Full wings,

Operating from airports where you believe that there is inadequate weather reporting so you err on the side of caution by using a tailwind is IMHO perfectly justifiable. It’s no different to assessing the level of runway contaminant.

But in an airport with accurate weather reporting, are you going to use tailwind data for ZERO wind conditions, and contaminated runway data for a dry runway?

I was under the impression from Metabolix that they want to use the tailwind data ALL the time.


Mutt

Well, not deliberately but I have, many times, set up for a tailwind or contaminated departure to find that the said tailwind or contaminant is not present when I get there. In that case I'm perfectly happy to go 'as is' because I'm pretty sure my aircraft performance will be better than planned in all respects. If that's OK, then I don't see a problem with using that data all the time if it gives you better figures (assuming the data is correct, of course). I don't think any safety margins are being eroded; if fact it would seem to be the opposite. If you can fit another bit of freight on to make more money for your company by using this technique, then I'm sure they'd be all for it.

Those last couple of sentences were part tongue-in-cheek, before anyone gets overly righteous. ;) Seriously, I can't see why the takeoff data using
a tailwind should give better weights but equally, if it's valid, I don't see why (in safety terms) it shouldn't be used for calm conditions. SOPs permitting, of course...

Hi guys, please let me in this chat and introduce my self in this forum:
My name is MAx and I´m a new 737 pilot from Argentina.

I understend that imprve speeds or performance of boeing, at least in the 737, is helpfull when you have a large rwy, but your limited weight is due to second segment or climb, so you can use it to rise this limit acceleratong on the rwy to an accurate speed to acomplish the second segment without obstales problems.

So, the differences beetwin the twoVr´s 0 wind and 10 kts tail wind is because if you delay the lift off plus 10ks tail wind your distance to 35 ft is longer, that you would have with head wind o without wind, and that you are using speeds greater than normal for that weight, you can reduce it to reach 35ft at the same point that you would with head wind, tail wind and head wind, has no efect at all on TAS, and it is no importan on take off speeds, only matter´s IAS and field parametters.

thank you and I hope to understood the discusion here,