Throttles Retard @ 80Kts during TO roll

[psierra88 0]

First 5 or so takeoffs worked went smoothly using TO/GA hot button on takeoff after it was pressed at 40% N1. But for the last few weeks, every time I use the function, once I hit 80 knots, the throttles retard like it's an RTO but the spoilers don't kick in and autobrakes don't activate either. Basically just lose thrust. Doesn't happen if i advance throttles manually and complete takeoff that way. Anyone have similar issues? Anyone have an explanation/fix? Peter

[Tyty7793 0]

I had that problem, but it doesn't anymore, as long as I push the hardwire throttle all the way up before engaging TO/GA

[psierra88 0]

Thanks, Jason. I'm just using a basic Logitech Extreme3DPro joystick. Nothing fancy...i am also finding that on landing, when i disengage A/T and manually advance and then retard throttles to idle, engines aren't spooling all the way back to 20-21% N1, but are staying at 30% N1 until I manually advance and retard a few more times. So I'm not at true idle thrust on my landing rollout.

[cmpbellsjc 2,960]

I had that problem, but it doesn't anymore, as long as I push the hardwire throttle all the way up before engaging TO/GA

Same here, as long as I keep my X52 throttle completely advanced forward its fine, but if I advance it to 40% and hit the TO/GA hot spot on take off and keep the X52 throttles back then I get the same result as the OP. Also, once I am airborne and if I keep the X52 throttle all the way forward, when it time to descend if I dont manually move the X52 throttle back to idle the A/T will not seem to override it and I will start down at full speed.I dont remember the throttles acting like this in prior HF'es. Seemed my X52 throttle would always be completely out of the picture when the A/T was engaged and it didn't matter what position my X52 throttle was in.Sean Campbell

[skipjack 0]

First 5 or so takeoffs worked went smoothly using TO/GA hot button on takeoff after it was pressed at 40% N1. But for the last few weeks, every time I use the function, once I hit 80 knots, the throttles retard like it's an RTO but the spoilers don't kick in and autobrakes don't activate either. Basically just lose thrust. Doesn't happen if i advance throttles manually and complete takeoff that way. Anyone have similar issues? Anyone have an explanation/fix? Peter

Peter, I had this problem too, ..I have a CH Control Column. The problem I think is when your'e speed hits 80 kts, it goes into THROTTLE HOLD Mode. which alows you to take over the power levers.Since you have only advanced yours throttles to only approx 40% NI, it senses you have retarded your throttles back to nearly idle so the power is brought back.I now simply advance my throttles to the computed NI for your take off after you've pushed TO/GA & take off proceeds normaly.I think that is your problem ...hope it helps.Regards, Stewart Thompson

[gbalean 0]

You can also fix this by changing the setting "A/T Manual Override" from "IN HOLD/ARM MODE ONLY" to "NEVER" (p56 Introduction pdf) so the CH Yoke doesn't accidentally override the autothrottle.

[Cras 6]

You can also fix this by changing the setting "A/T Manual Override" from "IN HOLD/ARM MODE ONLY" to "NEVER" (p56 Introduction pdf) so the CH Yoke doesn't accidentally override the autothrottle.

That is what I do. Otherwise I get the same thing the OP posted, and it has been like that since day one with the NGX. I tried the advance the throttles after pressing TOGA, but it just didn't feel right. So I turned the manual override to NEVER.

[Ralgh 43]

I had my A/T set to NEVER override but it changed to IN HOLD/ARM MODE ONLY when I installed Hotfix 4 and that's when I started having a problem. I changed it back but haven't had time to do a flight since but I'm assuming it will work the same as it used to.

[Scott434 12]

I had my A/T set to NEVER override but it changed to IN HOLD/ARM MODE ONLY when I installed Hotfix 4 and that's when I started having a problem. I changed it back but haven't had time to do a flight since but I'm assuming it will work the same as it used to.

This works and is how I have it set up. The other way is to simply move your throttles to N1 as has been suggested.

[fabio777 1]

Same here, as long as I keep my X52 throttle completely advanced forward its fine, but if I advance it to 40% and hit the TO/GA hot spot on take off and keep the X52 throttles back then I get the same result as the OP. Also, once I am airborne and if I keep the X52 throttle all the way forward, when it time to descend if I dont manually move the X52 throttle back to idle the A/T will not seem to override it and I will start down at full speed. I dont remember the throttles acting like this in prior HF'es. Seemed my X52 throttle would always be completely out of the picture when the A/T was engaged and it didn't matter what position my X52 throttle was in. Sean Campbell

This was definitely introduced with the latest hotfix. Prior to that I could advance the X52 throttle to 40% N1, hit TO/GA and A/T would take over regardless of the physical position of the x52 throttle. Regards, Fabio van Roon

[miguelpp 25]

Same here, but sometimes, work....weird.Now, the ac takes an eternity to slow speed in LVL Change...this was not present before HF4. Best. Miquel Egea.