Originally Posted by
scifi
I used to live in Northolt London when I was a Kid, and remember seeing NO marked on a gasometer, when passing on the tube.
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Ah! The good old "Gasholder Landing System!" I visited Northolt Tower a couple of times while working at LATCC in 1966/7. On one visit, Heathrow were using Rw 23L (long since redeveloped as a taxiway) and it was quite exciting how the final approach track crossed that of Northolt Rw 26 on short(ish!) final for both! Around that time, a PanAm 707 crew landed at Northolt by mistake! Since the two gasholders were in the same position relative to the two runways, the arrows were painted on as a backstop against crews taking the wrong visual cues. Fight Magazine had a humorous comment by Uncle Roger about how NO was YES if you were looking for Northolt, but NO if you wanted Heathrow!