By JANICE CASTRO

R.A.F. to U.S.A.F.: Gotcha!

People in parts of Nevada and southern California have noticed the loud sonic booms and strange pulsing noises for months. Seismologists at Caltech have been picking up echoes of extremely fast overflights heading east from Los Angeles. Now Royal Air Force radar technicians at the NATO base in Machrihanish, Scotland, have identified the cause of it all. Officially, the U.S. Air Force is mum. But insiders say Lockheed has been test-flying AURORA, the top-secret hypersonic U.S. spy plane, code-named "Senior Citizen," which can fly at speeds exceeding 4,000 m.p.h. That's about 90 min. from Washington to Baghdad.

Urban Renewal, L.A.-Style

Some merchants in burned-out Los Angeles neighborhoods may not be able to rebuild, even if they have the resources. They need permits. Many Angelenos in the ravaged areas are expected to oppose permits for so-called nuisance businesses: liquor stores, pawn shops, auto-repair shops and cheap motels. Says one gang member: "We were doing some renovation to the neighborhood. There are too many liquor stores in our community."

An Idea Whose Time Has Passed

Now that the "evil empire" has collapsed, many U.S. conservatives are eager to convert the Chinese to capitalism. Their nostalgic solution: RADIO FREE CHINA. The project would cost $110 million to launch and $34 million a year to operate. Among its critics is Chinese dissident Nien Cheng, author of Life and Death in Shanghai, the diary of her harsh 6 1/2-year imprisonment during the Cultural Revolution. Cheng notes that millions of Chinese are already devoted to Voice of America. And the new service might "give hard-liners an excuse to crack down on dissidents."

Your Enemy Is My Enemy

"Former KGB agent seeks employment in similar field. Tel: Paris 1-442-506 . . ." When spies have to resort to classified ads in French newspapers, times are clearly tough. Now 500 or so former Soviet intelligence agents have decided to network. Headed by onetime KGB Colonel Igor Prelin, the group has even started its own publishing arm, called Intel. Among the projects in the works: a memoir by a KGB agent who obtained American nuclear secrets, and a book by another who had dealings with Lee Harvey Oswald prior to November 1963.

Let's Boogie

Convinced that Harvard University's 32-year-old Let's Go travel handbooks have grown a bit stodgy, students from the University of California, Berkeley, are fanning out to describe the world in their own funky Fodor's series, THE BERKELEY GUIDES. The free-wheeling new guides offer warnings about beaches that "suck" and restaurants that are "yucko." The guides are printed on recycled paper with soy-based ink. Sniffs Pete Deemer, publishing director of the Harvard series: "Theirs may be more environmentally friendly, but ours won't get thrown out as much."

Forward Spin

BABY, IT'S YOU

Tim Robbins captured Hollywood as a baby mogul in Robert Altman's The Player. Now he's skewering politics with Bob Roberts. Possible next role: CEO, the selfless keeper of the bottom line.

GET ME AMTRAK

Congressmen are fleeing Washington. Many career Capitol Hill aides are also depressed and planning to quit. Look for soft real estate values in northern Virginia.

WORD WATCH

Sam Skinner's staff planned "private time" on official trips (for private things like playing golf). Over at Clinton headquarters, frazzled aides talk about a scarcity of "face time" -- opportunities to talk to the candidate in person. Next: "ear time," those moments when the boss is actually listening.

REALITY CHECK

Rappers "sample," building songs on pieces of other people's music. But with Gilbert O'Sullivan and others suing over it, sampling is getting expensive. On their new albums, the Beastie Boys and Ice-T feature actual musical instruments. Next they'll be carrying a tune.