UPS Cargo Jet Crashes Near Birmingham Shuttlesworth International Airport

[snydersnapshots]

Parlour talk moment...

Was this crash pre-dawn?

I'm thinking of the black hole effect which unfortunately seems to happen from time to time. You have only runway lights in a sea of blackness (didn't see approach lights depicted on the approach plates, AND we have the photographs of the barren field) and you think you are on a good approach path, but you get low.

(Yes, you are supposed to watch the altimiter too, but tell that to all of the pilots who have crashed before)

Good question. The other thing that popped into my mind was the time of day vs fatigue factor. I'll be interested to find out what day of the trip they were on (i.e. was it the first day of the trip before their circadian rhythm had time to adjust to the night schedule, or was it later in the trip?), and how long their duty day (night?) had been.

[TeeVee]

according to flightaware, the AIRCRAFT came from MEX into KSDF at 1218 on the 13th, after spending 12 hours in MEX, then left at 0504. same crew?

[obmot]

Good question. The other thing that popped into my mind was the time of day ...

Good point. I would have loved to become a jet driver but I for one can assure you, one does not want me at the controls of a jet - much less a riding lawn mower - between say 4am and 10am - although I have zero late night awareness issues, early morning has never been my prime time. I dont even think my heart beats at those hours.

[Evan]

I'm reading that there's a PAPI visual approach slope indicator on the runway, which should be a fairly obvious indicator if you are too low.

Almost as obvious as the instruments right in front of you.

[AVION1]

Having FOD on both engines seconds before landing is not fun, apparently they got pieces of wood, branches, etc, from a large tree.

[3WE]

Almost as obvious as the instruments right in front of you.

How about more useful than the instruments right in front of you. It's generally better to have your eyes outside the cockpit, with relatively quick instrument scans.

[Evan]

How about more useful than the instruments right in front of you. It's generally better to have your eyes outside the cockpit, with relatively quick instrument scans.

Relatively quick instruments scans with obvious indications.

[Gabriel]

Relatively quick instruments scans with obvious indications.

Having been there and done that (well, just a bit), I can tell you that it's quite hard to tell from the instruments if you are low, high or on target on an approach with no vertical guidance (ILS or similar glide slope indication).

[3WE]

Having been there and done that (well, just a bit), I can tell you that it's quite hard to tell from the instruments if you are low, high or on target on an approach with no vertical guidance (ILS or similar glide slope indication).

Indeed. The altimiter doesn't really help with the glidepath...I'd just as soon they watch the PAPI. (although they may have had a really fancy flight director)

The airspeed gauge doesn't help with the glide path either, but I kind of like knowing how fast I'm going...it's of some secondary value to avoid stalls and sea walls.

[obmot]

How about more useful than the instruments right in front of you. It's generally better to have your eyes outside the cockpit, with relatively quick instrument scans.

3WE - maybe this is a case of an unfortunate paradox...there might have been just enough twilight and runway lighting that the flight crew was "tricked" by their brains/minds into a sense of having greater visual cues/information than they truly had given the weather and time of day. They perhaps fell into a subconscious trap wherein they thought the eye-out cockpit window provided them enough or good enough information for the approach, but the reality was that they couldnt see the impending terrain/treeline (in the context of being a dot or so low) and suddenly they clipped the trees ingested material and that was that.

Stated another way, at the precise time of day (lighting) and weather when they approached, perhaps instruments would have provided more accurate information, but their eyes sort of fooled them because they could see pretty well out the window only because the bright runway lights were like a 'beacon' and the sky was starting to brighten. So they felt (again subconsciously) that they had a 6 or 7 out of 10 visual situation, when in reality it was only a 2 or 3 at that moment because they couldnt -actually- see (or distinguish) the treeline/slight hill in their path.

I wish I know how to express this concept more cogently.

[3WE]

I wish I know how to express this concept more cogently.

How about calling it "The Black Hole Effect".

However, the PAPI should be a very obvious cue to over ride such misperceptions- not that it would be 100% though either.

Bottom line- this is just as likely or just as unlikely as all of the other theories right now.

[Dispatch Dog]

If the NTSB says that the engines were functional before the accident, I can onlyy assume that the lack thrust at impact was due to the ingestion of tree branches. So at least one engine must have spooled down fairly quickly to have hit the ground hard without deforming all the fan blades.

Again, what happened after hitting the trees was inevitable. Question is how low on the glidepath do you have to be to hit them?

[snydersnapshots]

Again, what happened after hitting the trees was inevitable. Question is how low on the glidepath do you have to be to hit them?

The rule of thumb for a normal three degree glidepath is 3:1, that is, three miles per thousand feet, so at 1/2 mile out you should be around 500 feet +/-.

I did a little research on the ILS in the Aeronautical Information Manual and learned (re-learned?) that the width of the localizer approximately 700 feet at the runway threshold and the thickness of the glideslope is +/- 0.7 degrees for 1.4 degrees total. Gabriel will tell me if I'm wrong (at least I hope he will, math is NOT my forte'), but I believe that equates to about 140 feet/mile. At .5 miles, the thickness of the glideslope would be about 70 feet, so a full-scale deflection would give you about 35' below glideslope at 1/2 mile. If I'm wrong in my calculations, please let me know...

Of course, that's for a precision approach and I understand the runway in question does not have an ILS.

[Gabriel]

Of course, that's for a precision approach and I understand the runway in question does not have an ILS.

If you really want me to do the math, just ask.
But I don't see the point since there was no ILS available here.

If (again: IF) they were using an FMS generated glide slope, those ones don't follow the conic geometry of the ILS.

[3WE]

The rule of thumb for a normal three degree glidepath...the runway in question does not have an ILS.

And, to split hairs, the PAPI "setting" and the "glideslope" depicted on the R-Nav approach plate is ~3.5 degrees...

...probably not of great significance...then again it's probably steeper for a reason...

Edits:

http://155.178.201.160/d-tpp/1308/00050R18.PDF (Ok, 3.24 degrees for the virtual glidepath)

http://www.airnav.com/airport/KBHM (and 3.2 degrees for the PAPI).

So, of even less significance except that it's steeper for reason.