It's just local. Fox 4 and KTVT have shared a chopper for years. 4 and 5 shared a chopper before that. It's interesting to note that things started to change after the 2007 Phoenix TV disaster. Until 2008, Fox 4 had two helicopters. One was Sky 4 for news. The other was a traffic helicopter operated by Metro, but staffed with a Fox 4 personality. After the Phoenix disaster and Fox 4's traffic helicopter making a hard landing in a field in 2007, it only took about a year and the economic mess of 2008 for Fox 4 to get out of the traffic helicopter deal and put their traffic guy in the studio. It has gotten a lot more expensive to run these helicopters and TV news departments are not exactly awash in cash to afford that anymore. Sharing with one or two other stations seems to be the wave of the future.
I also think you'll start seeing stations use drones for some footage they used to get with a helicopter. Channel 8 already has one and I think at least two of the other stations here are getting them.