerably insofar as engineering/automation
reducing the pilot's manual workload extracting/starting/retracting the
engine, but to this day I don't consider any of them "push a button and wait
for the engine to save me-worthy."

Schempp-Hirth's implementations of "internal combustion sustainers on a
retractable stick" seem to be about as simple an internal combustion engine
setup as I think I'm likely to see in my lifetime...and I think only the Truly
Bold Among Us would consider 2-stroke engines paragons of reliability. That
said, at least the extended drag of a banana-bladed sustainer setup wouldn't
seem to me to be a "performance significant" problem impeding a successful
landout in the event it failed to start when desired....assuming Joe PIC
*plans* to land, while *hoping* the engine may permit a last-ditch option. How
last ditch is up to the pilot's boldness quotient...

"Electrically-driven props on a retractable stick" (e.g. Antares) would appear
to have very real reliability benefits (among others) over
internal-combustion-driven props, but monkey motion still equates to
complexity at some level. Arguably one might include jet turbines on a stick
in this category, or, place that particular flavor of engine somewhere between
retractable electrics and retractable internal-combustion recips.

The (self-launching/sustaining) flavors of FES seem to me to be electrically
and mechanically the simplest form of auxiliary power yet available, but
wires/connections/prop-blades can fail (though I know of none to date).

Bottom line - so it seems to me - is Joe Glider Pilot must be capable of
picking landable fields regardless of whatever form of auxiliary power is
available to him. To think otherwise is to set yourself up for expensive
failure and possible personal injury...both of which can happen in any case,
but the better trained and prepared a person is, the greater the chances for a
successful outcome. Personally, I imagine I'd treat auxiliary power less as a
"last ditch save insurance" and more as a "range-extending XC mechanism,
which, Oh-by-the-way, might just eliminate a few retrieves along the way to XC
bliss."

That said, I'm not arguing against self-launching, sustainers, or auxiliary
powered sailplanes. Options are good, insofar as the general health of the
sport is concerned. Just don't expect a free lunch to accompany your "boughten
dessert."

Bob W.