View Full Version : Probably a dumb question, but...
curiousgal
25th Jan 2002, 18:51
Hi,. .Hope someone can help - it should be an easy one for you!. .On a recent flight with United I spent most of the time listening to the ATC channel - fascinating stuff, even though I was convinced I was going to hear my pilot making a mayday call!. .Most of it was easy enough to understand, but the meanings of 2 words eluded me - 'squawk' and 'heavy' (as in "United 123 Heavy"). .Please can someone explain these in context?
Thanks lots!
Ahh-40612
25th Jan 2002, 19:29
Hi curious one.
Squawk followed by numbers or the word 'ident' is the request by ATC to the aircraft to transmit a number back to the ground which sends ATC details of identity and altitude which are then displayed on the radar screen. Ident gives a pulsing symbol to highlight an single identity on the radar.. .'Heavy', not solely for overweight US aircraft!! reminds ATC of the Wake Vortex category which may mean more spacing on arrival or departure, and also, to a lesser degree, that the rate of climb may be poor.. .Perhaps I should write a book or film!!. .Regards
Hi curiousgal,. .Just a thought...
I take it you were in the back using a scanner, not in the cockpit?. .Surprised the cabin crew didn't object if you were using a scanner. Current security climate aside, they're briefed to watch out for any electrical devices which could interfere with avionics. Admittedly a scanner by design shouldn't put out too much RF noise though.
If I've got hold of the wrong end of the stick, disregard all after "hi".
Cheers,
LXGB
The Bard of Hell's Ditch
25th Jan 2002, 19:51
LXGB, I believe United have ATC as an "entertainment" channel?
Warped Factor
25th Jan 2002, 19:53
LXGB,
United I believe make the r/t available through one of the in-flight entertainment channels.
Can be switched on/off as circumstances dictate.
WF.
curiousgal
25th Jan 2002, 19:56
Hi Ahh.... .Thanks ever so for your reply - our explanations for 'heavy' ranged from full of fuel to lots of fat people on board, so it's good to have it put right! I can now sleep easy again!
LXGB - nothing as hi-tech as a scanner! UAL transmit cockpit/ATC conversations on one of their radio channels! The films they were showing were crap, so I was looking at the radio listings, and saw this! You get to hear whatever's going on on the particular channel your crew's talking to, so I was warned well in advance of 'light chop at 290' and knew exactly when the plane in front of us was cleared for take off! It's a great idea though - kept me quiet for hours. If they could just combine it with the snazzy cameras they have on Emirates I'd never come down!
curiousgal
25th Jan 2002, 19:59
ok, so everybody else can type faster than me... <img src="smile.gif" border="0">
sf340driver
25th Jan 2002, 21:20
I'm sure that heavy title is to any aircraft that its maximum takeoff weight of 300.000 pounds,but I think that the FAA have lowered that weight a while ago to 250.000 pounds to include the Boeing B-757,Though its weired that the only 757 operators I've heard using the title heavy for their 757 is ATA,and Maxicana airline.but none of the other 757 operators like Northwest,American,united,and others.interesting.
jetfour
25th Jan 2002, 22:11
This is moving off the thread a bit, but for the information of anyone concerned, I have direct experience of a scanner seriously interfering with a marine band VHF transceiver. (c.156Mhz - Air Band 108 - 139+ Mhz) The scanner was 30-40 feet away from the other sets aerial at the time.
I have therefore resisted all temptation in the last ten years to attempt to use the scanner when flying as SLF.
I am not fully up to speed on the technicalities, but I believe it is due to the scanner 'generating' the frequencies in its PLL (phase locked loop) circuitry.
Maybe someone out there with the 'nous' could comment.
Hi again curiousgal,. .That's pretty cool letting the punters listen in. Do they switch it off before declaring an emergency <img src="smile.gif" border="0"> ?
Cheers,. .LXGB.
karrank
28th Jan 2002, 08:27
Most crew seem reluctant to declare abnormal operations (when they are of a piddling nature anyway) because anything interesting will be picked up by hundreds of plane-geeks with scanners and end up on the evening news.
If they're worried about panicking the pax as well they may never say anything....
curiousgal
28th Jan 2002, 18:35
Good afternoon LXGB - allegedly the channel was 'at the crew's discretion', but I'm not sure turning it off would be the first thing they'd think of in an emergency! It's one thing hearing about turbulence ahead, not sure I'd have been as interested in knowing an engine had failed <img src="eek.gif" border="0">