Apis M

[gotovkotzepkoi]

I am looking for an APIS motorglider, preferably with the 447 engine.
Anyone have one for sale?




--
gotovkotzepkoi

[Jacopo Romei]

Hello!
On GliderReview you may find some help for evaluation and quotations comparison.
http://www.gliderreview.com/glider/pipistrel-apis-bee-15m

Enjoy!

--
Jacopo

[Kris Herrick]

gotovkotzepkoi;936155 Wrote:
> I am looking for an APIS motorglider, preferably with the 447 engine.
> Anyone have one for sale?

Hello, I have a APIS M without the motor located in Dallas,TX. It has
about 150 hours on it in really good condition. The trailer is an
avionic. It need a annual but it is ready to fly. I was told by
Pipistrel you could order the engine. This is something you would want
to check on.

Kris
18173076788
N469KB




--
Kris Herrick

[frank...@hotmail.com]

Hello Kris. It's still available for sell? Thanks.

[son_of_flubber]

On Thursday, January 26, 2017 at 2:43:08 PM UTC-5, Kris Herrick wrote:

> Hello, I have a APIS M without the motor located in Dallas,TX. It has
> about 150 hours on it in really good condition. The trailer is an
> avionic. It need a annual but it is ready to fly.

Is it feasible to substitute an electric motor for a petrol engine in APIS M and their ilk?

[moshe....@gmail.com]

How hard can that be? :-)

[Martin Gregorie]

While the electric motor may be smaller and lighter than a petrol engine,
that certainly doesn't apply to energy storage: I did a comparison
recently because I was curious. I assumed the battery would be built from
SAFT LS13360 lithium-ion cells because SAFT supplied the cells used in
Antares 20E self-launchers and because I could find the numbers for SAFT
cells online.

I compared a battery pack with the volume of hydrocarbon fuel that
provides the same amount of energy. Petrol and diesel have very similar
densities and energy content per litre.

A battery made from SAFT LS13360 cells will weigh 18.34 times more than
the equivalent amount of gas and will occupy 49.7 times the volume. But,
in actual fact the battery will be a bit bigger and heavier than shown
here because I haven't allowed for the extra weight of the casing needed
to contain the batteries and I didn't allow for the amount of space
wasted when you pack cylindrical cells together and allow space round
them for cooling airflow.

However, given that an electric motor has a power conversion efficiency
of 85% while a small IC engine struggles to exceed 40%, factoring this
difference in makes the battery only 8.6 times heavier and 23.4 times the
volume.

The bottom line is that, while you can probably replace the engine on its
pylon with an electric motor fairly easily, squeezing in a battery pack
thats big enough to give a similar runtime to the petrol motor with its
standard tank may be quite a problem and positioning it so that its extra
weight doesn't affect the CG is another.


--
Martin | martin at
Gregorie | gregorie dot org

[Eric Greenwell]

Martin Gregorie wrote on 3/24/2020 5:08 PM:
> On Tue, 24 Mar 2020 15:11:28 -0700, moshe.braner wrote:
>
>> On Tuesday, March 24, 2020 at 6:00:37 PM UTC-4, son_of_flubber wrote:
>>> On Thursday, January 26, 2017 at 2:43:08 PM UTC-5, Kris Herrick wrote:
>>>
>>>> Hello, I have a APIS M without the motor located in Dallas,TX. It has
>>>> about 150 hours on it in really good condition. The trailer is an
>>>> avionic. It need a annual but it is ready to fly.
>>>
>>> Is it feasible to substitute an electric motor for a petrol engine in
>>> APIS M and their ilk?
>>
>> How hard can that be? :-)

.
.

.
>
> The bottom line is that, while you can probably replace the engine on its
> pylon with an electric motor fairly easily, squeezing in a battery pack
> thats big enough to give a similar runtime to the petrol motor with its
> standard tank may be quite a problem and positioning it so that its extra
> weight doesn't affect the CG is another.

The trick is realizing you rarely (if ever) run the fuel tank dry, so selecting a
smaller battery that covers, say, 95% of the situations, gives you a significantly
smaller, lighter, cheaper battery that is easier to integrate into the glider.

I recently went through that exercise to determine the 95% range for my ASH 26 E,
which I've flown for 25 years and 4000 hours. I decided a 100 mile retrieve range
would cover almost all of the 220+ self-retrieves I've done.

--
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

[Soartech]

On Tuesday, March 24, 2020 at 6:00:37 PM UTC-4, son_of_flubber wrote:

> Is it feasible to substitute an electric motor for a petrol engine in APIS M and their ilk?

Yes, there is a pilot in Slovenia, Roman Susnik, who has done that 11 years ago. Here is his video:
https://www.youtube.com/watch?v=fm3mliPyeeM

[Dan Marotta]

Eric,

Do your calculations include an electric self-launch or do they rely on
an air tow?

I agree that simply for self retrieves, the electric solution is a
viable alternative.

Dan, 5J

[Eric Greenwell]

The 90NM retrieve range was based on my experience with the 26E, and is simply the
range needed to get home. To determine the "useful" retrieve range of an electric
self-launcher, I'd use the energy remaining after a 2500' self-launch; ie, no tow.

At least two electric self-launchers meet that criteria: the GP15 and the AS-34.
The other two electrics I was considering - Silent Electro and miniLAK - did not;
nonetheless, those could easily be the best choices for some pilots. Accepting a
shorter retrieve range of, say, 50 NM, gives you more choices in gliders and at a
lower cost.

[Emir Sherbi]

I think that you need that range because you are flying a 18m ship.
Apis XC - task should be shorter and therefore the range needed.

[uncl...@ix.netcom.com]

On Tuesday, March 24, 2020 at 6:00:37 PM UTC-4, son_of_flubber wrote:

If you have a satisfactorily performing engine system I see no reason to change.
In my case it was not satisfactory which led to electric conversion project.
How hard could it be!
UH

[markm...@gmail.com]

Martin- You are in danger of making heretical comments about electric vs. hydrocarbon energy density. According to the millions of Unicorn believers, all problems are solved by "renewable" electric power provided free by the Sun and wind. Like wind turbines sprout from magic beans and photovoltaic cells somehow just proliferate at no cost, with no environmental impact in their manufacture. And they last forever, or so we are told. Engineers know this isn't true, but it is politically unwise to point this out on Facebook. That's the realm of political and Constitutional scholars, infectious disease experts and a lot of people who own a cat and a video camera. How can you argue against that kind of knowledge with a mere Masters Degree in Science? A degree in Eastern Philosophy or Literature trumps all.

I just want one of the "experts" to point out the solar powered solar cell factory.

[Martin Gregorie]

[:-)

> According to the millions of Unicorn
> believers, all problems are solved by "renewable" electric power
> provided free by the Sun and wind.
>

And that's quite true - provided only that you have enough batteries and
solar cell area available to match the requirement!

> Like wind turbines sprout from magic
> beans and photovoltaic cells somehow just proliferate at no cost, with
> no environmental impact in their manufacture. And they last forever, or
> so we are told. Engineers know this isn't true, but it is politically
> unwise to point this out on Facebook.
>

Guess why I won't touch FB with a bargepole. Having innumerate numpties
arguing about engineering is just as unappealing as the way its owners
scrape and sell everything they think they can deduce about me.

[Tom BravoMike]

Greta Thunberg: How dare you? How dare you denigrate the bright future of electric gliders?
Naomi Seibt: Be realistic. Speak science.

[markm...@gmail.com]

> Greta Thunberg: How dare you? How dare you denigrate the bright future of electric gliders?
> Naomi Seibt: Be realistic. Speak science.

Nothing wrong with electric gliders- I think they are cool. But their range and climb capability is limited by the length of the extension cord (or similar handicap invoked by battery technology.)

Energy ain't free. Energy storage and distribution is problematic. Except for hydrocarbons. Easily stored (with some risk, of course), easily transported (with some risk, of course), easily distributed worldwide through a mature system designed to make the product available (with some risk, of course. Most gas stations sell cigarettes and beef jerky.)

Modern high performance batteries require careful handling, have a significant environmental penalty from mining the base resources (lithium and rare earths) and present problems with proper disposal or recycling. And the "Best" of them still have about 1% the energy density of hydrocarbons (by weight). And when the battery goes dry, it weighs the same as when fully charged. (OK. I know there is some minute loss in mass, but it's not like a 20 gallon tank of gas going to empty.

I am eagerly awaiting this, but Amazon says it is "Currently unavailable."
https://www.amazon.com/Back-Future-Mr-Fusion-Replica/dp/B00NPADMRK

[Eric Greenwell]

markm...@gmail.com wrote on 3/25/2020 4:19 PM:
> On Tuesday, March 24, 2020 at 6:08:24 PM UTC-6, Martin Gregorie wrote:
>> On Tue, 24 Mar 2020 15:11:28 -0700, moshe.braner wrote:
>>

>> The bottom line is that, while you can probably replace the engine on its
>> pylon with an electric motor fairly easily, squeezing in a battery pack
>> thats big enough to give a similar runtime to the petrol motor with its
>> standard tank may be quite a problem and positioning it so that its extra
>> weight doesn't affect the CG is another.
>>
>>
>> --
>> Martin | martin at
>> Gregorie | gregorie dot org
>

> Martin- You are in danger of making heretical comments about electric vs. hydrocarbon energy density. According to the millions of Unicorn believers, all problems are solved by "renewable" electric power provided free by the Sun and wind. Like wind turbines sprout from magic beans and photovoltaic cells somehow just proliferate at no cost, with no environmental impact in their manufacture. And they last forever, or so we are told. Engineers know this isn't true, but it is politically unwise to point this out on Facebook.. That's the realm of political and Constitutional scholars, infectious disease experts and a lot of people who own a cat and a video camera. How can you argue against that kind of knowledge with a mere Masters Degree in Science? A degree in Eastern Philosophy or Literature trumps all.

>
> I just want one of the "experts" to point out the solar powered solar cell factory.

Nothing Martin said would offend a Unicorn glider pilot. Even they know electric
power for sailplanes is full of compromises, as is the sailplane itself, but the
future is already here. I'm accepting it with open arms, and an open wallet: I've
ordered a GP15 Jeta to replace my wonderful, still working like new, ASH 26 E that
I received in 1995. I'm looking forward to the change: The Jeta is smaller and
lighter, easier to operate, yet it will (as near as I can determine for a new
sailplane) equal the 26E in performance, even exceed it at places like Ely.

[Eric Greenwell]

Emir Sherbi wrote on 3/25/2020 1:18 PM:
> El miércoles, 25 de marzo de 2020, 15:12:45 (UTC-3), Eric Greenwell escribió:
>> The 90NM retrieve range was based on my experience with the 26E, and is simply the
>> range needed to get home. To determine the "useful" retrieve range of an electric
>> self-launcher, I'd use the energy remaining after a 2500' self-launch; ie, no tow.
>>
>> At least two electric self-launchers meet that criteria: the GP15 and the AS-34.
>> The other two electrics I was considering - Silent Electro and miniLAK - did not;
>> nonetheless, those could easily be the best choices for some pilots. Accepting a
>> shorter retrieve range of, say, 50 NM, gives you more choices in gliders and at a
>> lower cost.
>

.
.
.
>>>>>
>>>>> The bottom line is that, while you can probably replace the engine on its
>>>>> pylon with an electric motor fairly easily, squeezing in a battery pack
>>>>> thats big enough to give a similar runtime to the petrol motor with its
>>>>> standard tank may be quite a problem and positioning it so that its extra
>>>>> weight doesn't affect the CG is another.

>>>>the

>>>> The trick is realizing you rarely (if ever) run the fuel tank dry, so selecting
>>>> a smaller battery that covers, say, 95% of the situations, gives you a
>>>> significantly smaller, lighter, cheaper battery that is easier to integrate into
>>>> the glider.
>>>>
>>>> I recently went through that exercise to determine the 95% range for my ASH 26
>>>> E, which I've flown for 25 years and 4000 hours. I decided a 100 mile retrieve
>>>> range would cover almost all of the 220+ self-retrieves I've done.
>>>>
>>>
>>
>>
>> --
>> 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
>
> I think that you need that range because you are flying a 18m ship.
> Apis XC - task should be shorter and therefore the range needed.

I agree. Pilots have to assess their particular situation and preferences to
determine how much range they need, and it will also vary with the performance of
the glider, the area they fly in.

[India November]

Martin your assumption of 40% for the thermal efficiency of a typical 2-stroke engines used in aero applications is optimistic. 15% to 20% conversion of fuel to useful power is more realistic https://energyeducation.ca/encyclopedia/Two_stroke_engine

This means the batttery in an electeic conversion will "only" be 4 times heavier and 12 times the volume of an equivalent gas tank.

Still your point is a good one.
IN

[Mike N.]

When your Jeta is delivered can I have your ASH 26?

I'm kind of a unicorn killer anyway... 😉

[Eric Greenwell]

Mike N. wrote on 3/26/2020 6:21 AM:
> When your Jeta is delivered can I have your ASH 26?
>
> I'm kind of a unicorn killer anyway... 😉

You can have it now if you make a crazy offer ;^)

With a nominal Jeta delivery date of Feb 2021, I expect to offer the ASH 26 E for
sale in the Fall. There are always uncertainties for glider deliveries, especially
a new design, and now the pandemic adds another layer of uncertainty, so I might
be flying the 26 E far longer than I hoped. That's not a bad thing - it still
flies as well as ever, and the engine produces the same power it did 25 years ago.
It's the pilot that's changed over the years, who finds dealing with an 850 lb
glider (empty) and a trailer that's 2500 lbs loaded is not as easy as it was even
10 years ago.

[Martin Gregorie]

On Thu, 26 Mar 2020 05:31:12 -0700, India November wrote:

> Martin your assumption of 40% for the thermal efficiency of a typical
> 2-stroke engines used in aero applications is optimistic. 15% to 20%
> conversion of fuel to useful power is more realistic
> https://energyeducation.ca/encyclopedia/Two_stroke_engine
>

Thanks for the correction: I've not had any real ides of ICE efficience
apart from the recollection that a modern car engine was quite a lot
better than a 2-stroke.

I've just extended my spreadsheet to use an efficiency of 85% for
electric and 20% for ICE (nelecting friction, since our engines are
generally direct or belt drive and IIRC belts are rather more efficient
than gearboxes. This gives an efficiency ratio of 4.25 electric:ICE.

With this added, my spread sheet now thinks that a pile of SAFT Li-ion
cells would be 3.26 times the weight of petrol for the same energy
content and be 3.2 times the volume if packing density and outer battery
case are ignored.

> This means the batttery in an electeic conversion will "only" be 4 times
> heavier and 12 times the volume of an equivalent gas tank.
>

I now get 3.2 times heavier and 3.2 times the volume of petrol, so not
as big a problem as I originally thought, but still not easy to cram in.

[Martin Gregorie]

On Thu, 26 Mar 2020 17:02:04 +0000, Martin Gregorie wrote:

> On Thu, 26 Mar 2020 05:31:12 -0700, India November wrote:
>
>> Martin your assumption of 40% for the thermal efficiency of a typical
>> 2-stroke engines used in aero applications is optimistic. 15% to 20%
>> conversion of fuel to useful power is more realistic
>> https://energyeducation.ca/encyclopedia/Two_stroke_engine
>>
> Thanks for the correction: I've not had any real ides of ICE efficience
> apart from the recollection that a modern car engine was quite a lot
> better than a 2-stroke.
>
> I've just extended my spreadsheet to use an efficiency of 85% for
> electric and 20% for ICE (nelecting friction, since our engines are
> generally direct or belt drive and IIRC belts are rather more efficient
> than gearboxes. This gives an efficiency ratio of 4.25 electric:ICE.
>
> With this added, my spread sheet now thinks that a pile of SAFT Li-ion
> cells would be 3.26 times the weight of petrol for the same energy
> content and be 3.2 times the volume if packing density and outer battery
> case are ignored.

Correction: 7.7 times the volume: SAFT cells are just over half the
density of petrol.

[Dan Marotta]

Mark,

I think you're on the right track, but I think you've missed a couple of
opportunities, to wit:

An electric self-launcher with pylon mounted electric motor, could have
a wind-driven generator mounted to the aft side of the pylon, directly
behind the motor-driven propeller.  In this manner the propeller thrust,
in addition to propelling the aircraft for take off, would also provide
the wind to turn the generator, thus maintaining the battery in a fully
charged state.

My calculations (and political leanings) bear this out.  Using the
advice from my Electrical Engineering professors to "ignore resistance"
and my Mechanical Engineering professors to "ignore friction", it seems
to be a perfect solution AND the answer to the long sought perpetual motion.

I'll be awaiting my Nobel Prize from the cave in the Himalayas where
I'll be studying under a maharishi or hashish or something...

--
Dan, 5J

[uneekc...@gmail.com]

Now if we could find a way to ignore gravity we would have it all! lol

[Mike N.]

Actually if we ignored gravity, we would no longer have the motivating force to move our gliders forward... 😁

I guess we could get out and push but then you have to calculate for coefficient of friction of air vs body mass, vs glider mass.

Yea for gravity!

[Martin Gregorie]

On Thu, 26 Mar 2020 13:22:30 -0700, uneekcowgirl wrote:

> Now if we could find a way to ignore gravity we would have it all! lol

I wouldn't like that at all.
It would be like flying a balloon.

[uneekc...@gmail.com]

Hey Mike, next time you find yourself trying to scratch your way out of a hole around 800 ft agl I’m gonna refer you to this post LOL.....helium sacks in the wings, thats my secret lol.
Dan

[markm...@gmail.com]

I actually got in a bar "conversation" with a know-it-all lawyer who insisted that hooking a generator to the already spinning prop would provide all the electricity needed to maintain flight. Could NOT get past the basic concept of windmilling vs. thrust.

[Martin Gregorie]

I hope you congratulated him for re-inventing Perpetual Motion!

[AS]

On Thursday, March 26, 2020 at 3:45:44 PM UTC-4, Dan Marotta wrote:
> Mark,
>
> I think you're on the right track, but I think you've missed a couple of
> opportunities, to wit:
>
> An electric self-launcher with pylon mounted electric motor, could have
> a wind-driven generator mounted to the aft side of the pylon, directly
> behind the motor-driven propeller.  In this manner the propeller thrust,
> in addition to propelling the aircraft for take off, would also provide
> the wind to turn the generator, thus maintaining the battery in a fully
> charged state.
>
> My calculations (and political leanings) bear this out.  Using the
> advice from my Electrical Engineering professors to "ignore resistance"
> and my Mechanical Engineering professors to "ignore friction", it seems
> to be a perfect solution AND the answer to the long sought perpetual motion.
>
> I'll be awaiting my Nobel Prize from the cave in the Himalayas where
> I'll be studying under a maharishi or hashish or something...
>
>

> Dan, 5J

Dan - I installed extra large diameter tires on the rear axle of my van so it is constantly rolling down-hill. The fuel savings are staggering - I am passing on this discovery to this community free of charge! ;-)

Uli
'AS'

[Dan Marotta]

Take it to Elon Musk.  Surely using a generator attached to the motor
would alleviate all of the weight of the batteries.  The car could be
parked at night on angled ramps to give it an initial bit of "go" to get
the motor/generator system operating at full efficiency.

Maybe that system could be adapted to gliders. :-D(For those who don't
understand humor.)

On 3/26/2020 4:40 PM, markm...@gmail.com wrote:
> I actually got in a bar "conversation" with a know-it-all lawyer who insisted that hooking a generator to the already spinning prop would provide all the electricity needed to maintain flight. Could NOT get past the basic concept of windmilling vs. thrust.

--
Dan, 5J