Originally Posted by
Capt Fathom
Sounds good in theory, but not a lot of time to continually be doing your 318.4 times table down final. Even with the table on the chart, it’s not practical to be continually monitoring it, especially in good weather. Speed, thrust and rate-of-descent (and the view out the window) would be the indicators something was amiss.
Looks like in this case the GS went for a ride and the autopilot obliged. The crew recovered and regrouped.
Oh please. FMC has track distance to the airport. From once it's loaded, even if it's 16 hrs away. It's simple math, 300 x track distance + altitude. It's so simple people can even do decimals for a quick estimate. In this case 2.6 = 2 x 300' = 600' .6 x 300' (standby, left me find a calculator...) = 1800, drop the zero, 180. Now you need to do something with the 180. Well 3 miles is 900', and 2 miles is 600', so do you think you add or subtract the 180' to the 600'? Most people would add that. So 600' + 180' = 780'. Report says they were at 200' so they were approx. 580' below glide slope.
Reading your post and I'm starting to realize why guys have the speed brakes out diving to 2000' 25 nm from the runway. And yes, after leveling off intercepted a false glide slope and didn't realize it. Where is this DTG function on the FMC? PROG page 1/4.
Here's the really sad part - they were VFR (2214Z) -
VHHH 192230Z 09012KT 9999 FEW022 SCT035 24/19 Q1019 NOSIG=
VHHH 192200Z 09010KT 9999 FEW020 SCT030 24/19 Q1018 NOSIG=