Mode A code shortages
According to a 2001 Eurocontrol study, the effects of Mode A code shortage, which is the cornerstone of the case for Mode S equipage, should be kicking in and causing delays round about now, particularly in the London FIR. So, two sets of questions:
1) Is it currently possible to avoid allocating a Mode A code to an aircraft with a Mode S transponder? Is this the current practice? If not, when will we reach the point at which equipage with a Mode S transponder will "save" a Mode A code.
2) What evidence is there that we are at or approaching the capacity of Mode A codes in the London FIR (or elsewhere)? Are flights currently delayed through shortage of codes to allocate? If not, is there a way of finding out how close to capacity we are?
Thanks