I was just reading a thread from the past where as a real NG pilot stated the PMDG product reverse thrust is weak, winding up to only about 60%N1. In real life he said you can get up to 90% N1 in reverse...WOW! I never knew that.... but for years I have been editing the aircraft.cfg file line that contains (just do a ctrl-f search) for minimum throttle limit - and increasing the default values up a bit to about .30 or so that gives me up to about 80% reverser ability........never knew the real thing could get up to 90%.... the Beechjet I fly puts out a lot at about 80%, and I heard most bizjets only give up to about 70%

I found a QANTAS reference which says 91% N1 for the 747-400.

I found a QANTAS reference which says 91% N1 for the 747-400.

Yeah. But that's a 747-400.I've seen the number 80% N1 percent or so as a limit for SOPs. Not a hard limit. Apparently anything more is very uncomfortable for the judgmental people in the back.

I mention the 747 only because this is the general forum. As a newbie, I'd like to know how does one decide how much reverse thrust to apply since it is variable? Does one aim for a certain percentage under certain conditions? I had always thought it was all or nothing.

Gents-Please do not start monkeying with the air files...Unfortunately the folks who programmed FSX were largely ignorant of a significant portion of the physics involved in turbine engines, and the model they created for reverse thrust is so hackneyed that it can only be described as a poor.When we create our aircraft, we develop a physics based model to calculate the deceleration you should experience when reverse thrust is selected. We then use a number of techniques that we have developed in order to match the reverse thrust given to you by FSX so that the rate of decel is accurate within the sim.The unfortunate result is that the N1 figure doesn't match book value- but the resulting effect on braking is accurate.I say this now and again- but please please please: Look at the larger product that is the NGX and then please presume that if we are smart enough to create this detail level in the simulation- there is probably a reason why we have made certain design decisions...Again- do NOT go monkeying with the air file. You will wind up creating all manner of trouble for yourself.

And btw we had this tested in a Level D sim and the most reverse thrust we could produce was around 84% N1. The NGX does get there if you engage the reversers long enough, it just takes longer than real life to spool up to it. Was nothing we could do here on the speed, it's hardcoded into FSX.

I mention the 747 only because this is the general forum. As a newbie, I'd like to know how does one decide how much reverse thrust to apply since it is variable? Does one aim for a certain percentage under certain conditions? I had always thought it was all or nothing.

According to the FCOM, the second detent is where the reverse thrust should be. And immediately at that. In other words, get the reverse levers up and in the second detent ASAP when the mains touch. Unfortunately (but understandably), the second detent cannot be identified in the sim; so I'm looking for a good way to judge what should be used (typically full reverse for me, which keeps the brakes nice and cool).

i have assigned a reverser axis to the slider on my Saitek X52, a few milimeters of movement gives me idle reverse, about half way down is detent 1 which gives around 60% reverse, and the slider all the way down gives me detent 2, the full ~84% reverse thrust.

I just coded my saitek throttle thru FSUIPC to continuously press F2.When I release the throttle from the reverse zone, it presses F1 to return the throttles.If I don't get max reverse thrust from that, then I never will.

I just coded my saitek throttle thru FSUIPC to continuously press F2.When I release the throttle from the reverse zone, it presses F1 to return the throttles.If I don't get max reverse thrust from that, then I never will.

My Saitek Yoke 1st and 2nd "throttle buttons" are set up in FSUIPC to "decrease throttle 1/2" continuously (control repeat when held) and "throttle 1/2" cut respectively. This way multiple throttles can be set up to reverse their respective engine.

I noticed that the reverse thrust in the -900 only goes up to around 60%. Is this to simulate braking, or is it because it doesn't get above 60% in real life too on the 900?Btw, on the 747-400X, the reverse thrust only goes up to 55%! While in real life it goes much much higher.

Unfortunately the folks who programmed FSX were largely ignorant of a significant portion of the physics involved in turbine engines, and the model they created for reverse thrust is so hackneyed that it can only be described as a poor.

Couldn't agree with you more!

i have assigned a reverser axis to the slider on my Saitek X52, a few milimeters of movement gives me idle reverse, about half way down is detent 1 which gives around 60% reverse, and the slider all the way down gives me detent 2, the full ~84% reverse thrust.

That sounds great. Mind detailing how you went about that? I know how to set slider bands in X52 software. I'm just wondering how you programmed the different reverse thrust amounts. Does the NGX have keystroke assignments for it?