Tuesday, December 16, 2008

Geographica: Airplane Safety!

Today's Geographica harks back 30 years, to an article written in the August 1977 issue by Michael E. Long with photographs by Bruce Dale. The article is called "The Air Safety Challenge," and it was written in a radically different era of aviation history than our own. In the late '70s, commercial airlines were beginning to bask in the ubiquity (and remarkable workhorse capability) of the jet engine, and newer and more sophisticated equipment was starting its slow migration from the military theater to the civil one. Many of the finer points of aerodynamics were still unknown or only sketchily known, and President Reagan had yet to fire the air traffic controllers.

The '70s saw a marked drop in fatal aircraft accidents (4 in 1976), prompting Long to echo the famous line of Christopher Reeve's Superman immediately after saving Lois Lane from a near-fatal helicopter accident, "Statistically speaking, it's still the safest way to travel" (this line played considerably better in the late '70s than it did in the early 2000's when it was uttered again - without irony - by Brandon Routh's Superman). The increase in safety stats was probably due to a combination of factors, with an emphasis on consistently rigorous pilot training and the aforementioned advances in flight technology, although as Long points out, problems persist.

The main problem in this article is wind shear, the sudden and largely unforeseeable change in wind velocity that can wreak havoc with a jet engine, causing near-instantaneous losses of lift pressure, forcing pilots to make split-second decisions that are often counter-intuitive. "I was funneling all my years of flying experience into those moments," one veteran pilot tells Long, referring to a time when his craft encountered such unheralded wind shear. Naturally, the focus of this part of the article is the crash of Eastern Flight 66 at JFK in 1975, in which 113 people were killed; wind shear was fingered as the culprit, and the National Transport Safety Bureau did a thorough examination:

As part of its investigation, the NTSB re-enacted the accident in a 727 simulator. Computers programmed the winds encountered by Flight 66. Experienced pilots "flew" numerous approaches. Their instructions: Land if possible, make a missed approach if necessary, don't crash. Of 54 approaches, only five were successful.

One of the pilots told me, "I crashed five times in six approaches. I didn't believe a wind existed that could so overwhelm an aircraft."

Long also concentrates his attention on another key factor in pilot efficiency: their ability to see where they're going. Specifically, their ability to draw "vertical guidance" from visual clues outside their craft, so they can tell how high up off the ground they are. At one point, a 747 pilot allows Long to pilot the craft to its landing, which he does with some trepidation and immediate candor:

Am I asking you to believe that I stepped right into a 747 and landed it? No. But there's something I'd like you to understand: During that approach I had no trouble keeping the aircraft lined up with the runway. But I had to keep referring to the flight director and other instruments to maintain the proper descent angle. The name of this problem is "vertical guidance."

Of course the main obstacle to something like good vertical guidance is bad visibility - visibility being a key element in an era where electronic instruments were only for in-flight maintenance and pilots still used their eyes, their hands, and their instincts to land their planes. If your visibility is poor, if you're using guideposts that aren't accurate (or aren't what you think they are, or where you think they are), you'll lay yourself open to critical error, often with only seconds to recognize and correct what you've done. Long surveys the wide world of 70s aviation and comes to a quick conclusion about what will likely solve the problems of vertical guidance: "better gadgets."

The inevitable trend is automation. Someday a jetliner will be built that will fly itself from takeoff to touchdown; pilots will merely monitor its performance.

Or, as one veteran pilot puts it:

In the flight deck of the future, we might as well put the pilots behind glass and give the flight attendants an axe, with instructions to break the glass in case of emergency.

Long ends his piece on an upbeat note, looking forward to a future in which pilots continue to be rigorously trained, a future in which air-traffic continues to be carefully controlled and monitored, and a future in which the advances of aviation technology continue to make things easier for the pilots and safer for the passengers. He couldn't have known that in only a year into that future, despite the presence of all those advances, Pacific Southwest Airlines Flight 182 would collide with a private Cessna in San Diego, killing a total of 144 people, including seven on the ground ("Ma I love you" being the famous final words on the cockpit recording), although if he had known, he'd no doubt have said the technology will keep getting better, and tragic mistakes like that will someday be eliminated completely.

We'll take a look much, much further into that confident future, in the next Stevereads.

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