By Robert N. Rossier, EAA 472091
This story ran in the December 2019 issue of EAA Sport Aviation.
We like to think that at a nontowered airport, choosing the best
runway for departure or landing is a simple matter of determining the wind
direction and picking the runway best aligned with the wind. But more often, a
multitude of additional factors influence our decision. And when pilots have
conflicting ideas about which runway to use, danger can be just around the
corner.
A few months ago, a pilot friend of mine had a close call at a nontowered
airport. She was right seat with another pilot on a training flight in a Piper
Cherokee. The pilot was making a normal landing on Runway 32, the favored
runway at the time based on the winds. The pilot had made all the requisite
radio calls and was just dropping below the tree line, approaching touchdown.
Meanwhile, a Cessna had taxied out to the cross runway, Runway 25,
completed a runup, and was lining up on the runway for departure. It’s unclear
if the Cessna pilot had made any radio calls, but, if so, they might have been
stepped on. Presumably, the Cessna pilot made a final check for traffic before
starting his departure, but by this time the Cherokee would have been invisible,
about to touch down on the pavement behind the trees. About the time the Cessna
pilot pushed the throttle forward, the Cherokee was rolling out. Both aircraft were
hurtling toward the intersection, and neither knew the other was there.
One can only imagine the fiery crash that might have ensued as
the Cherokee decelerated through the intersection of runways 32 and 25, but
disaster was averted at the last moment. The Cessna pilot eased back on the
yoke and rotated just as he approached the intersection, clearing the Cherokee
by mere feet. My friend looked awestruck out the window to see the oily
underside of the Cessna pass overhead. The incident left everyone shaking. It
doesn’t get much closer than that.
This near-miss causes us to ponder the full spectrum of factors
that pilots consider when choosing a runway for landing or departure. And,
while we might silently curse the pilot who chooses the “wrong runway” at a nontowered
airport, we need to understand the factors under consideration, and why two
pilots might make different decisions. More importantly, we must consider the
potential conflicts that can arise and then take steps to ensure our safety.
Runway length is perhaps the most obvious reason for choosing a
runway not favored by the wind. Higher-performance aircraft such as turboprops
and jets often need more runway to meet their takeoff performance requirements
(accelerate-stop distances) and are more likely to suffer a crosswind than be
limited by a shorter runway. But this is just the tip of the runway choice
iceberg.
Aircraft performance and pilot proficiency are also at the top of
the list. Clearly, a pilot must respect the crosswind limitations and
performance data for takeoff and landing. Adding to that a safety margin to
compensate for any lack of skills and abilities, and we can see where one pilot
might choose one runway over another when a different pilot comfortably makes a
different choice.
In some conditions (e.g., night, reduced visibility), arriving
pilots might favor a runway with good lighting and good vertical guidance
(e.g., PAPI, etc.). Or they may prefer a runway served by a straight-in
instrument approach rather than one that is better aligned with the wind but
lacking the navigational advantages.
Another factor is the surrounding terrain. Especially on a hot day,
or with a low overcast, a pilot might choose a runway that offers more
favorable (lower) terrain over which to make that initial climb. Here again,
suffering a crosswind might be a safer route than attempting to claw over
trees, obstacles, and terrain.
Along the same lines, pilots often choose departure runways based
on the options available in the event of an engine failure or other emergencies
immediately after takeoff. For example, a pilot might take off from a cross
runway and initiate an early turnout to better (and sooner) position themselves
for an emergency landing on a cross runway. A pilot might also choose a runway
that departs or approaches over land rather than water to minimize the
potential for a ditching scenario.
Birds and wildlife can also create a hazard that makes it safer
to use a runway not necessarily favored by the wind. Bird and wildlife strikes
can put a pilot in peril, especially during takeoff and landing, so choosing an
arrival or departure path that avoids the hazard can be a smart choice, even
when wind conditions alone would suggest another choice.
In some cases — right or wrong — pilots will choose one runway
over another based strictly on convenience. Either the runway is better aligned
with their direction of departure or is better aligned for a straight-in
landing. Such choices seldom come with any measurably significant savings in
time or fuel, but pilots tend to make them regardless of that fact.
Many times, the sun angle (early morning or nearing sunset) can
play a pivotal role in determining which runway to use for takeoff or landing.
For example, a takeoff directly into a blinding sunrise puts a pilot squarely
in the danger zone, unable to see and avoid traffic, obstacles, and terrain.
Here again, choosing a runway with a crosswind within the performance
capability of the plane and pilot might be a much safer choice for takeoff and
climb-out, as well as for landing.
Sky conditions and visibility (think localized fog and low
clouds) can also play into the decision of which runway to use. I’ve seen many
a day when a lingering fog bank resulted in a strictly one-way-in and
one-way-out situation at an airport.
We also need to take into consideration what the other traffic is
doing. Even if the runway being used is slightly disadvantageous for us,
choosing a runway that is in conflict with the prevailing traffic can heighten
the risk level by a mile. The other day I watched as an aircraft departed
opposite direction from several other aircraft in the pattern because the wind
had shifted a few degrees, slightly favoring the opposite runway. Although no
accidents occurred, the risk was clearly heightened for a couple of minutes. In
a situation like this, it makes more sense from a safety standpoint to go with
the flow.
In many instances, a pilot or instructor may intentionally choose
a runway not aligned with the prevailing winds in order to provide an
opportunity for crosswind training. In such a scenario, the runway that is
aligned with the wind serves as an “out” in case the crosswind conditions are
too severe. But in the interim, conflicts with other aircraft may occur.
The take-home message is that choosing a runway is more than a
matter of wind direction. Many considerations will put pilots at odds when
selecting a runway for takeoff or landing at a nontowered airport. And with
that understanding, we can recognize the need for enhanced vigilance and
communication to ensure we avoid conflicts. Practices such as making radio
checks, multiple announcements of intentions, visually scanning the sky for
aircraft on approach to or departing from other runways, and checking the
screen on our ADS-B device can all help prevent the worst-case scenario, and
the close calls that leave us shaking.
Robert N. Rossier,
EAA 472091, has been flying for more than 30 years and has worked as a flight
instructor, commercial pilot, chief pilot, and FAA flight check airman.