Blame the early '90s: one of the most widely-recognized (and definitely loudest) symbols of Los Angeles is the circling police helicopter, aka the Ghetto Bird. KPCC tried to figure out if they actually do anything besides make LA feel vaguely like a police state at times (they also rode along on an illuminating chopper patrol) and the answers on that are pretty inconclusive, but on the way they did pull back the curtain on LA's most annoying icon (you know, besides Kim Kardashian):

-- The LAPD has the US's biggest police helicopter fleet--17 choppers, which mostly take off and land at the LAPD's helipad "just west of the Los Angeles River." This is the Hooper Heliport on top of the Piper Technical Center.

-- "Every day, there are at least two helicopters patrolling the sky in approximately two-hour shifts from 8:30 a.m. until 4:30 a.m. They're looking for criminals, flying over crime hot spots, checking on infrastructure, and providing back-up for ground officers."

-- The entire fleet logs about 18,000 flight hours a year.

-- "[I]t's rare for a helicopter crew to observe a crime from the air. Most chopper activity involves providing backup and monitoring crime scenes. And many patrols are uneventful."

-- While circling in search of a man with a gun on the KPCC ridealong, "[t]he chopper is about four to five hundred feet above ground."

-- In 2012, LAPD helicopters helped set up more than 1,500 perimeters, "when a helicopter positions ground officers to surround a crime scene."

-- Choppers made it to the scene first 16,000 times last year.

-- They served as backup more than 4,000 times.

-- In 2011, the year with the most recent stats, helicopters "'assisted' [i.e., provided ground officers with info] in one out of seven felony arrests."

-- The same year, they "recovered 51 stolen vehicles [and] helped ground units recover another 847 stolen vehicles," accounting for a total of six percent of 2011's recovered vehicles.

-- The only research that exists on the program is a JPL study from the late 1960s. It found that there were helicopters had reduced property crimes around USC and in the western Valley.

-- The fleet costs about $20 million a year.

-- "[P]olice officials say one of the helicopters' key assets is the hardest to measure: their deterrent effect."

· How effective are police helicopters at fighting crime? [SCPR]

· What's it like to fly on an LAPD helicopter patrol? [SCPR]