'Pay phones' in jetliners may lie just over horizon

Ever have the urge to keep in touch with your office or friends while flying along at 33,000 feet? If you do -- and if enough other airline passengers have a similar yen -- the day may come when radiotelephones are standard equipment in jet cabins.

Eric Ohrvall of Aeronautical Raio Inc., the company that provides communications services to the entire airline industry, estimates that some airlines may offer that airborne fringe benefit within the next two or three years.

How quickly the new service is offered depends on whether the added expense is affordable in this competitive age of deregulation and on just how much passengers really want it. And new technology must be developed to handle the expected number and length of calls that passengers would want to make.

Industry analysts suggest that the rush to make calls would most likely occur when planes are assigned a holding pattern over an airport. The potential volume of annual passenger calls from the air could reach 100 million a year by their estimates.

At present the Federal Communications Commission has assigned only 12 frequencies out of several hundred for thirty-party, air-to-ground communication. The congestion on these radiotelephone channels, which are operated by 75 independent radio stations, is already heavy.

The same frequency spectrum is used to suppoer mobile land phones, a privilege for which some 50,000 Americans are said to be waiting in line. One businessman who wanted to install a phone in his mobile home was recently told he would have to wait at least two years.

"You couln't use existing frequencies [for commercial plane phone service] -- you'd have to have several hundred more set aside for just that purpose," Mr. Ohrvall observes.

A companion problem that would have to be resolved is the limited radius of each radio station's "territory." As things stand, the average passenger flying along at 500 or 600 miles per hour would lose contact with one radio station after a conversation of about six minutes and would have to replace the call for a longer chat. A more efficient system, possibly involving the passing of the call from one station to another, is needed.

Most corporate jets already have radio telephones. But Ohrvall stresses that the number of passengers using them is far fewer than it would be on a commercial jet and that today's airborne callers have learned to cope with the existing system's limits, keeping calls short and few.

United Airlines this month finishes a five-month experiment with a cabin radiotelephone in a DC-10 which also relied on the limits of the existing system. The charge was the regular three-minute long-distance rate plus a $10 -a-call surcharge. A United spokesman says the airline will evaluate the results of the test but has no immediate plans to forge ahead with widespread passenger telephone service.

A number of other airlines are looking seriously at the whole radiotelephone concept. They would probably install them initially -- if at all -- on wide-bodies jets. But the ultimate question remains as to just how many passengers really want to stay in touch with the ground during a flight. Many passengers may prefer to savor the hours in the air for naps, homework, or chats with seatmates.

"The technical problems are not insurmountable -- it's basically a matter of airline and passenger interest." Ohrvall says.