MJ ‘balance of judgment on setting MDA’. Yep, all flying is a balance of judgment, but levelling at MDA on 28 would, IMHO, exacerbate the problems of a poor approach procedure. All major industry safety initiatives caution against level flight at MDA. When approaching 28 any level flight after VDP rapidly increases the approach angle and encourages pilots to ‘press on’, often in marginal conditions. The two aircraft that landed preceding the accident flew appalling flight paths (6 deg ‘dunk’ in 2000m with snow and rain – were there GPWS alerts?), those crews should be chastised as much as the accident crew.
‘You shouldn't be descending below MDA unless the necessary visual criteria are met’, but did anyone investigate if the Capt could have mistook the lights of a town during his ground contact call, was there opportunity for confusion, hesitation? Industry encourages an immediate missed approach from MDA and that advice should have been followed. If the first two aircraft had also followed that advice then would ATC have switched runways back to 14, thus no accident?
I remind PPruners of further hazards of the standard 28 approach. The 13-2 chart is subtitled GPS – this implies that it can be flown with LNAV; and thus VNAV, as has been suggested. However there may still be some VNAV systems that construct a straight line path from the final fix (CF28 at 4000 ft 8nm) to the runway threshold (50 ft); the resultant flight path would be below that charted, with reduced terrain clearance; then that 40 ft temp correction would be significant. N.B. this is not an approved procedure.
A more sensible procedure on 28 for both manual and VNAV would be to construct a constant 3.7 deg descent from 4000ft 7nm (approx distance as I have not calculated the exact value). Terrain clearance would be assured, there is a constant flight path, MDA = 2390 ft, the aircraft is aligned with the visual guidance, and the MAP should be at or just after VDP (MAP 3 DME?). This principle would also apply to steeper flight paths (STOL 28), it eliminates the kink in the vertical approach – and may enable the azimuth to be aligned with the runway.
Hindsight is a wonderful thing.