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-   -   A320 early flaps retraction (https://www.pprune.org/tech-log/370942-a320-early-flaps-retraction.html)

Franklin2008 21st April 2009 19:24

A320 early flaps retraction
 
Anyone flying Airbus A320 series using early flaps retraction technique (below 1500 Feet AGL) ?

We do have some concerns about this new "fuel saving initiative" as this configuration change may occur within the "Take-off Inhibit" phase.

Thanks for your comments

Max Angle 21st April 2009 19:41

We have been doing it at bmi for while now with no problems. To be honest in many ways it is better because you get the power back and the flaps running before ATC start talking to you again. Good point about the take-off inhibit but I don't really see the problem with reducing power and cleaning up before the end of inhibited phase, Airbus seem happy with it and approve the procedure.

Superpilot 21st April 2009 21:06

Would you mind explaining to the uninitiated what this means?

You retract flaps before 'F' and 'S' speeds???? by how much?

Endeavour 21st April 2009 23:22

The flaps are retracted at the usual speeds 'F' and 'S', but bmi now generally use a thrust reduction/accel altitude of 1000' rather than 1500' as a fuel saving initiative. Obviously if it needs to be higher for obstacle clearance or noise abatement then that takes priority.

ALK A343 22nd April 2009 06:10

In our company the standard thrust reduction / acceleration height has been 1000' AGL for many years now on the A320/330/340 and it has worked quite fine. Of course as mentioned earlier it is only applicable to airports where there is no local restriction either for noise abatement or terrain clearance. At those airports with restrictions we have amended thrust reduction and acceleration heights based on data published by the local authorities. However the question about the take off inhibit is quite interesting and I have just looked up FCOM 1 and 3.. Take off inhibit is active up to 1500' AGL or 2 minutes after lift off whichever occurs first. The only changes that occur between 1000' AGL and the end of take off inhibit would be thrust reduction and flaps retraction. The ECAM caution for FLAPS FAULT / FLAPS LOCKED is inhibited in phases 4,5 and 8 that means from 80 knots to 1500' AGL and from touchdown to 80 knots.
So if you took off in configuration 2 or 3 and you got a FLAPS FAULT / LOCKED while passing 1000' AGL and accelerating through F speed the caution will be inhibited until you reach 1500' AGL, though I doubt that you will hit the overspeed limit for your flap setting before passing 1500' AGL. Your Vmo displayed on the PFD will still be the one for the current flap position and all you need to do is select a lower target speed if you approach Vmo with or without the ECAM caution.
In configuration 1 take off I do not believe that you reach S speed before passing 1500' AGL at least not on the A320.

bobrun 22nd April 2009 07:55


Vmo displayed on the PFD will still be the one for the current flap position
No, it's not (not for the 330 and 340 at least). Vmo is displayed according to the flap lever position only, as is Vfe next. However, the overspeed warning and Vls are according to the actual flaps and slats position, regardless of where the lever is.

ALK A343 22nd April 2009 08:12

Sorry about the mistake. Bobrun you are right. Vmo and Vfe next displayed on the PFD are based on Flap-lever position on A320/330/340. The overspeed warning and CRC are based on actual flap position. Which in turn means that in case of a FLAPS FAULT / LOCKED between 1000' AGL and 1500' AGL one would be caught unaware until the master warning starts sounding.:ok:

ianrimmer 22nd April 2009 09:38

tom aircraft
 
would anyone happen to know what type of aircraft is scheduled to be on the man-lpa on the 6th may 2009 flt no tom 2350 as this is the first day it is running i would normally watch the screens at work but is not running yet cheers.

Gary Lager 22nd April 2009 12:20

*ignore previous post*

I wouldn't worry too much about the consequences of a flap-related failure being inhibited...have a look at your IAS as you pass 1500'aal, following a retraction at 1000'. It isn't much greater, on a FLEX & CONF 1+F TO you don't get anywhere near VFE until close to 2000aal with an accel alt of 1000'.

In the event of a lock/failure the flaps/slats need engineering attention anyway so a minor overspeed isn't going to cause a huge problem, and there are no essential immediate actions required in the event of a Flaps/Slats lock/failure which couldn't wait until above 1500' at the very earliest (which is only seconds later in any case).


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