Saturday, December 29, 2007

FAA History Lesson -- December 29

From the FAA Historical Chronology, 1926-1996...

”Dec 29, 1972: An Eastern Air Lines Lockheed L-1011 crashed in the Everglades northwest of Miami, killing 99 of the 176 persons aboard. Two survivors died later as a result of their injuries in this first fatal crash of a wide-body airliner. The National Transportation Safety Board cited the probable cause as the flight crew’s failure to monitor flight instruments. Preoccupied with a malfunction of the landing gear position indicator, they allowed the aircraft to descend unnoticed. “

Just in case you’ve forgotten how to do this...

You can go to the NTSB’s “query” page and search. Or in this case, in that we already know the date, you can go to the monthly listing page and look it up. That will get you to the report for this accident and as you can see, there isn’t much there in this case. It does, however, give you the all important accident number: DCA73AZ005.

With that number, you can usually find a lot of other information. I rummaged around a little and wound up at this site: The Crash of Eastern Airlines Flight 401 . You can learn more than you’d ever want to know about the flight from that web page.

For those old enough to have a few memory cells stimulated, this crash took on a life of its own. There was a book written about the crash, “The Ghost of Flight 401” and a movie was made about the book. Of more earthly concerns, this accident left us with two new rules from the FAA, trying to prevent any future occurrences.

From the FAA Historical Chronology, 1926-1996...

”Dec 24, 1974: FAA published a rule requiring installation of the Ground Proximity Warning System (GPWS) on large turbojet and turboprop airliners. The equipment was to provide both visual and aural signals when the aircraft was less than 2,500 feet above the ground. The rule’s implementation deadline of Dec 1, 1975, was subsequently extended due to persisting technical difficulties, but all major airlines were in compliance by the end of 1976. A rule published on Oct 10, 1978, extended the GPWS requirement to smaller commuter airline turbojets if able to seat as many as ten passengers. (See Dec 1, 1974, and Mar 17, 1992.)“

From the FAA Historical Chronology, 1926-1996...

”Nov 5, 1976: FAA commissioned the first Minimum Safe Altitude Warning (MSAW) system, an add-on computer software feature specially devised for use with the ARTS III radar terminal system, at Los Angeles International Airport. MSAW had the capacity to spot unsafe conditions by automatically monitoring aircraft altitudes and comparing them to terrain maps stored in the computer's memory. If aircraft descended dangerously close to the ground, aural and visual alarms on their consoles alerted controllers who could then radio warnings to pilots (see Oct 28, 1977). Sperry Rand's UNIVAC division developed MSAW under a contract announced by FAA on Jul 17, 1974. The need for such a system had been highlighted by the crash of an L-1011 near Miami (see Dec 29, 1972). “

The rule requiring the Ground Proximity Warning System (GPWS) was also spurred on by another fatal (and famous) accident on December 1, 1974.

Don Brown
December 29, 2007

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