badderjet

Why? I don't get it. Not a 747 driver here, but on the 737 you can perfectly have the parking brake set and the indication anywhere between zero and the green band, as long as your system B is off and the accu is more or less depleted, e.g. if you hit the brake a few times. Don't know a thing about the 747 but I would assume it could be a similar system design so intuitively I would not know why that px should be too low. In fact it could be a lot lower, i.e. zero.

+1. Surely hope for a fix in SP2, should that ever be considered.

And is there a change log for that?

Thanks, again great read and well explained.

Yeah, but I'm not sure if there is a very easy way to determine MFRA for each takeoff. He can't, he doesn't have LIDO. And full names please. Where did Navigraph get them from, if they apparently supply them?

Your original proposal, by the way, might be a fairly good guess for a vast majority of airport runways, nevertheless. At least if you don't have complex terrain etc. in the surroundings.

Thanks a whole lot for that detailed information. Very insightful and a good read. Sure enough I noticed variations in all but the N1 parameters IRL and sure enough attributed them to slight variations between the engines, but I didn't know about the internal adjustments to the EEC. Still I'm not 100% sure if I understood that part: In your second last post you say N1 (you mean actual RPM here?) equals thrust, but then you say a new engine might need 97% N1 to produce 24K, and an older one might need 99.5%. So in fact these two are running at two different speeds but yet produce the same thrust (and in that case N1 would not equal thrust), right? I understand a worn engine might need a higher fan speed to produce the same amount of thrust, I'm just not getting it together with the N1 value. If I understand the essence correctly, you are saying the engines (or their indications) are 'matched' in a way so that if you have the same N1 displayed on the flight deck, they produce the same amount of thrust even if the actual RPMs (hence the actual N1) might differ slightly, is that correct? Sorry for the confusion.

As said, second that...

To me yes, to you probably no. Except for if you work for an airline or, for that matter, LIDO. Furthermore operators may have their own specific EO procedures based on each airport, runway etc. so I'm afraid such data is not available publicly.

LIDO has EOSIDs wherever applicable.

That's interesting. Simply because I was very sure that N1 (especially max N1) corresponds to a fixed RPM value, same for N2. And since, as you say, the displayed N1 values are always the same, I assumed the engines would be at the same speed as well. So you are saying at the same displayed N1 value on the EICAS the fans could in fact have different RPMs? What would be the reason for that? Or asked differently, what is that EEC trim setting for?

Not sure where the 20 seconds are coming from, but the 10 at least are from NP.21.33, Engine Start Procedure. Does anyone have a reference to the other figures?

Of course they are not, still the N1 is the same for both engines anytime. A/T controls N1. What you see IRL is simply a split in all other parameters, Other than that N1 is the same for both engines.

As it's not really mentioned in the secure procedure I see no point in doing this. Setting it to on during aircraft initialization makes sense as it is usually on all the time. I just don't see a reason to turn it off under normal conditions.

Kind of. It happens during a lot of approaches IRL. Not necessarily a bad thing per se, it could be intended. Just an indication the A/T can't keep the speed. If the setup is intended just hit the flashing light to stop it.