747x Interesting Observation

[craig_read 43]

Hi,First, don't panic! This isn't a serious bug that I'm expecting to be corrected, nor am I even sure it is a bug and not my machine but I thought I would mention it and see what you technical guys might suggest, if anything.While I was helping a friend setup his throttles (Saitek) for the 747, I noticed something quite strange. On the upper EICAS, you have your N1 indicator for each engine, the demanded throttle is denoted by a white bar sitting on this indicator, as one advances the throttle and reduces it, this white bar moves with the commanded thrust demand from the throttle levers. You will then see the actual N1, the sold white fill, rise up as the engine spools up to meet that demanded thrust. These indications are the same for engines 1 through 4, ignoring other indications like those for thrust reductions etc..While I was conducting some experiments, parked, park brake on, aircraft operating normally, I advanced engine 1 only. The white bar rose with the demand I set using the throttle lever, and the engine began to spool up. I also noticed, that the white bar on the engine 3 (I think) indicator rose too without moving the lever, but not as much, it seemed to be proportional to the throttle demand on engine 1 though, perhaps a 3rd. However, with one distinct difference, the engine did not spool up to meet this demand. This occured too with engine 2, this also had an effect on another engines demand, but the engine did not spool up to meet this demand.This was interesting, I tried it with engines 3 and 4, these functioned as expected, not effecting any other engine demands at all. I am suspicious of my flight controls, as the throttles for engines 1 and 2 are on saitek throttle 1 (comes as part of the yoke), and the engines 3 and 4 are on saitek throttle 2 (indepdent of the yoke). But I couldn't explain the lack of rise of N1.Anyone got any ideas, I appreciate I need to clarifiy this a little more and I will try to take some screenshots tonight of the situation so you can have a look. I am 90% sure it's my controls or I couldn't explain the normal behaviour of engines 3 and 4 which (a bit too) conveniently seem to sit on a different throttle unit.. Is there some interference perhaps? I am not sure, but the N1 not rising was curious, could the control be sending a throttle demand then an idle demand and doing this so fast that the N1 never increases? I mean it's a minor problem, and certainly nothing to worry about or go rushing away to try to fix, I imagine I am unique with this anyway, so please don't take a lot of time pouring over this but suggestions would be nice if you have them.Thanks in advanceCraig

[veldthui 0]

I have the Saitek throttles (the one that comes with the yoke + and additional standalone) and they work 100% properly. I don't use them through FSX and feed the inputs through FSUIPC and it sends the commands straight from there and when you move the #1 lever only the #1 comes up to speed and no other indications.

[Guest SkullxBones]

I used to have this problem when I had both throttles set up but after one developed severe spikes I am only using one throttle now. I posted about it a few months ago but never got a reply. I had this problem with the PW and RR engines but the GE engines worked fine.