Landing Distance Calculation with no wind A320

[WhiteKnight]

Hello all,

let`s say you have an "emergency elec conf" on the A320. According QRH your delta Vref is 10, Flaps 3, and the landing distance factor is 3,15.

I would like to know the resulting approach correction with no wind and no ice accretion.
According the table in the QRH(80.14) the approach correction is the highest of :

5kts if A/THR is on and/or in case of ice accretion OR
1/3 Headwind

In case of "emergency elec" you have no A/THR and if you also have no wind, there should be no additional approach correction. Is this correct?

The other day I calculated this scenario in our landing distance tool on the flight deck. It calculated an approach correction of 5kts and an additional factor of 1.1 for the landing distance. Why?

Can someone help, please?

[rudderrudderrat]

It's because you'll only have Alternate brakes with no anti skid - so are restricted to a maximum of 1,000 psi (rather than 3,000 psi) brake pressure.

Edit: since you have only 2 spoilers per wing, there is less weight on the wheels initially, therefore less grip with the tyres and consequently much less deceleration.
You will consume runway distance rapidly at the higher speed.

[b215]

Doing my endorsement now but read it the same way you do. No wind, no autothrust, delta Vref less than 10kts, no Appr cor.

[rudderrudderrat]

Hi b215,

no Appr cor.

Apart from this bit
"LANDING CONF........ APPROACH SPEED
Use FLAP 3..............VAPP = VREF + 10 kt + APPR COR/140 kt"
do you mean?

[b215]

Think were saying the same thing.Yep that's what I meant.