Stabilized approach thread

[3WE]

I would expect the plane to cross the threshold with 50 ft regardless of runway length.

Disconcur.

From extensive perving and a few rides, pilots tend a bit high on STL 12R (11,000 feet, with convenient turnoffs) vs 12L (9000 feet and more likely to have to “back taxi” to the gate). The tire marks show full thickness at the aiming mark on 12L, but ~500 feet further down on the right.

Granted, this is done during good visibility.

Also, our pilots here have stated that on short runways (in visual conditions), they will (probably brief) and announce that they are dipping below the glide slope.

Now, this is all done with robust safety margins….13 feet high, 700 feet from the threshold is a little bit inconsistent with 50 ft over the threshold which is an extremely common target, consistent with butt-loads of glide slope and PAPAE.

[System not letting me upload a Google Earth Historical Image when STL regularly landed on 12R]

[3WE]

Here it is:

IMG_5358.jpeg (443.8 KiB) Viewed 173 times

[Gabriel]

You sure?

STL12LR.jpg (746.45 KiB) Viewed 162 times

[3WE]

You sure?

STL12LR.jpg

It’s subtle and there’s lots of variance, but yes.

On the long runway, the rubber smear reaches full width about 500 feet past the aiming mark.

On the short runway, it’s full width right at the aiming mark…

And I have a few “landings” on 12R, there just doesn’t seem to be a hurry to get down.

Look at this cool YouTube channel. Be sure to like and subscribe.

https://youtu.be/X9dFOh_FUDM?si=yg1IgxERVYiY03pq

[flyboy2548m]

Interesting FB post.

IMG_5354.jpeg

The wind gusts of 25 knots played a roll (sic) in the accident.

Oh, shut the bleep up...

[3WE]

Oh, shut the bleep up...

Should there have been some automation warning them they were below the glide slope, or is it likely that such automation is “off” because this runway is one of those New York specials where you have relatively tight maneuvering and a relatively short final?

…not that PAPI lights and altimeters, and genius visual glide slope perspective are damn good indicators of being too low.

[flyboy2548m]

Should there have been some automation warning them they were below the glide slope, or is it likely that such automation is “off” because this runway is one of those New York specials where you have relatively tight maneuvering and a relatively short final?

There should be and there is.

[Gabriel]

Look at this cool YouTube channel. Be sure to like and subscribe.

https://youtu.be/X9dFOh_FUDM?si=yg1IgxERVYiY03pq

Oh, a datapoint. How beautiful!

I have one too!

Plane landing almost 1000ft past the aiming mark... on 12L.
https://youtu.be/S9EhEmUsKa4?si=N68BCDVW8DKCm3n8&t=229

[3WE]

I have one too!

Indeed.

#1. I don’t see many markings and it looks to me like it sets down just past the fixed-distance marker.

Soooooo….

It is consistent with my point.

The shorter 12L where the taxi to the gate is facilitated by not_landing long, they land very much “by the book”.

I’d also point out that this is IMC-ish weather where they ARE going to be close to the glide slope….AND IF THEY WERE ON THE RIGHT…most likely they’d be touching down just past the markers.

But in severe VMC, on a LLOONNGG runway, pilots are not_going to ALWAYS cross the threshold at 50 feet.

Footnote: I provided a shitpot of black rubbery datapoints (using the appearance of the maximum width) as a graph of central tendencies.

[3WE]

Oh, shut the bleep up...

Evan and Gabe are in fine form over there.

I’d snidely suggest you pay attention to their recommendations, but of course you have given them your classic “noted”.

[Gabriel]

I have one too!

Indeed.

#1. I don’t see many markings and it looks to me like it sets down just past the fixed-distance marker.

Soooooo….

It is consistent with my point.

You can do better than that. They are touching down past the 3rd marker, just short of the 4th marker, aligned with the far edge to TXW N.
The aim point is the 2nd marker.

You can see that they fly by V, F, RWY 06-24, S, then during the flare they float over a marker (that's the 3rd marker), then N where they touch down aligned with the far end, and immediately after they run over the 4th marker.

In any case, all this is pretty irrelevant. You can intend a shorter flare, a firmer touchdown, etc if the runway is shorter or if it is convenient for taxi. You should not aim to cross the threshold below the PAPI slope, let alone intentionally fly with 4 red from thousands of feet short of the threshold all the way to the touchdown.

Again, not saying that this is what the pilots did in the United accident. Rather the opposite. I am assuming that there must be another explanation for it.

[3WE]

I have a question in with flyboy and may be wrong- but I’m still thinking a pilot can (using the tiniest common sense) dip a little below the glide slope and not_take out a light pole.

Now, I could be wrong on a detail (maybe they dip after the threshold), but conversely I stick my neck out…using good sense (say you have a long displaced threshold) one does not always cross the threshold vey close to
50 ft.

Ironingly, I later stumbled on a IMCish WN 737 landing on the long runway…they touch down way long with respect to “the textbook” target.

***Rather the opposite. I am assuming that there must be another explanation for it.***

You realize this is an endless circular argument? The short runway is very likely a contributing factor, than cannot be dismissed.*

But I ass-ume we agree that someone or something screwing up is likely a much bigger contributing factor, while the plane leaving the gate was a smaller (albeit a more certain) contributing factor.

*No implication that the runway be banned.