The NOTAM Number is U 0488/05
I am in contakt with the German AIS about that. They told me that a Series U Notam is a millitary NOTAM , which isn´t transmitted to civil AIS Units.
So NO civil Aircraft going to Northolt gets a sufficient NOTAM Briefing.
I wrote Northolt a Mail, asking for their Comment about that Problem, but they haven´t answered yet.