Flying Stemme S10 Glider, 115HP Rotax in Germany

Status
Not open for further replies.
Joined
Feb 15, 2003
Messages
15,545
Location
Jupiter, Florida
I just flew our brand new Stemme S10 glider from Strausberg, Germany to Pennemunde, Germany (yes where the V2 rockets were developed) .

It has a liquid cooled Rotax 914, 115HP turbocharged engine. It's maximum powered service ceiling is 30,000 feet (higher than Mt. Everest) What an incredible machine. It's a great glider, with a best lift over drag of 50 to 1. Because the engine is behind the cockpit, and the prop is completely hidden up front, it has no powerplant created drag, like so many other "so called" motor-gliders. So, once up to altitude, one can shut off the engine, stow the prop, and expect high performance soaring action.

But, more interestingly, it's also a very good cross country aircraft. It's seating position is "zero gravity" and amazingly comfortable. The engine has very little vibration and is extremely quiet. The prop turns at a lazy 2100 RPM, so prop noise is also minimal.

The prop has 2 settings, a take off position, and a cruise position. It takes about 2 minutes for the prop to go from one position to the other. It does this by 12V heating elements, that expand wax in 2 pitch control capsules. They move the complex mechanism that changes the blade pitch. The airplane needs no other prop settings. Since it's a folding prop driven by a driveshaft and gearbox, this design is a logical choice.

My trip to Pennemunde was quite remarkable. As you might expect, nothing but rubble remains of the buildings and test sites. However, there is an excellent museum there, located in the (rather horrific) huge old powerplant. That old powerplant is as spooky/creepy/awful smelling as humanly possible, as you might expect anything from that time in Germany to be. Yet, the rocket displays were remarkable, with plenty of technical bits to keep me interested.

The fuselage assembly below is not of an S10, but the S10 is similar construction. Very robust!

6qj3zNc.jpg


OciIWMV.jpg


PmB2H7M.jpg


1Bdn5pv.jpg
 
Last edited:
Here is a picture of the amazing prop mechanism. Light, robust and completely hidden when not in use.

6YsfGSW.jpg


And a pic of the engine installation. Also completely hidden when not in use. There are 2 side scoops that open and a belly fairing that opens when the prop dome is moved forward.

mLyAh5Z.jpg


This is how the prop looks when stowed, the gearbox that drives it, and the mounting plate that holds the entire assembly. The assembly is mounted on rubber insulators (as is the engine) , so prop and engine vibration is quite minimal.

CZXzMKL.jpg
 
Last edited:
Nice post !! Pretty cool. Any in-flight scenery photos?

Been so obsessed over LSA's that I've never thought of a motor glider, and I'm completely ignorant about soaring in general. Assume you can only do it in class E airspace? What if you get in an exceptionally strong thermal and end up in class A? (told you I was ignorant about it...)

edit: lol, you've added the in-flight photos while I was composing my post :^)
 
A co-worker of mine has a license to fly a glider. He's originally from California. Says Ohio doesn't have good thermals to fly one here.
 
D6839I5.jpg


And of course, the frame without the engine

bcaWIeR.jpg


Here is the memorial for soldiers

IdYwVlZ.jpg


And a very interesting mechanical "elevator" for large canal sized cargo ships.

B7wpl4F.jpg
 
One can fly a motorglider anywhere. You might want to keep the engine running while landing at a controlled airport. Or expect a bit of questioning....

Our cruise true airspeed was around 115Kts at 3.8GPH, 6500 feet. Remarkable. It's capable of going considerably faster, especially when at high altitudes (remember, it's turbocharged) but getting down takes some time.... as it wants to remain aloft. A descent at Vne seemed like it was less than 300FPM. (I could be wrong on that one, but it certainly was not much of a descent rate)
 
Nice pictures, I envy you since I always wanted to visit Pennemunde.

P.S. -Dang that thing is almost half a mill.
 
Originally Posted By: horse123
How is it a glider if it's powered?


All airplanes are gliders when the power is off. It's just that some are a bit better than others.
 
It's not really a glider, it's a glider body with an engine in it, which makes it a regular airplane that happens to be good at gliding. It is cool, but glider is a stretch :p
 
Originally Posted By: horse123
It's not really a glider, it's a glider body with an engine in it, which makes it a regular airplane that happens to be good at gliding. It is cool, but glider is a stretch :p


The S10 was never a glider without an engine. It was designed as you see it, as an extremely high performance self launching glider that can also cruise cross country.

At 50 to l, lift over drag, full span ailerons that reflex 10 degrees, a completely hidden landing gear and powerplant, the Stemme S10 is among the worlds highest performance gliders. In fact, it can thermal and soar competitively as such.

Take a look at just how clean it is in flight. (yes, it has a very large wingspan to carry the additional weight of the powerplant) However, that does not negatively affect performance. Wing loading is on par with other high performance gliders.

The S10 is as clean as the record setting DG505 (which is also 50 to 1 L/D) non powered glider. And thermals just as well.

DG505:

913.JPG


Stemme S10:

stemme.jpg
 
Last edited:
Been a huge fan of that design for 30 years. Never had the bux necessary at any one time to get one. To these eyes it is the perfect pleasure craft.
 
Originally Posted By: SEMI_287
What's the approach speed on that baby, 30 KIAS?
crackmeup2.gif



I imagine that with the amount of aileron droop available, the approach speed is whatever you'd like it to be, within reason.

I've been flying gliders for many years and believe me, this plane is a glider or maybe more correctly, a sailplane.

Having a built in motor is really convenient in so many ways and someday could even be a much appreciated safety device to protect life and limb or having to land short of the field somewhere and damage one very expensive sailplane.
 
Bathroom? At my age That is the most important consideration. Motorized gliders are really interesting. Ill bet it is economical gallons / lbs. per hour . Seems flying is a fast way to get some place or just being up in the air. Back in the 1980, Popular mechanics had an article on a motorized glider and I loved the idea.
 
Status
Not open for further replies.
Back
Top