In message , Clive D. W. Feather
writes

I've been reading some of the old threads in this newsgroup along with
Clive's Piccadilly Line page (which FINALLY helped me figure out how
the Heathrow loop works), and I was just wondering if there's any news
on what sort of Piccadilly Line services will be run to Heathrow after
Terminal 5 is opened.

Well, the plan *was* that half the trains would continue to run round
the loop, not serving T5, while the other half would run to Terminal 5
and so would miss out T4.

We've been told that it will be about 1/3 round the loop via T4 and 2/3
to T5.
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