When a Sheriff's Helicopter is flying over your neighborhood, it is because deputies on the ground are conducting an operation, making a rescue, fighting a fire, searching for a missing person, looking for a suspect or other law enforcement activity.

There are several factors that affect the quality of public service announcements from a helicopter. Orbit, altitude, location and other noise all play a role in where and how sound waves travel. The helicopter's rotors can also disrupt the very narrow area where announcements are understandable.

Call or text "Hello" to (858) 866-HELO (4356) to receive helicopter messages straight to your phone.

This is not an automated or a push notification service. You still need to call or text "Hello" to (858) 866-HELO each time you hear Sheriff's ASTREA making announcements over your area.

If there is more than one active broadcast at any given time, you have the option to choose the message that impacts your location. Currently, this service is only available for Sheriff's Department patrol areas. To learn more about the communities we serve, visit sdsheriff.gov/patrol.

While this program is free, you might have to pay to receive text messages depending on your phone plan.

This phone line is not for reporting a crime or emergency. For emergencies, call 9-1-1. For non-emergencies, call (858) 565-5200.

If you observe suspicious activity that may be related to our law enforcement operation or see a person matching the description of the helicopter public service announcements, call 9-1-1.

You can follow the Sheriff's Department on Twitter at @SDSheriff. We do not currently staff our social media presence around the clock, so not every incident involving ASTREA results in a social media alert.

When an ASTREA law enforcement helicopter circles a location for more than a minute or two during the day or night, ASTREA is assisting deputies or police officers on the ground. Searchlights are not always used at night because helicopters are outfitted with thermal imaging systems that can detect heat in outdoor environments and aid in locating a suspect. Crew members typically utilize night vision goggles to enhance nighttime vision.

ASTREA law enforcement helicopters generally fly at a minimum altitude of 500 feet above ground level. This altitude is generally accepted as the minimum altitude needed to make a safe and emergency auto-rotational landing if a mechanical malfunction occurs. At night, for safety and noise abatement purposes, air crews are trained and encouraged to fly 1000 feet above ground level. For noise abatement purposes, ASTREA Fire/Rescue helicopters (Bell 205) fly at 1000 feet above ground level when transitioning to and from calls.

As members of the aviation community, we recognize aircraft noise is a concern to many residents within the County of San Diego. It is the goal of every ASTREA crew member to minimize aircraft noise to the communities and cities served while simultaneously balancing the region’s aerial law enforcement needs. When supporting law enforcement activities on the ground, ASTREA makes every effort to not orbit an area longer than necessary.

Countless number of helicopters can operate in and around San Diego County including helicopters owned by the military, state and federal law enforcement agencies, other fire/rescue agencies, medevac, corporate, agriculture, student pilots and power line helicopters.

You may discuss any concerns you have with an ASTREA supervisor by calling (619) 956-4930 Monday through Friday during business hours.