glider development

Garry Morgan

Morgan range of aircraft
#1
Glider development is said to be German rocket science, but after a lot of research I find it isn't. Some country's build there first glider and prove it to be one of the worlds best the JSI ,Sparrow hawk. etc. Gliders are like racing boats and cars. they follow the trends, of development and they finish very much the same.
When fibreglass gliders came along the home building form plans stopped and if you wanted a new glider you had no choice but to pay big money for it.
My aim is to change this. A high performance glider and self launch. 90% of new gliders now have some sort of motor. It will have all the latest design improvements, and of the highest performance. No specials moulds, i think this is where most people think inside the box. Yes a foam core, not a hot wire foam core and glass,this wont work on a glider with the filler shrinking at different rates, and in no time the 4 th max surface roughness is exceeded.
Using the same 60kg sq m foam 5mm thick when glassed one side only it will still flex, bonded over foam ribs. When glassed on both sides the shape is locked in. not only that the surface is very flat , there is very little filler needed leaving little work to finish off for paint. The learning curve here that with the foam ribs ( which are not in a moulded wing) make for a very stiff piece, in turn makes weight. this is another learning curve.
The glider is an 18m 4 piece wing self launch, which is where gliding is going. And designing a build process one can do at home with hand lay up. but you will need a lot of time on your hands and like being in the workshop, but then it is a very special aircraft, and not many could afford to go and buy a new one. but 15k and hard work could get you one.
 

Garry Morgan

Morgan range of aircraft
#2
The Cheyenne has its first flight last week, not even a trim change was needed, x wind taxing is a problem and we now have a steerable nose wheel which works well. The 18m wing has a very large turning radius when flying in lift, and being near the coast with tight thermals, we are looking at maybe a 15m wing could be better with the same wing loading. The 2.2 jabiru motor was perfect all round .
The Shawnee single seater has the fuse almost glassed now and getting the steel frame set up .
 

bexrbetter

Well-Known Member
#3
Glider development is said to be German rocket science, but after a lot of research I find it isn't. .
I laugh every time I have read this, many of them are elitist so and so's (and as with everything, some really nice guys too of course) and one Dutch guy in particular known to a few here would not only scoff at your remarks, but even when you get it flying he will refuse to admit it even exists! He, indirectly, even refuses to admit aircraft like the Morgan Sierra exist!

Hope it works out for you for no other reason than just to shut him and a few others up. :spot on:
 

Garry Morgan

Morgan range of aircraft
#5
I am still trying to get it to how much the wings flex.
Yes for many only German built gliders will win comps. the JS1 from SA is doing a good job.
When gliders like the Jantar ,Pic 20 etc of that vintage have 150mm thick wings. 25mm thicker wing equals 1 fuselage of drag. wings now are about 2"thinner so take two fus of drag off a glider of that vintage you are coming close to the new performance of today
 

Nobody

Well-Known Member
#6
Great news!!!! It would be great to see some pictures.
You must be the first glider pilot to wish for shorter wings!!!!:cheezy grin:Unless they are de-rigging. How will shorter wings work better in tight thermals? Less flex?
 
#7
18M gliders today perform as good as 22 and 25M gliders of 10 years ago. Material technology is making the wings change as Garry suggests rather than the discovery of new aerofoils. Thin wings are good as long as they are strong enough.
 

Garry Morgan

Morgan range of aircraft
#8
The longer the wing the bigger the turning radius, thus being near the coast the thermals are norrow, when you bank over the quicker it will sink. wider shorter wing with the same wing loading will get into the core better. For a touring motor glider which isnt as good as a pure glider.
 

Nobody

Well-Known Member
#9
The longer the wing the bigger the turning radius, thus being near the coast the thermals are norrow, when you bank over the quicker it will sink. wider shorter wing with the same wing loading will get into the core better. For a touring motor glider which isnt as good as a pure glider.
That seems counter intuitive. All the derivations for turn radius I have seen involve only speed and bank angle. To turn tighter, you have to fly slower and bank more. Now higher angles of bank an lower speeds, require higher angles of attack and higher lift coefficients which everything else being the same should favor a wing with a higher aspect ratio.
 

pylon500

Well-Known Member
#10
should favor a wing with a higher aspect ratio
Technically you are correct, however, overall span becomes a function of turn radius.
The answer then becomes small spans, with high aspect ratios, ie; small wings!
The new trend is to build small gliders, that are very light, and can then fly with a smaller wing area, which can be translated into small, high aspect ratio wings...
Have a look at the SparrowHawk Glider;
Sparrowhawk.jpg
Empty weigh = 70kg!
Span = 10.9m,
L/D = 37:1 similar to an Astir (for half the weight).
 

Marty_d

Well-Known Member
#11
Technically you are correct, however, overall span becomes a function of turn radius.
The answer then becomes small spans, with high aspect ratios, ie; small wings!
The new trend is to build small gliders, that are very light, and can then fly with a smaller wing area, which can be translated into small, high aspect ratio wings...
Have a look at the SparrowHawk Glider;
View attachment 35850
Empty weigh = 70kg!
Span = 10.9m,
L/D = 37:1 similar to an Astir (for half the weight).
Where does the pilot go???
 

Nobody

Well-Known Member
#13
Technically you are correct, however, overall span becomes a function of turn radius.
The answer then becomes small spans, with high aspect ratios, ie; small wings!
The new trend is to build small gliders, that are very light, and can then fly with a smaller wing area, which can be translated into small, high aspect ratio wings...
Have a look at the SparrowHawk Glider;
View attachment 35850
Empty weigh = 70kg!
Span = 10.9m,
L/D = 37:1 similar to an Astir (for half the weight).
They are pretty amazing aren't they!!!! But I suspect that the light wing loading(at 29kg/m2 about the same as a puchacz) is the reason for the ability to turn tight rather than the short wings.

What I still don't understand is how reducing the span and keeping the wing loading the same by increasing the wing chord, as Gary says he is planning on doing, will result in an an increase in the performance of his motor glider in tight coastal thermals.....
 

Garry Morgan

Morgan range of aircraft
#15
Yes you are all right , but the weight of motor 2 people etc. changes the design some what. the problem in small thermals which are not very strong is that you cannot bank over very much, as the sink rate increases with the angle of bank. Living near the coast we have small tight thermals.
 

Garry Morgan

Morgan range of aircraft
#17
Well things are progressing slowly as the work and time to make and remake control mixer system and setting up the steel frame with the motor mount and retract undercarriage, all in a small space and every thing you do effects every thing else in its way, so I have spent the last month cutting and re doing all of this, the motor has been fitted but not the lifting system as yet, the mixer now works and the u/c is in. Now I will fit the spars into the steel frame before I glass in to the fuse.
The Cheyenne is having the span cut to 15m with the the same wing loading, this will take 2-3 months.
 

Garry Morgan

Morgan range of aircraft
#19
I don't have any pictures of the Cheyenne flying as yet as one guy did take some but i haven't as yet,pictures of the Shawnne single if you can e mail me I can send you some as I dont know how to put them on the site. I am wrapping the spar root ends now so when I can fit them to the steel frame, then I can glass in the steel frame, then many other parts can be started on as the fin post, seat, rudder peddles etc. This is by far the most advanced aircraft i have tried to build, it is very compact and conplex. And i think the pinnacle of design.To get this aircraft on paper as a home built from planes will be a very big achievement for gliding.
 

Garry Morgan

Morgan range of aircraft
#20
The Cheyenne is flying, and the test flying complete and now passangers have been carried and have thermalled up to cloud base at easter. With the 80hp Jabiru it climbes at 700fpm and in a long climb the motors gets colder, so no over heating problems. With the weight the rool is a little slower be have found it is normal for this type of aircraft.it will easly cruise over 100kts at 60% throttle. A trailor is being built so it can be shipped to NZ where i can chase the wave
 
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