Steven P. McNicoll wrote:

Ah, so he had it when he crossed the other runway. Well, the tower
shouldn't have instructed him to taxi to the apron if that involved crossing
a runway being used by a departing aircraft.

I don't know how it is in the USA, but in this part of the world, a taxi
instruction does *not* imply the right to cross a runway.

the tower controller has to bear a
good share of the blame.

No, as I pointed out. But anyway, this isn't the question. Good security
management is designed to be redundant. Being on the right frequency is
just one of several security layers.

For details and an airport map look at the link I posted earlier.

I clicked on it, got a .pdf file in German.

That's right. The airport chart is on page 17.

Stefan