ground speed mini on a boeing?

[fuelevaporator]

when will one manufacturer admit that the other might have good ideas too?

for b787 on an approach below 1000ft a sudden speed drop of 15kts wants to be treated as a windshear but on an airbus you "order a coffee"...

the moment tower gives you a landing clearance and normally includes a wind reading you can calculate the expected ground speed over threshold within maybe 5 seconds and should you see on your display that your actual ground speed is well below this value what is it telling you?

right, sooner or later you will have to add ground speed and if today is not your lucky day this might have to happen within a second when there is a sharp - negative - windshear ahead!

airbus is doing this calculation for you well before because you are entering the atis wind which is the basis for this "expected ground speed over threshold and the airbus plane will never fly slower" concept.

airbus does not request you to adjust the value in the fms upon getting the updated wind with landing clearance and believe this is because flying pilot has no time to check whether assisting pilot makes a gross error which destroys this neat protection - when too high head wind is entered.

however have tried to copy concept on non airbus planes and because these had moving throttles I used to overpower throttles below 500ft in order to get the ground speed I wanted and believe me, it helped a lot!

[stilton]

If it was worth incorporating Boeing would have done it.


I have a question for the Airbus experts out there.


Why, on approach do Airbus Aircraft, even in calm winds constantly make significant power changes. The difference between an Ab product and a Boeing is night and day in that respect.


Could it be they are routinely operating further on the back side of the drag curve allowing slower approach speeds and the characteristic high Airbus pitch attitude on approach with the resultant speed instability or is the Airbus autothrust that bad it can't hold speed accurately ?


This same philosophy / technique seems to make you more vulnerable to windshear.


Half the steady and all the gust works well for me.

[fuelevaporator]

since easiest explanation for autothrottle behaviour is what priority was given in the software - comfort or safety - can not see a problem with more agressive behaviour of airbus autothrottle system.

however am allways - company accepts it - switching off autothrottle before reaching 1000ft so don't know whether this results in even more nervous thrust changes or not.

am aware autothrottle would help me between 1000ft and 50ft but below I WANT to feel the parameters for my flare and fiddling around with throttle at 50ft just doesn't make sense to me.

ground speed mini still works since this depends on the magenta speed target offered by the "managed speed mode" and taking care of windshear as mentionned above.