Aero Mail - 1020/06

June 2010 7
Aero Mail
Real Fowler Flaps
On page 113 of the April Model Aviation I was
intrigued to read that Jim Hiller was going to fit “fowler
flaps” to his model in an attempt to “ … see if they are
as effective on a model as they are on a full-scale
aircraft.”
I am intrigued to see how he handles the intricately
machined dual tracks (at each end of the flap recess)
necessary for Fowler flaps (Note upper case F) to
properly function. Why the tracks? They are
necessary because Mr. Fowler’s flaps are area
increasing flaps.
A “roller skate” cam follower at the end of each
flap is engaged in the dual tracks at each end, so that
the flaps are guided to travel aft a considerable distance … and
lowering only about three degrees to the loiter position … before commencing to
steeply move down to the maximum lift and drag position. This was plainly visible on the
P-38, as well as the Constellation airliner.
Any other type of flap, on which the flap hinge is located well below the bottom wing
surface, is nothing more than a simple slotted flap, as seen on the humble Cherokee and
some airliners. The Cessna Paralift (TM) flap is only a variation of the Fowler, since it, too,
follows a track.
In all fairness, I don’t see how your columnist can inform his readers if his RC model
flap is better than the full size equivalent anyway, since he neither has “hands on the stick”
nor the instrumentation to inform him if the design parameters are being met. He has only
the humble mk 1 eyeball … and that is far from accurate.
In any case, will he be following the clearances (defined by NACA) between the flap
and the airfoil trailing edge lip? These are necessary for a slotted flap to produce the desired
results with any airfoil section. Add to that the confusion caused by Mr. Reynolds and his
Numbers at model scale.
Jim Newman
Kent City, Michigan
Nice Box—Found!
I am writing you about the Aero Mail (April 2010) in
Model Aviation (Nice Box). I am a manufacturer of the
flight box that you are talking about.
I have three models but I have only made them for
local flyers here in Utah. The shipping is quite a lot
because of the size and weight. So I have a version of the
ultimate flight stand that I have shipped. I am willing to
build and ship anything as long as someone wants to pay.
Here’s my contact information. Thank you!
Custom Cabinets by Brent
196 East 400 South
Manti, Ut. 84642
(435) 835-1721
[email protected]
Brent Simmons
via e-mail
Before You Watch, Think
My name is Mark Lineberger, and I finally had a chance to read through the April 2010
issue of MA and your article that included talking about safety reminded me of something I
have wanted to mention. That is the increasing amount of on line video featuring people
shooting either paint ball guns or some times real lead slinging firearms at model aircraft.
It sends a very unsafe message out to people who already do not enjoy the RC hobby,
(mainly folks who do not like the sound of models in the park). I think these videos send an
improper message to people who are interested in learning to fly—that it is OK to engage in
such activities.
Those of us who enjoy flying and teaching others to fly have enough problems trying to
keep our privileges alive with all that is going on in the world. I know that the examples that I
speak of are not your fault or that you can do much to fix them but I think that all of us who are
involved with model aviation need to remind everyone else that being safe and responsible in
our hobby is the most important thing, otherwise we might just have those privileges revoked.
Mark Lineberger
Mustang, Oklahoma
®
April 2010 $4.95
SINCE 1936
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