SOME OF THE slopes we fly from have plenty of
height, and steady winds from a favorable direction,
but lack a clear area large enough to make safe
landings that don’t beat up our aircraft or make us
climb trees to recover our models. This is particularly
true in mountainous terrain with forest cover, such as
the Adirondack Mountains in the East and the Rocky
Mountains in the West.
It’s a shame for those who live in hilly, treecovered
terrain to be unable to fly locally just because
available landing areas are small, rocky, or surrounded
by trees. We can often find an open area that is large
enough to launch and fly from but is way too small and obstructed
to have much of a chance for a safe landing.
Of those who have faced this situation, who among us hasn’t
considered that if we had a net we could snag our sailplanes from
[[email protected]]
Radio Control Slope Soaring Dave Garwood
Using nets to catch Slope Soarers in small or hazardous landing areas
Also included in this column:
• Flying with an onboard electronic
airspeed recorder
John Collins (North Adams MA) lines up for a
recovery-net landing with his Windrider Bat at the
Mohawk Trail flying site, which offers little clear
space to land.
A successful recovery of John’s Bat in the soccer net, held by Joe Chovan (L)
and Andreas Mergner. The net’s looseness holds the model rather than
bouncing it back. North Adams lies in the valley below; Taconic Mountains
form distant visible horizon.
Fred Stillman (Lakewood CO) scores a successful landing at
Midwest Slope Challenge 2002. The net is designed for recovering
models at Rocky Mountains slope sites with small landing areas.
It’s pulled taut, but stretching it looser reduces the chance that
models will bounce out.
John Collins and Joe Chovan deploy a soccer-goal net in a small
landing zone at Mohawk Trail. We see the landing zone’s longest
dimension, roughly 50 feet, and trees surrounding the flying site
on three sides.
the air after a flight, and we could fly from smaller launch areas?
Last fall I observed and tried a recovery net deployed by
Berkshire Flyers at the Mohawk Trail flying site in North Adams,
Massachusetts. There was approximately a 1,000-foot rise above
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wind, and generally excellent lift, but the
prospects of landing there were daunting.
The small cleared area we launched from,
which was roughly the size of two volleyball
courts, featured some grass, many rocks, and
was bordered on three sides by trees. Once
in awhile we could execute a precise
landing, but it was all too common to put a
model into rocks, bushes, or tall trees behind
the launch point at the end of a flight.
On this day John Collins (jca52north
@msn.com) brought his “recovery net”: a
soccer-goal net that travels neatly in a
medium-size duffle bag. When ready for use
it is held in position by two helpers standing
approximately 25 feet from each other,
reaching upward roughly 7 feet, giving a
landing target of approximately 175 square
feet.
Does that seem easy enough? Well, it’s tougher to hit that target
than you would think, but the sailplane is trapped safely when you
do.
Given that the net is located at the edge of the bluff, if a pilot
misses an approach on the high side he or she can shoot out into the
lift again and make another approach. If the pilot misses on the low
side, he or she plows the model into the grass and rocks, as we often
do with no net.
Shooting landings into the net takes some skill and practice, but
it makes for big fun trying. It becomes a new slope-flying game in
itself.
A few years ago I tried another recovery-net design built by Fred
Stillman ([email protected]) and his nephew, Rick Stillman.
These die-hard slope pilots live and fly in Colorado. As Rick
observed, “The Rocky Mountains are definitely rocky.”
At the 2002 Midwest Slope Challenge in Lucas, Kansas, Fred
and Rick erected their net in two locations on two days during the
event. Plenty of fliers got the chance to try landing in it.
The Stillmans built a frame for a 12 x 20-foot (240 square feet)
hockey net from PVC pipe. The netting material is 3.5mm twine in
4 x 4-inch squares.
We learned by observing the first and second days’ setups that
leaving a little slack in the net, so that it forms a “belly,” helps keep
the sailplane in the net after it lands rather than having it bounce out.
Following is further advice from Fred’s experience.
“1: Do not place the net too close to the lip of the slope. When
too close, the gliders get back into slope lift and make hitting the
net difficult.
“2: To make hitting the net easier, the pilot should stand behind
the net and fly the slope sailplane in just as if you were going to
catch it in your hand. This gives the pilot the
need to settle a bet or gain bragging rights.
For those who don’t pack a radar gun,
there is a miniature airspeed-recording
instrument that works as airspeed indicators
do on full-scale airplanes. Winged Shadow
Systems’ How Fast Model Aircraft
Airspeed Instrument records airspeeds from
15 to 500 mph with 1 mph resolution.
After a flight the How Fast can report
the highest airspeed attained by signaling
flashes via an LED mounted on the tiny
onboard recording instrument. To read the
stored data (before turning off the receiver
after the flight), wave your finger over the
LED for maximum airspeed report and
count the flashes emitted in a series for
each digit of the airspeed.
When used with another Winged
Shadow Systems device, the See How, the
How Fast can record up to nine in-flight
speeds, recorded at points controlled by
transmitter-stick command, and the See
How extends the resolution to 0.1 mph.
Both devices are available with metric
(kilometers per hour) readouts.
Preparing to measure the speed of more
than one slope sailplane, I mounted a How
Fast, the pitot tube, and the static pressure
tube on a small plywood frame designed to be
attached to a fuselage with tape or rubber
bands. I mounted the circuit board with
double-stick foam—the kind used to mount
servos.
The instrument needs a DC electrical
source ranging from 3.2 to 12.0 volts and is
shipped with a “universal” plug and designed
to receive its power from a receiver. I plugged
mine into a receiver, which was plugged into
a 4.8-volt pack, blew gently into the pitot
tube, and got a reading of 48.9 mph.
We had a warm, clear summer day with
steady west winds, and I headed to the
Mohawk Trail flying site to try the
instrument. Andreas Mergner volunteered
an aircraft, and with his Bowman Models
JW in a long dive he hit an indicat