A380 VASFMC overspeed!

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eddm
Posts: 40
Joined: 09 Aug 2011, 23:18

A380 VASFMC overspeed!

Post by eddm »

Hi,
I don't know whether I may ask this, but since there is no VASFMC support forum...:

When using the VASFMC variant of the A380VC, I get an overspeed warning when exceeding Mach 0.81 (the A320 limit!). The autopilot will not exceed this speed, though the A380 has a cruising speed of about Mach 0.85. Is there a way to modify the VASFMC cfg file to change the speedlimit?

Thanks

Alexis
Posts: 444
Joined: 02 Jul 2009, 02:03

Re: A380 VASFMC overspeed!

Post by Alexis »

Max mach speed depends on the altitude you're flying. I haven't had problems flying up to .84-.86 at higher altitudes (FL320 and higher). What altitude were you flying at?

eddm
Posts: 40
Joined: 09 Aug 2011, 23:18

Re: A380 VASFMC overspeed!

Post by eddm »

Hi,
I was cruising at FL300 and I think there is not much airspeed difference to FL320. To my knowledge I also tried it on FL330.
Due to the heavy weight I don't think even with step climb it is usual, to get this bird to a higher crz altitude than FL330.
The vasfmc seems to represent the A320 limits, and I get the red mark on the speed tape at about Mach 0.81 and the autothrottle levels off there. The whole VASFMC autopilot implementation seems based on an A320, so is there any way to change these limits?

777beats340
Posts: 95
Joined: 29 Jul 2010, 14:29

Re: A380 VASFMC overspeed!

Post by 777beats340 »

Question are you using the a380 profile on vas.

Your situation does not occur in my experience. However something else maybe the issue. Step climb on the a380 is really an exhaustive process since if your fully loaded, possibly crossing the pond, Your looking at a lot of calculations between each FL, since vasFMC doenst provide automated step.

Your best best to solve the situation:
1) confirm your using the correct a/c profile.
2) Then if the problem exists, I suggest trying to reach said cruising speed using a different panel. Default for instance would work. If your able to obtain the correct mach speed of .85 then its problem related to the vasFMC installation. If not then your a.c is probably corrupted, and i would suggest getting a new copy from the downloads section.

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