AOPA Pilot Magazine - June 2014 - 14

WAYPOINTS

BY THOMAS B. HAINES
Editor in Chief

Traffic dead ahead?
The ADS-B traffic debate

EDITOR IN CHIEF

Tom Haines flies
his Beechcraft
Bonanza A36
for business and
pleasure.

14 | AOPA PILOT June 2014

THE CALLOUT JOLTED ME from a zone of concentration while intercepting a radial off of the Westminster,
Maryland, VOR. "Traffic. 12 o'clock. Same altitude. One
mile," came the loud voice in the headset. The yellow
caution screen was flashing on the Garmin GTN 750
showing the traffic dead ahead. My safety pilot in the
right seat was scanning the sky as I flipped the instrument hood out of the way and tried to see the traffic in
the haze of the setting sun. "There," he said, pointing.
"Turn right." I banked the airplane sharply in time to see
the Cessna 172 pass just below us. He didn't appear to be
maneuvering, so most likely he never saw us.
Even at our leisurely approach speed and his likely
speed, our closure rate was some 220 knots, meaning
less than 20 seconds to cover the one-mile distance.
The incident, one of three close calls over the past
year since I upgraded the panel in my 42-year-old
Bonanza to include traffic information, reminded me
of the benefits of ADS-B available now, more than five
years ahead of the FAA's mandate for everyone to be
equipped (see "Safety Pilot Landmark Accident: See and
Avoid?" page 70). While the new means of controlling
air traffic is controversial and not what we all thought
it was going to be when first envisioned 20 years ago,
the benefits of in-cockpit weather and traffic are real.
For those who already have equipped with a WAAS GPS
for the benefit of LPV approaches, the step to ADS-B In
and Out can be relatively inexpensive. A Mode S transponder with extended squitter (ES) connected to the
WAAS signal can serve as an Out solution. With that, a
portable system-such as the Stratus, Garmin GDL 39,
or any of a number of other ADS-B receivers-can serve
as the conduit for traffic and weather into the cockpit to
be displayed on a portable device, such as an iPad. Even
without ADS-B Out equipage, those portable systems
can provide weather and limited traffic into the cockpit.
Most airplanes capable of LPV approaches have a
panel-mount display also capable of depicting weather
and traffic. For that, a built-in ADS-B solution, such as
the Garmin GDL 88, is an option, which is what I chose.
For use in the United States and below 18,000 feet, the
GDL 88 can be the entire ADS-B In and Out package.
In any case, one must still maintain a transponder,
whether Mode C or S-mostly to satisfy the Traffic/
Collision Avoidance System (TCAS) needs of airliners. As originally envisioned, ADS-B would obviate the
need for transponders, at least for flights in the United

States. However, when the FAA issued rulemaking in
2007 requiring all aircraft be equipped with ADS-B Out
by January 1, 2020, the rule also required the continued
use of transponders indefinitely.
The transponder mandate and the stubbornly high
cost of equipage for those who don't already have panelmount displays and a WAAS receiver have caused many
pilots to wait to equip with ADS-B Out. While portable
solutions can provide excellent ADS-B weather information, the problem is that without ADS-B Out, the
traffic shown on the portable devices is less than complete. It takes an ADS-B Out position to trigger the FAA
ground stations to transmit the traffic information back
up the datalink to the participating aircraft. Without
that, the only traffic a portable ADS-B In system can see
is nearby ADS-B Out-equipped aircraft (each of which
is broadcasting its position). If an ADS-B Out aircraft is
within about 15 miles, an airplane with ADS-B In only
may be able to display traffic sent up to the other aircraft, but the information will be referenced to the other
aircraft, making position determination difficult.
The cost to equip an airplane for ADS-B Out when it
doesn't already have a WAAS position on board can run
$6,000 to $8,000, a big hit for casual fliers.
The frustration is in the waiting for lower cost
options, which many believe are coming. Meanwhile,
the 2020 mandate moves ever closer. With every passing day, the likelihood of finding an avionics shop able
to handle the influx of work needed to install the systems by then diminishes. Few FAA equipage mandates
in the past have been met by their original date. But so
far, the agency has shown no signs of pushing the date
back. It has, after all, been a 13-year window.
For me, with WAAS and displays already installed,
paying about $4,000 for the GDL 88 was a cost-effective
way to get a traffic system. Otherwise, active traffic systems start at about $10,000 and go upward to $25,000.
And although I flew safely for decades without a traffic
system, I appreciate how many airplanes are out there-
some nearby-that I never saw before. Some suggest
traffic systems cause pilots to be lazy in looking for traffic. I find it just the opposite. With the help of the system,
I find myself working harder to spot traffic.
AOPA
EMAIL thomas.haines@aopa.org

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AOPA Pilot Magazine - June 2014

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