View Full Version : Airbus Questions

12th Jul 2004, 17:19
Had no luck posting in the other forum, would be very greatful if somebody could answer these questions for me. :D

1. Packs
Ok when are the packs switched on and off ie boarding, engine startup, takeoff, landing and shutdown.

2. APU and external power
Is external power needed to start the APU or can the APU be started independently?

3. Flaps
How do you decide what flap is used for takeoff or landing (obviously runway length etc) but is there something to refer to on how you decide?

4. What is the max detent of the spoilers in flight?

5. FLEX and TOGA
What conditions are FLEX not to be used in?

6. Wing Anti Ice
I know you are not allowed to land or takeoff with it on so what conditions would you use the wing anti ice in?

7. Autobreaks
What autobreak setting is preferred..even on a long runway is MED sometimes used to vacate quickly?

8. Selected/managed climb/descent
How often is selected v/s used in the climb or descent when ATC gives you different altitude restrictions..would you ammend the FMS altitude constriction and continue managed or just do it selected down or up to the new altitude!

9. What do the following stand for?
VLS (Vertical lowest selectable speed)?
VAPP (Vertical Approach speed)?

10. Approach speeds
For example 160 to 4dme is given to pilots after 4 DME is VAPP selected straight off with flaps as required?

VLS>>is this the landing speed, what is the difference between this and VAPP?

11. Could you guys give me some examples of cost indexes for charter and scheduled airlines.

12. Does anybody have any real checklists they could send or type up as an example of what they would be.


12th Jul 2004, 17:22
What version of MS flightsim are you on?

12th Jul 2004, 18:30
FS9..I fail to see how this would effect the questions above?

12th Jul 2004, 21:15
Will try and help.......

Had no luck posting in the other forum, would be very greatful if somebody could answer these questions for me.

1. Packs
We use the APU bleed (when available) to power the packs prior to boarding if the OAT is too cold or too hot. After start the apu bleed is selected off, meaning the engines power their respective packs.

2. APU and external power
The APU can be started by the aircraft batteries.

3. Flaps
Generally speaking the flap setting used is dependant on runway length. (95% of the time flap 1+F is used.

4. What is the max detent of the spoilers in flight? Dont know off the top of me head and the books are in the attic - sorry. Can say the in the A320 you only get half deflection with the autopilot in - full deflection in manual flight (A321 gives full deflection at any time)

5. FLEX and TOGA
Flex will not be used if the airfield is too hot and high - most airlines use TOGA as standard is windshear has been reported on finals.

6. Wing antice - only generally used in heavy icing conditions - crap answer.

7. Autobrakes. you are correct in saying that MED is used when min runway occupancy time is an issue - LOW used when runway length allows.

8. Selected/managed climb/descent
Depends entirely on how you want to fly it - you can put the new restriction into the box or just use good old fashioned mental arithmetic to sort it out.

9. What do the following stand for?
VLS - Is the lowest speed allowable before you enter alpha prot
VAPP- Is the calculated approach speed - usually VLS+5kts

10. Approach speeds.
160 to 4dme is common with the london airports - ILS will usually be flown Flap 2 gear up, approaching 4d gear lowered, flap 3 then flap full in quick succesion. Managed speed is usually pushed just before 4d although ground speed mini can actually make you speed up in strong winds, if thats the case then selected speed is used until a sensible managed output can be achieved.

11. Could you guys give me some examples of cost indexes for charter and scheduled airlines. Cost index the we use is 35, couldnt comment on other airlines.

12. Does anybody have any real checklists they could send or type up as an example of what they would be.
Try writing to a few airlines and see if they'll pass one onto you - dont be surprised if you dont get any joy - they will probably cite security issues as the reason.

Hope this helps.

12th Jul 2004, 22:02
Thanks for the answers - exactly what I was looking for! :D

12th Jul 2004, 23:50
Interesting about the 160 till 4 DME. By what height must you be satbilised? We have problems getting it slowed down by 1000' in such cases.

12th Jul 2004, 23:58
One last question..are the packs turned off for take off ..if yes-why?
(and engine start like other aircraft)


13th Jul 2004, 00:24
Don't take this as gospel but from a pax point of view you hear the air-con go off on engine start. This would suggest that the packs have been turned off.

Whether this is done automatically by the aircraft when IGN/START is selected on the ignition mode selector or done manually I don't know.

13th Jul 2004, 02:58
A couple of non Airbus specific answers...

Selected/Managed altitudes and V/S usage
Heads-down button pushing changing your active flight plan is not the best thing to be doing if you are in a busy terminal area and ATC is throwing altitudes and radar headings at you. Chances are you've been given headings that have taken you off your planned track so there's little point in amending the altitude constraints in the flight plan anyway. Much easier to select the new altitude and use open climb/des or V/S.

Good use V/S can be made in terminal areas during the early part of the climb and latter part of descent and also for level changes during cruise.

During cruise, its a passenger comfort thing - if you use say a 500fpm climb, most pax will probably not notice the change.

In terminal areas, V/S has a number of uses.
1) Pax comfort again. To cope with a worst case engine failure at V1 and max TO weight, all twins need to be generously overpowered. Given a low fuel load on a short sector and climb thrust is capable of producing impressive inital rates of climb. While some of us quite like a 6000+fpm climbs, the average pax will feel like they're in an F14 rather than a commercial transport so it's better to use V/S to moderate it.

2) High vertical speeds can panic ATCOs into thinking you're going to bust through your assigned level. So again, use V/S to moderate the climb/descent. eg In the US, ATC requests you climb or descend quickly but then reduce the vertical speed to 500fpm for the last 1000ft. That makes it easier for them to plan movements and they can immediately see if you're going to miss your level while they still have time to intervene.

3) High vertical speeds in busy airspace cause unnecessary TCAS RAs. TCAS doesn't know both you and the intruder aircraft fully intend to level off at your assigned levels - it just sees your combined vertical closure rate as being above its alerting threshold. So again, use V/S to moderate climbs and descents especially with other traffic in the vicinity.

Pack usage
Just drive round in your car for a bit and see the difference in performance and fuel economy with the air-con on and off. Now scale that up to aircraft size! On a hot, high or short runway with a heavy plane, having the packs off or on could be the difference between being able to take off or not.

Normally, the air for engine start is going to come from the APU bleed so it makes sense to switch the packs off rather than have two high demand systems competing for compressed air.

Flight Detent
13th Jul 2004, 03:14
Hi all AB users,

I saw the title to this thread and thought, "me too!".


13th Jul 2004, 16:15
idg - we should be stabilised by 1000' throwing it all out at 4d usually has the engines spooling up with about 100' to spare - our is sop states the the a/c MUST be stabilised with engines above idle at 500' or a GA must be flown. Although with light winds/tailwinds its definately a good idea to drop the gear and flap 3 a little earlier!!

3202b - our company uses the apu bleed to power the packs on takeoff purely to get a better flex temperature - the higher the flex the better as far as engine wear and tear is concerned.

13th Jul 2004, 16:20
Packs turn off automatically when selecting start.