CHICAGO, Ill. -- In business — any business — there are very few (legal) ways to boost profits: increase revenue and/or cut costs. In the highly competitive airline business, the emphasis for several years has been on the latter. Personnel costs were a first, easy target: fewer workers, less cost.

That strategy has, for the most part, been played out. So airlines are now implementing more subtle cost-cutting measures that take aim at reducing the weight of airplanes and of the contents they take aloft.

"The math here is simple, and so are the potential savings," says Alyson Challren, an airline efficiency consultant. "For every five pounds an airplane carries for an hour, it burns one pound of fuel. And with jet fuel prices rising just like they are for your automobile, you can see why the airlines are looking to reduce weight wherever possible."

Toward that end, airlines have been skipping on paint jobs, eliminating on-board magazines, removing seats, even setting up subsidiary airlines for naked flyers. Now Err Travel has learned that JetRed Air Lines will soon be taking more "personal" weight-reducing/cost-cutting measures. The targets this time: airplane lavatories.

Next month JetRed will begin removing about half of the lavatories from airplanes used on its transatlantic flights. That will be followed later in the year with the removal of half of the lavatories from the remainder of its fleet. Completion of the project is expected by the first of the year.

To accommodate the reduction, the airline will limit the number of times each passenger is allowed access to an on-board lavatory. Boarding passes for each passenger will be imprinted with a code that, when inserted into an optical reader in a lavatory door, will allow access to the compartment. According to company memos, the allotted number of passenger accesses will be a function of route, distance, passenger load and cabin class.

The reasoning behind JetRed's moves was explained by Challren. "It takes about a gallon of fuel to carry the amount of water needed to flush a lavatory toilet 4.3 times," she said. "Assuming that the average passenger uses the lavatory 0.47 times per hour (the airlines actually keep these statistics) then the cost of fuel just to carry the water to flush the toilets on a Boeing 777 flight from Chicago to London can exceed $87,400."

Challren also pointed out that JetRed is able to add an additional 3 rows of seats for each lavatory removed, thus increasing the plane's load factor.

Passengers will be able to use frequent flyer miles or purchase additional lavatory visits when they make reservations. In flight, the optical readers in the lavatory doors will also accept credit cards. The charge for each additional access is expected to be $3.25.