Mode A code change on Approach (B747-400). Why?
Hope someone here can enlighten me with an odd observation a colleague made today.
When landing at Heathrow, with the work load underway in the cockpit, would it be easy to misenter a new Mode A code? As far as I'm aware it's not standard practice to made a change at this late stage so I'm not really sure why this would happen, but I have seen it occur!
I'm wondering, purely for better understanding of how these things can happen, whether a Mode A code could be accidentally reset when a different task was intended or through RT confusion, or maybe there was a genuine reason? I can't really say what the codes were for sake of annominity of the a/c, but the a/c in question was a B747-400 if that helps with flight deck layout.