Originally Posted by hermanr
Sorry about that, I'm talking about the DFW area.
For CareFlite in the DFW Metro area, you'll hear the initial alert on this LTR Passport system: Teletouch (Dallas-Fort Worth Passport) Trunking System, Dallas-Fort Worth Area, Texas - Scanner Frequencies
While this is a system type no scanner can trunk track, it will show up to import in Win500 to import (I just checked). But your scanner can't track it. However, it's relatively easy to monitor, if you just enter the frequencies & listen to it conventionally. The system is lightly used. Most of the traffic I hear is CareFlite, either the helicopters or their ground ambulance division. You will occasionally hear some of the tank trucks hauling salt water waste from the gas wells in the Barnett Shale areas. I hear more of that the farther west I go.
Initial alert for the crews is on the Passport system
(same as linked above). This includes the ones based in Dallas, Fort Worth, Denton, Frisco, and Granbury. They could get a 'ground standby', where one of the outlying agencies has asked that a copter be available if needed for an accident of some type, an "airborne standby", where the crew goes ahead and lifts off, even though it's not yet a confirmed request for response, or they may go straight to a "scene response". The crew then launches as soon as possible and heads to the requested location.
Once they get the "go", the dispatcher will give the crews the heading from the launch location (whichever base), along with an approximate distance. Also passed during this time is usually the scene contact information- agency, radio frequency or talkgroup- that n5ims is referring to, along with any notes provided (so far) by the requesting agency as to landing zone, obstructions, anything the pilot needs to know, and usually the nature of the call. Motor vehicle accident, heart attack, electrocution, something to give the medical personnel on the bird an idea what to expect.
Once airborne, you'll hear the response up to final approach at the scene on what they call "Cern", or "Cern Tower". That's a repeater tower just south of the Dallas County line, in northern Ellis County between Cedar Hill & Midlothian. The frequency used, 464.100MHZ, 123.0 PL, has a strong signal, and can be heard for a wide radius around the metro area. Usually, other than when at scene, you'll hear the CareFlite units talking to Dispatch on Cern, with flight status (fuel, souls on board, eta's, whatever). Occasionally, they will use their AirInc frequencies: 131.450 on the east side of the metro, 131.675 on the west, for the flight following communications. You may hear medevacs from elsewhere in North Texas check in on 131.450 or 131.675, if they are bringing in a patient to one of the Dallas/Fort Worth hospitals. This helps to keep everybody on the same page as to which helipads are in use by who, at various hospitals.
For other Texas medevac frequencies, see the database