I've been having a problem lately while using the FLEX temperature for my takeoff. This last flight, I entered all of the usual information - packs on, flaps 12, flex 40C, upslope 0.5 and a headwind of 3 knots....Using TOPCAT, I chose flex 40 which would give me an N1 setting of 103.1% for this takeoff. So here's what's happening....Before takeoff, I select NAV and PROF and arm the autothrottles with AUTOFLIGHT. I advance the throttles to 70% for a few moments and then advance to takeoff thrust. Everything is fine until 80 knots - TO CLAMP is displayed, but then the power to reduces to 93% N1 for the remainder of the takeoff. In the climb, when thrust changes to climb thrust, the power advances back up to 98% approx. which was correct.This has happened a couple of times before, but not on every takeoff. Does this have something to do with whether or not I'm using packs, or related to runway slope? Flap settings? Or am I just missing something here?Any input is appreciated.ThanksRobert

I've had this problem. To deal with it I simply continue to advance the joystick throttle to near full after slowly bringing the engines to 70%. If I stop advancing the joystick throttle when I see the TO Clamp I'll almost always get that throttle reduction to 93% that you described.I'm using the Saitek AV8tR-01, for reference.Ken Carlin

I've been having a problem lately while using the FLEX temperature for my takeoff. This last flight, I entered all of the usual information - packs on, flaps 12, flex 40C, upslope 0.5 and a headwind of 3 knots....Using TOPCAT, I chose flex 40 which would give me an N1 setting of 103.1% for this takeoff. So here's what's happening....Before takeoff, I select NAV and PROF and arm the autothrottles with AUTOFLIGHT. I advance the throttles to 70% for a few moments and then advance to takeoff thrust. Everything is fine until 80 knots - TO CLAMP is displayed, but then the power to reduces to 93% N1 for the remainder of the takeoff. In the climb, when thrust changes to climb thrust, the power advances back up to 98% approx. which was correct.This has happened a couple of times before, but not on every takeoff. Does this have something to do with whether or not I'm using packs, or related to runway slope? Flap settings? Or am I just missing something here?Any input is appreciated.ThanksRobert

Thanks for the reply. Interesting....I usually just quickly advance the throttles after my 70% runup until I hear the "click" sound. I'm usually just shy of having my CH yoke throttle full forward. Maybe I'll try to pushing it all the way and see what happens.

Yeah, stuggled with the same problem for the longest time ....frustrated the #@#@ out of me. Since then I've been fine as long as I put the thottle on my joystick to full when I hear the clamp.

Thanks for the reply. Interesting....I usually just quickly advance the throttles after my 70% runup until I hear the "click" sound. I'm usually just shy of having my CH yoke throttle full forward. Maybe I'll try to pushing it all the way and see what happens.