SRS flex?

[Robini]

Hi,
Heard on many videos on youtube when taking off with the A330
that they say for example ''SRS flex''.
Flex takeoff: http://www.youtube.com/watch?v=TgquZ5_A5t0
TOGA takeoff: http://www.youtube.com/watch?v=fnoysS-5mL8

They are still saying ''SRS (TOGA or FLEX)''...
So the question is what does SRS mean?

Thanks!

//Robini

[Tight Slot]

SRS - Speed Reference System. It guides the flight director to a pitch to maintain a speed after rotation. Norm V2 plus 10 kts. With a constant level of thrust, ie FLEX or TOGA, it will command a pitch up or down on the FD bars.

Best regards,

[Chris Scott]

In the context of the FMAs on Airbus PFDs, SRS = Speed Reference System.

Haven't flown the A330, but Airbuses generally have 3 fields of FMAs, positioned at the top of the PFD display. From left to right, they are: Thrust; vertical (pitch); horizontal (roll).

It is common to see "FLEX - SRS - RWY" at the beginning of the take-off run. "SRS" means that, once the aeroplane has left the ground, the initial vertical (pitch) mode of the flight director will give pitch-bar commands to achieve V2+15 (all-engine) or V2 (engine-out). At the acceleration altitude (often the same as the thrust-reduction altitude, but not necessarily so), SRS mode will automatically change to one of the climb modes, using pitch change to accelerate to, and then maintain, the appropriate climb speed ("selected" or "managed").

[The above is from memory, so terminology may not be as per the current FCOMs. "FMA" = Flight-Mode Annunciator.] Hope this helps.

[student88]

Wow, it was like watching an episode of 24!

Great videos!

S88:ok: