AOPA Pilot Magazine - April 2013 - 83

SIGTRONICS
AVIATION HEADSETS

the airplane’s GPS-derived groundspeed,
not indicated airspeed, so pilots must be
mindful of winds.
But can any iPad app really help pilots
in such extreme circumstances?
To find out, I completely blacked out
the rear-seat portion of an RV–4 canopy
with tape and opaque plastic materials,
placed an iPad II running Xavion in front
of the rear-seat pilot, and recruited a pair
of instrument-current general aviation fliers to serve as guinea pigs in that darkened
chamber. In two successive flights and six
simulated power-off approaches, I’d climb
above 3,500 agl, reduce engine power to
idle, and hand over the aircraft controls.
The rear-seat pilot would press the emergency Fly Hoops key and follow the Xavion
guidance to the nearest runway.
Even though neither of the pilots, Luz
Beattie and Chris Lawler, had previously
flown an RV–4, Xavion allowed them to control pitch, bank, and attitude with precision
and get to a runway threshold in position to
make a safe landing.
“It’s not enough to maintain best glide
and fly in a straight line towards the nearest airport,” Meyer said. “Xavion takes you
to the runway endpoints in a way that allows
you to manage your airplane’s energy so that
you arrive in position to land safely.”
Still, there are no guarantees. On
Beattie’s second simulated power-off
approach, she had to contend with a 30-knot
tailwind at 3,000 feet agl, and the airplane
got uncomfortably slow as the Xavion flight
director commanded a pitch up because it
wrongly concluded the airplane was far
above its 74-knot best-glide speed. When
I noted the airspeed was getting slow (the
RV–4 has no audible stall warning), Beattie
reduced the angle of attack and the rest of
the approach went smoothly. Meyer said he
plans to use ADS-B weather to incorporate
wind information in future Xavion versions.
Beattie flew using the iPad’s internal sensors only, and she noted the flight
director was “jumpy” at times and tricky
to follow.
The next series of approaches with
Lawler incorporated a Levil AHRS to
enhance pitch and roll information, and he
said the flight director was mostly smooth
and stable. Lawler’s first approach (also

with a strong tailwind during descent)
was high but would have been salvageable with an aggressive slip. The second
was a thing of beauty flown to 100 feet agl
and directly over the runway centerline.
On the third, Xavion erroneously warned
throughout the approach that the runway
was too distant to reach, but Lawler got
there with altitude to spare by flying near
the airplane’s best-glide speed (and possibly catching a tailwind).
Meyer said he’s considering altering
Xavion so that, if a runway becomes reachable, the warning disappears.
In sum, the $99 Xavion app is an impressive piece of safety equipment that could
be a lifesaver in an actual engine and/or
avionics failure. It vastly enhances pilot situational awareness by constantly showing
airports within gliding range at a glance, and
its terrain database and GPS-derived synthetic vision depict mountains, rivers, roads,
and valleys in colorful detail.
The iPad’s internal sensors do a surprisingly good job of staying oriented
during normal flight, although they can be
confused, at least momentarily, by uncoordinated flight and unusual attitudes. When
linked to the Levil AHRS, however, Xavion
precisely matches aircraft pitch and bank.
(Also, the Levil AHRS can be linked to the
aircraft pitot/static system to provide indicated airspeed and barometric altitude).
Xavion’s glass-panel representation will
seem quite familiar to pilots accustomed to
modern avionics, but steam-gauge pilots
could find the transition jarring, particularly
during an actual aircraft emergency. Like
everything else, realistic practice enhances
performance. (And in this case, pilots can
practice on home computers using X-plane.)
Xavion and its $50 little brother
X-vision (which shows the EFIS representation without the engine-out guidance)
can be displayed on the iPad, iPad mini,
and iPhone, but not Android devices;
Meyer plans to produce the apps for Apple
products only.
Meyer also is working with Vertical
Power on the VP-400, an automated system designed to allow digital autopilots to
fly coupled approaches to runway thresholds at the push of a button (see “Avionics:
Runway Seeker,” August 2012 AOPA Pilot).
www.aopa.org/pilot AOPA PILOT | 83

S-20 Headset
• Articulating Mic
Boom
• High Noise
Environment
Microphone
• Foam Ear Seals
• 3 Year Warranty
• Youth Version
with Child sized
Headband available

S-45 Headset
• Gel & Foam Ear Seals
• Air Pillow Headpad
• 5 Year Warranty
• High Noise
Environment
Microphone
• Stereo, Helicopter,
and Youth
versions

S-58 Headset
• Flex Microphone
Boom
• Powder Coated
No-Glare Frame
• Headset Bag
• Gel Ear Seals
• 5 Year Warranty
• Stereo, Helicopter,
& Youth versions

S-68 Headset
• Flex Microphone
Boom
• Gold Titanium
PVD Frame
• Headset Bag
• Gel Ear Seals
• 5 Year Warranty
• Stereo, Helicopter,
& Youth versions

All Sigtronics headsets are built in the U.S.A.
with high quality cables and components.
Visit our web site for info on our complete
line of headsets, intercoms, and accessories.

Sigtronics Corporation
909 305-9399 • www.sigtronics.com

http://www.sigtronics.com http://www.sigtronics.com http://www.aopa.org/pilot

AOPA Pilot Magazine - April 2013

Table of Contents for the Digital Edition of AOPA Pilot Magazine - April 2013