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View Full Version : Can confirm this about 320 GA mode?


Microburst2002
22nd Mar 2010, 11:08
In the various FCOMs, there used to be a contradiction, or so it seemed to me.
CLB mode cannot be engaged in the FMGS GO AROUND flight phase (FCOM 1.22.30 p21). In p57, the "typical FMA at GA" shows CLB armed. I understoodd that at accel alt it is OP CLB what engages, even with NAV . Therefore, in final approach we have to select in the FCU the first at (or at or below) constraint in the missed approach procedure, if any.

In the FCOM 4.05.80 p2, I see now that this is what happens, but some time ago it was different. My imagination or it was ammended?

And in brand new models, apparently, NAV will engage, like in a take off, instead of GA TRK, unless you have preset a HDG.

longobard
22nd Mar 2010, 17:11
Whatever CLB or OPEN CLB, since the SRS will remain engaged passing through the GA accelleration altitude (both AEO or OEI), ref. GA DISENGAMENT CONDITIONS FCOM 1.22.30, alt constraints are not considered by the system. I understand that FCOM 4 is misleading..other experiences?

Microburst2002
22nd Mar 2010, 20:31
SRS disengages at GA accel alt with all engines, according to both FCOM 1 and my experience.
What I don't recall is wether CLB or OP CLB engage, NAV being engaged.

Anyway, my conclusion is that we have to select the first altitude constraint of the GA procedure, if any, in the FCU.

any comments?

foff
22nd Mar 2010, 23:23
hi,
first thing first.
airbus philosophy is that each msn has its own complete FCOM. thus contradiction never exists.
regarding the automatic acceleration at the acceleration altitude, it is effective (it works) only on some msn. at the time of acceleration, if NAV is displayed it should go to CLB, if GA TRK is displayed, it should go to OP CLB.
if there is no automatic acceleration, then one must pull the ALT button to exit the SRS mode (that will stay until ALT *) and engage the OP CLB mode, to be repush to get CLB provided NAV is displayed

Microburst2002
23rd Mar 2010, 07:28
I know of an airline with five 320 and they all have its own FCOM pages.

If there are so many differences in the way a 320 performs a GA, they should do a power point or something to clarify things. We don't practice that manoeuvre very often (in the sim every 6 months).

TyroPicard
23rd Mar 2010, 11:59
No time to look at a Powerpoint presentation during a go-around - just monitor the aircraft, watch the FMA changes and make it do what YOU want. That works whatever FCOM says.

longobard
23rd Mar 2010, 16:58
Microburst, you are right:

SRS will remain engaged passing through the GA accelleration altitude (A330: both AEO and OEI, A320: OEI case only)

Microburst2002
23rd Mar 2010, 21:27
Thanks

But Tyro is right. Monitor FMA. Don't like? don't ask why, just intervene.