High fuel prices are hammering the airline industry. I’m aware of that, and that all these annoying surcharges that have recently been announced—for luggage, for drinks—are attempts to somehow make up for the extra fuel costs.
What I didn’t know was that airlines are also saving money on fuel by simply not filling up the tanks as high as they ought to. The U.S. Federal Aviation Administration requires that an aircraft carry enough fuel to reach its destination and the most distant alternate airport, plus an extra 45 minutes’ worth. It’s not to an airline’s advantage to carry any more than the minimum requirement: more fuel means a heavier plane, and a heavier plane gets worse mileage.
Of course, the calculations are based on estimates—estimated passenger weights, estimated luggage, estimated speed. But after my last flying experience, in June, I’m thinking that the airlines are estimating a little low.
I flew from San Francisco to Newark, N.J., on a Continental Airlines Boeing 737. Great weather on both ends, only a little turbulence in between. A lovely flight, actually—the best I’ve had in a long time. The flight attendants were cheerful; passengers got two drinks and a bagel-and-egg sandwich without charge.
A little more than four hours into the flight, the pilot reported that we’d be landing about half an hour ahead of schedule, and the flight attendants began collecting trash in preparation for our approach. Perhaps 10 minutes later the pilot announced that we’d have to slow down a little to get in line for landing, but we’d still arrive well ahead of schedule. I was thrilled; this would be my first flight in at least a year that landed on time. Perhaps I could even call a friend for dinner.
And then, just a few minutes later, the pilot came on the public-address system again: ”Uh, folks, we’re going to make a quick stop for refueling.” Huh? Passengers looked at each other in surprise. Flight attendants passed rapidly through the cabin checking seat backs and tray tables and strapped themselves in. Minutes later, we landed at Stewart Air National Guard Base, in Newburgh, N.Y., less than 100 kilometers from our destination. After a long ride on the ground past National Guard cargo planes, we parked and waited for the fuel trucks.
I was flabbergasted. I’ve logged a lot of airline miles over the years, but I’ve never been on a flight that ran out of gas. The pilot blamed the problem on air traffic delays, but from what he had said the delay seemed minimal—certainly not enough to eat up the 45â''minute reserve the FAA requires. I wondered about the fact that we’d gotten so far ahead of schedule; likely we’d been flying a little faster than is optimal for fuel conservation. Or could the European tourists on board have gotten carried away by the cheap dollar and brought back a lot of extra luggage? Turns out, though, that the U.S. Department of Transportation recently singled out Continental for having the most of what it calls ”minimum fuel declarations” on approach to Newark International Airport last year: 96, which is more than twice the amount it had the previous year. Declaring ”minimum fuel” tells the air traffic controllers that if incoming planes need to be delayed they shouldn’t delay this particular flight too much. The DOT also found that Continental has been pressuring pilots to cut back on the amount of fuel they carry, for ultimately the pilot makes that decision. Last October, the airline sent a memo to pilots pointing out that ”adding fuel indiscriminately without critical thinking ultimately reduces profit sharing and possibly pension funding.” Maybe that’s why I ended up sitting on a deserted runway for an hour and a half?
Next time, Continental, forget the bagel. Just fill up the tank.
A version of this column appeared in IEEE Spectrum’s Tech Talk blog on 26 June.