The A/C left 1700 ft 2 NM before the G/S intercept point and dived with 2700 fpm. Eventually becoming stabilized with -2000 fpm' for 40 seconds until approx 400 ft AGL. Then an adjustment was made reducing to -300 fpm for another 40 seconds, still descending to surface
I hadn't seen this. No approach has such high descent segment and that itself is an indicator that something is wrong and immediately it should have been stopped. Shudder to think if GPWS was U/S.