Streamlining the handling of air traffic without expanding airport facilities could lead to a backup of planes in the air and on the ground waiting for runway space.
So say a growing number of those otherwise in favor of a modernization plan being put forward by the Federal Aviation Administration (FAA). The plan ignores airport development, they say, and would divert funds from badly needed expansion and improvement of airports.
''The lack of attention to the need for more airport capacity is the weakest point in the plan,'' says Air Line Pilots Association spokesman John Mazor.
''It's the availability of concrete (runways) that really limits growth -- planes have to land somewhere,'' agrees Larry Jenney, who has been reviewing the FAA plan for the congressional Office of Technology Assessment.
Even FAA administrator J. Lynn Helms concurs that the lack of runway capability is the strongest limit on future aviation growth. But he talks of such options as setting quotas on and controlling the flow of plane traffic into airports.
By far the loudest critic of the FAA plan is the Airport Operators Council International, an organization representing most of the cities and other governing bodies that own and manage US airports.
Traditional sources of funding for airports have become less reliable in recent years. The Airport and Airway Trust Fund, fed by passenger, fuel, and cargo ticket taxes, was originally set up to support airport development. But Congress hit a stalemate two years ago on the future direction and scope of airport development funds. Most of the aviation tax increase the Reagan administration now proposes would support the FAA modernization plan, not airport improvement. Airports in fiscal 1983 would receive only $450 million, or about two-thirds of their traditional allotment.
The Reagan administration has also talked of dropping about 70 of the largest airports from the trust fund altogether on the theory these large operations are able to generate their own revenue more easily. The airport operators group endorses that proposal on the grounds that the trust fund is no longer big enough to support all the airports. But it also wants Congress to lift the current prohibition against setting a local tax on airline tickets.
The airline industry, however, is vehemently opposed to the idea of allowing local ticket taxes.
''That's where the carriers and the operators part company,'' says Air Transport Association spokesman William Osmun. He says the airline industry favors keeping all airports in the federal funding system and increasing support.