LOS ANGELES — Helicopters swooped low over the Sepulveda Pass the weekend of July 16 to monitor the shutdown of Interstate 405. The week before, paparazzi helicopters hovered as Prince William and his wife, the Duchess of Cambridge, settled into Hancock Park. Indeed, every day brings a steady swarm of buzzing copters crisscrossing the vast Southern California sprawl in what many officials say are greater numbers than ever before.

It has reached the point that the only thing louder than the aerial armada — which during the shutdown weekend seemed to have flown straight out of “Apocalypse Now” — are the cries for relief from the noise-stressed neighborhoods below. “It’s the wild, wild West up there, with nobody taking control,” said Richard Close, head of the Sherman Oaks Homeowners Association.

But one thing has become clear during these most recent onslaughts: there is not much anyone can do about it.

Ask the Federal Aviation Administration, city officials, the police department, beleaguered residents or the tourist pilots who are more than willing to fly low for the promise of a tip. This is, for all intents and purposes, an unregulated industry, an increasingly frustrating realization for Los Angeles as it experiences what many people say is the most intense period of helicopter use in memory. One neighborhood leader said he was afraid of complaining too loudly for fear that the helicopter operators would retaliate — legally — by parking over his house.