United's channel 9 while fling over ocean!

[Chananya Freedman]

hi guys,
my question for you today is the following!
I know that some united airline pilot's allow their passage's to listen to the ATC over the headset's provided by the air line or their own.
How does it work when a plain is going over seas?
Do  they play the hf frequencies or do they only play this when they are over land.
I am very curious about this so get back to me when you can!

THANKS,

   

[tyketto]

hi guys,
my question for you today is the following!
I know that some united airline pilot's allow their passage's to listen to the ATC over the headset's provided by the air line or their own.
How does it work when a plain is going over seas?
Do  they play the hf frequencies or do they only play this when they are over land.
I am very curious about this so get back to me when you can!

THANKS,

The way Ch. 9 works is that if they turn it on, you hear everything that the pilot hears, except if the flight attendants are saying something over the PA, or if the pilot/FO says something over the PA. The internal PA will override any of the IFE that they have. But other than that, if they leave it on the entire time they are oceanic, when they go HF, you hear what's going on on HF. That's how it was for me, KLAX-NZAA-YMML and back.

BL.

[inigo88]

When I flew with them domestically a couple of years back only COM 1 was active on CH 9, so it may be hit or miss depending on how it's set up (or how the flight crew chooses to set it up). On my flight, no communication with Ramp/Company Freq (in range etc)/ATIS other uses of the second COM radio were heard, which was too bad.   I know a lot of this can be handled via ACARS but it was definitely only one flight crew member's radio and not both.

Glad to hear your international flight had better luck Brad. But just wanted to let you know:

The way Ch. 9 works is that if they turn it on, you hear everything that the pilot hears.

This isn't always the case.

On the plus side, it was originally turned off at the beginning of the flight, and after asking the flight attendant nicely they were kind enough to turn it back on for me - so no complaints here.

Inigo

[MikeGranby]

The way Ch. 9 works is that if they turn it on, you hear everything that the pilot hears, except if the flight attendants are saying something over the PA, or if the pilot/FO says something over the PA.

Sure about that? My understanding was that Ch.9 was driven from the observer audio panel, and could thus be tuned to any combination of audio sources independant of the pilot or co-pilot's audio panel settings.

[Chananya Freedman]

From  what i know, thee second radio where they listen to the ATIS are never on Chan 9!
To reply to what the guy said above me, I've had a similar situation, where the pilot turned on the Chan for me, and then after the flight since I'm always the last one of the plan due to my disability! I had the pleasure of meeting the pilot! also on that flight my mom was looking out the window and thought she saw a land mark and asked the flight attendant if she was right! The flight attendant asked the pilot and the pilot told everybody on the flight what see saw!
Just some story's from the United Chan 9!

[bjen9337]

tap.....tap...tap..... Does this thing have spellcheck?

[tyketto]

The way Ch. 9 works is that if they turn it on, you hear everything that the pilot hears, except if the flight attendants are saying something over the PA, or if the pilot/FO says something over the PA.

Sure about that? My understanding was that Ch.9 was driven from the observer audio panel, and could thus be tuned to any combination of audio sources independant of the pilot or co-pilot's audio panel settings.

Yep. positive about that. Ch. 9 has nothing to do with the passenger being able to change the channel at their leisure. When you switch to Ch. 9, you hear what is coming from the flight deck. If you switch to Ch. 8, you get classical music (an example). Passengers can change the channel on their seat to anything they want. Ch. 9 lets you hear what the Captain/FO hears.

BL.

[phil-s]

Just to be clear (and this was said already), Ch 9 gets you exactly what the flight deck hears but only if they want you to hear it. They can perfectly well flick a switch and you hear elevator muzak. But can someone tell me how this actually works in the cockpit?  Do they switch Ch 9 to a specific radio? so that if they wanted you could listen to their company ops channel instead of ATC? I've been on quite a few transcon flights where the folks up front piped in a ball game (e.g World Series or NCAA finals) via commercial radio stations. As we got out of range of one they'd prowl the dial until they found another.  Don't recall if that came through on ch 9 though.  So can they just select any of their various radios?

[Chananya Freedman]

Cool! I didn't know that that could happen! I want to know more!

[joeyb747]

Channel 9 is linked to Comm Radio 1, witch means you hear what Comm Radio 1 is tuned to. If Comm Radio 1 is tuned to Ground, you will hear Ground. If it is tuned to Tower, you will hear that...etc....

You will not hear what Comm Radio 2 is tuned to. 90% of the time, Comm 1 is tuned to Ground/Tower/Center. Comm 2 is usually where ATIS is checked, and Clearance Delivery is received.

[inigo88]

Yep. positive about that. Ch. 9 has nothing to do with the passenger being able to change the channel at their leisure.

No you are not positive about that! The "Observer's Audio Panel" is the 3rd Audio Panel for the 3rd VHF COMM radio on many aircraft located in the flight deck. On many aircraft it's located aft of the overhead panel on the ceiling - but in the Boeing 747 it's located on the center pedestal with the other two VHF COMM radios. See this photo:

http://www.airliners.net/photo/Air-France/Boeing-747-428/0765937/L/

The "Observer's Audio Panel" is the audio panel located in the left partition of the pedestal, below the top left VHF COMM radio (Captain's Radio control panel aka "COMM 1"), Audio Panel ("Captain's Audio Panel"), and the second VHF COMM radio ("Observer's Radio control panel" - some might call this "COMM 3" - with F/O radio being "COMM 2" although this is not technically correct by the Boeing vocabulary).

I assume the Observer's VHF COMM radio and corresponding Audio Panel get their name for the same reason Jump Seats originally exist - to accommodate a Check Airman / Pilot Examiner performing or "observing" a competency check (forgive my vagueness here as I'm not up on the Part 121 equivalent vocabulary for "check ride").

See the awesome B747 flight deck simulation here:
http://meriweather.com/747/fd-747.html
Go to the Pedestal, and mouse over it to observe its title "OBS Audio Panel."

The use of the Observer's Audio Panel to control CH9 function is really quite brilliant, and something I've long suspected and appreciate the confirmation of (either using it, or one of the audio panels sometimes hidden in the rear flight deck areas on maintenance panels adjacent to the jump seats). All the audio panels are exact copies of each other, and the 3rd one is rarely going to be in use outside of checkride/MX conditions. Notice how instead of labeling the VHF radios "1,2,3" Boeing labels them "VHF Left, Center, Right." (I'm assuming the 3rd Observer VHF radio is 'Center' - and I imagine its often used in "ACARS" mode to maintain the ACARS data link.)

The reason then that you often only hear the "COMM 1" (Captain's VHF Left radio) on CH 9 is because if the CH9 system is slaved to the Observer's Audio panel - to turn on the channel 9 functionality, they simply push the VHF L volume knob down (to turn receive on, which turns it green) and set the volume, and be done with it. Bear with the flight crew - their primary duty is to FLY THE AIRPLANE and I appreciate them taking the time to even go this far to let us hear the primary VHF radio.

The fact that you guys have heard HF on CH9 on international flights is outstanding, because that means one of the crew members took the time to push HF L to "on" on this third audio panel! Also, the baseball game anecdote is hilarious, because it may have been unintentional on their part. I've often heard stories of bored pilots using the ADF to tune in AM radio stations and listen to them by selecting the ADF on the Audio Panel (a feature intended to let you listen to and identify the morse code station identifier!). I think your pilots in this case were using the Left VHF radio (COMM 1) for ATC, Right VHF radio (COMM 2) for ATIS/Company Freq, Center VHF radio (COMM 3 / Observer's) for ACARS or not in use (with receive unselected), tuning in local AM radio stations on the ADF looking for the baseball game, and then interfacing it into the intercom system using the Observer's Audio panel and either forgetting or not caring that it was commanding the Channel 9 system!  (Along the same lines, don't forget about "FINGERS" on 123.45 MHz which serves a similar purpose.)

I hope that clears up the confusion - and thanks Mike for confirming my longtime suspicion about the system.

Inigo

Final EDIT: Note the placard on the throttle quadrant in this photo:

http://www.airliners.net/photo/Aerolineas-Argentinas/Boeing-747-475/0504248/L/

"DO NOT USE VHF-C FOR ATC COMM WITH ACARS OPERATIONAL." This confirms my assumptions both on the naming "Observer's Radio = VHF C", and the fact that VHF-C is primarily connected to the ACARS system. If attempting to use it with ACARS operational, the aircraft's ACARS would transmit the "chirp"-like data link sounds over an ATC frequency. Uh oh! 

[SkyViking]

On all my UAL flights, so far Ch 9 was on.  It seems they do not broadcast their ramp freq.   At ORD while at the gate waiting for the push, you can hear metering but you know they are communicating with their ramp controller on the other comm. until ramp hands them off to ground/metering.

If I see the crew after landing, I always mention a thanks for having 9 on.  I actually plan my travel, if possible around UA's mainline aircraft that offer Ch9.

[tyketto]

Yep. positive about that. Ch. 9 has nothing to do with the passenger being able to change the channel at their leisure.

No you are not positive about that! The "Observer's Audio Panel" is the 3rd Audio Panel for the 3rd VHF COMM radio on many aircraft located in the flight deck. On many aircraft it's located aft of the overhead panel on the ceiling - but in the Boeing 747 it's located on the center pedestal with the other two VHF COMM radios. See this photo:

Inigo, my point is that even if Ch. 9 is enabled, a passenger can easily change the channel at their seat to something else, and Ch. 9 would still be available to other passengers. So yes, a passenger can change their channel at their leisure, while Ch. 9 would still be available to others.

BL.

[inigo88]

Misunderstood. Yes - I concur that the passenger has no control over what is heard on CH 9 - it is controlled by the "observer's audio panel" on the flight deck. My understanding reading this thread was that the "observer's audio panel" was being misunderstood as "the little in flight entertainment channel buttons" on each passenger's arm rest. This is not the case, they are two different things.

Inigo