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.