Airbus SRS explanation?
Thread Starter
Joined: Nov 2005
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From: UK
Airbus SRS explanation?
Hello,
I am in the process of reading up on a few areas of Airbus technology, and for some reason cannot find a concrete defenition on the SRS system.
I know it provides guidence to 1500ft AGL after take off and during a go-around, but where does it get this data from and what is the reference for the speeds i.e. is it V2 +10???. Tried the FCOM's and other associated material but cannot find out.
Any further explanations would be much appreciated.
Thanks
I am in the process of reading up on a few areas of Airbus technology, and for some reason cannot find a concrete defenition on the SRS system.
I know it provides guidence to 1500ft AGL after take off and during a go-around, but where does it get this data from and what is the reference for the speeds i.e. is it V2 +10???. Tried the FCOM's and other associated material but cannot find out.
Any further explanations would be much appreciated.
Thanks
Joined: Aug 2005
Posts: 1,693
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From: fairly close to the colonial capitol
SRS - Speed Reference System manages aircraft speed by changing pitch during takeoff and GA.
Yes, V2+10 is the reference - engine out is V2+10 or current A/S - whichever is greater. Primary inputs are A/S and attitude.
The aircraft must have at least the slats extended before this mode will engage. Operates until acceleration ALT or other vertical mode takes over.
Provides attitude protection (limits pitch up during rotation) and vertical path protection (minimum climb rate assured). During SRS Takeoff and GA modes, the FD bars are the primary reference - there is no birdie.
There is some limitation on engagement if you are using FLEX thrust instead of MAX/GA - might need to manually program your V speeds ?
I recall most of this from school. Perhaps someone actually typed in the A320 could better explain.
Yes, V2+10 is the reference - engine out is V2+10 or current A/S - whichever is greater. Primary inputs are A/S and attitude.
The aircraft must have at least the slats extended before this mode will engage. Operates until acceleration ALT or other vertical mode takes over.
Provides attitude protection (limits pitch up during rotation) and vertical path protection (minimum climb rate assured). During SRS Takeoff and GA modes, the FD bars are the primary reference - there is no birdie.
There is some limitation on engagement if you are using FLEX thrust instead of MAX/GA - might need to manually program your V speeds ?
I recall most of this from school. Perhaps someone actually typed in the A320 could better explain.
Joined: Jul 2001
Posts: 194
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From: the Milky Way
It is the speed guidance during the Take Off and Go Around phases.
Commanded speed at TO is:
2 engines: V2 + 10
1 engine: V2 or speed existing at time of failure (but not less than V2)
The V2 is always that manually entered in the MCDU. SRS is only armed with this condition and flap handle not at 0.
It is engaged by setting TOGA or FLEX (provided a flex temp has been entered in the MCDU).
At go around: speed at time of go around, but not less than Vapp (Vapp=Vref+5)
SRS maintains a minimum ROC of 120fpm.
SRS guidance ceases at the accel alt (at which time the aircraft will automatically accelerate to the climb speed) or engagement of another vertical mode.
Commanded speed at TO is:
2 engines: V2 + 10
1 engine: V2 or speed existing at time of failure (but not less than V2)
The V2 is always that manually entered in the MCDU. SRS is only armed with this condition and flap handle not at 0.
It is engaged by setting TOGA or FLEX (provided a flex temp has been entered in the MCDU).
At go around: speed at time of go around, but not less than Vapp (Vapp=Vref+5)
SRS maintains a minimum ROC of 120fpm.
SRS guidance ceases at the accel alt (at which time the aircraft will automatically accelerate to the climb speed) or engagement of another vertical mode.
Answers
