A would-be shocker that, for all its chillingly authentic asides on air crashes, never gets off the ground. In a notably unsuccessful amalgam of technical fact and stereotypical fancy, Alan Wilcox, a senior investigator in the National Transportation Safety Board's western regional office, doubts that a series of fatal and near-miss accidents involving jetliners controlled by on-board computers can all be chalked up to pilot error or random software anomalies. While exhaustive post- mortems fail to support the intrepid sleuth's suspicions, he perseveres at no small risk to his personal happiness and professional reputation. A master at analyzing ``scatterpath'' (the telltale trail of wreckage left by a doomed aircraft on its, literally, final descent), the man from NTSB dashes to and from disaster sites throughout the US in search of the elusive evidence that could save countless lives. Wilcox soon appreciates that he's up against a homicidal hacker who (thanks to absurdly easy access to assembly lines, repair depots, and other of commercial aviation's vulnerable venues) can program certain makes of planes to fall, without a clue, from the sky. Only when the villain brazenly starts to call his shots, however, do Wilcox's dim-bulb superiors realize their lad was right all along. They join him in the chase, and the attention-seeking saboteur is brought to book at San Diego's busy airport in a predictable climax before he can wreak further havoc. Notwithstanding the author's dead-on command of black-box and procedural detail, then: a clumsy, suspense-free narrative whose cul-de-sac plotting keeps it earthbound.