Cockpit Confidential (24 page)

This is what I'm pondering, midflight across the Atlantic Ocean. And it's that latter category, I figure—that most mystique-less and prosaic of crashes—that awaits us, should we plummet to a sudden and watery doom. Three guys in a cargo plane? We'd be lucky to get a mention in the paper. Depressing.

A pilot's worst nightmare, other than his airline going bankrupt or the caterers forgetting the meals, is an onboard fire. This old jet has two identical fire detector systems for its 150-foot-long upper cargo deck. These are rotary dial things with yellow annunciator bulbs at the bottom. The bulbs say: CARGO SMOKE. Of course, this is an airplane laid out when Eisenhower still had a combover, so guess what? Thanks for the heads-up, but there's nothing to actually put the fire out with once it has been detected. (DC-8s are all but extinct and were taken out of the passenger-carrying business a long time ago, so don't worry.) There are bigger, brighter lights in this cockpit, but it's those square, innocuous-looking yellow lights that I do not ever want to see come on, particularly when the closest spot of land, two hours away, is the glaciered coast of Greenland.

I'm also aware, however, that in the compartment behind us are 20,000 pounds of fresh-cut flowers from Belgium and the Netherlands headed to America. The scent of the flowers has made the cockpit smell like baby powder. And it happens that when thousands of pounds of flowers are piled together, they tend to give off clouds of microscopic dust—tiny bits that fill the air like a fragrant cloud of powder. Meanwhile, the DC-8's old-fashioned detectors are designed to detect not flames or heat, but smoke particles, and are very susceptible to false alarms triggered by dust or powder.

So I'm staring at the warning lights, waiting for them to tell me we're on fire over the middle of the ocean. Or is it only dust? And I think about how, after planes crash at sea, they go out on a boat and toss flowers into the waves, and how if something happened and we found ourselves in a watery grave, we'd save everyone the trouble by spreading a veritable slick of tulips halfway to Labrador.

Making matters worse, the captain takes out a chart and starts playing with the GPS. “Ha!” he shouts. Bored and curious, he has plotted the exact latitude and longitude of the wreck of the
Titanic
, which is 40,000 feet below us (28,000 of air and 12,000 of salt water), just a short ride south of our course.

“Oh come on,” I say. “Don't be doing stuff like that.”

I sit in front of my instrument panel—a wall of dials and switches, all arranged in a perfect working sequence, with a collective purpose nothing short of mechanical infallibility. Green lights, red lights, blue lights, circular windows with quivering white needles. In modern planes it's all LED or liquid crystal, but these are the old-style analog gauges, which give the cockpit that U-Boat look. Old, and dizzyingly complex for just that reason. I slide back my seat and consider it all, with the criticism and respect an artist might give to his canvas.

In that moment I am a maestro of ordered technology. But if only you could see what lurks
behind
that console. The maintenance people sometimes take the panels off, and there's pandemonium back there: wildly knotted bundles of wires and cables, like a spaghetti factory has exploded. Most people have never seen the guts of an airplane—those vast and complex blocks of machinery conspiring to fool gravity. When you look at the eyes of a pretty girl—that superficial beauty of an iris in the sunlight, do you consider the tangle of optic nerve behind it? And in that brain of hers, what is she
thinking?
Like a fire secretly smoldering behind me, amid all those flowers. And when it's finally too late: CARGO SMOKE.

No, not this time. And a few hours later we're safe at Kennedy.

And doesn't it always end this way? Amazing that it all works, all those wires and pumps and moving parts—almost infallibly and every time. But it does, and that's the point about these spooky ruminations. It's our imagination, not our technology, that is prone to failure.

The other lesson here is that we're all afraid of flying on some level and that it's perfectly healthy to be that way. Particularly if you're a pilot. Our job, in essence, is the management of
contingency
. Passengers will ask pilots if we're ever frightened; do we consider the possibility that the next flight could be our last? This always has struck me as both a profound and asinine question. “Yes,” I'll answer. “Of course I am scared. I am
always
scared.” You can take that with the wink it deserves, but nonetheless, it contains a nugget of truth. Fires, explosions, physics gone bad—all the nasty scenarios the simulator instructors love—it's all there, coiled behind the instrument panel, waiting to spring in a game of comfortable, though never perfect odds. And the pilot's role is to spring right back. Do pilots worry about crashing? Of course they do. As a matter of practicality, they have to. It's their job. It's in their best interest, and yours as well.

Your tray has to be latched so that, in the event of an impact or sudden deceleration, you don't impale yourself on it. Plus it allows a clear path to the aisle during an evacuation. The restriction on seat recline provides easier access to the aisles and also keeps your body in the safest position. It lessens whiplash-style injuries and prevents you from “submarining,” as it's called, under the seat belt. Keep your belts low and tight. Nothing is more aggravating than hearing a passenger voice the theory that should a crash occur they are guaranteed to perish, so what's the point? Most crashes do have survivors, and something as simple as a properly buckled belt could mean the difference between serious and minor injury.

Raising your window shade makes it easier for the flight attendants to assess any exterior hazards—fire, debris—that might interfere with an emergency evacuation. It also helps
you
remain oriented if there's a sudden impact—rolling, tumbling, etc. Dimming the lights is part of the same strategy. Burning brightly, the glare would make it impossible to see outside. And by pre-adjusting your eyes, you won't be suddenly blinded while dashing for the doors in darkness or smoke.

This pertains to twin-engine Airbus models: the A320 series (includes the subvariants A319 and A321) and the larger A330. In the United States, the largest operators of these types are Delta, United, jetBlue, and US Airways. Almost every frequent flyer has encountered this sound at one time or another. Crews rarely make efforts to explain it, leaving passengers befuddled and sometimes worried. Because the noise is akin to a motor repeatedly trying—and failing—to start, there's often the assumption that something is malfunctioning.

What you hear is a device called the power transfer unit, or PTU, which is designed to ensure adequate hydraulic pressures during single-engine operations. To conserve fuel, it's fairly routine for two-engine planes to taxi with an engine shut down. Each engine normally pressurizes its own hydraulic system, but with a motor not running, that leaves one system without a power source. That's where the PTU comes in, helping left power the right, or right power the left. Since it is activated only when the pressure falls below a certain level, the PTU cycles on and off, on and off, on and off. Due to pressure fluctuations, the noise will sometimes continue even after both engines are up and running. It also does a self-test when the starboard engine is started, so you'll hear it then as well. Some Boeing aircraft also employ a PTU, but the operation is slightly different and it doesn't bark like a dog.

Another noise peculiar to Airbus models is a shrill, prolonged whine heard at the gate prior to departure and again after landing. This is an electric hydraulic pump used to open and close the cargo doors.

Filthy, germ-laden, rotten, disgusting, wretched, skanky, rancid, putrid, fetid, and fart-filled are just a few of the adjectives used to describe cabin air, and legion are the accounts of flyers allegedly made ill by microscopic pathogens circulating throughout a plane. In reality, the air is very clean.

On all modern aircraft, passengers and crew breathe a mixture of fresh and recirculated air. Using this combination rather than fresh air only makes it easier to regulate temperature and helps maintain a bit of humidity (more on the humidity in a moment). The supply is bled from the compressor sections of the engines. Compressed air is very hot, but the compressors only compress; there is no contact with fuel, oil, or combustion gasses. From there it is plumbed into air conditioning units for cooling. It's then ducted into the cabin through louvers, vents, and the eyeball vents above your seat. (The AC units are known to pilots as “packs.” That's an acronym for pneumatic air cycle kit. Usually there are two per plane.)

The air circulates until eventually it is drawn into the lower fuselage, where about half of it is vented overboard—sucked out by the pressurization outflow valve. The remaining portion is remixed with a fresh supply from the engines and run through filters, and the cycle begins again.

Studies have shown that a crowded airplane is no more germ-laden than other enclosed spaces—and usually less. Those underfloor filters are described by manufacturers as being of hospital quality. I needn't be reminded that hospitals are notorious viral incubators, but Boeing says that between 94 and 99.9 percent of airborne microbes are captured, and there's a total changeover of air every two or three minutes—far more frequently than occurs in offices, movie theaters, or classrooms.

One persistent urban myth holds that pilots routinely cut back on the volume of airflow as a means of saving fuel. It's especially regrettable when even our most august and reliable news sources parrot this baseless assertion. Case in point: the following is from a 2009 issue of
The Economist
: “Typically an airline will strike a balance by using a 50:50 mixture of fresh and recirculated air,” says the magazine. “Although pilots can reduce the amount of fresh air to save fuel. Some are thought to cut it back to only 20 percent.” My mouth dropped open when I read this. I love that sentence, “Some are thought to cut it back to only 20 percent,” with its oily overtones of conspiracy.

To start with, pilots cannot tinker with a plane's air-conditioning systems to modify the ratio of fresh to recirculated air. This ratio is predetermined by the manufacturer and is not adjustable from the cockpit. On the Boeings I fly, we have direct and accurate control over temperature, but only indirect control over flow. If you asked me to please “cut it back to 20 percent,” I would politely inform you that this is impossible. The switches are set to automatic mode prior to flight, and the packs more or less take care of themselves. So long as both engines are turning and everything is operating normally, the flow is perfectly adequate. Only when there's a malfunction are the settings changed.

I am not as familiar with Airbus models, but let's talk to somebody who is.

“Airbus series aircraft, from the A320 through the much larger A380, do provide a way for pilots to vary airflow,” says Dave English, an A320 captain and aviation writer. “But not in the way characterized by
The Economist
.”

English explains that the Airbus controllers have three positions, labeled HI, NORM, and LO. “Almost all the time you're in the NORM position, and flow control is automatic. The HI position is used when you need a rapid change in temperature. The LO position does as the name implies. It reduces flow and provides some fuel savings, but they are minimal and this isn't used very often. Company guidance is to use LO whenever the passenger load is below a hundred. It's not a big change. Sitting in the cabin, it's almost impossible to notice the difference.”

You'll occasionally notice a strong odor when the plane is on the ground—a pungent smell similar to the exhaust from an old car or bus that fills the cabin shortly after pushback. Usually this happens when exhaust gases are drawn into the air conditioning packs during engine start. The wind is often to blame, causing air to backflow or blowing fumes through the pack inlets. It normally lasts only a minute or so, until the engine is running and stabilized. It's unpleasant but little different from the fumes you occasionally breathe in your car while stuck in traffic.

If passengers have one very legitimate gripe, it's about dryness. Indeed, the typical cabin is exceptionally dry and dehydrating. At around 12 percent humidity, it is drier than you will find in most deserts. This is chiefly a by-product of cruising at high-altitudes, where moisture content is somewhere between low and nonexistent. Humidifying a cabin would seem a simple and sensible solution, but it's avoided for different reasons: First, to amply humidify a jetliner would take large quantities of water, which is heavy and therefore expensive to carry. Humidifying systems would need to recapture and recirculate as much water as possible, making them expensive and complicated. They do exist: one sells for more than $100,000 per unit and increases humidity only by a small margin. There's also the important issue of corrosion. Dampness and condensation leeching into the guts of an airframe can be damaging.