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Bill,
Here are the pix... The one below is of the material - Curved Mylar tape
with glue under the red peel off, top side of Mylar tape and leading edge safety
tape (very thin, very strong) plus the mfr info (TESA 4104 tape).
The Mylat is about 1.1" wide. Wider tape is used on the rudder.
The next pic is gap tape on the upper skin ahead of the aileron
If you want more I've got it.....
Scott
In a message dated 4/18/2012 10:01:20 A.M. Central Daylight Time,
bbradburry@bellsouth.net writes:
Scott,
Do you have pictures
of your gap seals? How are they attached?
Bill
B
From:
Lancair Mailing List
[mailto:lml@lancaironline.net] On Behalf Of
Sky2high@aol.com
Sent: Tuesday, April 17, 2012 9:52
AM
To:
lml@lancaironline.net
Subject: [LML] Re: L320 flap
setting
There must be as
many different ways to fly these airplanes as there are different wee
Lancairs. The techniques I use work for me, but there are other pilots
that use totally different methods with respect to flap management. I
tend to use distances, altitudes and speeds that would be similar to GPS
instrument approaches. From about 10 NM out I will slow to 160 KIAS
merely by reducing power and nearing a safe maneuvering altitude. Over
the next 5 NM the flaps are moved in 2 steps to down about 7 degrees (from
full up), level flight is then stabilized at around 120 KIAS. For the
next 3 miles, I descend to about 1100 AGL with power set to 15-17"
MAP. Depending on the type of pattern entry and with about 3 miles to
fly (downwind entry or straight in), flaps are brought down another few
degrees, gear is extended and speed is stabilized at about 100
KIAS. Descent is then managed so that when field is made, flaps
usually go to full down and power is controlled so that the
over the fence speed is also about 85 KIAS. I am not sure of the
other speeds as I am looking outside, but it seems touch down is at about 70
Kts since the round out also reduces speed and throttle reduction finishes it
off. The runway I generally use is 6500 feet, but the exit I
use is 2450 feet from the landing end (I see your runway is 2300
feet long) with very little braking. If there is a good crosswind I will
land with less flaps.
My flap is marked so
that all take offs are at 10 degrees down and lift off is at about 80
KIAS although the stick is pulled back to lighten the load and gain better
directional control as 40 knots is passed. I start every takeoff
run with the elevator trimmed to the same neutral position and I think I never
could fly off the runway without gradually pulling back on the
stick. Every pre take off configuration is the same so that
conditions different from the norm are under pilot control. For me,
the most efficient climb out is at about 135 KIAS for good
cooling and a very good climb rate while escaping the airport environment
quickly.
Since I enter the
"pattern" at no more than 120 KIAS, gear extension on a downwind takes
the speed down quickly. I do not fly the killer square pattern -
downwind to final is accomplished in a continuous turn so that any adjustment
for runway alignment can be made throughout the turn and not as a
correction to an already tight 90 turn from base to final. I do not fly
"close in" patterns.
My airport is at 700
MSL and I can understand your adjustments for altitude, shear, slope and
runway length. I know several pilots that are happier landing with no
more than 30 degrees of flap.
I have glider type
gap seals on the bottom of the flaps, and both sides of all other control
surfaces. Speeds increased by about 6-8 KIAS. Rudder control
became effective about 5 Kts sooner than before the seals. It becomes
more difficult to go down and slow down at the same
time.
In a message dated
4/16/2012 7:56:05 P.M. Central Daylight Time, lancair@meier.cc
writes:
this is very
interesting!
Could you write
down some more flap positions which you use for take off and landing in
different take-off weight configurations.
And also when you
arrive in the landing-circuit in cruise speed. How best to slow down to flap
speed in the downwind.
Actually when I
arrive from cruise, I put the engine to idle pull nose up to reach 120kt
drop gear, set flaps to +10 (17 from full
reflex)
and drop
nose and put back low power setting. After all this I get my 100kt and
turn to base leg. In final I use +20 / +25 and will also
land
in this setting.
My runway is 700m long and has a 1% down slope and is located in 2200ft alt.
If I use more flaps to land the plane won't sit
down.
Speed over the
fence is 90-85kts because of shear winds just before the
runway...
What speeds do you
use in short final?
Does it help to
stick some gap seals over the hinges of flap and aileron like all the
gliders do?
The purpose of
reflexed flaps (wing TE) is for reduction of drag at cruise
speeds. After certain minimum speeds, induced drag is lessened by
reducing lift through a reflexed TE (also reducing anti
lift at the horiz stab). Parasitic drag in a laminar flow
environment may also be reduced by reattaching the airflow at the
reflexed flap. The basic fat wing design helps when the leading
edge gets dirty (disrupts laminar flow) because lift is only slightly
reduced but draq increases (ice, rain, bugs - see note 1). This is as
opposed to a thin laminar wing which may lose lift when dirty. The fat
wings allows our grocery cart wheels to be stowed within.
When the flap is
reflexed, the point of lift moves forward where higher speeds require more
nose down trim (less negative AOA at the horiz stab) and lower speeds
require a higher angle of attack to achieve adequate lift. In general,
below a max Vf (160 to 140 KIAS), the flaps may be taken out of reflex
(to 0 degrees) where the attitude of the airplane can be changed
by up to 6 degrees nose down (as measured digitally at the
longeron) and this will require substantial nose up trim for level flight
while the speed drops (about 15 KIAS) from increased drag. For this
wing, further reflexing beyond -7 has little effect on speed in
cruise (Note 2).
This form of wing
is not unique - reflexed trailing edges are used in all tailless (and
non-canard) aircraft. In such aircraft, changes in CG are compensated
for by changing the angle of reflex (changes fwd/aft point of lift).
Remember that the same is true with the 200/300 series wings. (hint: aft
CG wallow may be reduced by taking a bit of reflex out of the
wing). Remember also that slow speed operation with flaps
fully reflexed requires a high AOA to compensate for the reduction in
lift from the reflex. Be careful out
there.
Max lift, min drag
at 70-100 KIAS is with the flaps at TO position (about +10 degrees
down from full reflex). After about +17 degrees down from full
reflex, the flaps seem to merely add drag that is useful in higher than 3
degree descent angles (preservation of kinetic energy) - keeping the
speed controlled (below 100 KIAS) at low power settings and also
keeping the nose low.
Maybe next time I
will record AOA digital display data in some of these
configurations.
Note 1: In an Air
Venture x-ctry race, KARR was a turning checkpoint that required I descend
over the monitor. In that descent I ran through a mass of little
black bugs (so did others) and my return to level flight as the same race
power resulted in speeds 6-7 KIAS less than before the encounter.
Later, I noted that the splattered bugs were very close together (less than
a 1/4") and had completely messed up the laminar flow at the leading edge of
the wings. Slow downs have also occurred in flight through
rain.
Note 2: Certain
320/360 racers experimented with more reflex with the conclusion that there
was no significant improvement in speed.
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Gap%20Seal%20stuff.JPG
Gap%20seal%20aileron.JPG
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