Problem on approach A319

[STUART_H 12]

Can anyone help?Whilst flying with the PSSA319 at the weekend, on approach the speed suddenly dropped drastically, which I didn't notice, and the aircraft went into an unrecoverable stall...at the time the AutoThrottle was on and the Speed was in Managed mode. The throttle went into Alpha Floor mode but the aircraft wouldn't recover and 'dented the ground'!The only thing I can think of is related to the speeds, or rather lack of them, set in the FMC for the approach legs - could this have caused the aircraft to drop speed to unrealistic levels? Is it imperitive to ensure that approach speeds are programmed into the Legs page of the FMC?Regards,Stuart Hyett

[Guest dt1951]

I avoid that problem by going to manual on the throttles below 10,000 feet. I want positive control over my speeds when I am on approach.

[Guest Calum]

Hello Stuart ,i think i have experience what you describe once or twice , and have found it to be my fault lol.you dont ( maybe even shouldnt ) have to switch to manual control of the all new airbusses until retarding the throttles at 20-30 ft off the landing runway , but you can if you want , you just have to be sharpe on the speed tape ;)I always have the Vapp ( approach speeds ) in on the FMS on any flight , partly becausse when you enter in your Zero Fuel Weight and Fuel onboard , it automatically puts them in anyway once in the air , so you cant help but have them in , all you have to do is set your ZFW and Block fuel at start of a flight ( you can also set it up for touch and go's if training but thats different from here.So when on approach , you should autopilot on , autothrottle engaged and the speeds in. You should see the purple (D) and your speed should be about 240-250knts until that point ( all this is done automatically with Autothrottle set in CL mode , i am just saying this so you know what to watch for ) , then , passing the purple (D) , you speed will drop to around 180-190knts ( depending on weight ) just in time for you to intercept the " LOC ". After that , when you put more than " 1+F " flap in , the speed drops to Vapp automatically. Bringing me on ....Remember your problem might have been not enough flap , did you notcie a very high pitch up attitude before the stall ? When passing 180knts on the speed tape for approach , have in at least " 1+F " flap , and by Vapp , have in Flap Config 2 or even 3 depeding on weight and position. That should stop you stalling aerodynamic wise ( because PSS couldnt ( not their fault ) simulate normal law fully , you can still push the airbus out of the envelope ).Hope i helped and sorry if i dented your intelegence by going through it step by step by step :) just making sure you get what should happen.Calum

[STUART_H 12]

Thanks for the advice Calum,I can't recall whether I experienced significant pitch up before stall, but probably.I think on reading other tuorials (on BAV online training site), I think my mistake was to leave the speed setting on "managed". They recommend switching to "selected" speed under 10,000 feet on approach, and manually adjusting speed in line with flaps.I'll try that on my next Bus flight and see how I get on.Thanks again,Regards,Stuart Hyett, BAW848

[Guest Calum]

Hi Stuart , yes , you can do that , but you can make the aircraft work automatically without touching the throttles until touchdown , i always let it handle automatically to allow me to do other things preparing for approach.But , like you say , try it manual and use whatever works best for you :)Good LuckCalum