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Old 09-15-2014, 11:15 AM
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CRM114
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Originally Posted by AF330 View Post
1) How does the pump work? With fuel? But what is the use? Is it to move the fuel?
Could you just have a photo of it while moving something?

2) There were pipes, to bypass the pump stuff, but the pipes shouldn't have valves, so basically the fuel can also go inside even if there are no pump failures, or is there something else so that it doesn't go inside it at any time?
Pumps don't move the fuel as much as they attract the fuel. Like a magnet, the pumps can attract of repel fuel. When in 'ionic mode A" the chemical ionic bonds are bias to draw fuel toward them. In "ionic mode B" the pump polarity is reversed and the electrochemical magnetic dissonance can keep the fuel in it's place. The bypass pipes are wrapped in biasing coils to provide mode A or mode B attraction or repulsion. In ground school, they teach as "fuel come here" or "fuel - stay!"

Originally Posted by AF330 View Post
3) What is the horizontal and vertical guidance for an RNAV approach, for example the glideslope or the LOC for an ILS approach?

4) How does a plane knows where to go? With GPS?
The RNAV unit figures out where it is, by calculating where is not. In approach mode, the time delay on the GPS only allows the aircraft to calculate where it was which is subtracted from the IRS flight plan of where it wants to go (where it was - where it wants to go). Based on the implied position, the glideslope is determined. It's all self contained so that LOC and GS are supplementary.



Originally Posted by AF330 View Post

5) When a VOR has been captured, does it still use GPS?
It sometimes will, but not always. See above.

Originally Posted by AF330 View Post

When the plane is ditching the packs closes.

6) Does all the ventilation system closes?

7) Do the outflow exits close?

8) Do the outflow valves close?

9) If the plane is ditching, you still need air below 12500 ft. But the packs are not working while ditching. So will the "last air" that was there will remain to maintain that pressure at least till we level off or stop ditching?
The Airbus uses Wink/Blink mode. When ditching, one inlet and outflow valve close (wink mode) and the other modulates to maintain a breathable level. If the level isn't good enough, the other inlet, and possibly the other outflow valve can close (blink mode) until the air is OK at which time the system reverts to wink mode (it never is stuck with "last air"). Upon touchdown in ditching command, the aircraft will automatically go to sink mode until the proper differential pressure is achieved.

Originally Posted by AF330 View Post

10) Are the A330 QNH autopilot change altitude when we pass the QNH from standard to the real QNH?If not, why?

11) When are QNH is 1018, our airport altitude is below sea level, isn't it?
The A330 altimetry is a tricky beast. Maybe an Airbus guy can clarify.
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