Author Topic: Transponders  (Read 54145 times)

Offline Charlotte, NC

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Re: Transponders
« Reply #25 on: February 06, 2012, 07:12:47 PM »
It is used in the process of one of the secondary ways to radar identify an aircraft.  Also, when ATC deems that the secondary is not necessary upon the aircraft getting within 15 nm from destination airport, they may instruct to turn off the transponder.  Also during certain phenomena such as ring around, ATC may instruct the pilot to turn off the transponder to reduce ring around or if there is a high population of actual targets (aircraft) to reduce scope clutter.

100% WRONG, in 30 years ive never ask to have a TXP turned off because i didnt think i needed the secondary target.do you even know what happens to an ARTS/STARS data block when the TXP is turned off ?...IT DROPS OFF AFTER 3 SWEEPS WITH WITH OUT A TXP SIGINAL


You've never flown to Oshkosh or Sun N' Fun, Have you?

Offline ogogog

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Re: Transponders
« Reply #26 on: February 07, 2012, 08:17:42 AM »
Oshkosh and Sun N Fun ARE NOT NORMAL OPERATIONs with special procedures , and what dose it matter if ive ever flown there that has to do with this?

Offline StuSEL

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Re: Transponders
« Reply #27 on: February 09, 2012, 12:48:08 AM »
Oshkosh and Sun N Fun ARE NOT NORMAL OPERATIONs with special procedures , and what dose it matter if ive ever flown there that has to do with this?
There's no need to shout over this...

The statement posed from eltors0 was "Also, when ATC deems that the secondary is not necessary upon the aircraft getting within 15 nm from destination airport, they may instruct to turn off the transponder," to which you responded "100% WRONG..."

Eastman is pointing to a specific example to cite the statement you said was "100% wrong."

Where do you control?

Offline eltors0

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Re: Transponders
« Reply #28 on: February 09, 2012, 03:57:37 PM »
I am pretty sure he gets it now that it has been explained.  No need to beat a dead horse.

Offline MikeNYC

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Re: Transponders
« Reply #29 on: February 12, 2012, 06:28:35 PM »
I was recently listening to ISP Tower feed, and they were telling 2 a/c that were doing Touch n Gos in the pattern to Squawk Standby.

I had that happen to me at ISP several years ago when training. I was told to squawk Standby while in the pattern.

Offline MikeNYC

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Re: Transponders
« Reply #30 on: February 12, 2012, 06:31:46 PM »
...allowing the radar system to include the altitude information next to the aircraft's target, as well as receive the transponder code and include some flight plan data next to the altitude information. When a transponder is turned off or not equipped on an aircraft (some GA aircraft do not have transponders), ATC can still pick up the aircraft on primary radar. While a primary radar target does not have the altitude or flight plan information next to it...

The transponder does not provide any flight plan data, at all.  The only thing it broadcasts to the radar system is a 4-digit beacon code, and an altitude.  Radar automation systems do the rest.

Terminal or Enroute automation systems manage the flight plan data via the NAS HOST computer system, and parts of that data are presented on the radar system for the controller to access.  It is true, the radar system cannot display altitude information for a primary target, or one for non-mode C equipped aircraft either.  But the datablock will still have exactly the same flight plan information displayed as a transponder-equipped aircraft would because flight plan data is independent of an aircraft's transponder.

And by the way, a primary-only, or non-mode C track in the enroute environment can still display a controller-entered altitude in the datablock despite the equipment limitations.

A Mode S transponder broadcasts more than a 4-digit beacon code and an altitude. It also broadcasts a unique hex code that can be correlated to the aircraft's N-Number in the FAA database, and is also able to broadcast an 8 character "Flight ID" which can be the N-Number or aircraft callsign, or other string manually entered.

Offline Twocky61

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Re: Transponders
« Reply #31 on: February 13, 2012, 04:52:45 AM »
Thanks MikeNYC