Rarely is the heterodyne discussed as a central factor in what happened that day in 1977. Instead, the crux of the event is lost in a quarter-century-long legacy of human factors analysis: The pilots were stressed and tired. They used incorrect terminology. The tower controller was distracted by a soccer game playing in the background. And so forth.

Sure, if van Zanten hadn't initiated his takeoff roll without permission, nobody would have died that day. But since when have we left our fate entirely in the hands of one person's judgment? If that were the case, there'd be fewer dials, alarms and flashing red lights in a cockpit. People make stupid mistakes, and technology is supposed to be there to back us up. There are products for sale than can greatly lessen -- even eliminate -- the danger from most occluded radio calls. These products are cheap, effective and readily available. Added to an aircraft's communication system, the devices monitor VHF channels and inhibit a pilot or controller from speaking onto an already busy frequency.

Worldwide, some airlines have voluntarily equipped their fleets with such units, the most common of which is made by British Aerospace and trademarked as CONTRAN. One airline, Britannia, a large U.K. operator of 757s and 767s, began outfitting its planes with CONTRAN in 1999. Virgin Atlantic also volunteered to test it on some of its 747s. A ground-based CONTRAN for ATC was put into operation at several British airports.

But despite their fiscally precarious positions, and even with their reputations on the line, it is doubtful the rest our biggest airlines will follow the likes of Britannia and Virgin. Sensible as it may seem, it rarely ever happens this way. Instead, the industry will need some coaching and persuasion from the FAA, its best friend and/or worst enemy, depending on the issue or whom you ask.

While the use of anti-blocking units like CONTRAN is recommended and encouraged by authorities both in the U.S. and abroad (the FAA, the U.K.'s CAA, etc.), it is not mandatory. Not until this technology is required aboard all commerical aircraft will frequencies remain clear of heterodynes and their potential dangers.

In the past, the FAA has eventually gotten around to legislating a host of important regulations after various accidents. After two high-profile midair collisions, one in 1978 and a second in 1986, an airborne traffic collision avoidance system, known as TCAS, is now found in the cockpit of every airliner. Following the crash of ValuJet in the Everglades in 1996, fire suppression was mandated for cargo holds. And after a long pathology of something euphemistically called CFIT, or, "controlled flight into terrain," ground proximity warning systems (GPWS) became standard equipment.

Generally, not only were these fixes mandated long after they should have been, but they came in the form of expensive, overly complex warning systems. Things like GPWS and TCAS probably thrilled the engineers who designed them, but their color-coded depictions, variable-pitch aural warnings and multistage alarms often use up more gray matter than a pilot may have to spare in the heat of battle.

This time what's needed is not another acronymic "system" of high-technology prowess, but a back-to-basics, low-tech solution to an old and very high-stakes problem. The fix is so low-tech, in fact, the airlines and regulators should be ashamed and embarrassed even to debate the matter.

In some instances, serious problems do not require cumbersome or costly solutions. It's too late for those killed on Tenerife, but 25 years later, another clipped transmission could find us back on a foggy runway asking, "Why?"

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