Originally Posted by
oicur12.again
Greetings all,
I dont usually turn to forums to solve technical questions about the Airbus however our FCOM’s have been slowly “boeingised” at my airline and as such some information that has been readily available for years is no longer contained in our version and I no longer have older original Airbus copies of FCOM from previous airlines to consult.
Firstly, many of us have noticed that on the A319 following the use of speedbrake during descent, once configured for landing and stable, the autothrust carries 10-15 knots extra speed on top of VAPP. The only way to get back to VAPP is to disengage and reengage the auto-thrust. I am sure in a previous life seeing documentation to this effect however my present company has nothing written about it and I am struggling to find anyone in the training department that even understands what I am talking about. I very rarely fly the A319 as its only a small part of our fleet. Can anyone shed some light on this?
Secondly, my recent sim dealt with windshear as a result of the new upset training syllabus and during our briefing, the instructor mentioned that when receiving a predictive windshear warning it was company policy to turn away from the windshear displayed on the ND. However, I am certain that in several previous companies (many years ago admittedly) the procedure specifically advised not to turn away from a windshear icon on the ND. Can anybody provide some history to this issue, was there or is there still an FCOM recommendation NOT to turn away from a windshear icon on the ND?
Cheers all and thanks for any input
The first thing you are seeing is most likely ground speed mini. This is not annunciated to the crew, but it is active whenever the auto thrust is engaged. It takes the tower reported winds entered into PERF APPR page and calculates a minimum energy level the aircraft should have at touchdown - aka "ground speed mini". During the approach, the FMGS computes the speed target, based on the actual winds experienced by the aircraft, to maintain the ground speed above the minimum target. This is your real time gust factor protection and why you do not insert a gust protection yourself as you might in other aircraft. By disconnecting the auto thrust, you are eliminating your gust protection. Again, this function is not annunciated to the crew, but you can tell it is active whenever the speed target goes above the targeted VAPP during the approach.