Airbus MCDU Speeds - Air Canada 875 Tailstrike

[mstram]

It would seem to me, that it would be possible (easy ??) to have the Airbus software calculate the corect V1, V2, Vr speeds and the c.o.g. postion, based on having sensors in the cargo and passenger compartments that would calculate the total weight and weight distribution.

Second best, would have the software pick up a wide discrepency between the entered V speeds.

The software should at least know that at XX tons of weight V1, Vr = SSSS is impossible ???

For manual backup, aren't there any charts that correlate the V speeds and the aircraft weight ?

Is it normal for V1, Vr to differ by 30 knots ??

Mike


http://www.bst.gc.ca/en/reports/air/2002/A02F0069/A02F0069.asp

[viking737]

Two check airman flying together.........
Better post a NOTAM.....

[404 Titan]

mstram

On the 330/340 I fly we now have an automated procedure for retrieving RTOW figures via ACARS. You enter airport ID, Rwy, temp, QNH, config, surface cond, wind, ZFW, TOW, and MEL items. After a minute or so it prints out the numbers. No system is foolproof. Garbage in garbage out. For now we will also have to rely on the ground staff for load sheets, as this is all that is available. Maybe in the next generation of buses an automatic system of calculating CofG and stab trim setting will be available. We will have to wait until then.

:)

[Rynopilot]

Air Canada has an identical automated procedure for retrieving take-off performance data via ACARS-WAT.

As a back up procedure an OPS computer transaction or a weight limitations chart is calculated by flight dispatch.

Best Regards,

Ryan

[mstram]

404,

What about the 30 knot difference ?

Is that normal ? .. possible ?

Will the V speeds differ depending on where the c.o.g. is ? .. or is "200 ton" = 150 knots" regardless of where the c.o.g is ?

Mike
C172 driver :)

[Rynopilot]

Mike,

Although take-off performance data is calculated automatically, the pilot must manually enter the appropriate speeds into the CDU.

When calculating the take-off performance data the aircraft CG is not factored.

Best Regards,

Ryan

[RatherBeFlying]

Don't mean to reignite a Boeing vs. Airbus flame war, but my impression of the 744 FMC is that confirming the calculated V-speeds on the FMC automatically enters them on the PFD airspeed tape.

One less opportunity for a keyboard error to really mess things up -- as long as you enter the weights correctly;)

[mstram]

Ryan

>When calculating the take-off performance data the aircraft CG is not factored.

Thx, that's what I thought.

But I was not absolutely sure, when it comes to the "big iron" :)

Mike