Large Transport
Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented
ATC Equipment / Nav Facility / Buildings; Equipment / Tooling
We approached ORD during multiple B747 operations.  On final during a visual approach Tower cleared a B747 for takeoff.  When he taxied for takeoff he blocked the localizer and caused us to get multiple full scale deflections. We were on a stable visual approach and made a normal landing.
Pilot flying in to ORD reports of a bad signal on the ILS due to B747 traffic taxiing in front of the signal.