Originally Posted by
destinationsky
Incorrect - the ILS could not have been adjusted as the glide slope would physically need to be moved to accommodate the extra angle. Some aircraft utilising LHR at the time of the initial trial were also not certified to fly above a 3.15 angle. You are also unable to offer CATIII approaches over 3.15 so resilience would take a hit. The RNAV was the best option and allowed HAL to keep a CATIII approach in place for resilience
Er, yes - that's why I said "in theory", with the caveat that it wouldn't have been practicable for a variety of reasons.
