Monday, July 01, 2002

A Chain of Events

When Air Florida Flight 90 crashed into the 14th Street Bridge 20 years ago, killing all but 6 passengers seated in the tail, the National Transportation Safety Board (NTSB) began an investigation that lasted months. It interviewed witnesses on the ground at National Airport, on the streets near the bridge, the surviving passengers. It examined the Flight Data Recorder and the Cockpit Voice Recorder and radar information. It talked to the people who made the plane and the people who maintained it. It talked to employees and officers of Air Florida. It was, as they say, an "exhaustive" investigation. If you read newspaper accounts of the final report, you would probably believe that the NTSB concluded that the crash was caused by "icing on the wings and airframe." The plane had been deiced but then waited a long time--almost an hour--in the snow and slush, and had gotten a fair coat of ice on it.

But if you have ever read an NTSB report, you know it said a great deal more than that. I have had a pilot's license for about 6 years, and so I, like most pilots, pay an extraordinary amount of attention to such things. If you pick up any copy of "Flying" magazine at the airport newsstand, towards the back you will see a summary of reports on 5-10 accidents, and a column, called "Aftermath" that dissects some particular accident in great detail, so as to teach other pilots about mistakes that can kill them.

In the case of AF 90, the NTSB concluded a number of things. (I'm quoting from memory here, so may have a few details slightly wrong. Bear wih me). The NTSB found that AF did not keep particularly good maintenance records. AF's pilots were generally made "Captain" with fewer hours than the industry average, and its planes were older than average. It found that its Flight department met FAA requirements, but wasn't especially interested in exceeding minimum requirements.

In the sequence of events leading up to the crash, the weather was extremely cold--around -5 C--and the airport was closed for 45 minutes or so to plow the runway. Incredibly, during the pretakeoff checklist, the pilot and copilot called out that the anti-icing equipment was turned "off" but neither remedied the situation. The captain tried to use the exhaust of a plane in front of them to deice, to save time, but that just moved the ice around. After 30 minutes, he was supposed to request a new deicing, but the flight was already delayed an hour and a half because of the airport closure. The copliot noticed a problem with one of the engine gauges, but was too intimidated by the prospect of correcting his captain (he had requested not to fly with him any more) and so didn't take decisive action. During the takeoff, even when the plane started to descend, neither man advanced the throttles to full power, either believing them already generating max thrust because of the faulty gauge (which malfunctioned because of ice) or responding the way their airline had trained them, to resist full power for fear of giving passengers an unnnecessarily bumpy ride. Less than a minute after take off, the plane hit the bridge and sank into the Potomac, allowing only 6 passengers to escape and be rescued by helicopter and the heroics of a few people who dove into the freezing water to save them.

Why do I tell you any of this?

Well, in spite of the "cause" being identified as "icing" the report makes it clear, as it does in virtually all aircraft accidents, that the actual cause was a chain of events, and that breaking the chain at any point probably would have prevented this particular accident, but only understanding the chain will prevent future ones. This is the single most important reason that US airlines have such an unbelieveably good safety record. The NTSB is not content with "icing" as an explanation.

So, too, then, with the Situation in our Church. Many people are suggesting a cause for it, but the proximate cause of an event is not the whole story. The chain of events in this case stretches back decades, and probably includes many of the things suggested by bloggers and the media alike. But "media bias", "ephebophiles", "clericalism", "gays in the priesthood", "sexual libertines", "Vatican II", "heterodoxy" and all the other things put forward are not by themselves sufficient cause. If we want to prevent further problems, it will take so very much more than addressing one or two of these items. Breaking the chain at any one point will stop the present Situation. Fixing every link in it is the only way to prevent future problems. How to form an NTSB-like team to investigate and draw conclusions is way beyond my meager powers to offer.

But I can tell you what makes the NTSB work, in the hopes that the smart folks out there can use that knowledge to suggest the right mix of people to examine and investigate. That will be the subject of a post later today or tomorrow.


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