Flying is an exercise in risk management. We identify potentially risky conditions or situations, and take positive action to either mitigate the risk or avoid it altogether. A simple example is the preflight inspection. We lessen the risk of a mechanical problem occurring in flight by conducting a thorough visual inspection of the airplane before starting the engine.
I was conducting a preflight not long after the airplane had been through an annual inspection when I discovered that the nut was about to fall off the bolt that secures the trim tab actuator to the trim tab. A cotter pin that was supposed to secure the nut was missing, and the nut had backed off almost to the end of the bolt. If the nut had come off in flight the bolt probably would have fallen out of the bracket, rendering the trim tab uncontrollable. Who knows how that would have affected my ability to control pitch?
Obviously, I did not fly the airplane until the problem was corrected. I saw the problem, took action, and avoided the risk by not flying. See and avoid, you might say.
That phrase--see and avoid--usually is applied to the basic method of avoiding a small but extremely serious risk in flying: colliding with another airplane. The odds that it will happen, that you or I will be involved in a midair collision may be miniscule, but the deadly results of a midair make even a tiny risk unacceptable. That's why a midair collision is on my very short list of things to absolutely avoid when flying. The other items on that list: thunderstorms and icing.
It's a lot easier to avoid or mitigate the risk of encountering thunderstorms and icing than it is a midair collision. Avoid the risk of encountering thunderstorms or airframe icing by not flying when they are present. If that is not an option, mitigate the risks by steering well clear of thunderstorms--20 miles at a minimum--and flying well below the clouds.
The only way to completely avoid the risk of a midair is to not fly. Ever. That is not an option, so we work to mitigate the risk.
The recent, tragic midair collision in New York City's Hudson River corridor has raised questions among the public and in the pilot community about the wisdom of relying on see and avoid as the primary tactic for avoiding collisions. No doubt someday we'll all fly with an effective, full-time electronic system that keeps any two airplanes from occupying the same waypoint at the same moment, but until that day arrives we have to rely on the only collision-avoidance equipment that is in every general aviation airplane ever built--Mark I eyeballs.
That's what's in the piston twin I fly for a small company. I'd like additional help because I think our exposure is significant. We fly a lot, and one of our frequent destinations is a major metropolitan area with several airline and general aviation airports. Moreover, the area is ringed by some of the busiest flight-training airspace in the country. I've researched the collision-avoidance options, and have discussed my choice with the owner. The one I like is not cheap--about $10,000 installed--but in my opinion it's the most bang for the buck.
Convincing someone to spend that kind of money on a black box that doesn't make the airplane go faster or farther or use less fuel or dress up its appearance is tough. Besides, we've never had a close encounter with another airplane, right?
Well, almost. On a recent trip I was flying VFR with radar advisories from air traffic control, and got several callouts for traffic at 12 o'clock, opposite direction, within 1,000 feet of our altitude. We spotted two of the airplanes, but didn't see anything of the other two.
A little later a Bonanza suddenly flashed by directly overhead, 500 feet above our altitude. But for that modest altitude separation, we were on a collision course. The controller never called out the Bonanza.
That flight made an impression. If you only spot half the traffic that's pointed out to you by a controller, what are the odds you'll see all conflicting traffic when you aren't receiving radar advisories? And the sudden sighting of the Bonanza was a sober reminder that ATC is required to provide separation service to IFR aircraft only; traffic advisories are provided to VFR aircraft on a workload-permitting basis. I suspect I'll be calling soon to schedule installation of that collision-avoidance device. Even so, I still must consider see and avoid as primary simply because the best way to avoid a threat is to first see it.
The Achilles heel of do-it-yourself collision avoidance is that it is an active system, and the pilot is the active element. It is only effective when the pilot is engaged and practicing it. The moment attention is diverted to some other task, the critical "seeing" part of see and avoid stops. It's foolish to think we can spend 100 percent of a flight with our eyes outside and head on a swivel. We need help and, fortunately, it's available. Electronic aids are wonderful partners, but they are not without their faults. Less-expensive portable devices that sit on the glareshield do not have the same reception quality as do systems that rely on antennas mounted on the top and bottom of the fuselage. You can't be certain that any electronic collision-avoidance device is picking up all potential conflicting traffic.
Over-reliance on electronic collision avoidance is one problem. The other is ignoring warnings of a potential conflict. In high-traffic areas, a collision-avoidance device can be a busy little box, articulating its message that traffic is nearby and may pose a threat. Too many electronic alarms tend to annoy, especially if you're concentrating hard on some other task such as navigating complex airspace or talking on the radio.
It's a Catch-22. You have electronic collision avoidance that you rely on, yet because you are so dependent on it your brain finds it easy to ignore the warnings when they interfere with your concentration on something else.
Along with electronic aids, there are other collision-avoidance tools at your disposal, and the good thing is they are free for the taking. Most passengers in general aviation aircraft are more than happy to help scan for traffic. It makes them feel like they are members of the crew--which they are--and it helps relieve any anxiety they might feel about sitting helplessly in a small, seemingly frail aluminum capsule several thousand feet above the ground. Give them a few simple instructions on where and how to scan, and let them call out that airliner 30,000 feet overhead. Pretty soon they'll realize what constitutes an actual threat.
Your ears are extremely important in avoiding traffic. Monitor the communications chatter and visualize the position of other pilots on the frequency. It's something we all do in the pattern, but it's also helpful when cruising away from the airport.
Analyze the airspace you're in to rate the potential for traffic conflicts. It's highest around airports because that's where all traffic converges, but be careful around the periphery of controlled-access airspace including Class B, C, and D areas. Pilots who don't want to deal with ATC will skirt the borders of the airspace, possibly creating a conflict with crossing traffic. But don't be one of those pilots who doesn't like to talk to ATC. Ask for radar advisories when you fly VFR. It's not always available, but if you are given a frequency and transponder code, it's easy and invaluable assistance in monitoring other traffic. But be aware that the controller may not alert you to every potential conflict.
When it comes to avoiding collisions, the bigger your toolbox the better prepared you are to mitigate the risk. Just don't let your first and most basic tools get lost and rusty in the bottom of the box.
Mark Twombly is a writer and editor who has been flying since 1968. He is a commercial pilot with instrument and multiengine ratings and flies a Piper Aztec.
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