Channel 9 is the channel (obviously) on the plane's inflight entertainment system that broadcasts the plane's radio communication with Air Traffic Control. You can list to the ATC centers across the country as they tell your pilots what to do and where to go. You listen in as your pilots talk back to ATC. And you can listen to all the ATC communications with other planes in your area and on your frequency.
It's in the arcane language of ATC-Pilot speak, but after a little while you can figure out most of what they're saying.
I'm amazed at how fast the flight seems when I zone out listening to the hypnotic rhythms of flight levels, turbulance warnings, directions, and assorted heading requests.
Seven years ago this morning, Channel 9 users had a different experience. I wasn't flying that day, but Putt4Eagle was on a flight from Chicago to Phoenix. A few years ago, in a chilling post on Flyertalk.Com, he recounted his experience listening to Channel 9 as the FAA shut down all US air travel for the first time in history.
On 9/11, I was listening to Ch. 9. I was on a flight out of ORD to AZ (757) seated in 5F. We had just taken off and where climbing to cruise. A flight out of Rockford, IL was squeezing between us and the UA in front of us. I watched as he lined up to get on the highway westbound. Then, abruptly, the Rockford flight called ATC and requested immediate clearance to return to home. ATC responded with some quick direction and asked if they were experiencing trouble. No, just directed to return home by company pronto. Hmmm, strange I thought.I don't know Putt4Eagle, but this post stayed with me from the first time read it.
Then the UA in front of us requested emergency clearance back to ORD. Loooong pause from ATC. Now, this is Chicago Center air space. There are no pauses. Certainly not 30-40 seconds of dead air. Hmm, man that is weird, I thought. Then like a starters pistol went off, the comm light up. Another plane req. clearance, then another, another.... boom, boom, boom. Nothing from ATC. I nudged the guy next to me and said put on Ch. 9. He could see by the expression on my face, I was serious.
ATC got on the air and started by saying this was going to go quick and pilots needed to listen up. "Protocol responses are not required, just do exactly as I say quickly". Then it began. "UA ###, turn right heading blah, blah expect Springfield airport. SWA ###, turn left heading blah, blah expect Rockford. Delta ###...." This went on for about 3 solid minutes before I rang the bell for the FA who was passing out breakfast. Our number had not yet been called. The FA came by and I said "We are all going back to O'Hare, they are landing every plane in the sky. What is going on?!?" She looked at me in disbelief and kind of leaned down to look out the window. I could see that she was about to start to tell me not to worry about it when we pitched right at about 45*s. It was so quick it nearly dumped the FA in my lap.
My Mother was in lower Manhattan that morning. Her story is here.