If you're old enough to order a drink on an airplane, you've probably noticed some changes.

Teh planes are faster, wider and longer. They carry more passengers. But there's something else: a new breed of flight attendants.

Today's flight attendants may be male or female, and range in age anywhere from their late teens up to their sixties. They come in all shapes, weights and sizes (as long as it's "in proportion"), from virtually every background and geographical location.

One airline has lawyers and dentists moonlighting as flight attendants. Another's attendants commute to their U.S.-based jobs from Chile, Italy, even Bali.

Few if any fit the stereotypical flight attendants of a decade or more ago.

Yesterday's "stewardesses" and "stewards" tended to look alike: young, cute (or handsome), immaculately coiffed, poised and all smiles. In the earliest days of commercial aviation, they were called "air hostesses," but behind their backs it was "glorified waitresses," and more disparaging, "beautiful bubbleheads."

At TWA 50 years ago, the job was limited to women. Of the 2,000 original applicants, the airline hired and trained two dozen, and started them at $100 per month.

Early hostesses were white, female, single, under 26 years, and stood 5-feet-4 or less. They alaso were registered nurses (to enhance passengers' peace of mind). They were reuqired to inspect and clean lavatories, sweep the cabin floor and dust the windowsills before each flight, control the craft's heating system, distribute cold box lunches, cigarettes and chewing gum, take care of baby passengers, point out places of interest below adn, when out of uniform, chrew a pack of gum a day to ward off double chins.

Today's flight attendants have other, more demanding duties. They're screened for psychological and diplomatic balance, and are rigorously trained to deal with potentially catastrophic situations, anything from air accidents to terrorist incidents to helping deliver babies, six miles up.

There may be as many as 30 applicants for each vacancy, and it isn't unusual for 10 percent of those accepted to drop out before completing training.

Uli Dereckson, senior flight attendant aboard TWA's Flight 847, hijacked last June, for example, was credited with saving the life of at least one of her craft's American passengers, and intervening on behalf of many others (She also used her personal credit care to charge $11,000 of fuel after officials at Algiers Airport refused to refuel the plane because TWA didn't have an account there.)

Where flight attendants averaged 18 months to 2 years service in the 1960s, today's average service is about 12 years.

"The real change, in terms of people making a commitment to careers as flight attendants, came with the turmoil caused by lawsuits in the late '60s, and action by the courts and Congress to remove discriminatory rules concerning marriage and age limits," asserts Joe Madison, research director of the Transport Workers Union.

"Appearance was stressed in the old days, but now we fosuc our training on interaction with the customer, safety and operation of the cabin equipment.

Flight attends must, for example, be able to evacuate all passengers from an aircraft in 90 seconds or less. They are responsible for the entire aircraft, except the flight deck. They are trained to identify and handle medical emergencies, fight fires, operate the galley equipment and electrical system.

More and more people are choosing the field as a career, and others are using it as a jumping-off point for corporate advancement. An attendant willing to work a maximum amount of overtime can earn about $35,000 a year, and sometimes more than $40,000.

Robert Wessler, a 34-year-old New York-based attendant with Pan Am, says he was drawn into the field because of the travel opportunities along with the flexible work schedules.

As with the dentist and lawyer flight attendants, they can use their free time ot develop businesses of their own. Several attendants are in the export-import business and use their time between flights to develop contacts.

Becky Ehmann, 45, the mother of girls 24 and 21, didn't even know she was applying for a job as a flight attendant when she answered a People Express advertisement for "customer service managers."

Employe-owned People Express uses the term "customer service manager" because the job inovlves administrative and other chores in addition to flight attendant duties. Ehmann says she spends about half her time as a flight attendant and the other half in an office.

Adam Kenaio, 35, worked as an auto mechanic, airframe and power plant mechanic before "I got tired of the grease and decided I wante dto be more involved with people"

H eearned his real estate license and after an unsuccessful stint in that field, finally applied for a job as a flight attendant, finding a niche iwth Republic Airlines. "I really like the work, because you get to meet so many intersting people, both the other attendants and the passengers. I also like the changing routine. Maybe I'm a gypsy or something."

It today's attendants don't seem as attentive as in the past, one reason might be that they don't have time. In the good old days, the 14-passenger DC-2 carried one hostess, who had plenty of time to deal with just a few passengers. Today's 747s can carry more than 400 passengers, with only 12 or 13 attendants -- a ratio of one attendant for 30 or more passengers.

On the transatlantic flights, the flight attendants have to prepare and distribute two meals, handle beverage service, oeprate the duty-free cart, distribute earphones, run the in-flight moves and handle individual customer requirest.

There's a saying, notes the Transport Workers' Joe Madison, "Flight attendants walk across the Atlantic." FLYING COLORS Profile of today's flight attendant:

*Salaries start at about $1,000 per month for about 65 hours' work, with a ceiling of about $35,000-$40,000, depending on seniority and routes flown.

*Education requirements call for either a high school or college diploma, depending on the airline.

*Height minimums and maximums vary, depending on the types of aircraft used by the airline.

*Weight must be in proportion to height.

*Age minimums vary but run between 12 and 21/ Because of the physical demands of the job, only a handful of flight attendants work past age 60. (Back in the mid-1930s, when "air hostesses" were only staying in their jobs for a year or two, one TWA instructor reportedly told his class, "If you haven't found a man to keep you by the time you're 28, TWA won't want you either).

There currently are about 60,000 flight attendants. While Eastern Airlines has announced plans to lay off a number of attendants, most airlines are looking for qualified applicants. In cases where airlines have laid off attendants, well over half chose to return to their jobs when called back.

"Things have changed dramatically from the early days," says Joe Madison. "As late as the 1960s, female flight attendants couldn't marry and remain in their jobs. Today, 50 to 60 percent of them are married." A number of flight attendants meet and marry other flight attendants and stay in the field.

The ratio of female-male flight attendants now stands at about 85-15, unlike the mid-1940s, when most were male. The earliest PanAm flights, explains Madision, were over, and landed on -- the water.

"The flight attendants had to get out and beach the aircraft so the passengers could get out."