Squawking 1000 in Germany

[b737bbj]

Hi. Can anyone please explain to me why one is often told to Squawk 1000 when entering German airspace? As well as other traffic being given the SAME Code. How does their system recognise the different aircraft if they are on the same Transponder code?

Hope someone can assist... thanks.

[Tom!]

It is because your flightID from your mode S transponder is used to correlate your flight plan to the radarblip on the screen /ATC system and no longer your unique squawkcode is used for it. By squawking 1000 your previous code is released back in the system for use by other aircraft and multiple aircraft squawking 1000 is not a problem because the system uses your mode S id and not the code.

[DaveReidUK]

Discussed at length here

http://www.pprune.org/atc-issues/484742-squawk-1000-a.html

[FE Hoppy]

it stops your transponder replying to mode A/C interrogations. Reducing FRUIT.