There's more to that Global Express prang than you make out. They were low on the PAPI, slow and going lower. Had they been on slope (even though one of the lenses had "sunk" 0.1°) they would have been OK.
Agree, but only just OK!
From the report :"At this point, the aircraft dipped below the APAPI glide path, which if followed would have resulted in a main wheel TCH (threshold crossing height) of approximately 8 feet"
That wasn't the point I was trying to make though. I had drifted the thread a little to show how little knowledge of EWH and PAPIs, together can conspire against us Swiss cheese style. Just an example that I thought was quite interesting and (almost) on topic.
Other points from the report:
"Although consideration had been given to the aircraft's larger size in regards to ground manoeuvring, no consideration had been given to the Global 5000 greater eye-to-wheel height (EWH) and the implications of the larger aircraft flying the accustomed flight profile at CFH4"
"The profile flown on the occurrence day would have provided enough height for a CL604 to cross the threshold and land in the first 500 feet of runway"
"The crew members were also not aware that the APAPI was only suitable for aircraft with an EWH of less than 10 feet."
And finally:
"Knowledge of aircraft EWH (eye to wheel height) is necessary to assess whether a visual glide slope indicator (VGSI) system is appropriate for the aircraft type being flown. However, it was determined that this is an area that is not well addressed during pilot training and is therefore generally not well understood by pilots."