On Sun, 9 Sep 2007 00:29:10 +0100, "John Rowland"
wrote:

James Farrar wrote:

Wikipedia's page on [[RAF Northolt]] states "In days before such
navigational aides as instrument landing system (ILS) and the global
positioning system (GPS), the letters NO (for Northolt) and HR (for
Heathrow) were painted on two gasometers situated on the approach to
each airfield, one at Southall for the approach into Heathrow and one
at South Harrow for the approach to Northolt in an effort to prevent
recurrence of such errors." - this seems to imply that they're no
longer there, and certainly I cannot find any evidence from a quick
Google Maps search.

The Southall gasometer seems to still have LH on it...
http://maps.live.com/default.aspx?v=...0103&encType=1

Ah, it's on the side, not the top. Thanks.