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MysticHuman

(219 posts)
Mon Mar 17, 2014, 06:37 PM Mar 2014

I have a question about planes "Transponders".....

Can anyone give me one good reason why transponders have an "off" switch?

As important as they are why would this be an option?

Just as the engine "ping" cannot be disengaged ... you would think airlines would make transponders continue to communicate while the plane is running.

My humble question of the day....

MH

9 replies = new reply since forum marked as read
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I have a question about planes "Transponders"..... (Original Post) MysticHuman Mar 2014 OP
yea, I had the same question. The answer is quinnox Mar 2014 #1
I asked that question yesterday. moondust Mar 2014 #2
Thanks moondust.... MysticHuman Mar 2014 #5
Probably so you can maintain the plane without bothering the tower jmowreader Mar 2014 #3
As I stated to Moondust - using a different frequency or band would MysticHuman Mar 2014 #7
It is a good question. The answer is in the other responses. longship Mar 2014 #4
As has been said in the thread, Mojo Electro Mar 2014 #6
Just open the circuit breaker Kilgore Mar 2014 #8
I am sure this could be prevented MysticHuman Mar 2014 #9
 

quinnox

(20,600 posts)
1. yea, I had the same question. The answer is
Mon Mar 17, 2014, 06:39 PM
Mar 2014

when all the planes are on the ground, then it would cause a big mess for the controllers trying to taxi the planes to take off safely.

MysticHuman

(219 posts)
5. Thanks moondust....
Mon Mar 17, 2014, 07:04 PM
Mar 2014

My only thought on it would hamper ground control is that it shouldn't be hard to put the a transponder on a different frequency thus eliminating interfering whenn it is on the ground.

I did read some are moving to overcome the interference issue which is good..but this should have been done years ago.

Thanks again

MH

jmowreader

(50,447 posts)
3. Probably so you can maintain the plane without bothering the tower
Mon Mar 17, 2014, 06:43 PM
Mar 2014

If you need to run the engines as part of a service, you've got to power up the plane but ATC doesn't need to know about it because you're not going anywhere.

MysticHuman

(219 posts)
7. As I stated to Moondust - using a different frequency or band would
Mon Mar 17, 2014, 07:08 PM
Mar 2014

solve this issue.

If you need two transponders ...one that does show up to the tower... and one that doesn't and can't be turned off ... have two then.

For me there should be no reason that a transponder transmitting on a separate channel should be possible.

Thanks for your input.

MH

Mojo Electro

(362 posts)
6. As has been said in the thread,
Mon Mar 17, 2014, 07:06 PM
Mar 2014

there are times when it is apropriate for the transponder to be off. I believe it's really only used while in flight.

It is actually just put in "standby" mode where it is not transmitting, though I believe it can be disabled by pulling the circuit breaker that supplies power to it.

Here is a picture of the transponder control panel on a 777 console, which is positioned in between the 2 pilots on the right side next to the seat, with the transponder switch shown in the "standby" position.







Kilgore

(1,733 posts)
8. Just open the circuit breaker
Mon Mar 17, 2014, 07:56 PM
Mar 2014

Not having an off switch would just mean opening the appropriate circuit breaker to kill the system.

Kilgore

MysticHuman

(219 posts)
9. I am sure this could be prevented
Tue Mar 18, 2014, 04:45 AM
Mar 2014

I am just saying there has to be a way to keep some type of communication from the plane to the ground that can't be stopped or overridden.

Mh

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