I was flying a little Cessna around London a few years ago and noticed that for every controller I spoke to I had to reset my squawk code.

Consequently workload increased and I heard some poor read backs from others too, which decreased capacity.

In the US, France, Germany and Spain it is generally one code - one flight. Much more efficient and less workload.

New European AIC for Transponder failure coming out next month. Set 7800 and continue last ATC clearance.

Soaringhigh: I don't see much hardship changing SSR code when you also have to change radio frequency. In any case, the 'cunning plan' means that controllers at each radar unit can tell which unit is working a particular aircraft and thereby can co-ordinate if necessary, and can see who to contact if the aircraft infringes controlled airspace.

Which, of course, is only necessary because of the UK's rather quaint departures from (or interpretations of) SARPs and the somewhat fragmented and uncoordinated system that is used within the State. But I guess it must be the rest of the world that's doing wrong ;).

The xpdr doesn't always sit on the central radio stack. It is sometimes found beneath and to the right of the RHS yoke. Also if you happen to use one of these while hand flying the plane by yourself:

http://www.lxavionics.co.uk/images/tt21-parts.jpg

You'd be spending a good 20-30 seconds twisting those knobs to get the right number and maybe not looking out the window. ;)

In many other countries it is not a problem as it is usually set once and we leave it there for the flight.

Strange that 'progress' seems to make things more difficult. I'm used to a transponder with a separate knob/thumbwheel for each of the four numbers; takes a lot less than 20 secs to change one of those, especially when one or more of the numbers may be 'common'.