Ask the pilot

Why can't planes drive backward? Plus: In-flight fireworks, angry husbands, and what are the two best songs ever written about unemployment?


Patrick Smith
July 8, 2005 11:30PM (UTC)

On the night of June 30 I went to bed nervous. The column I'd just submitted, scheduled to run the following morning, would be Ask the Pilot's most ambitious installment to date -- a somewhat hair-raising and sentimental yarn involving a pretty girl, an airplane and another airplane. I'd really worn my heart on my polyester pilot's sleeve, and wasn't sure what to expect, envisioning a potential onslaught of ornery e-mails up to and including one from Dorothy Meyer's lawyer. (Or husband: "You cad! How dare you call my wife cadaverous and beautiful.") The next day I opened my mailbox and began scanning the subject lines for telltale signs that I'd overreached and made an idiot out of myself.

In the minds of some I may have, but the outpouring of kudos and commendations has been, to my pleasant surprise and considerable relief, unprecedented. Though possibly tempered by the light readership and generous moods of a holiday weekend, feedback was strong enough to make the story Ask the Pilot's best-received chapter in more than two years.

Advertisement:

I bring this up not in the interest of self-congratulation or to justify future experiments of treacly indulgence, but as a way of thanking readers for having the courage to appreciate flight -- and writing about flight -- through a format that is perhaps more impressionistic and provocative than one might expect. The overarching point of this column is to inform, and always has been, but the occasional digression, I believe, keeps people thinking and helps instill the core topic of flying with the color and drama it surely deserves. If I insisted on presenting the facts and fancy of air travel in the timeworn, unwavering style of a "Wings" documentary, this series would have died a long time ago.

One aspect where last week's column did fall short, however, was in failing to draw old Dorothy Meyer out of the woodwork. The story feels oddly incomplete without some follow-up commentary from her side. There's still a chance she'll turn up, of course, to insist that I fabricated the whole thing and to deny having kissed me. A few reports have trickled in from people who once knew her, but the trail peters out in Seattle around the late 1990s. The picture these sightings paint is not unlike the one I imagined: Dorothy having shared a romance with a member of Pearl Jam, a life amid musicians and artists while holding down incidental jobs in bookstores or boutiques. The standard life drift for beautiful creative types.

Does that sound bitter?

And for the record, in my defense, I do not hold any unusual fondness for "The Love Cats" or any other song by Robert Smith and the Cure. For all its ultimate timeliness and irony, I did not ask that song to catch itself in my brain the morning of the incident in 1986. It simply happened, in that random, infuriating way of songs.

On that note, I'm reminded of the time I compiled a whole column of songs about flying, and there's a temptation to do another one. This time, though, it'll come with a twist, celebrating the darker aspects of flight. If "The Love Cats" is the official song of in-flight near-misses, we'd need representation for all the other sad realities of aviation: crashes, hijackings, lost luggage and airline bankruptcies. For instance, the two greatest songs ever written about unemployment are the Clash's "Career Opportunities" and the Jam's "Smithers-Jones." Thousands of laid-off airline workers would be able to commiserate with the sentiments of Strummer and Bruce Foxton (he, not Paul Weller, composed "Smithers-Jones"). The best of the bunch could then be marketed as a compilation CD called "Tailspins."

Watching our local Fourth of July fireworks extravaganza, I was wondering what it looks like to see a massive display from the cockpit. Maybe it's possible to leave New York at the right time, and catch fireworks shows all across the country as you head west!

Advertisement:

Despite how it looks from a spectator's point of view, fireworks presentations take place fairly low to the ground. Even the most impressive displays don't go much above a thousand feet -- about the height of a skyscraper. From an airplane at cruise altitude, the bursts of color appear tiny and distant, provided they're visible at all through haze, cloud, or other obscuration. During takeoff or approach it can be somewhat more interesting, but still not nearly as dramatic as when seen from the ground at close range. And fireworks should be an auditory experience as much as a visual one. Distance and ambient airplane noise make this impossible.

I've witnessed plenty of fireworks events from aloft, but usually the view is so lackluster as to not warrant mention to passengers. Considerably more exciting was the time several years ago, flying along the Hudson River in a 15-seater, that we encountered a light show atop the World Trade Center. A high-intensity beam swept across our flight path, filling the entire cabin and cockpit with a dazzling fluorescent glow.

Airplanes cannot fly backward, that much I understand. But what about on the ground? You explain in your book how jet and turboprop engines are able to operate in reverse. Yet we always see planes being pushed from the terminal using a truck attached to the nose wheel. Why can't they back from the gate under their own power?

Some can and do. American Airlines is one carrier that has allowed its MD-80 aircraft to operate "powerbacks" at select airports. However, bear in mind that a jet engine does not reverse in a pure sense, whereby thrust would be redirected 180 degrees. Movable, hydraulically activated parts of the cowling will slide or rotate into place, deflecting the air in an acute, semi-forward vector. It's not unlike blowing into your cupped hands. Thus, to actually drive a plane backward from a stationary position takes quite a bit of thrust and makes a great deal of noise (that same roar you hear after touchdown, when the reversers are deployed to aid in deceleration), so the procedure has never been popular. And although it saves long-term wear and tear on the nose gear assembly, the current price of jet fuel makes this a marginal benefit at best.

Advertisement:

Certain aircraft are better suited for powerbacks than others. A plane like the MD-80 (a DC-9 derivative) has aft-mounted engines close to the tail, an arrangement with at least two benefits. First, such placement keeps noise and blast away from the terminal, personnel and ground vehicles. Additionally, because the engines sit close to one another along the fuselage, the overall thrust vector stays right along the plane's centerline, enabling easier directional control. Powerbacks using wing-mounted engines would put people and equipment in greater jeopardy, and there's a risk of side-to-side sway should the powerplants not spool up evenly. Weather conditions, local airport regulations, and weight-and-balance considerations are also factors. If the ground is wet or snowy, reverse thrust can kick up large clouds of spray, and traction is important for smooth stopping. Rolling backward, a tail-heavy plane is liable to tip on its rear end if the brakes are applied forcefully enough.

Reversal of a turboprop engine is more true. The propeller blades twist longitudinally to drive the air forward. Again, though, it's extremely loud and potentially hazardous. At least one regional airline used to authorize powerbacks of its twin-engine turboprops. The plane was a high-wing design, and although the props were well clear of the ground, the force was known to blow the orange wands out of the hands of the marshaller standing near the nose.

My flight from Chicago-Midway is delayed on the runway while, according to the captain, "the tower calculates the thrust needed for takeoff, so that we don't hit nearby buildings." Now, I hesitate to guess, but I'd speculate that this particular airframe -- an older Boeing 737 -- has taken off from Midway approximately 1 billion times during its life to this point. Why are these buildings suddenly a concern, and what the heck is really going on?

Advertisement:

What you describe is one of those times when pilots, in their attempts to present complicated information in ways the layperson can digest and understand, become their own worst enemies by inadvertently dumbing things down and scaring the hell out of people.

First of all, "the tower" does not calculate thrust settings for anybody. This was a poorly chosen euphemism referring to the airline's flight operations staff -- the behind-the-scenes team of dispatchers and planners who put together the predeparture paperwork, part of which outlines the thrust, flap and speed settings for takeoff. Every departure is different, dependent on weight, weather, runway length, off-field instructions (there are your buildings) and so forth.

Most of the time this information is ready to go before pushing from the gate. Once in a while, however, it's not, especially if the flight was subject to last-minute loading changes or if the parameters are particularly tight. Handicap a maximum-weight takeoff with things like a strong crosswind, an icy runway or an inoperative anti-skid system, and your numbers might require some careful scrutiny to ensure all the safety buffers are accounted for. The crew is able to calculate this data if need be, but the dispatchers can do it more quickly and will transmit the results via computer or radio.

Advertisement:

- - - - - - - - - - - -

Do you have questions for Salon's aviation expert? Send them to AskThePilot and look for answers in a future column.


Patrick Smith

Patrick Smith is an airline pilot.

MORE FROM Patrick SmithLIKE Patrick Smith

Related Topics ------------------------------------------

Air Travel Ask The Pilot Business




Fearless journalism
in your inbox every day

Sign up for our free newsletter

• • •