Originally Posted by
DaveReidUK
On the contrary, it appears to be almost twice as steep as a 3° approach
Slightly steeper approach trial update
In theory the ILS/MLS could have been adjusted to the steeper angle, but that would have required all landing traffic to make use of it. Instead, a 3.2° RNAV approach was created for use by the airlines participating in the trial.
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