Wing Extensions

Seems like it might be useful to have removable wing extensions for an
experimental. There are times when you want a fast airplane for cross
country and you can stand a long runway for the high TO/landing speeds
and then there are other times you want the low speed handling for
short field, etc. Flaps do this to some degree depending on how
exotic you want to get and have the advantage of being adjustable in
flight but the wing extensions would appear to extend the flight
envelope (on separate flights) beyond what can be done with typical
flap configurations.

A solid composite structure, perhaps 2 feet on each side that plugs
into the main spar(s) would do nicely to allow you to have both a high
speed clipped wing plane (when removed) and a long wing high lift
plane, of course not at the same time. The further out you go on the
wing the less the loads are so these wouldn't have to be built up as
strong as other parts.

They could be made with no control surfaces or other moving parts.
You could even select a different airfoil for that section if you
wanted. No problem plugging composite extensions into an aluminum
main wing. Of course the main short wing would have to be built to
allow access to the main spar(s). A hollow rectangular cross section
spar could accept an insert to mate with removable extensions.

I guess you'd need some sort of plastic overlay for the airspeed
indicator to remind you of the new critial speeds.

Anyone seen anything like this?

Anyone seen anything like this?

A kitplane under design has a cruise and loiter wing.

Go to www.vulcanaero.com/index.html to see it.

Best Regards

"Jay" wrote in message
m...
Seems like it might be useful to have removable wing extensions for an
experimental. There are times when you want a fast airplane for cross
country and you can stand a long runway for the high TO/landing speeds
and then there are other times you want the low speed handling for
short field, etc. Flaps do this to some degree depending on how
exotic you want to get and have the advantage of being adjustable in
flight but the wing extensions would appear to extend the flight
envelope (on separate flights) beyond what can be done with typical
flap configurations.

A solid composite structure, perhaps 2 feet on each side that plugs
into the main spar(s) would do nicely to allow you to have both a high
speed clipped wing plane (when removed) and a long wing high lift
plane, of course not at the same time. The further out you go on the
wing the less the loads are so these wouldn't have to be built up as
strong as other parts.

They could be made with no control surfaces or other moving parts.
You could even select a different airfoil for that section if you
wanted. No problem plugging composite extensions into an aluminum
main wing. Of course the main short wing would have to be built to
allow access to the main spar(s). A hollow rectangular cross section
spar could accept an insert to mate with removable extensions.

I guess you'd need some sort of plastic overlay for the airspeed
indicator to remind you of the new critial speeds.

Anyone seen anything like this?

Glasairs have optional wingtip extensions. They add about 5 ft to the
wingspan of the airplane.

http://www.newglasair.com/glasairSIIspecs.html

Rick Pellicciotti

Rick Pellicciotti wrote:

Glasairs have optional wingtip extensions. They add about 5 ft to the
wingspan of the airplane.

http://www.newglasair.com/glasairSIIspecs.html

Rick Pellicciotti



Granted that this would have been taken into account by the designer,
but wouldn't this play hell with the center of lift and by extension
throw off the CG? That is, it wouldn't modify the CG, just change where
it SHOULD be.

I'm thinking that it isn't a good idea in just any old plane.

--
----Because I can----
http://www.ernest.isa-geek.org/
------------------------

Chopping the wing will effect the center of lift for swept wing
aircraft, but most homebuilts (e.g RV) have a wing that just goes
straight out, chopping wing just chops lift (and drag). And I'd have
to agree, it ain't a good idea on just any old plane. First of all,
you make the basic wing on the short side for your highest speed
operation, then you have to expose the load bearing elements of the
wing structure for your extensions to be able to couple. The
structure must be able to handle the extra load from whatever longer
wing extension you attach. But in the end, you have a plane with a
wide operating envelope.

The idea dawned on me after looking at the regular structure of an
RV-8A wing I was watching being built up and comparing an aquintances
shaved wing EZ that he says he needs to come over the fence at 100kts
minimum but it goes real fast on a small HP motor.

Ernest Christley wrote in message
Granted that this would have been taken into account by the designer,
but wouldn't this play hell with the center of lift and by extension
throw off the CG? That is, it wouldn't modify the CG, just change where
it SHOULD be.

I'm thinking that it isn't a good idea in just any old plane.

Earlier, (Jay) wrote:

...Anyone seen anything like this?

It's been common practice in the soaring world for several years; many
if not most current production machines have wingtip extensions
available as options. So you can choose 15 meter span, 18 meter span,
winglets, and things like that depending on what sort of flying you
think you'll be doing that day. It's also handy to remove the winglet
for stowage and trailering.

My HP-24 project is slated to have a standard 15 meter span, with
extensions to 18 meter, including aileron extensions. The gross
weights will be different, but the speeds will be pretty much the
same.

Bob K.

(Bob Kuykendall) wrote in message
snip
My HP-24 project is slated to have a standard 15 meter span, with
extensions to 18 meter, including aileron extensions. The gross
weights will be different, but the speeds will be pretty much the
same.

Bob K.


As Bob knows, my Nimbus 3 has 22.9m, 24.5m and 25.5m tips for the
various wing span I wish to fly with. Choice is driven by weather
(lift) conditions and desired wing loading for the day. I also have
positive and negative flaps - as do all or most flapped sailplanes. We
also put hundreds of pounds of water in our wings on good days, but
that would not be recommended for powered aircraft ;-).

Are there any powered aircraft out there with negative flap positions
for faster cruising/lower drag?

There was a sailplane built some years ago with a telescoping wing - I
recall it worked OK, but was not successfull.

Jim

(Bob Kuykendall) wrote in message
snip
My HP-24 project is slated to have a standard 15 meter span, with
extensions to 18 meter, including aileron extensions. The gross
weights will be different, but the speeds will be pretty much the
same.

Bob K.


As Bob knows, my Nimbus 3 has 22.9m, 24.5m and 25.5m tips for the
various wing span I wish to fly with. Choice is driven by weather
(lift) conditions and desired wing loading for the day. I also have
positive and negative flaps - as do all or most flapped sailplanes. We
also put hundreds of pounds of water in our wings on good days, but
that would not be recommended for powered aircraft ;-).

Are there any powered aircraft out there with negative flap positions
for faster cruising/lower drag?

There was a sailplane built some years ago with a telescoping wing - I
recall it worked OK, but was not successfull.

Jim

"Jim Phoenix" wrote in message
om...
(Bob Kuykendall) wrote in message
snip
My HP-24 project is slated to have a standard 15 meter span, with
extensions to 18 meter, including aileron extensions. The gross
weights will be different, but the speeds will be pretty much the
same.

Bob K.


As Bob knows, my Nimbus 3 has 22.9m, 24.5m and 25.5m tips for the
various wing span I wish to fly with. Choice is driven by weather
(lift) conditions and desired wing loading for the day. I also have
positive and negative flaps - as do all or most flapped sailplanes. We
also put hundreds of pounds of water in our wings on good days, but
that would not be recommended for powered aircraft ;-).

Are there any powered aircraft out there with negative flap positions
for faster cruising/lower drag?

There was a sailplane built some years ago with a telescoping wing - I
recall it worked OK, but was not successfull.

Jim

One of the Maule variants used 10 degree negative flap for a little extra
cruise speed.

I seem to recall that flapped wings should have an airfoil selected for
negative flap for that option to be really useful. Still, it's a cheap way
to get a little more cruise speed.

Wing extensions could be a seasonal change to cope with the much higher
density altitudes in summer.

Bill Daniels

On 18 Jul 2003 11:39:27 -0700, (Jay) wrote:

Seems like it might be useful to have removable wing extensions for an
experimental. There are times when you want a fast airplane for cross
country and you can stand a long runway for the high TO/landing speeds
and then there are other times you want the low speed handling for
short field, etc. Flaps do this to some degree depending on how
exotic you want to get and have the advantage of being adjustable in
flight but the wing extensions would appear to extend the flight
envelope (on separate flights) beyond what can be done with typical
flap configurations.

A solid composite structure, perhaps 2 feet on each side that plugs
into the main spar(s) would do nicely to allow you to have both a high
speed clipped wing plane (when removed) and a long wing high lift
plane, of course not at the same time. The further out you go on the
wing the less the loads are so these wouldn't have to be built up as
strong as other parts.

You are describing the Glasair II, Super II, and Glasair III wings.
There is a set of 2 foot extensions available from the factory, and
others of different lengths from other sources.

Down low the short wing loading in nigh onto 30# per square foot..
With tip extensions it's just a tad of 27# ft^2

The aspect ratio is 6.67 and 7.64 with the factory extensions.


They could be made with no control surfaces or other moving parts.
You could even select a different airfoil for that section if you
wanted. No problem plugging composite extensions into an aluminum
main wing. Of course the main short wing would have to be built to
allow access to the main spar(s). A hollow rectangular cross section
spar could accept an insert to mate with removable extensions.

I guess you'd need some sort of plastic overlay for the airspeed
indicator to remind you of the new critial speeds.

They don't change all that much. You leave them set for the shorter
wing. There are no real critical speeds...at least in the G-III. Vne
is listed at 335. They are routinely flown at 350 (mph) doing
aerobatics.

Maneuvering speed, (Va) is listed at 201. I've flown aerobatics at
Vne.
Vno is listed at 280 while 75% gives a POH figure of 282.
I've done letdowns at Vne. and have absolutely no worry about flying
that fast.

The wing tips will hold 5 1/2 gallons each, main tanks 53, and the
header 8...unless you have brake cylinders on the right and that
probably drops it to about 5. Many have additional wing bays turned
into tanks as well.

The Glasair (New Glasair) company recommends using the extensions
until the pilot is thoroughly familiar with the plane and during the
early phases of the flight test program.

With a turbo at high altitude you are looking at a cruise that is well
in excess of the book figure for Vne,

The plane is way over engineered. Book figures are +6, -4 Gs, but
again the plane has been tested wayyyy beyond that.


Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)
Anyone seen anything like this?