Reflections of a ModemJunkie

TRIANGULATION-Then and Now

by Leonard Grossman

Computers are amazing. Every day we are impressed by the number of things we can do with computers that we simply couldn't do before.

For example:

Wait a minute. That next sentence should have come easily. Each day there are stories in the news papers about the computer industry. The stock markets follow closely the latest news in the browser wars or chip development. Yet, finding something really new eludes us.

There was a story in the New York Times the other day about a small company on the east coast that was proving invaluable in sorting out claims of various purported eye witnesses to the TWA Flight 800 disaster. According to this story, there is a gap in the information provided by Air Traffic Control and by the flight crew itself during the last few minutes of a flight as the crews prepare to land and the final runway decisions are made. Because of these delays, ground crews could be unable to prepare for the actual landings and support services could be severely delayed.

However, it appears that this small firm has found an answer using information provided by transponders on each plane which are required by the FAA. Using computers it is able to use a form of triangulation to identify each plane and give ground crews much more accurate information as to the location of each plane and to provide much more accurate estimates of actual landing times than is available from other sources. In the case of the TWA crash the data provided precise information as to when the engines on Flight 800 ceased operation, while conventional radar continued to show the path of the jet, even after the explosion.

In addition this ability proved particularly useful in analyzing eye witness information surrounding the crash of TWA Flight 800. By reviewing its records the firm was able to determine the precise position and path of each plane in the area at the time of the crash. Using this information, crash investigators were able to evaluate the quality of the eye witness information provided by crews and passengers in the vicinity at the time.

This information is recorded at a number of airports around the country and except for the firms, like United, which have contracted for the information, few people are aware that such records are kept. The firm has become a silent monitor for a number of airports around the country. This time, the information they quietly stored was available for a quite unintended and unexpected purpose.

How amazing I thought. Where would we be without computers? Then I read "Snow Falling on Cedars" the magnificent novel I referred to in last month's column. In that novel, a young Japanese-American is accused of a maritime murder. The prosecutor has everything: motive, opportunity, weapon. Everything but a witness to the act itself. The reader knows something isn't right. But in the face of such overwhelming circumstantial evidence, how can this young man possibly be acquitted? The novelist carefully develops the character of the major figures. The reader doesn't want to believe that the young man is guilty. Yet the overwhelming evidence seems to convict him. If only there were some independent evidence to corroborate or contradict the circumstantial evidence.

Well (I hope I am not ruining this book for anyone; it's been out in paper for years), there was a silent witness that night too.

It turns out that at a lonely lighthouse on this island off Puget Sound, a Coast Guard employee regularly made a manual log of the soundings made that foggy night. The logs would reveal just which boats were in the ship channel that foggy night and how close to one another they passed. One way or another they would reveal the truth.

No one had ever looked at those notes. They were just silently filed away. At the last minute, a major character in the novel discovers these logs and presents them to the court. Compared to the sophisticated transponders and computer analysis used in the crash of Flight 800, these manual logs were decidedly low tech. But the technique was essentially quite similar.

Unfortunately all of our modern technology hasn't provided the answers to the crash of Flight 800, at least not as of this writing. But it is comforting to know that there is truly nothing new under the sun.

REV. 9/29/96 7:52:06 PM