In Los Angeles they are running out of billboard space so they put ads in the sky. You can be lying near a swimming pool and look up to see that "So-and-so stops sunburn pain" in puffs of letters of fluffy white spurted out by an airplane. A current movie about killer bees is being hawked there in the same way.

Space is time in television, and since the networks now tend to run out of commercial time no matter how humdrum the prime-time schedules may be, ways are being found to expand it surreptitiously. The TV industry is breaking its own rules about limiting the amount of commercial time on programs in order to make greater profits than ever.

For television reviewers, there is no such freedom as freedom from advertising. Even so-called public TV is peppered with plugs for the underwriters of programs. Lest anyone think the underwriting is a purely philanthropic gesture, Time-Life Television, distributors of "Civilisation," "The Ascent of Man" and other British TV imports, pitches them to potential underwriters with the come-on, "What Can Our Programs Do for YOUR Corporation?"

Commercial television is, of course, maintained through commercial advertising, but now old restrictions on the amount of advertising stations can inflict on viewers are crumbling in the scramble to increase profits year after year.

The airwaves are as polluted as the air.

In February, reporter Larry Michie looked into the expansino of commercial time for Variety. He and his wife looked into the expansion of commer-stop watch to find out if TV industry self-regulation on ad time was being violated.

About two-thirds of the TV stations in the United States are members of the National Association of Broadcasters (NAB), which has rules, enforced only gingerly, about the amount of "nonprogram material" that can be aired during certain broadcast hours. The FCC does not directly restrict the number of commercials a station can air or their frequency, and stations that do not belong to the voluntary NAB, like Channel 20 (WDCA) in Washington, can saturate programs with virtually as many commercials as they can sell (though they may have to answer for themselves at license renewal time every three years).

Michie found that the networks were squeezing out additional ad dollars with their nightly "newsbreak" features, which contain 10-second ads that the networks do not count against their self-imposed limit of six commercial minutes per hour. Over the course of a year those "newsbreaks" earn the networks an estimated $30 million, Michie reported.

CBS started the news update features but it wasn't the news department that came up with the idea. It was the sales department. The news department had to comply.

As Laurence Bergreen reported later in TV Guide, the networks have found other ways to find more time to sell to sponsors. It was decided that since movies were costly programming, the maximum number of commercial minutes per hour could be pushed up from six to seven. This policy was subsequently extended to include made-for-TV movies and miniseries and now anything that runs over an hour, especially ad-packed sports events.

A single two-hour show can be considerably more profitable to a network than two one-hour shows - garnering an additional $200,000 per program, according to Bergreen.

But the latest and most conclusive data on the expansion of commercial time comes from a study undertaken by Westinghouse Broadcasting Co., which owns five television and nine radio stations. Westinghouse studied the commercial time on network TV during the '77-'78 TV season to see how often the networks exceed their own proclaimed limits.

The percentage of half-hours in which the networks went beyond three commercial minutes went up from 24.5 percent in '76-'77 to 34.7 percent last season, the study found. Not only is there more commercial time, there are also more commercials, because the 30-second spot has become far more popular than - and has almost made obsolete - the 60-second spot. The number of 30-second spots on the networks increased from 1,118 in '75-'76, the study found, to 1.583 this year.

That increase and the additional commercial time meant added revenue for the networks of $20 million over a mere eight-month period, the study estimates.

Local stations do not share directly in this additional network revenue. So, naturally, local stations around the country are up in arms over the increases - they're the ones who hear from angry viewers - and over the so-called "clutter" that results when 30-second commercials and network promos start tumbling out at viewers in not-such-gay profusion.

To calm this uproar and head off protests at the pass, NBC TV President Robert E. Mulholland announced grandly to the network's gathered affiliates at their June convention that starting in the fall, NBC "unilaterally will reduce the network promotion time 45 seconds in the period preceding the 11 p.m. newscasts." And NBC is sponsored a resolution at the NAB that would reduce the allowable level of "nonprogram material" in prime time to nine minutes per hour, as opposed to the current 9 minutes and 30 seconds, he said. That means 51 minutes of actual program per hour.

Ancil H. Payne, multistation owner and chairman of the NBC TV affiliates board, had led complaints at the network about clutter and has carried the so-called "51/9" Mulholland proposal to the affiliate boards at the other networks. So far the response has been either a turn-down (from CBS) or a shrug (from ABC).

The matter will not come up at the NAB until late August and cannot be acted upon until the TV Code Board of the NAB neets in October and NAB spokesman said yesterday.

Meanwhile, the battle over clutter and excessive commercialization is not simply a matter of the good-guy local stations versus the big and black-hatted networks. One way the networks get local stations to accept the idea of more network commercial time is to give them the opportunity for more local commercial time.

In this business money doesn't talk. It screams.

And so NBC has recently joined the other two networks in giving stations time for a 40-second news update of their own in prime time each and every night. To call this interruption of programming "news" is to stretch the term to the snapping point. The news updates are nothing more than a chance for stations to plug their profitable 11 p.m. newscasts and "tease" viewers with incomplete news items and prevocative headlines.

They are news promos - nothing more. You will always bear the so-called newscaster implore you to "join us at 11" or promise that there will be "more" information on the newcast itself. At this point what TV passes off as journalism becomes unadulterated salesmanship, and, to top it off, the news updates contain enough time for a 10-second commercial and a sponsor I.D. (identification).

When networks and stations give more and more time over to commercials, promos and so-called news, the time has to come out of only one possible source: the program.

Thus it was that during Sunday night's one-hour telecast of a "How the West Was Won" rerun on ABC, nearly a quarter of the hour - 13 minutes and 20 seconds, to be exact - was given over to something other than the actual program and its story.

There was 6 minutes and 40 seconds of commercial time on the program, including local spots inserted during so-called station breaks. Another 2 minutes and 40 seconds was taken up with promos for ABC programs, including two ads for the revamped ABC "World News Tonight" program within the same hour.

The opening and closing credits took up 3 minutes and 15 seconds, and a 40-second ABC "Newsbrief," which included a 10-second beer commercial and an identification of the beer company, ate further into the hour.

As one neared the hour's end, the clutter became especially fast and infuriating. The fifth and final act of the program was followed by two 30-second commercials, a one-minute promo for the next episode of the show, the closing credits - during which a "voice-over" announcer recited promos for no less than five different ABC shows, four of them airing on Tuesday - the "Newsbrief" with its built-in 10-second spot and a 15-second promo for the network's "20/20" magazine show.

And then it was time for the local station to put on a few more commercials and program plugs.

Things are even worse when you venture out of prime time. On Monday night, the CBS "Late Movie" managed to turn a 91 minute MGM clinker called "These Wilder years" into a two-hour program; the amount of commercial and promotional time increased its original length by a third.

During two of the breaks in the movie there were nine consecutive messages - commercials, promos or public service announcements (PSAs) - in succession, like this: four 30-second commercials, one 30-second network promo, another 30-second commerical, two-30-second PSAs from the local station and a 30-second local station promo.

Since the NAB rule only stipulates how much "nonprogram" material can be aired in an hour - not, specifically, how many commercials - a program's opening and closing credits are included in the allowable time. That is why the networks fade out the closing theme music of every program on the air for an announcer's breathless ballyhoo of upcoming shows. The networks feel this is dead time anyway, so they might as well make it pay.

Indeed, it begins to seem that all the networks care about is time that pays, and that time that entertains, informs or merely diverts viewers is becoming more and more endangered. The growing amount of commercial time the networks and stations permit themselves makes further encroachments on the poor old shows themselves, and there is no clear sign the industry is anxious to do something about it.

As cable TV continues to make inroads into the American consciousness, more and more viewers who become fed up with the population explosion of commercials will discover there is an alternative - paying for shows directly out of their pockets. Networks and stations may find they hve precipitated their own crisis.

As Westinghouse president, and arch clutter-foe. Donald McGannon told TV Guide, "I don't know what the divine number for commercials is, but I think we're killing the goose that laid the golden egg."