A320 ATHR and Managed modes
 

Hello.
Post sim and awaiting line training slot, time to kill and so I ask about systems integration if I may.

I recall a quick situation in sim where engine N1 mode (IAE engines) as result of demonstrations, and not completion to landing. We explored setting manual thrust, removing Thrust Lock etc etc. Doing descent manually with thrust changes, open descent was straight forward. I am seeking opinion or pointing in the direction about use of managed modes (speed) as there seems not to be much direction in FCTM or FCOM about this scenarios and using / complying with safe operations. They talked N1 settings and about approach but didn't demonstrate. On descent worked well with just open / selected and adjusting thrust as required.

What is left / advisable for approach - can you safely use managed speed ? (will the system still guide speed and have us act as 'auto thrust'?) Is there anywhere listed inadvisable? Or should we use selected speed and thrust manual? Thanks for your replies.

Nutha

Not really sure if I understand your question, but if you’re asking if you can use managed speed without autothrust, the answer is yes.

Can't be sure what's the question but from whatever I can make out I will try and answer. About speed, managed speed is given by FMC and selected you give it on FCU. Who will maintain? If ATHR is available and active it will maintain if not you move the thrust levers and maintain. OP CLB and OP DES are fixed thrust modes so in manual thrust you either put the levers in CLB or IDLE and once ALT* comes manage the speed with manual thrust. The trend arrow is a good guide for that.

If you are referring to an Approach with vertical guidance, and at least 1 engine in N1-rated mode:
You should normally use managed speed, because it will give GS-mini.
You will definitely use manual thrust because the AT doesn’t work in N1 mode.
On the Approach, the AP will pitch for GS, it will be your job to keep the speed around Vfas (48-53% N1 should do it).