744 Ldg Flap Setting

[rgamurot 1]

Now in the FMC, you can either set the VREF for flaps 25 or 30. I remember reading that you normally land at flaps 25 but can land at 30 if necessary. My question is, in what circumstances would you use 30 degress flaps?Ryan Gamurothttp://www.precisionmanuals.com/images/forum/supporter.jpg

[cowpatz 243]

Actually there are all sorts of pros and cons with using Flap 25 or 30 as the norm. It varies between airlines. One of the reasons for flap 25 is that there is less wear and tear on the trailing edge flap mechanisms. It does increase landing speed by about 7 kts and increase landing distance by about 200 metres. Ever since the Qantas overun at Bangkok there has been a move back to flap 30. We use Flap 30 as the norm but can use 25 if we wish subject to certain conditions.CheersSteve

[rgamurot 1]

>Actually there are all sorts of pros and cons with using Flap>25 or 30 as the norm. It varies between airlines. One of the>reasons for flap 25 is that there is less wear and tear on the>trailing edge flap mechanisms. It does increase landing speed>by about 7 kts and increase landing distance by about 200>metres. Ever since the Qantas overun at Bangkok there has been>a move back to flap 30. We use Flap 30 as the norm but can use>25 if we wish subject to certain conditions.>Cheers>SteveSo then, what are the conditions I would use either flaps 25 or flaps 30? Is there anything in particular like winds or aircraft weight? Also, what's this about a Qantas overun at Bangkok?Ryan Gamurothttp://www.precisionmanuals.com/images/forum/supporter.jpg

[cowpatz 243]

Our procedure is a little bit of an over reaction to the Bangkok incident but anyway Flap 30 is our norm. We can use Flap 25 but must have the following:LDW below 260,000 kgRWY length greater than 3000mNo standing waterHalf the crosswind limitWeather above normal ILS minimaNo tailwindNo unserviseability that could effect landing performance.No autolandQantas overun: http://en.wikipedia.org/wiki/Qantas_Flight_1http://www.atsb.gov.au/publications/invest...r199904538.aspx