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Since the plane has turbo compressors and bleeds it makes it a bit redundant, since they do the same job.

I can only guess on that one (much as on all the other items), but if you had the #2 turbo failing, the only way to get any pressure into the ducts would be the #2 engine bleed. As you say, redundancy.


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This was great fun since the start valve is physically on the engine and there is a tiny hole in the cowling where the junior mechanic would insert a long screwdriver into the hole and push on a button which would open the start valve.

I've highlighted the vital word.  ;D
'Who has to go out in the rain and search that button?' 'Oh, look, we have fresh mechanic right there!'