I'd like a requirement for lights to be positioned at several (say three) heights 100/150 ft apart.
I went past the building in question at 22.30 the night before last.
There were obstruction lights about halfway up, and again three quarters of the way up. I expect there were lights on the top but I couldn't see them from ground level.
Additionally, just about every other floor was lit internally by what looked like strip lights - as is just about every office building in London, 24 hours a day (so much for being green).
I'm not saying that all or any of these lights were or weren't on at the time of the accident, just that they were on during the night before last.
The recovery crane was also showing a red at the top of the jib.
From the Directorate of Airspace Policy:
"Article 219 expresses the requirements for “en-route” structures (ie those away from the vicinity of a licensed aerodrome) and dictates a statutory requirement to provide aviation warning lights for structures of a height of 150 meters or more. The Article 219 specification requires that medium intensity (2000 candela) steady red lights be mounted as close as possible to the top of the structure and at intermediate levels not exceeding 52 metres. Such lighting should be displayed at night and be visible from all directions."