When new jetliners ordered recently by just about every major airline start taking to the skies in the early 1980s, they'll look very much like the planes flying today. But inside, there may be some changes due to the efforts of a new (and growing) segment of the travel market - the handicapped.

The big three manufacturers of commercial aircraft - Boeing, Lockheed and McDonnell-Douglas - have set up a committee to work on design of new planes that will remove barriers and make air travel more accessible to the handicapped. And the airlines, which said they couldn't have afforded the changes individually, are all for the modifications.

The push originated through a voluntary agency called Rehabilitation International USA, a nonprofit, nongovernment agency dedicated to providing services to disabled people throughout the world.

It's a heavyweight. It has the emotional, financial and active executive participation of the country's top industrial giants, including F W. Woolworths, Serox, Insurance Company of North America and Gulf Oil. It also works hand-in-hand with such organizations as the American Cancer Society, the American Foundation for the Blind, the Muscular Dystrophy Association, National Easter Seal Society and United Cerebral Palsy Association.

That the nation's estimated 35 million disabled (that figure includes more that those confined to wheelchairs or with other mobility problems) will be getting a fairer shake is not only in the cards, but already in effect in many cases. The change has come about as a result of orders issued by the U.S. Department of Health, Ducation and Welfare to stop discrimination against the handicapped. The rules have spurred a wide range of projects in transportation and building. And more recently, President Carter signed a bill to expand government services for the handicapped. The bill established a new Insititute of Handicapped Research which consolidates all the federal agencies.

Though aid for the handicapped traveler may be in the works, it is still slow going. A U.S. Department of Transportation survey of urban areas shows that handicapped people are affected by inadequate transportation. This means that one of every eight households in urban areas have transportation-handicapped persons over the age of 5. Of this group, 26 percent are those who use mechanical aids such as wheelchairs.

Internationally known violinst Itzhak Periman, whose concert appearances make domestic and international travel a necessary part of his life, is honorary chairman of the group's "access to the skies" program. Periman, 33, an Israeli was stricken by polio when he was 4 years old. He notes that some public transportation systems have begun making changes to facilitate travel for the disabled. Many railroads, for example, now have elevated platforms that are level with the train's floor. In the San Francisco Bay area, the rapid transit system is completely accessible to wheel-chairs.

Amtrak's new "Amfleet" cars and Rohr turboliners are equipped to serve handicapped travelers on most of the short-medium trips. The superliners, with specially designed sleeping accommodations and coach seats, serve the wester long-distance routes. Over 60 major rail stations have been built or renovated in recent years to provide barrier-free access.

Rehabilitation International USA said that on the national, state and local levels, there is growing awareness of the disable. The U.S. National Park Service had developed an extensive "national park guide for the handicapped." The service is now working to build new facilities that easily accommodate the handicapped, and to remove existing obstructions. "Access National Parks: A Guide for Handicapped Vistors" is available for $3.50 from: Superintendent of Documents, U.S. Printing Office, Washington, D.C. 20402.

According to the group, many states and cities have developed excellent access guidebooks that detail buildings from banks and hotels to churches and various recreational facilities.

These and other publications for the handicapped are included in the 1978-79 "International Directory of Access Guides," which is available free by writing to Dept. JL, Rehabilitation International USA, 20 West 40th St., New York, N.Y. 10018. The directory also lists access guides for many foreign cities in Australia, Belguim, Canada, Denmark, France, Germany, Ireland, the Netherlands, Norway, Spain, Sweden, Switzerland, England and Scotland