Transponder on A320

[onedaymaybe?]

Just a quick question

In flight if I should change the squawk code on the transponder, do I need to put it to STBY or not.

I know in the old cessna's I used to fly we had to do this, but I have been told 2 different things by 2 different captains.

1 said "YES" always, another said "No need"

Thanks a lot, for any ideas

[FlapsOne]

No.

The previous code remains active until a complete new code is entered. Even use of the clear button does not de-activate the previous code until a new one is entered.

There is no (well little) risk that an emergency code could be accidently entered so little point in going via sby.

[fireflybob]

>In flight if I should change the squawk code on the transponder, do I need to put it to STBY or not.<

This is a query which seems to crop up ad nauseum and a search on pprune will find its been aired on several occasions and you seem to get at many pilots/ATCOs who are adamant one way or the other!

There is an arguement for leaving the transponder on when changing codes in CAS since, I believe, there is a requirement to have the transponder switched on at all times in airspace where carraiage of same is mandatory.

IF, when you change codes you chose to pause between digits and happen to dial thru any emergency codes.....well, I ask you, what pilot in his sane mind would do this?!

Personally cannot see the point in selecting standby but will probably get flamed by the 50% that do it the other way now!

[Localiser]

I'm with FireFlyBob on this one.

Even pressing clear (twice) on the transponder fitted to the A320 series aircraft won't actually clear the transponder code (although it does visually). Only when the new 4 digit code is entered will the actual code being squawked be replaced.

As buttons are used to enter the code, I think you'd have to try very hard to put in an emergency code. More relevant to the days of physically dialling it up I reckon.

My airline gives no guidance on this. I NEVER turn it to sby and so far, I've never been picked it for it by any trainer or picky line-captain either. Something else to consider too (my understanding anyway).... Based on the squawk the ATC guys have a number of other entries such as callsign, departure and arrival airport etc. If putting to standby (effectively stopping the transponder squawking anything) will this information 'tag' be lost? Perhaps some Air Traffickers would care to comment on the merits (or not) of this?

Personally, I think there's far more to get excited about. Like Kylie for example. She's worth getting excited about!

LOC :ok:

[FlapsOne]

Kylie has a transponder!!!!!

...and I just thought she had a cute ...........

[Max Angle]

Not all A320 transponders are the button type, we have both on our fleet with the button type only on 319s. Going to standby turns off TCAS for starters so we just dial the new code in without switching off first.