Like a lot of others, I have been having problems with the speed brakes deploying on landing. So, I followed the suggestions on the forum -- disengage A/T, push F1 to force idle, etc. -- this has worked well.So, I'm flying along with A/T engaged and notice that my joystick throttle is still advanced -- I returned it to idle position -- no problems. Then, I think maybe I should push F1 to clear out any settings there. I push F1, the engines go from about 96 N1 to 60 N1 and the airspeed drops dramatically. With the A/T on, everything recovered in a minute or two.I was under the impression that with A/T engaged the keyboard engine controls (F1-F4) would be inactive. Is this true?Thanks.

F1 sets the throttle (joystick axis) to idle so when you release the auto-throttle, you will be commanding idle. To auto-deploy spoilers, the throttles must be commanded at idle.When A/T is engaged the throttles will move on the Boeing unlike what happens on the Airbus where you typically stay at the CL detent.