Best Overall Motorglider available today?

Dave Walsh wrote on 9/16/2020 1:11 PM:
Despite the reported lack of vibration the bolts holding
some Wankel engines together seem to have a habit of falling out?
Assuming all motor-gliders are unreliable seems a safe bet.

The 26E was not affected, so I am not an expert on it; however, my understanding
is it's a bolt problem, not vibration related. Seriously, it has so little
vibration, I can't imagine that it could break a bolt. Vibration is simply not an
issue in our Wankel powered gliders.

It is a bad bet to assume all motor-gliders are unreliable, when so many are quite
good. I have had fewer lost soaring days because I couldn't self-launch than when
I had to use tows, and I'm very glad to be a FORMER owner of towplane!

It is not a good bet to assume the engine will start when it is your only chance
of avoiding a crash. It's not just the engine that may malfunction, but the pilot
might make a mistake.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

The question comes down to what do you want, power-plane flying with some soaring ability or self-launch, self retrieve cross country sailplane? And how much money do you have?
For the latter mission, the ASH31 is right now a great glider. (Of course, my toy.) Strong climb performance -- I self-launch at Truckee, often 8000+ density altitude, with full water ballast, and no trouble. It has great cross country performance, keeping up well with 18m contest gliders. Its one limitation is not quite enough water ballast (legally), 10.8 lbs/sq foot. The 26 is a good substitute if you don't have lots of money. No 21 meter wings, top about 9.2 lbs, for much less money you lose a few MPH on your friend in a 31. The engine is very reliable.
I would not choose it though if I routinely wanted to fly 100s of miles under power and occasionally soar a bit.
John Cochrane BB

Very astute, Eric.

On 9/16/2020 3:20 PM, Eric Greenwell wrote:
It's not just the engine that may malfunction, but the pilot might
make a mistake.

--
Dan, 5J

The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

On Wednesday, September 16, 2020 at 5:56:25 PM UTC-7, Ramy wrote:
The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

Personally, I am not satisfied with the reliability and safety of the FES batteries and would not fly with them. The percentage of installations that have had fires is unacceptably high. Eventually, the glider community will acquire millions of hours of operational data to establish its reliability (or lack thereof).

Tom

2G wrote on 9/16/2020 9:10 PM:
On Wednesday, September 16, 2020 at 5:56:25 PM UTC-7, Ramy wrote:
The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

Personally, I am not satisfied with the reliability and safety of the FES batteries and would not fly with them. The percentage of installations that have had fires is unacceptably high. Eventually, the glider community will acquire millions of hours of operational data to establish its reliability (or lack thereof).

Tom

What is the percentage of installations that have had fires? What would be an
acceptable percentage of installations with fires? And are the hours you mention
motor hours or airframe hours?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Thursday, September 17, 2020 at 8:48:10 AM UTC-4, Eric Greenwell wrote:
2G wrote on 9/16/2020 9:10 PM:
On Wednesday, September 16, 2020 at 5:56:25 PM UTC-7, Ramy wrote:
The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

Personally, I am not satisfied with the reliability and safety of the FES batteries and would not fly with them. The percentage of installations that have had fires is unacceptably high. Eventually, the glider community will acquire millions of hours of operational data to establish its reliability (or lack thereof).

Tom

What is the percentage of installations that have had fires? What would be an
acceptable percentage of installations with fires? And are the hours you mention
motor hours or airframe hours?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Airframe hours, years, charge cycles...

Anecdotally I got the impression that there have been more battery fires in FES gliders than fires in gliders with gasoline-fueled engines, at least in recent years, and the number of FES gliders is relatively small. Li-ion seems risky. Personally I hope better battery chemistry will be developed, that is both safer and has the needed energy density. LiFePO4 is safer, and its energy density is improving, some electric cars are switching to it. Other chemistries are in the pipeline.

wrote on 9/17/2020 8:23 AM:
On Thursday, September 17, 2020 at 8:48:10 AM UTC-4, Eric Greenwell wrote:
2G wrote on 9/16/2020 9:10 PM:
On Wednesday, September 16, 2020 at 5:56:25 PM UTC-7, Ramy wrote:
The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

Personally, I am not satisfied with the reliability and safety of the FES batteries and would not fly with them. The percentage of installations that have had fires is unacceptably high. Eventually, the glider community will acquire millions of hours of operational data to establish its reliability (or lack thereof).

Tom

What is the percentage of installations that have had fires? What would be an
acceptable percentage of installations with fires? And are the hours you mention
motor hours or airframe hours?


Airframe hours, years, charge cycles...

Anecdotally I got the impression that there have been more battery fires in FES gliders than fires in gliders with gasoline-fueled engines, at least in recent years, and the number of FES gliders is relatively small. Li-ion seems risky. Personally I hope better battery chemistry will be developed, that is both safer and has the needed energy density. LiFePO4 is safer, and its energy density is improving, some electric cars are switching to it. Other chemistries are in the pipeline.

Because there were significant changes in the FES batteries after the fires, I
think the current reliability should be estimated using the number of fires
post-updates. I'm not aware of any, but perhaps there are not enough
hours/flights/years on the revised batteries to have a good estimate.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Thursday, September 17, 2020 at 5:23:05 PM UTC+2, wrote:
On Thursday, September 17, 2020 at 8:48:10 AM UTC-4, Eric Greenwell wrote:
2G wrote on 9/16/2020 9:10 PM:
On Wednesday, September 16, 2020 at 5:56:25 PM UTC-7, Ramy wrote:
The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

Personally, I am not satisfied with the reliability and safety of the FES batteries and would not fly with them. The percentage of installations that have had fires is unacceptably high. Eventually, the glider community will acquire millions of hours of operational data to establish its reliability (or lack thereof).

Tom

What is the percentage of installations that have had fires? What would be an
acceptable percentage of installations with fires? And are the hours you mention
motor hours or airframe hours?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
Airframe hours, years, charge cycles...

Anecdotally I got the impression that there have been more battery fires in FES gliders than fires in gliders with gasoline-fueled engines, at least in recent years, and the number of FES gliders is relatively small. Li-ion seems risky. Personally I hope better battery chemistry will be developed, that is both safer and has the needed energy density. LiFePO4 is safer, and its energy density is improving, some electric cars are switching to it. Other chemistries are in the pipeline.

The UK AAIB/EASA did an investigation into the fires, which is a great and thorough read : https://assets.publishing.service.go...GSGS_09-18.pdf
30 word summary: Suspected either metal contamination at manufacture or owner physical damage to the battery, recommended all batteries be withdrawn from use and redesigned/refurbished, which they .

Don't think there have been any since the redesign in ~2018. There is a fire warning system in new FES gliders now.

On Thursday, September 17, 2020 at 5:48:10 AM UTC-7, Eric Greenwell wrote:
2G wrote on 9/16/2020 9:10 PM:
On Wednesday, September 16, 2020 at 5:56:25 PM UTC-7, Ramy wrote:
The Carat has relatively low performance according to a pilot I fly with often.
For me (cost constrain, strong tendency towards simple low maintenance, reliable, simple, safe and quick to operate with small risk of getting into trouble, minimal performance compromise, as close to pure glider as possible) the only solution I can think of is adding Self launching FES option to my glider.
I figured it would have got me home 80-90% of the times I landed out, and to a better landout place the rest of the time, have the potential of saving my butt if I make bad decisions again, and may allow me to fly when the tow plane is grounded, there is a long line or I want to fly from somewhere else, and would allow me to explore further than I would otherwise, and overall reduce my dependency on others.
Range is not a significant constrain, I rarely land out more than 100km from home.
Unless someone convinces me I am wrong, I will seriously consider adding an FES to my ASG29.

Ramy

Personally, I am not satisfied with the reliability and safety of the FES batteries and would not fly with them. The percentage of installations that have had fires is unacceptably high. Eventually, the glider community will acquire millions of hours of operational data to establish its reliability (or lack thereof).

Tom

What is the percentage of installations that have had fires? What would be an
acceptable percentage of installations with fires? And are the hours you mention
motor hours or airframe hours?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Would have to know the total number of installations and fires, and I don't know either, but it is going to be in the one or two percent range. An acceptable number would be 0.1% or less.

Tom