Thread: Wing Extensions
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Old July 20th 03, 12:16 AM
Roger Halstead
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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?


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