Bonanza 35
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types
Flight Crew Took Evasive Action
Procedure; Human Factors
Low IFR conditions in the area with a reported ceiling of 400 FT OVC at IAH and we were running simultaneous operations to Runways 8L and 8R. A BE35 was cleared for an ILS approach to Runway 8L and was talking to the Local North Controller. Traffic Management had coordinated an airport flow change and we were to begin landing to the west (26R/26L.) When the BE35 was very short final and leaving 400 FT the Tower Controller 'swung' the localizer creating for a potentially deadly situation. The Bonanza lost all points of reference for navigation at a very critical phase of flight. The aircraft was IMC at the time and had to abandon the approach. This is like throwing a blindfold on the pilot. The pilot then began to drift right of course in the direction of an air carrier departure off of Runway 9. There were also incredibly strong winds in the area associated with convective activity. Provide re-training.
I90 Controller described an unsafe event when; prior to an anticipated runway configuration change; the Tower changed the localizer with an aircraft on the ILS; on short final and in IMC conditions.