Friday, March 7, 2008

Too close for comfort

Okay, as promised, today's entry has no discussion of the presidential campaigns. Instead, I'll talk about near midairs - as in 'near mid-air collisions'. The government, and aviation particularly, has abbreviations and acronyms for everything; we know these as "NMAC's". The definition of an NMAC is when there is a collision hazard between aircraft with a proximity of less than 500 feet. As an air traffic controller, let me be clear that this is not normal operating practice. As a rule, we aim for at least 500 feet vertical clearance between aircraft in visual conditions; most instrument operations will have 1000 feet vertical separation. That's vertical; lateral separation is measured in miles, and three miles is the normal minimum. Various factors can push that up to five miles or more.

The impetus for this discussion is a near-midair that took place earlier today, involving a couple of regional jets (another acronym: we call these "RJ's") near Pittsburgh. The news reports that I've seen state that the aircraft came within 400 feet of one another after a controller-in-training turned one toward the other. See these articles:

At this writing, that is the sum total of my info
rmation about this incident; I haven't any inside scoop to share (sorry). I can, however, give you a picture of a pair of RJ's:

The aircraft involved in today's incident were very similar to these, except that the smaller of the two was USAir, not United as seen here.

How did this happen? Not being there and not having seen/heard the replay, I don't know. I won't waste your time trying to speculate, but will mention that training was in progress. On-the-job training (OJT) is a fact of life for an air traffic controller. When you start, it takes a couple of years' worth of training before you reach journeyman status, what we refer to as 'FPL' -Full Performance Level. Actually, although we still use it everyday, that's now an obsolete term, having been supplanted by 'CPC' - Certified Professional Controller. Any time a controller moves to a new facility, the training begins again. Not because the rules are different - they're not - but because each airport is different. Just like when you move from one city to another, you have to learn new roads and travel routes. When you're not in training, there's a good chance you'll be tasked with training someone else. I've personally had trainees nearly everywhere I've ever worked, and in fact have one currently. When training is taking place, the trainee and instructor are plugged in together at the position; the instructor can see and hear everything the trainee sees and hears. Actually, quite often the instructor, by virtue of experience, can see and hear things that the trainee doesn't see or hear - yet. The instructor also has the ability to override the trainee on the radio, thus correcting things before they get out of hand. So, why did the instructor allow this to happen? Again, not having been there, I can't say. I will comment that there are times the instructor has his attention on some other situation, or is involved in sorting out some other problem while the trainee keeps working.

What 'saved' these airplanes? As mentioned in one of the referenced articles, on-board equipment warned the pilots. This system, known as "TCAS", for Traffic Collision Avoidance System, has been mandated in all airliners for about the last decade, and has also spread to many of the freight and corporate operators. The system in each aircraft is able to 'see' and track nearby aircraft, and warn the pilots if another aircraft is likely to be a hazard. In addition, the system can communicate with systems in nearby aircraft to coordinate evasive maneuvers, if necessary. When the pilots receive a Resolution Advisory ('RA'), they are to follow the system's indications.
All of this happens exclusive of air traffic control radar or instructions; that's apparently what happened today.

I've been asked by various people if the air traffic system is really as stressed as they've recently heard in the news. Simply put, the answer is yes. Is it dangerous? Sadly, on occasion, again the answer is yes. It offends my professional pride to have to admit this, but it's true. Right now, there is a big turnover taking place in the controller workforce, as many of the controllers now on the job are either eligible for retirement or soon will be. After several years of denying that there was an impending problem, the FAA is finally hiring new controllers in number. Unfortunately, they all have to be trained, a process that can take a couple of years. And not all of them make it through the training: let's face it, not just anyone can make it as an air traffic controller, despite our best efforts.

All that said, this country still has the best air traffic system in the world. Period. Virtually every plane makes it safely to its destination every day. On some days, there's nothing to report anywhere. Most of the things that do happen aren't dangerous, they're just violations of the standards that controllers are held to. These standards are there to keep planes safe, and violations are taken seriously even if nobody else notices. Unfortunately, today's incident was the exception.

I could go on, but it's midnight and I wanna go home. More later.

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