An old chestnut,SSR code change,EGPX

[atceng]

To Scottish Information:- ('cos I'm unlikely to be let loose elsewhere)

Which method of changing squawk would you prefer,(or to be exact your oppos on radar) ,using an old box which doesn't have an 'enter' button.

1) Leave on mode C,select the assigned code irrespective of any emergency or other codes briefly transmitted.
Presumably returns may transiently show incorrect code

2)Leave on mode C,carefully and craftilly change code to avoid even brief transmission of emergency codes.
Returns should not occult or show random codes but pilots head may overheat and fail to achieve objective.

3)Go to standby,change code,reselect mode C.
Original paint will momentarily occult .(As this may take me more than one scan).

4)Any other spiffing wheezes.

atceng,profuse over Denny.

[liam548]

i was always told to change to standby before altering codes

[GBOACdave]

I don't work any radar unit up in that cold and windy place some call Scotland, but as long as you don't start flashing up the emergency squawks personally I don't really care how pilots change squawk. As long as the requested code appears within a reasonable amount of time that's good enough for me - I don't stare expectantly at a return to monitor what codes s/he cycles through to get to the one I want to see.

Of course, if I asked you to squawk 7742, for example, and you were already squawking 7000, I'd hope that you wouldn't cycle through 7500, 7600, 7700 on your way to getting 7742 on the box.

Probably not the answer from any books, but as a day-to-day radar bod that's my take.

[BossEyed]

Always go to Standby when changing. That's (partly) what it's for.

Doesn't your aircraft document pack have the transponder manual available?

[atceng]

Yes, the transponder manual, ,just as you have recommended, says go to standby before changing codes.

But an opinion was expressed that this caused a loss of trace on the SSR,and the ATCO to say 'where the h has he gone?',
as the plastic 'planes I try to fly have a poor or non existent primary radar return.

atceng

[GBOACdave]

But an opinion was expressed that this caused a loss of trace on the SSR,and the ATCO to say 'where the h has he gone?',
as the plastic 'planes I try to fly have a poor or non existent primary radar return

Even the most plastic of aircraft usually paint sufficiently well for me to be able to tell that it's an aircraft. A momentary loss of SSR trace is not an unusual thing; even if there is no primary contact I'll still be able to keep track ident if the time with no SSR return is sufficiently small. However, this is quite unusual as primary radar is pretty damn good - and from your name I think you probably know more about that than I do!

So, if you drop off the SSR for a few sweeps it's no big deal, and certainly doesn't cause my heart to start skipping beats.

Now it's well past my bedtime, so half an hour or so with Harry, Ron and Hermione and I'll be happy in the land of nod.

Dave

[atceng]

Don't know much about the latest surveillance radars,seem to be a lot better than the S264 of my days,which at about one mile would probably have cooked the occupants of a plastic spam can,but the MTI would have lost the return.somewhere in the aquarium delay line.

'night all.

atceng