In the lower left hand corner, FAF to MAP times are 1:53 at 150 kts GS, and 1:34 at 180 kts GS. This would tell me, as a pilot, that if I were flying a CAT C or D aircraft on this approach, I should be configured, and on approach speed well before the FAF, and have my estimated ROD figured out before I hit the FAF. If I had a tool in the cockpit that allowed me to create a 3.28 glide slope that keeps me above min altitudes before FAF, all the better.
It looks as though the approach need ~700 fpm ROD if GS is 180, ~580-600 FPM ROD if GS is 150.
I'm just a driver, not a rocket scientist but you might want to re-check those numbers for a 3.28 degree glide path.
Airbubba: The approach plate I am looking at is dated 25 July 2012, from SE-4, AL-50(FAA). Glide slope noted as 3.28 degrees. The math went like this. (It may or may not reflect said glide slope. I don't have my old GS table at hand ...)
Hmm, you have a point, my calc was to MAP, not touchdown.
I'll try a different method.
If I start at the IAF at 3500 feet (as shown) and arrive at threshold (644 feet), I lose 2856 feet over a distance of 12.8 nautical miles.
150 kts GS gives me 2.5 nm per minute (5.12 minutes) 558 FPM.
180 kts GS gives me 3 nm per minute (4.27 minutes) =670 FPM. (Not far from ~700 fpm)
Granted, one should cross the threshold higher than 0 feet AGL. Call the total delta in alt -2800 feet and decrease ROD slightly to hit the box.
From discussions on a PPRuNe sister forum, UPS pilots use Jepps.
I was thinking the crew would probably shoot the RNAV (GPS) RWY 18 approach but they certainly were legal to do the LOC Rwy 18 (don't know why it's RWY on one plate and Rwy on the other).
Anyway, take look at the LOC Rwy 18, chart 11-2 dated 17 AUG 12.
There is a small rate of descent table on the left side. For 140 knots groundspeed, the rate is 803 fpm, for 160 knots, 929 fpm. This seems about right from my experience, your ROD numbers appear to me to be too low for the groundspeed.
You are not flying into a black hole if visibility is 10nm, you are below the scattered cloud and you can see eight bright red lights in front of you.
PAPIs either work or they don't. They are either on or off and they don't change angle once they are installed and certified. Even if I was Albert Einstein I would trust eight red lights over my calculations.
The BHM 10-9A chart has the notation PAPI-L (angle 3.2°), as HDRW points out, there would only be four red lights in this case.
It has been claimed by ALPA in defense of the pilots in the 2002 FedEx TLH crash that moisture can affect the operation of PAPI's:
ALPA is disappointed that the Board did not fully explore the possibility that moisture condensation on the visual approach aid (Precision Approach Path Indicator, or PAPI) gave the crew a false indication. The FAA was aware of this problem as far back as 1983.
ALPA Reaction to NTSB Findings in FedEx Accident. - Free Online Library