2StgTurbine

Follow the glideslope until 50 feet. No need to "duck below" or "adjust your aim point." A normal ILS gives you all the guidance you need to cross the runway threshold at height to land within the touchdown zone.

Turbosina

I guess nobody got the "Airplane" reference...

at6d

Remember…we’re all counting on you.

ridinhigh

surely you can't be serious.
it's an airline forum.

flensr

LOL

VMC at BUR MDW or SNA in a heavy -800, following the GS to touchdown is a recipe for either a floating go-around, a firm touchodown forced at the last touchdown point, or badly over-heated brakes. Yea, it's legal. But that extra 500' can mean an awful lot if weather conditions permit a more appropriate visual approach aimpoint and glidepath instead of blindly following an *instrument* glidepath.

It's procedurally correct, but it does require some actual judgement instead of blindly following instrument procedures in VMC when it's obvious to almost everyone that there's a better solution. Set your aimpoint to land in the touchdown zone. Not "blindly follow instrument glideslope guidance which at some airports usually ensures a touchdown at the far end of the touchdown zone".

rickair7777

My shop is allowed to duck below (technically adjust aimpoint) and we usually do at those airports. But if it's gusty I'll likely just stick with the papi to be safe and go around if it doesn't work out.

But a heavy 800 (or 700) at flaps 40 will do just fine on dry or wet (grooved) pavement. Worst case chop the power a little earlier and a little faster and sacrifice the greaser to buy some margin.

I think it's just fine to routinely fly the GS/PAPI to the flare, just be prepared to GA if you don't make the LTP.

It's not going to worth putting the wheels in the grass if you catch a bad gust just to avoid a firm touchdown.

2StgTurbine

No need to laugh, it’s just math. I never said blindly follow the glideslope to touchdown. It brings you to a safe height above the threshold to touchdown within the normal touchdown zone of even a short runway. Adjusting your aim point thing is a myth. By the time people attempt it, there is no time for it to have any effect.

A glideslope leads you to a point 50 above the threshold. If you maintain a 3 degree angle, you will touchdown at 950 feet. Allowing for a 2 second flare at. 145 knots means you will touchdown at 1,400 feet.

If you cross the threshold at full glideslope deflection, you will be at 39 feet. At a 3 degree descent from that point, you will touchdown 750 feet. With a 2 second flare, that’s 1,250 feet.

So, if full scale deflection is worth 150 feet of runway, what are you doing to save 500 feet?

at6d

What about at 160 knots, max weight, wet runway and max braking?

Yeah, I’m going to want that 500 feet.

tnkrdrvr

Im reading this conversation and wondering what happened to your landing data. Is it not predicated on flying the glide slope to the runway with a normal flare? If you have good data to stop on the runway available, why do you need to duck under(adjust aim point, etc.)? Do you have any data for your duck under? In my experience, the box stopping distance numbers are pretty easy to beat.

If you fly per the FOM/AOM/landing data and it turns out braking is NIL and you slide off. You are covered. Trying to force it down early has a long track record fatal accidents.

Mozam

The HUD follows the GS down to TD. When entering using the HUD for landing data it increases the landing distance.