Originally Posted by
hans brinker
Nope. SWA should have been well past the DER (LLZ antenna) before FDX got to 3.3NM (OM equivalent in KAUS 18L) on final.
Yup, both the LLZ and the G/S Antenna were unprotected for the B767 due to the clearance that the ATC gave. The G/S starts to be filtered out of the guidance for the APFD as a function of altitude, but was still going to be impacted with a plane on the TH of the runway. The LLZ was going to be interfered with and increasingly so as the B737 passed down the runway, and the last time I investigated messed up ALAND functions, there was no filtering of the LLZ to avoid oscillations of the LLZ signal. The B767 happens to be one of the most sensitive APFD I ever used for ALAND, compared to any of the other Boeings or Buses, from the B747, B757 B777, B737, A320, A330 or A340-600, the B767 would get squirrelly with a minimal change in environmental conditions.
HUGS if fitted will incorporate a filtering for the FPV in most but not all cases, that gives INU and GPS inputs, and it is not bad but can be out. The whole thing with the 5-G and the ATC services in the USA seems to be a move towards finding out at what point do the operators stop flying under such a messed up system. KJFK on a good day is a mess, on a bad day, it is unpleasant. KORD in winter is not far behind. KLAX actually seems to have become better, KSFO is pretty and concerning in equal doses.
Failing to protect the ILS in bad weather is plain dumb. The crew of the B767 had every right to make an objection at that moment in time, but they were undoubtedly engrossed in the flight they were doing themselves...