Spurred by a soaring number of complaints about shoddy airline service, lost luggage and flight delays, a new consumer group yesterday launched a national campaign to lobby Congress for improvements in air travel.

"People are getting like the character in the 'Network' movie," said Sam Coats, former head of the now-defunct Muse Air and a board member of the newly formed Airline Passengers of America. "They're mad as hell, and they're not going to take it anymore."

The group, described as the aviation equivalent of the American Automobile Association, promises to maintain -- for an annual membership fee of $48 -- a 24-hour hotline for travelers needing substitute flight information after they have missed connections or had flights canceled.

It also plans to publish a newsletter with airline ticket-shopping tips and pressure Congress and the Reagan administration to improve air travel.

"We were created out of sheer necessity because today's air traffic system is such a mess," said J.J. Corbett, general counsel to the group and former vice president of the Airport Operators Council International. "Airport terminals are filled with angry passengers who believe the system's performance is a disgrace."

Between last October and June 30, the Federal Aviation Administration counted 300,000 flight delays of 15 minutes or more. Complaints received by the Transportation Department skyrocketed last month to almost six times the number received last June.

Corbett said the group was organized because the air traffic control system has been pushed to the limit, because airlines no longer provide dependable service and because neither the government nor the airlines is protecting the rights of the 50 million passengers who fly every year.

The group will press the FAA to set up a call-in air traffic advisory line so travelers can locate delays on a daily basis. It also will push Congress to require airlines to provide more accurate information about flight schedules, delays and cancellations.

The group published an Airline Passengers' Bill of Rights and a list of 10 hints for avoiding airline delays, such as: "Never book the last flight of the day to your destination" and "Use carry-on size luggage."

The consumer group was formed as the nation's aviation industry opened a campaign to improve its tarnished image and prod Congress to upgrade the air traffic system. Since spring, the industry has faced constant publicity about deteriorating service, flight delays and safety concerns.

Six lobbying groups, from major airlines to general aviation pilots, began meeting this week with congressional leaders and FAA officials. The industry group was organized by J. Lynn Helms, a private consultant and former FAA chief.

The groups are pushing, more forcefully now, for a longstanding list of proposed changes: more federal spending on airport and air traffic control improvements, state-of-the-art instruments to detect hazardous weather, and research on equipment to help planes avoid collisions.

The new consumer group and the industry coalition say their primary goal is to persuade the administration to spend an almost $6 billion surplus in the aviation trust fund, which is financed in part by an 8 percent tax on passenger tickets.

Meanwhile, the House Public Works and Transportation aviation subcomittee yesterday approved a bill that would require the government and airlines to disclose on-time performance records.

The bill also would require airlines to disclose how much baggage is lost or damaged on a flight and how often flights are canceled or connections missed. A similar bill is under consideration in the Senate.