Read Online Cockpit Confidential by Patrick Smith - Free Book Online

about them. The crash of Eastern flight 66 in New York in 1975 is considered the watershed accident after which experts began to study the phenomenon more carefully. Since then, windshear has become relatively easy to forecast and avoid. Major airports are now equipped with detection systems, as are planes. Pilots are trained in escape maneuvers and can recognize weather conditions that might be hazardous for takeoff or landing.
Over the Atlantic in a 747, we heard a loud bang, followed by a vibration through the cabin. The captain informed us we’d suffered an engine stall.
    This would have been a “compressor stall,” a phenomenon where airflow through the engine is temporarily disrupted. The compressors of a jet or turboprop consist of a series of rotating airfoils—each blade is, in essence, a tiny wing—and if air stops flowing smoothly around these airfoils or back flows between the sequential stages, your compressor is stalling. It can damage an engine, but chances are it won’t.
    Miscellaneous engine peculiarities, compressor stalls included, can sometimes put on a show. Aside from a bang, you might see a long tongue of flame shooting from the back, or even the front, of the cowling. Tough as it might be to accept, the engine is neither exploding nor on fire. This is the nature of a jet. Any time the engine is running, fuel is combusting, and certain anomalies will unleash this combustion rather boldly.
    The stalling compressors of an Alaska Airlines 737 once made the news when, by chance, a burst of flame was captured by somebody’s camcorder on the ground. The video was alarming, but the stall was effectively harmless. And when this sort of thing happens at the gate or during taxi, passengers have been known to initiate their own evacuations. One such panic took place aboard a Delta plane in Tampa, Florida. A stampede of frightened passengers made for the exits, refusing to heed flight attendant commands. Two people were seriously hurt.
If all of a jet’s engines were to fail, can the plane glide to a landing?
    While it may surprise you, it’s not the least bit uncommon for jets to descend at what a pilot calls “flight idle,” with the engines run back to a zero-thrust condition. They’re still operating and powering crucial systems, but providing no push. You’ve been gliding many times without knowing it. It happens on just about every flight.
    Obviously an idle-thrust glide is different from the engines quitting outright, but even then, the glide itself would be no different. There’s no greater prospect of instant calamity than switching off the engine in your car when coasting downhill. The car keeps going, and a plane will too. In fact, the power-off performance of a large jet is better than that of a light Piper or Cessna. It needs to glide at a considerably higher speed, but the ratio of distance covered to altitude lost—close to 20:1—is almost double. From 30,000 feet, you could plan on a hundred miles worth of glide.
    Total engine loss is about as probable as a flight attendant volunteering to give you a shoe-shine, though it has happened. Culprits have included fuel exhaustion, volcanic ash, and impacts with birds. In several of these incidents, crews glided to a landing without a single fatality or injury. In other cases, one or more engines were restarted before reaching the ground.
How is a plane pressurized, and why?
    Pressurization is one of those things that few folks understand and that many fear needlessly. Something about the word “pressurization” causes people to picture the upper altitudes as a kind of barometric hell. I’ve been asked, “If the plane wasn’t pressurized, would my eyes pop out?”
    Cruising in an airplane is not the same as dropping to the Marianas Trench in a deep-sea diving bell. The cabin is not pressurized to keep your eyes in but to allow you to breathe normally at high altitudes,