Twinjets are usually have a Engine Out climb profile limited by thrust.

If you select Flaps 1 and then immediately suddenly lose an engine, it might not be able to meet the minimum climb restrictions with CLB power only.

 

 

No, I'm not talking FAA or safery or aircraft certification or otherwise. You are taking my words of context, so why would I say that to the FAA? I'm simply referencing acceleration. If you have an abundance of thrust, and are light enough, then reduce that thrust but yet still have an abundance (and attitude, etc etc all allow), you will still accelerate. Hence, in some cases, like my original statement, yes. I'm not going to argue that point or safety hypotheticals and it's a tangent anyway, so that's my last word on that subject.

 

I'm really not.  There's an inherent safety factor as a reasoning behind how the actions of the automagic functions.  The determination on where the actual thrust reduction occurs, in relation to flap selection or flap position was probably decided in the end in determining the safety of the flight.

 

Think about it:

You're climbing in pitch for speed to your ACCEL altitude, at which you pitch over.  The Boeing FCTM has you select Flap 1 when passing the Flap 5 maneuvering speed, for the reason that you'll likely be up around the Flap 1 maneuvering speed before the flaps get there because of the aircraft acceleration.  This, of course, is predicated on the idea of constant acceleration.

 

If you're in a pitch for speed mode (in this case, I believe the FD commands a set pitch to allow speed to increase, so it's more a PITCH HOLD mode, but still), and then cut your engine thrust, you're going to lose acceleration.  Sure, you're still accelerating, and the change would depend on the situation (as you mentioned), but again, you're making an unnecessary change in the middle of another change that's affecting your margin of safety (you'll note, the FMC will not command a speed below a flap maneuvering speed until you adjust the flaps accordingly - again, a safety issue built into the automagic).

 

...and in the end, who approves that aircraft for operation utilizing that automagic that affects aircraft safety?  The FAA (or whatever other regulatory authority, but I saw your location is KAPA).

 

So, as much as you might think it's a tangent on the surface, it really isn't.

 

 

 

Not claiming to be an expert by any means, I'm the first to admit that. Not trying to pick a fight either. Flew a 777 sim once for a few hours that didn't use flap reduction method, and not it is scientific or hard fact but a few of the World Air Routes 777 DVDs show this, hence my question to the general community of experts. A few aircraft I've flight tested as well have reduction behavior like this.

 

I wasn't trying to pick a fight.  I was attempting to add in some other perspective for you.  It didn't appear that you were looking at it from the safety-of-flight perspective, which has a decent amount of its roots buried in the FMC logic.

 

The DVDs are specifying that they're using a Flap-based de-rate, and it's adjusting thrust based on the selection of that flap setting over the indication of the flap position?

 

 

 

Just because there's a counterpoint doesn't mean it's a fight.  No need to get upset, or bail on the discussion.