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View Full Version : Does FES make soaring more or less accident prone?


son_of_flubber
April 6th 15, 01:29 AM
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.

BobW
April 6th 15, 03:05 AM
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.

jfitch
April 6th 15, 03:23 PM
On Sunday, April 5, 2015 at 5:29:47 PM UTC-7, 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 agree with your comments 2 and 3 (from what I know of them). On comment 1, if you are flying into areas with poor landing sites that risk your glider or your life, in theory a motor that works half of the time reduces that risk by 1/2. I would not consider that a wise set of choices.

BobW comment of it bing a "range extending XC mechanism" seems to me to presuppose that you will decide to fly into areas you would not have, sans motor. Again this does not seem wise.

I do fly further and longer with the motor than without, but it is exclusively due to the ability to self retrieve from a safe landing site, reducing the inconvenience of that retrieve. I have yet to use the motor to remove me from an unsafe situation, and would consider it a life threatening mistake to do so. And I fly an ASH26e, which has probably the most reliable auxiliary IC motor installed in a glider (it is not a 2 stroke).

Bob Whelan[_3_]
April 6th 15, 03:46 PM
On 4/6/2015 8:23 AM, jfitch wrote:
<Snip...>
> BobW comment of it being a "range extending XC mechanism" seems to me to
> presuppose that you will decide to fly into areas you would not have, sans
> motor. Again this does not seem wise.

Didn't mean to suggest, in landout terms, that at all...I meant simply that
many times on XC days a sky area/time may be reached when the choice of
continuing into dubious lift conditions in hopes of continuing for a longer
O&R vs "wimping out" into a better-bet-at-the-time multi-leg cat's cradle (or
something...) is in one's immediate future. By nature a crewless, O&R distance
pilot, having a "perceived reliable" auxiliary potential thrust bailout would
undoubtedly have influenced many of my XC choices more towards "exploratory
boldness" and away from conservatism. Landouts per se have never bothered me,
but a landout "before a day's potential time" was always (ahem!) a "downer!"
>
> I do fly further and longer with the motor than without, but it is
> exclusively due to the ability to self retrieve from a safe landing site,
> reducing the inconvenience of that retrieve. I have yet to use the motor to
> remove me from an unsafe situation, and would consider it a life
> threatening mistake to do so.

Your technique sounds exactly what I imagine myself doing, and "Ditto," on
both counts.

And I fly an ASH26e, which has probably the
> most reliable auxiliary IC motor installed in a glider (it is not a 2
> stroke).

"Again, ditto." The Wankel seems to have found a good niche there.

Bob W.

Bill D
April 6th 15, 06:19 PM
On Monday, April 6, 2015 at 8:23:35 AM UTC-6, jfitch wrote:
I fly an ASH26e, which has probably the most reliable auxiliary IC motor installed in a glider (it is not a 2 stroke).

Indeed the '26 Wankel rotary is reliable but it's a mistake to categorically condemn 2-strokes. There are reliable ones and some not so reliable - it all depends on the engineering invested in the engine's design.

I once owned a 2-stroke Jawa/CZ motorcycle which would always kick-start on the first try even when cold-soaked well below zero. In fact, one didn't even need to kick it as it would start by slowly depressing the kick-start lever by hand. To call it dead-reliable would be an understatement. Maintenance consisted of periodically cleaning/replacing the spark plugs and nothing else.

The issue with many 2-strokes which require mixing oil with the fuel is that oil congeals in the carburettor passages if the engine is not run regularly. There are some expensive synthetic 2-stroke oils that claim to mitigate this.

Mike the Strike
April 6th 15, 09:02 PM
I have related this story many times, but one more won't hurt. About ten years ago, I arrived at Parowan for a Regional contest just as a self-launcher camp was finishing. The ramp was littered with engine parts that were being worked on and there was the flash of a welder as someone re-attached a silencer. All the self-launcher pilots appeared to be either working on, testing or discussing engines. It reminded me of a vintage British car rally where the focus is on how you keep them running not how you drive them!

Electric motors have few moving parts and almost never fail to start when required.

Mike

Jonathan St. Cloud
April 7th 15, 12:29 AM
I think the glider offerings by Lange Aviation were very original in thought and well executed, moved the lever forward, engine extracts and starts. The only problem is according to recent articles Lange has serious issues and customers have had to sue to get return of their money. Very sad. So the current offering of gliders have gas or jet engines. I did spend some time of the FES web site and it appears as if these units cannot be installed in Europe on certified gliders. Kind of limits the viability of yet another good idea.

son_of_flubber
April 8th 15, 01:10 AM
On Monday, April 6, 2015 at 7:29:40 PM UTC-4, Jonathan St. Cloud wrote:
> ...I did spend some time of the FES web site and it appears as if these units cannot be installed in Europe on certified gliders.

Things change fast. As of 10/2014 LAK17B FES has EASA Type Certificate.

http://www.front-electric-sustainer.com/news.php

Schempp-hirth seems confident about EASA Type Certificate for Ventus FES

http://www.schempp-hirth.com/index.php?id=126&L=1&tx_ttnews[tt_news]=640&tx_ttnews[backPid]=130&cHash=745a0119cc

Robert Fidler[_2_]
April 9th 15, 04:32 PM
On Sunday, April 5, 2015 at 8:29:47 PM UTC-4, 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 believe statistics show, any time your make something more complicated, statistically the device will have a greater chance to be more prone for mistakes. Unfortunately, aircraft tend to be less forgiving than other devices..
Sad but true.

Eric Greenwell[_4_]
April 20th 15, 05:22 AM
Robert Fidler wrote on 4/9/2015 8:32 AM:
> I believe statistics show, any time your make something more
> complicated, statistically the device will have a greater chance to
> be more prone for mistakes. Unfortunately, aircraft tend to be less
> forgiving than other devices. Sad but true.

It depends on what you consider the "something". You are likely
considering the glider only, which will be more complicated with an
engine; however, I consider the "something" to be the soaring I will do
with the glider.

When I flew unpowered gliders, I'd land out a few times a year - that
makes soaring more complicated.

For the last 20 years, I've flown a powered glider, and my wife says
"it's the best glider we've ever had - it always gets home!" Life is
simpler now, with a powered glider. And, I get to do a lot more soaring
in a lot more places than I did before, because it's a self-launcher,
not a sustainer. But, if you can get a tow when you want it, the
sustainer can be the best choice (density altitude caveat).

Read my Guide (see link below) to discover how I avoid increasing my risk.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"

https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/Guide-to-transponders-in-sailplanes-2014A.pdf

krasw
April 20th 15, 07:47 AM
On Monday, 6 April 2015 03:29:47 UTC+3, 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.

I've seen statistic that 5% of outlandings result some sort of damage to glider (usually minor). My personal statistics agree with this. Question is not whether engine increases risk compared to no-risk outlanding, but which of the risk is greater, landing out, or failing to start engine and then landing out.

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