Originally Posted by
safetypee
Confusious,
1-4
But I doubt that posting a link to Pprune would have the desired (any) effect !
Also, with sceptical demeanour, what hope of action; any past histories of similar issues.
“…
but it wasn't a mistake not to have executed a Go-Around”.
but your quote ‘mistake’ is constructed with hindsight; is that a mistake …
The professional core of this thread appears to conclude that the operation is safe without intervention (my conclusion without further justification).
So why are some operations experiencing such variability in TCH at this airport
N.B. previous long video of many approach and landings.
Back to # 102. Upslope, visual approach, oversea, PAPI, and # 142
For info; ‘A Study of Normal Operational Landing Performance on Subsonic, Civil, Narrow-Body Jet Aircraft During
Instrument Landing System Approaches’, DOT/FAA/AR-07/7
Chart of ‘
estimated’ TCH from
precision approach landing measurements.
A sample ≈ 1% of total.
Caution; datum ref not known. wheel ht, ILS deviation at 50ft RA, or cg.
probably ILS - RA thus wheel ht would be less, cf touch down.
Was an interesting study. It used an estimate of the the flight path down low based on the D/S deviation which has some issues, but at least the methodology was retained for all cases. The G/S signal is not a linear transmission in close, it has a scallop from ground plane effects that is factored into the siting and calibration of the aid. works fine out at 200' normally, (except where there is any anomaly that affects the ground plane, thinking flooding of a plain out at midfield, was a habit at U-tapao in the wet. The cues to the bus assist in reducing speed variability, which helps with touchdown dispersion, however the vertical distribution is tighter on the B737 than the bus. The approach attitude and body lengths in the study would give some effects there.
If the CEOs want the guys to operate into these airfield, then give them good HUD's, a dialled in desired FPA and a live FPV gives a much more accurate finals and minimises the spread of the touchdowns. The collimated displays are great, but lightweight and effective HUDs are available if there is a desire to reduce the need for the cone of shame.