Man I’m with you. This isn’t hard. I’m not sure what the malfunction is with all the mishaps but we get zero info on the flight line of any info to digested and reenactment’s of what actually happened so we can learn and possibly be aware of something to look for. But what we do get is 3,000 different memos about how we can be on time and how “D”is changing things from how AIRBUS says to do things just so he can change it again in 6 months back to what AIRBUS says…. I’m beginning to think somebody doesn’t want to be a rsv CA in las so he reinvents the wheel ever few months so he can live in Denver…

 

Speed is already added by the FMGS. No need to add for wind shear. That's what groundspeed mini does. You're not smarter than the box no matter what you think. Never been an auto land tail-strike.... EVER. Think about it.

 

Okay, I've thought about it. You often aren't allowed to autoland during windshear conditions because of wind limitations. Maybe you are the one not smarter than the (any?) box?

GSmini only adds steady state headwind component to the bug to (try to) keep GS constant. Does nothing for gusts, or cross wind, and gusts from the side during the flare can definitely increase the chance of tailstrike.

 

Maybe you can inform f9 training department thier APPROACH in wind shear profile is incorrect than. Lol.

 

I’ve noticed that a lot of people misunderstand GS-mini. Our manuals (including the Airbus QRH Landing Performance Vapp Determination chart) recommend adding an additional speed margin (up to Vls plus 15) for a strong/gusty crosswind. Key word being crosswind. As mentioned above, GS mini will take the headwind component of gusts above the headwind component of what’s input into the into perf page when computing its target speed. Any amount of wind or gust that is not a headwind component will not be “taken care of” by GS mini like I’ve heard so many people brief. It’s pretty important to consider the amount of headwind vs crosswind component when deciding whether it might be appropriate to add additional speed.

This said, I also agree that the NEO auto thrust does seem to lag quite a bit from how I manage in manual thrust when getting a little below Vapp

 

If you take a dump in the flare you can; decrease mlw, extend your glide by 4 ft, and decrease rollout by 2ft.

#The more you know
#NEatO

 

Correct me if I am wrong.
The box calculates Vapp based on weight.
On the PERF page we enter winds (without gusts, at least at NK) from the ATIS.
The box calculates the headwind component during the touchdown based on those winds. It ads that HWC to Vapp to get minimum ground speed for the part of the approach in the landing configuration. Limited on the upper end by flap speed, and on the lower end by Vapp (no correction for tail wind component). At no point are gusts or cross wind taken into account in this part, hence ABs' recommendation to add up to 15kts, based on Vls, not Vapp, to Vapp, in gusty conditions.
GSmini will not look at the HW component of gusts, because those were not put in the PERF page (again @ NK).

 

As far as I understand you are correct in your assumption of the initial calculation done by the box for GS mini, but it will dynamically adjust the target speed as you are flying to account for the headwind component of any gusts. You don’t input the gust into the perf page because that would just lower the “baseline” ground speed, and GS mini would essentially be doing nothing since you would already be at or above it’s computed baseline ground speed.

GS mini is sort of a counterintuitive design in that it will increase target speed (and also thrust, assuming the gust lasts a little while) when encountering a headwind gust.

Watch your target magenta speed bug closely next time you fly an approach when there is a strong low-level wind with lighter wind at the surface (usually indicated by a “wind shear” line in the TAF). Your target speed will start significantly above Vapp, but will eventually be very near it, assuming winds are as advertised.

The added speed recommendation is pertaining to gusty crosswind. And that’s because GS mini isn’t doing a whole lot when the wind component is mostly from the side. Gusts in that case are not going to appreciably alter your ground speed. Obviously, there is some judgement calls necessary depending on conditions, etc.

 

I think we are somewhat talking about different things. While on the Approach it will constantly adjust the target speed. That's based on wind variations at that spot on the approach (as opposed to gusts, because that refers to surface winds) during that phase. Surface wind gusts as reported by the tower/ATIS are not entered on the PERF page and have no effect on GSmini. During the flare the target will be Vapp, regardless of the wind you entered into the PERF page, and gusts, regardless of direction are completely disregarded. And that is why we add gust correction. It is totally separate from GSmini.

Think we both added things, and yes, agree with that

 

Thats correct. Ground speed mini keeps a target speed based on winds on the approach so that your energy level at touchdown will equal vapp. Vapp is not looking at gusts at touchdown therefore neither is mini.