Pilotage

Mark R. Twombly is a former editor of AOPA Pilot who now avoids collisions in Florida.

A recent AOPA Air Safety Foundation seminar in our town drew a near-capacity crowd, in part because several pilots brought their spouses or friends to the session. That surprised me because the subject of the seminar was collision avoidance — a subject bound to make nonpilot passengers cringe.

The term collision avoidance is ripe for euphemistic enhancement. Which pilot is more likely to frighten a timid passenger: one who says that he's banking the airplane right and left in the climb so he can avoid a collision, or one who explains that the technique assures "continuous separation of traffic"?

There was much gnashing of teeth and shaking of heads among the "first officers" in the collision avoidance crowd as ASF speaker Chuck Berry described how disturbingly easy it is for two aircraft to arrive at the same point in space at the same time. You'd expect that the consequences would be disastrous every time, but that's not the case. The foundation reports that eight of the 18 midair collisions that occurred during 2000 did not result in fatalities. The flip side is that the other 10 midairs were fatal.

Midair collisions occur despite the generous proportions of U.S. airspace. (According to ASF, if all aircraft in this country were summoned to appear over Texas at the same time at the same altitude, each would have a square mile of airspace in which to drone around without encountering other traffic.) But aircraft aren't likely to come together over the open stretches of Texas. The sky is big in those parts because there are few airplanes to fill it. Collisions are more likely to occur where the sky isn't so big, which is around uncontrolled airports on nice weekend days. That's when everyone wants to fly, that's where the airplanes congregate, and that increases the potential for a collision.

The objective of the ASF seminar is to make pilots aware of when, where, and how separation can go to zero, and to provide them with tools to prevent it from happening. We certainly were receptive to that message. The subject of collision avoidance is top of mind here in Florida, given the concentration of traffic and intensive flight-training activity along the coastlines. Two accidents that occurred in the state illustrate the two ends of the midair-collision spectrum. The first was that amazing incident when a single-engine trainer on final approach to Plant City Municipal Airport was struck from behind by another single, which then stuck to the lead airplane's fuselage. The pilot of the aircraft on the bottom managed to continue the approach in piggyback mode and land safely. That was a typical example of the classic midair scenario in which one airplane overtakes another in the pattern of a nontowered airport, with a flight instructor on board at least one of the aircraft. The mantra when operating at a nontowered airport is to practice see and avoid, make precise position reports, practice see and avoid, use by-the-book pattern procedures, and for good measure, practice see and avoid.

The second midair did not end so fortunately. The pilot of a Cessna 172 died when his airplane collided with an F-16 inside the Sarasota, Florida, Class C airspace. The Air Force pilot sustained minor injuries after ejecting. An Air Force investigation noted several gross errors that contributed to the accident. The F-16 was the second airplane in a two-ship formation on its way to a practice bombing range in Central Florida. According to the investigation, the pilot of the lead F-16 made several crucial errors during the flight — including losing situational awareness, failing to notice a position error in the navigation display, and making an incorrect navigation entry that resulted in the airplanes' being nine to 11 miles off course.

The jets penetrated Tampa Class B airspace without a clearance, descended, and were flying at an estimated 400 knots when the collision occurred. The Air Force investigation also said that ATC predicted the potential for a collision and generated an alert, but controllers failed to communicate that alert to the Cessna pilot, who might have been able to maneuver to avoid the collision.

We're in a time of transition with respect to decreasing the potential for midair collisions. See and avoid may never lose its number-one ranking on the list of collision avoidance tools, but electronic traffic surveillance devices will continue to evolve and become more accessible to small general aviation aircraft and, therefore, much more important in the overall collision avoidance strategy. Based on the phrase we hear spoken on approach control frequencies every day — "I've got him on my TCAS" — it's easy to believe that all the big jets are so equipped. Not so. My cargo-pilot brother tells me that the Boeing 727s he flies are not required to be fitted with a collision avoidance system. Remember that the next time you assume that the big cargo jets have their electronic eyes on. They may be as legally blind as you.

Until all airplanes have some sort of electronic traffic sentry on board, it's going to get harder to maintain continuous separation. More pilots are spending more time with their eyes buried in the cockpit, managing sophisticated new flight-management systems. I dream of having one in my airplane, and being able to see at a glance precisely where I am in the world. But I also know that if I don't discipline myself to look away from that colorful screen and out the windshield, someone else whose head also is down might be vying for that same little piece of the world.