Transponder selection???

[Filtonman]

During my commercial flying training I was taught to select the transponder to standby when changing squawk in case I selected an emergency code an set your alarm bells a ringing.
Once I got into my airline they tell me I dont need to do this as there is around a three second time delay in modern transponders to prevent such panic/saves us selecting stanby.

An F/O mentioned the other day that he had been told we need to select standby when changing now because ,as we scroll through the squawks, we could activate other peoples flight plans well before they got off the ground....does this ring any bells?:rolleyes:

[mainecoon]

filt

your original training is much better than your company stuff

you are correct if scrolling thru you could cause mayday(flash)etc but starting flights maybe but highley unlikley

always do standby first please
regrds
mainecoon:)

[BDiONU]

Standby please. You are correct on both counts. Its possible to have the radars detect 7700 but the most frequent occurence is for the UK's Flight Data processing system to pair your incorrect squawk with a different a/c. Happens quite a lot unfortunately.
Thanks for asking the question.

[JuicyLucy]

It takes two (or three?) rotations of the radar to cause the problems mentioned. Local airport radars whizz around at about 15 RPM (area radars are slower) so long as you select the digits within about 8 secs then you are OK.

[matspart3]

I flew in a TB20 a few months back with a digital Tranponder that doesn't start transmitting until you've entered and verified the new 4 digit code, hence no need to select standby...if that sort of gizmo is fitted to a tiddler, it may also be on your flight deck?

[5milesbaby]

regularly we get 'scrollers' setting off the emergency codes, and once I got a time update on an a/c scrolling through a previously assigned code that caused computer message to be sent to Paris an HOUR early. I'd agree with DEFINATELY selecting standby first.