L.A. helicopter situation is tough: I've frequently lost sleep or been unable to work due to the noise, but obviously I would prefer safety to complete silence. I try to trust that LAPD et al aren't breaking out the helicopters to hover/circle except in significant situations. – A West L.A. resident*

 
This is part three of a series about helicopter noise in Los Angeles. Read part one on the nature of the noise, part two on the FAA and part four on the communities' response.

Cole Burdette flies over Los Angeles in one of the LAPD’s 19 omnipresent helicopters to assist in calls as serious as a shooting and as widespread as vandalism.
 
Contrary to what you might think, they don’t respond only for the most serious crimes or car chases.
 
“We keep a lot of things that seem routine from going beyond routine because of our presence,” Burdette said. “We respond to all calls, burglaries and shootings, but also vandalism.”
 
Last year, air patrols responded to 50,000 different incidents and they flew 18,400 hours - meaning there was the equivalent of two choppers in the air 24-hours a day for 365 days, according to Burdette.
 
Having the largest police aviation unit in the country allows Los Angeles to have a relatively low crime rate and fewer officers, said Burdette, who has been manning a chopper for 16 years. And L.A.’s homicide rate is about the same as New York, Boston, Phoenix and Omaha and crime rates are at lows not seen since the ‘60s.
 
In L.A. there is about 1 officer for 400 residents, compared to New York, Philadelphia and Chicago where they have about 1 officer for every 200 residents.
 
“This is because we use helicopters to augment our officers,” Burdette said. “It makes us quicker and more efficient. Helicopters reduce crime and are a force multiplier.”

Flights originate at Parker Center downtown between 8:30 a.m. and 5 a.m. covering Los Angeles’ 475 square miles. They return to base every 2.5 hours as another helicopter takes their place. 

The chief tactical flight officer either flies the smaller AStar 350 B2 or the Bell 206 Jet Ranger, which is louder and bigger. To hear Burdette tell it, you could argue the ghettobirds are omniscient as well.

INFOGRAPHIC: Click here to launch "Helicopter Noise Reduction by Altitude"

by Brian Frank

They usually fly between a little higher than the new 54-story tower at L.A. Live. The news media helicopters generally fly above 1,000 feet – about the height of the U.S. Bank Library Tower, the city’s tallest building – to avoid conflict.

“We are always conscious about noise and we try to fly higher to not bother people,” Burdette said.

The difference in sound of a helicopter flying at 500 feet and at 1,000 feet is 9 decibels – dropping from 87 to 78. That effectively cuts the noise impact in half.

The Helicopter Association International stated that to fall under the generally accepted criterion of 65 decibels, small helicopters should fly at altitudes no less than 1,000 feet. For medium helicopters, the recommended height is 2,000 feet, and, for large helicopters, 4,000 feet.

Burdette points out 300 feet is the length of a football field and adding that distance puts an incredible strain on seeing what’s going on at ground level.

“This is based on human limitations,” Burdette said. “Ultimately the city would be less safe if we were not there. It would be less safe for the officer and for the public.”

From above, helicopter pilots can see over tall fences, can use thermal imaging in the dark to find suspects, can look through stabilized binoculars to locate criminals and use GPS mapping to route officers.

“We can identify where suspects might be; we can check a yard before an officer goes into it,” Burdette said. “We can see people who might be in harm’s way and not aware of it.”

The unit started in 1956 with a single helicopter to help with traffic control on the freeways and didn’t add another chopper until 1963. But it was clear the power an eye in the sky could have. In 1968, the city purchased its first Jet Ranger, the model still used today.

So it should not be a big surprise that the LAPD didn’t see value in modernizing their fleet for sound’s sake. When the LAPD looked into modifications to reduce noise further, they found the additions were too expensive and/or affected performance, Burdette said. 

Following the Watts Riots in 1965, an LAPD study found:

• The number of property crimes is reduced when an LAPD helicopter is overhead.
• Arrests increased threefold with the involvement of LAPD aircrews.

The 1970 study, when the fleet consisted of about five helicopters, also concluded “citizens of Los Angeles accept helicopter patrols as a necessary part of the city’s police system and strongly favor their continuation.”

“We do everything we can to not alienate the community,” Burdette said. “We are here to help and support. It is part of a cost benefit analysis and helicopters are necessary to make a safe environment in a huge urban area with lots of crimes.”

Today there may not be blanket support.

Next Up, Part 4: We take a look at how communities and politicians have fared in their struggle to implement helicopter noise regulations. It's not exactly good news for residents.

We are fine with the LAPD air support doing their job above our part of Venice. We feel somewhat safer knowing that they are able to see things the ground units cannot. We have lived here for a little over five years, and in the last year the LAPD air support presence has seemed to increase rather dramatically at night. The hovering and circling overhead can sometimes last until 3:30 - 4:00am on a work night. We have had to buy a white noise machine for our bedroom to try and drown out the sound. We really do hear the helicopters at least once a night. ... The increased LAPD helicopter presence seems to be a part of a bigger problem we are having in Venice. – A Venice resident*