What is involved regulation wise adding an electric motor to a glider?

On Wednesday, February 3, 2021 at 11:35:51 AM UTC-8, Bob Kuykendall wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:

Others have pointed out that this is easier for an Experimental glider. It is easiest for an experimental, amateur-built glider. For E-AB, depending on the operating limitations, you might have to notify the FAA and repeat Phase I testing. But nobody wants to see your engineering validation, and only the person signing off the annual condition inspection needs to review your workmanship. The FAA or DAR only wants to see that the paperwork is correct and that placards and operating limitations are correctly spelled out.. A good DAR will look the airplane over to make sure it doesn't look particularly dangerous, but they aren't required to.

We have FES going into one of our glider kits right now, and are preparing for the installation of electric self-launch systems in future models.

--Bob K.
Since I am new here what kit do you produce? Are you preparing for FES or retractable pylon?
Any idea how much thrust an FES produces? My search came up empty.

Not to hijack the thread, but in response to the reliability issue of two-stroke engines, the primary culprit seems to be the different altitudes at which the engine is supposed to start and operate. The fuel/oil/air mixture has to be within certain parameters for decent running and starting reliability. An increase in altitude (or high density altitude conditions) reduces the amount of available oxygen, which contributes to fouling the spark plugs. I used to ride the Yamaha RD-350 and TZ-250 motorcycles from Albuquerque (elevation ~5,500 ft. MSL) up to Sandia Crest (10,678 ft. MSL) and used to have to stop and adjust the needles in the carburetors four times on the way up and four times on the way down or risk plug fouling or overheating and possibly seizing the engine. About a 1,000 ft. change in altitude was all it took to affect the performance and reliability. Newer two-stroke engines with more sophisticated fuel injection systems seem to be much more reliable in motorgliders.

On Wednesday, February 3, 2021 at 5:10:11 PM UTC-6, Mark Mocho wrote:
Not to hijack the thread, but in response to the reliability issue of two-stroke engines, the primary culprit seems to be the different altitudes at which the engine is supposed to start and operate. The fuel/oil/air mixture has to be within certain parameters for decent running and starting reliability. An increase in altitude (or high density altitude conditions) reduces the amount of available oxygen, which contributes to fouling the spark plugs. I used to ride the Yamaha RD-350 and TZ-250 motorcycles from Albuquerque (elevation ~5,500 ft. MSL) up to Sandia Crest (10,678 ft. MSL) and used to have to stop and adjust the needles in the carburetors four times on the way up and four times on the way down or risk plug fouling or overheating and possibly seizing the engine. About a 1,000 ft. change in altitude was all it took to affect the performance and reliability. Newer two-stroke engines with more sophisticated fuel injection systems seem to be much more reliable in motorgliders.

Oh, that brings back memories. I too rode an RD-350 (voted as the "Bike most likely to lose you your driver's license"). Even tried production class road racing on it a couple times (scary). Had the same experience as you with riding in the mountains. Used to stop on the way up to Deal's Gap and drop the carb needles a notch. Put 38,000 miles on the bike. Never failed to start and run. Stopped being scooter trash and became glider trash, but still have that bike (mothballed since 1981).

Talk about hijacking...

I've had my Harley Davidson Wide Glide for almost 17 years and 137,000
miles and don't ride it too much any more though I did get it out a
couple of days ago when the temperature got up to 60 deg. Just
wondering what you did to mothball it. I've never done more than to put
on a battery charger now and then.

Dan
5J


On 2/3/21 9:36 PM, Wallace Berry wrote:
but still have that bike (mothballed since 1981).

On Thursday, February 4, 2021 at 10:51:36 AM UTC-6, Dan Marotta wrote:
Talk about hijacking...

I've had my Harley Davidson Wide Glide for almost 17 years and 137,000
miles and don't ride it too much any more though I did get it out a
couple of days ago when the temperature got up to 60 deg. Just
wondering what you did to mothball it. I've never done more than to put
on a battery charger now and then.

Dan
5J
On 2/3/21 9:36 PM, Wallace Berry wrote:
but still have that bike (mothballed since 1981).
Drained the transmission case and replaced with fresh oil. Drained the fuel tank, lines, carbs. Flushed everything with clean fuel and stabilizer, then drained again and let dry before reassembly. Drained the forks and replaced the fork fluid. Drained the front brake hydraulics. Fogged the cylinders with Marvel Mystery Oil and turned them over a few times. Threw the battery away. Heavily Armor All'ed the exterior rubber and vinyl. Probably should have used products expressly made to pickle engines, but I didn't know I was going to keep the bike stored for 40 years. Front fork wipers, brake lines, and tires have deteriorated. Everything else seems OK. RD 350's were still being made (in India) up into the late 1990's or early 2000's so parts are still available. Hoping to do a complete restoration as a retirement project, but I don't plan on taking up riding scooters again. Old bones and all...

Thanks!

Took mine to the store today and it was too cold for me. Temperature in
the 40s. Put her back to sleep...

Dan
5J


On 2/4/21 1:13 PM, Wallace Berry wrote:
On Thursday, February 4, 2021 at 10:51:36 AM UTC-6, Dan Marotta wrote:
Talk about hijacking...

I've had my Harley Davidson Wide Glide for almost 17 years and 137,000
miles and don't ride it too much any more though I did get it out a
couple of days ago when the temperature got up to 60 deg. Just
wondering what you did to mothball it. I've never done more than to put
on a battery charger now and then.

Dan
5J
On 2/3/21 9:36 PM, Wallace Berry wrote:
but still have that bike (mothballed since 1981).
Drained the transmission case and replaced with fresh oil. Drained the fuel tank, lines, carbs. Flushed everything with clean fuel and stabilizer, then drained again and let dry before reassembly. Drained the forks and replaced the fork fluid. Drained the front brake hydraulics. Fogged the cylinders with Marvel Mystery Oil and turned them over a few times. Threw the battery away. Heavily Armor All'ed the exterior rubber and vinyl. Probably should have used products expressly made to pickle engines, but I didn't know I was going to keep the bike stored for 40 years. Front fork wipers, brake lines, and tires have deteriorated. Everything else seems OK. RD 350's were still being made (in India) up into the late 1990's or early 2000's so parts are still available. Hoping to do a complete restoration as a retirement project, but I don't plan on taking up riding scooters again. Old bones and all...

On Wednesday, February 3, 2021 at 3:10:11 PM UTC-8, Mark Mocho wrote:
...I used to ride the Yamaha RD-350 and TZ-250 motorcycles...

I raced RD-250 in 250 Modified Production and TA-125 in GP classes during my mis-spent youth. Fun stuff, but there is no way I'd trust my life to the continued operation of a tightly-wound two-stroke motor. I didn't think I'd mess around with motorgliders at all until brushless motors and Lithium batteries came along. Now I think that electric motorgliders are poised to become the core of our sport, with pure sailplanes becoming more of a fringe activity.

On 2/5/21 6:31 PM, Bob Kuykendall wrote:
but there is no way I'd trust my life to the continued operation of a
tightly-wound two-stroke motor. I didn't think I'd mess around with
motorgliders at all until brushless motors and Lithium batteries came
along. Now I think that electric motorgliders are poised to become the
core of our sport, with pure sailplanes becoming more of a fringe activity.


if you're trusting your life to the operation of any motorglider engine,
you're screwing up bigtime. Electrics can and do fail, right along with
the others.

On Wednesday, February 3, 2021 at 5:31:51 PM UTC-5, David Scott wrote:
On Wednesday, February 3, 2021 at 11:35:51 AM UTC-8, Bob Kuykendall wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:

Others have pointed out that this is easier for an Experimental glider. It is easiest for an experimental, amateur-built glider. For E-AB, depending on the operating limitations, you might have to notify the FAA and repeat Phase I testing. But nobody wants to see your engineering validation, and only the person signing off the annual condition inspection needs to review your workmanship. The FAA or DAR only wants to see that the paperwork is correct and that placards and operating limitations are correctly spelled out. A good DAR will look the airplane over to make sure it doesn't look particularly dangerous, but they aren't required to.

We have FES going into one of our glider kits right now, and are preparing for the installation of electric self-launch systems in future models.

--Bob K.
Since I am new here what kit do you produce? Are you preparing for FES or retractable pylon?
Any idea how much thrust an FES produces? My search came up empty.

Look up https://hpaircraftblog.wordpress.com
Lots of interesting info there- especially the old school stuff showing all the work it takes to get set up to produce a kit sailplane.
UH

On Wednesday, February 3, 2021 at 3:52:46 PM UTC-8, Hank Nixon wrote:
On Wednesday, February 3, 2021 at 5:31:51 PM UTC-5, David Scott wrote:
On Wednesday, February 3, 2021 at 11:35:51 AM UTC-8, Bob Kuykendall wrote:
On Tuesday, February 2, 2021 at 1:26:10 PM UTC-8, David Scott wrote:

Others have pointed out that this is easier for an Experimental glider. It is easiest for an experimental, amateur-built glider. For E-AB, depending on the operating limitations, you might have to notify the FAA and repeat Phase I testing. But nobody wants to see your engineering validation, and only the person signing off the annual condition inspection needs to review your workmanship. The FAA or DAR only wants to see that the paperwork is correct and that placards and operating limitations are correctly spelled out. A good DAR will look the airplane over to make sure it doesn't look particularly dangerous, but they aren't required to.

We have FES going into one of our glider kits right now, and are preparing for the installation of electric self-launch systems in future models..

--Bob K.
Since I am new here what kit do you produce? Are you preparing for FES or retractable pylon?
Any idea how much thrust an FES produces? My search came up empty.

Look up https://hpaircraftblog.wordpress.com
Lots of interesting info there- especially the old school stuff showing all the work it takes to get set up to produce a kit sailplane.
UH
I was wondering if that is what he was talking about. I followed that blog for a few years so am somewhat familiar with it.