<br /><br /><br />That might be Apple's perspective on computers, but this is an airliner.One of the first things you learn in 737 ground school is this: The 737 can slow down and it can go down, but it can't slow down and go down.

It is actually a simulation. Are you saying that you should not reduce speed when in a descent?Jim C

If you descent on lvl change and change your speed the ACFT has to change its decent rate. Descent in lvl chg means: engines idle and pitch for speed. Thus if you increase the speed, the ACFT will pitch down to pick up speed until it has reached that speed.

I'll try the thing on FSX this afternoon and see if that makes any difference.JC

hi pilots,1. Be sure you're not using spoilers/gear on descentturns together with lvl-change.2. During descent, 20° bank or greater Turns with lvlch and flaps lower than 15 could result in an excessive produce of drag, which gives automatically a high rate of descent in lvlch mode. Certainly, the weight is also a factor. 3. It could also a possible aircraft.cfg error the reason for it. [flight_tuning]cruise_lift_scalar=1.000pitch_stability=1.000roll_stability=1.000yaw_stability=1.000parasite_drag_scalar=1.000induced_drag_scalar=1.000elevator_effectiveness=1.000aileron_effectiveness=1.000rudder_effectiveness=1.000elevator_trim_effectiveness=0.80aileron_trim_effectiveness=1.00rudder_trim_effectiveness=1.00[Flaps.0]type=1span-outboard=0.690extending-time=35.000system_type=1damaging-speed=260.000blowout-speed=280.000lift_scalar=1.050drag_scalar=1.000pitch_scalar=-6.000flaps-position.0=0.000, 0.000flaps-position.1=1.000, 0.000flaps-position.2=2.000, 0.000flaps-position.3=5.000, 0.000flaps-position.4=10.000, 0.000flaps-position.5=15.000, 0.000flaps-position.6=25.000, 0.000flaps-position.7=30.000, 0.000flaps-position.8=40.000, 0.000[Flaps.1] // Cookingtype=1span-outboard=0.950extending-time=35.000system_type=1damaging-speed=250.000blowout-speed=270.000lift_scalar=1.000drag_scalar=1.000pitch_scalar=-12.00flaps-position.0=0.000flaps-position.1=3.100flaps-position.2=4.000flaps-position.3=5.725flaps-position.4=4.000flaps-position.5=0.000flaps-position.6=0.000flaps-position.7=0.000flaps-position.8=0.000[Flaps.2] // More cookingtype=1span-outboard=0.950extending-time=35.000system_type=1damaging-speed=190.000blowout-speed=210.000lift_scalar=-1.000drag_scalar=-2.550pitch_scalar=12.75flaps-position.0=0.000flaps-position.1=0.000flaps-position.2=0.000flaps-position.3=0.000flaps-position.4=0.000flaps-position.5=0.500flaps-position.6=3.500flaps-position.7=7.200flaps-position.8=8.000[Flaps.3] // KREUGER FLAPStype=2span-outboard=0.001extending-time=7.5system_type=1damaging-speed=250.000blowout-speed=270.000lift_scalar=0.000drag_scalar=0.000pitch_scalar=0.000flaps-position.0=0.0flaps-position.1=25.0flaps-position.2=25.0flaps-position.3=25.0flaps-position.4=40.0flaps-position.5=40.0flaps-position.6=40.0flaps-position.7=40.0flaps-position.8=40.0------------------------I don't know, if these values are original ones by PMDG, but my 739 is in all situations (tested few minutes before ^^) in limits and does not descent faster then 2200fpm and this only in turns with F40/Gear down.hope it helps

Did the same test yesterday with 738, same results as you have. (even with bank angle at 30). When leveling off, the ACFT descended 50 feet below target which is perfectly aceptable.Best Regards,Bert.

It is actually a simulation. Are you saying that you should not reduce speed when in a descent?Jim C

Don't expect a fool-proof operation on an airliner. It's not built to that standard.I'm not saying your shouldn't reduce speed in a descent. I'm saying, if you're following a 3:1 descent path from 10,000', you'll have a hard time getting it slowed without going high. Some planes can slow down and descend well at the same time (eg DC-9 series, turboprops).

Don't expect a fool-proof operation on an airliner. It's not built to that standard.I'm not saying your shouldn't reduce speed in a descent. I'm saying, if you're following a 3:1 descent path from 10,000', you'll have a hard time getting it slowed without going high. Some planes can slow down and descend well at the same time (eg DC-9 series, turboprops).

I was not aware of this and it certainly seems that so long as you reduce speed on the level stages of flight, the system behaves itself.Many thanks.

I was not aware of this and it certainly seems that so long as you reduce speed on the level stages of flight, the system behaves itself.Many thanks.

That's one way of doing it. It's about 1 mile per 10 knots to slow in level flight (ie it takes about 4-5 miles to go from 250 to flaps up speed).You can also slow in Level Change while configuring, but your descent rate will be shallow while you're doing so.

Maybe I mis-read this, but he shouldn't be descending to the GS, which is same as capturing from above. Descend to MSA or ATC clearance then hold that and capture GS from below.

Maybe I mis-read this, but he shouldn't be descending to the GS, which is same as capturing from above. Descend to MSA or ATC clearance then hold that and capture GS from below.

I've spent most of the day shuttling between Manchester and Cardiff/Liverpool and Dublin and it seems that the golden rule is to keep speed constant whilst descending. Whether this is true of the prototype, I do not know but on a recent trip from Berlin to Liverpool, we started our descent more or less over the east coast and kept a clean profile until about ten miles from touchdown. It is the first time I have ever known the wheels to go down before the flaps. Anyway, many thanks for all your help - I am most grateful.Jim