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Jul 24

Final Approach Speed ( FAS )


Hello,

I have one question for Landing Speed to final Approach,

The my question Final Approach Speed ( FAS ) :

The airspeed to be maintained down to 50 feet over the threshold

how to calculate my FAS ?

The tRisulate FAS = Vref+Correction

The Correction to aplication on Vref, is normaly based on operation factors such as Wind, but can on abhnormal ( landing ) configuration.

The question tipically how to increase the speed for correction on ( FAS ) ?

Tanhs for repaly,

Roberto


Hi @Roberto Costanzo !


In case of normal landing:

You select the VREF on the Approach Ref page depending on your final configuration (Flaps 30 or Flaps 40).

The FAS when autothrottle will remain engaged until landing:

FAS = VREF + 5 knots

The FAS when autothrottle is planned to be disconnected prior to landing:

FAS = VREF + wind additive (minimum 5 knots maximum 15 knots / or landing flap placard speed minus 5 knots, whichever is lower)


In case of landing with non-normal landing:

You are instructed by the QRH to set new VREF. For example"Set VREF 40 + 40 knots". If VREF 40 is 140 knots, your new VREF is 180 knots. This new VREF does not include the wind additive and same conditions apply as in the case of normal landing (except for VREF ICE where maximum wind additive should not exceed 5 knots)


Following is a quote from FCTM:

"If the autothrottle is disconnected, or is planned to be disconnected prior to landing, appropriate wind additives must be added to the VREF to arrive at command speed, the speed used to fly the approach. For example, if the checklist states “use VREF 40 + 30 knots”, command speed should be positioned to VREF (VREF 40 + 30 knots) plus wind additive (5 knots minimum, 15 knots maximum)."


-Petr

Just Excelent Answer. Maybe the FCTM, General Information, Command Speed content can also help, right? What do you think?