Motor-glider talks at SSA convention in Reno

[Dave Nadler]

Hi Guys - For those of you interested in what
motor-gliders can and cannot do, safety, trade-offs
between types, etc, we have a couple talks in Reno
next week. Stephen Dee is speaking on Saturday, and
I'm speaking Thursday. Should clear up some of the
"interesting thoughts" on RAS recently ;-)

Hope to see some of you there !
Best Regards, Dave "YO electric"

[Key Dismukes]

On Saturday, February 22, 2014 2:36:17 PM UTC-5, Dave Nadler wrote:
>Dave
> For those us who can't make it out there, are you planning on making your slides or notes available?

thanks,
Key


>
>

[Dave Nadler]

On Monday, February 24, 2014 3:56:27 PM UTC-5, Key Dismukes wrote:
> For those us who can't make it out there, are you planning
> on making your slides or notes available?
> thanks,
> Key

I'll post this after the convention - usually I have a few
updates prompted by questions!

Sorry you can't make it to Reno,
Best Regards, Dave "YO electric"

[Dave Nadler]

On Monday, February 24, 2014 3:56:27 PM UTC-5, Key Dismukes wrote:
> Dave
> For those us who can't make it out there, are you planning
> on making your slides or notes available?
>
> thanks,
> Key

Some bizarre ideas on RAS about motor-gliders!
I did post this, if anyone is interested in,
ya know, facts and experience, as opposed to
Random Aviation Speculation...

Sane motor-glider pilots do not do an air-start
until they have a pattern planned and are in position
for landing after a worst-case failure...

Enjoy,
Best Regards, Dave


http://www.nadler.com/papers/2014_So_You_Think_You_Want_A_Motorglider_MS_PPT_up dated_with_speaker_notes.pdf



http://www.nadler.com/public/NadlerSoaringIndex.html

[Dave Nadler]

On Monday, February 24, 2014 3:56:27 PM UTC-5, Key Dismukes wrote:
> Dave
> For those us who can't make it out there, are you planning
> on making your slides or notes available?
>
> thanks,
> Key

Some bizarre ideas on RAS about motor-gliders!
I did post this, if anyone is interested in,
ya know, facts and experience, as opposed to
Random Aviation Speculation...

Sane motor-glider pilots DO NOT try an air-start
until they have a pattern planned and are in
position for landing after a worst-case failure,
which takes more altitude than landing an
un-powered glider...

Enjoy,
Best Regards, Dave


http://www.nadler.com/papers/2014_So_You_Think_You_Want_A_Motorglider_MS_PPT_up dated_with_speaker_notes.pdf

http://www.nadler.com/public/NadlerSoaringIndex.html

[jfitch]

On Wednesday, April 16, 2014 5:21:10 AM UTC-7, Dave Nadler wrote:
> On Monday, February 24, 2014 3:56:27 PM UTC-5, Key Dismukes wrote:
>
> > Dave
>
> > For those us who can't make it out there, are you planning
>
> > on making your slides or notes available?
>
> >
>
> > thanks,
>
> > Key
>
>
>
> Some bizarre ideas on RAS about motor-gliders!
>
> I did post this, if anyone is interested in,
>
> ya know, facts and experience, as opposed to
>
> Random Aviation Speculation...
>
>
>
> Sane motor-glider pilots DO NOT try an air-start
>
> until they have a pattern planned and are in
>
> position for landing after a worst-case failure,
>
> which takes more altitude than landing an
>
> un-powered glider...
>
>
>
> Enjoy,
>
> Best Regards, Dave
>
>
>
>
>
> http://www.nadler.com/papers/2014_So_You_Think_You_Want_A_Motorglider_MS_PPT_up dated_with_speaker_notes.pdf
>
>
>
> http://www.nadler.com/public/NadlerSoaringIndex.html

Interesting talk. I have two comments:

You recommend not beginning the engine start (attempt) until on downwind leg in the pattern. This adds all of the engine start workload in the middle of a pattern, a pattern that will need to be altered perhaps radically depending on the result of the start attempt. For this reason I always attempt to start the engine above a landable field and well above pattern altitude. It if fails to start, I can now set up a pattern appropriate to the configuration of the glider and concentrate on its execution. This requires the discipline to know when to quite fiddling with the engine. With the electric, it probably makes more sense because it either works or not, but with gas there are quite a lot of things to fiddle with, if it doesn't catch immediately.

Second, while you mention the addition to pilot workload while trying to start the engine, I believe there is a significant addition to pilot workload anytime you are near the glideslope to safety. Perhaps I overthink things, but when I get near the glideslope, I begin to think: Should I start the engine now? If it doesn't start will I still have options with my now 20:1 glide? Should I give up on the engine and concentrate on my straight in approach? Should I have started the engine 5 minutes ago? How cold is it from my last 3 hours at 17,000? Etc.

These things are running though my mind when I really ought to be thinking about flying the glider as a glider, and distract me well before the decision to start the motor has been made.

[Eric Greenwell[_4_]]

Dave Nadler wrote, On 4/16/2014 5:21 AM:
> On Monday, February 24, 2014 3:56:27 PM UTC-5, Key Dismukes wrote:
>> Dave
>> For those us who can't make it out there, are you planning
>> on making your slides or notes available?
>>
>> thanks,
>> Key
>
> Some bizarre ideas on RAS about motor-gliders!
> I did post this, if anyone is interested in,
> ya know, facts and experience, as opposed to
> Random Aviation Speculation...
>
> Sane motor-glider pilots DO NOT try an air-start
> until they have a pattern planned and are in
> position for landing after a worst-case failure,
> which takes more altitude than landing an
> un-powered glider...
>
> Enjoy,
> Best Regards, Dave
>
>
> http://www.nadler.com/papers/2014_So_You_Think_You_Want_A_Motorglider_MS_PPT_up dated_with_speaker_notes.pdf
>
> http://www.nadler.com/public/NadlerSoaringIndex.html

It's a decent presentation, but I do think "plummet mode" grossly
exaggerates the situation: my ASH 26 E does not have a "plummet mode",
nor do similar gliders like the DG 800, Ventus self-launchers, etc.

My ASH 26 E thermals almost as well with the mast in the cooling
position as fully retracted, and landing with the mast extended only
means using a bit less spoiler than with it retracted. I'd reserve the
term "plummet mode" to sustainers that require diving to start the engine.

For a thorough discussion of self-launching sailplane operation, I
suggest you read my 60 page "Guide", available free from the ASA
(Auxiliary-powered Sailplane Association) website:

https://sites.google.com/site/motorgliders/publications/download-the-guide-1

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

[Dave Nadler]

On Wednesday, April 16, 2014 10:48:39 PM UTC-4, Eric Greenwell wrote:
> It's a decent presentation, but I do think "plummet mode" grossly
> exaggerates the situation: my ASH 26 E does not have a "plummet mode",

As was discussed in the talk, had you bothered to attend...


> nor do similar gliders like the DG 800, Ventus self-launchers, etc.

Wrong...


> ... I'd reserve the
> term "plummet mode" to sustainers that require diving to start the engine.

If you had flown some of the planes I have, you would
have a rather different opinion.


You are losing the plot. The sink rate of many of these
planes with motor out and not running is much, much,
higher than what glider pilots are used to. Not planning
for this has led to many, many accidents...

Be careful out there,
Best Regards, Dave

[Eric Greenwell[_4_]]

Dave Nadler wrote, On 4/17/2014 3:08 AM:
> On Wednesday, April 16, 2014 10:48:39 PM UTC-4, Eric Greenwell wrote:
>> It's a decent presentation, but I do think "plummet mode" grossly
>> exaggerates the situation: my ASH 26 E does not have a "plummet mode",
>
> As was discussed in the talk, had you bothered to attend...
>
>
>> nor do similar gliders like the DG 800, Ventus self-launchers, etc.
>
> Wrong...
>
>
>> ... I'd reserve the
>> term "plummet mode" to sustainers that require diving to start the engine.
>
> If you had flown some of the planes I have, you would
> have a rather different opinion.
>
>
> You are losing the plot. The sink rate of many of these
> planes with motor out and not running is much, much,
> higher than what glider pilots are used to. Not planning
> for this has led to many, many accidents...

Perhaps there is some confusion over "much, much". I'm talking about no
more than twice the sink rate of best L/D - how much are you thinking?

How about the ASH 26 E? Do you now agree it does not have a "plummet
mode"? I do not experience What I think is a high sink rate when the
mast is up.

The ASH 26 E, DG and Ventus models I'm talking about are not the "engine
on a stick" variety, but the newer (last 20 years or so) types with the
"buried" engine. There is a significant difference between, for example,
the old 15 meter PIK 20 E with it's "engine on a stick", and the newer
18 meter ASH 26 E, DG 800, etc, with their "buried engine".

Regardless of the sink rate, it is important for pilots of any glider to
practice landings with the propeller extended, so they are aware of the
gliders performance in that condition, and know how to handle the
situation when the engine does not start. There should never be a case
of "not used to it".

--
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 - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

[John Firth[_4_]]

At 02:29 19 April 2014, Eric Greenwell wrote:
>Dave Nadler wrote, On 4/17/2014 3:08 AM:
>> On Wednesday, April 16, 2014 10:48:39 PM UTC-4, Eric Greenwell wrote:
>>> It's a decent presentation, but I do think "plummet mode" grossly
>>> exaggerates the situation: my ASH 26 E does not have a "plummet mode",
>>
>> As was discussed in the talk, had you bothered to attend...
>>
>>
>>> nor do similar gliders like the DG 800, Ventus self-launchers, etc.
>>
>> Wrong...
>>
>>
>>> ... I'd reserve the
>>> term "plummet mode" to sustainers that require diving to start the
>engine.
>>
>> If you had flown some of the planes I have, you would
>> have a rather different opinion.
>>

The PIK20E with engine extended has a glide ratio no
better than 10:1 at 50kts.
John F

>>
>> You are losing the plot. The sink rate of many of these
>> planes with motor out and not running is much, much,
>> higher than what glider pilots are used to. Not planning
>> for this has led to many, many accidents...
>
>Perhaps there is some confusion over "much, much". I'm talking about no
>more than twice the sink rate of best L/D - how much are you thinking?
>
>How about the ASH 26 E? Do you now agree it does not have a "plummet
>mode"? I do not experience What I think is a high sink rate when the
>mast is up.
>
>The ASH 26 E, DG and Ventus models I'm talking about are not the "engine
>on a stick" variety, but the newer (last 20 years or so) types with the
>"buried" engine. There is a significant difference between, for example,
>the old 15 meter PIK 20 E with it's "engine on a stick", and the newer
>18 meter ASH 26 E, DG 800, etc, with their "buried engine".
>
>Regardless of the sink rate, it is important for pilots of any glider to
>practice landings with the propeller extended, so they are aware of the
>gliders performance in that condition, and know how to handle the
>situation when the engine does not start. There should never be a case
>of "not used to it".
>
>--
>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 - Feb/2010" also ADS-B, PCAS, Flarm
>http://tinyurl.com/yb3xywl
>

[Eric Greenwell[_4_]]

John Firth wrote, On 4/20/2014 5:19 AM:
> At 02:29 19 April 2014, Eric Greenwell wrote:
>> Dave Nadler wrote, On 4/17/2014 3:08 AM:
>>> On Wednesday, April 16, 2014 10:48:39 PM UTC-4, Eric Greenwell wrote:
>>>> It's a decent presentation, but I do think "plummet mode" grossly
>>>> exaggerates the situation: my ASH 26 E does not have a "plummet mode",
>>>
>>> As was discussed in the talk, had you bothered to attend...
>>>
>>>
>>>> nor do similar gliders like the DG 800, Ventus self-launchers, etc.
>>>
>>> Wrong...
>>>
>>>
>>>> ... I'd reserve the
>>>> term "plummet mode" to sustainers that require diving to start the
>> engine.
>>>
>>> If you had flown some of the planes I have, you would
>>> have a rather different opinion.
>>>
>
> The PIK20E with engine extended has a glide ratio no
> better than 10:1 at 50kts.

I've read it's more like 15:1. Do you have a reference for the PIK20E
glide angle? I don't remember such a bad glide angle on the one I flew a
number of times.

In any case, the 18 meter, buried engine self-launchers have a much
higher "mast extended" L/D.

--
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 - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl