I have spent a lot of time with Timothy's FMC tutorial, and it has been a great help.However, I have problems with landing the PMDG Boeing 737NG.I intercept the ILS at 180 KIAS flaps 5, and the descent to the runway goes fine and nicely. But as I am very near to landing, I get "Caution Terrain", "Too Low Flaps" and "Don't Sink". After this, the airplane suddenly climbs like crazy and flies away from the airport at high altitude. Sometimes the airplane also climbs and descends strongly at the last part of the ILS, and then finally climbs very steeply just before landing and flies away from the airport.I have been reading the Approach part of the tutorial closely, and I thought that I was following everything correctly.What could be wrong?I am in doubt about how to control the speed and the flaps in the right way. It seems the speed and flaps limits are already in the FMC; I don't need to set them manually? Then, should I just leave the MCP Speed window alone? Should I go directly from flaps 5 to flaps 30, or should I do it in steps?Thanks very much in advance for any help.Nico

When the glideslope comes active, extend the landing gear and set flaps to 15 and set VREF to MCP SPD, when you get closer to VREF set flaps to 30 or whatever flaps you have selected on FMC. Also make sure that the ILS frequency is tuned in in BOTH of the NAV radios, and the second autopilot (CMD) is activated.These are all explained in the manuals, btw.

Then you have not read my question.Like I said, I have read the tutorial very closely, and I follow every part of it, including the things you suggest.I am not forcing you to repeat something which is already described, either.Nico

Well Nico, perhaps I haven't seen this tutorial, so I don't know what's described in it and how?Let me quote you: "I am in doubt about how to control the speed and the flaps in the right way. It seems the speed and flaps limits are already in the FMC; I don't need to set them manually? Then, should I just leave the MCP Speed window alone? Should I go directly from flaps 5 to flaps 30, or should I do it in steps?"I answered to this question for you, when the glideslope comes alive you extend gear etc etc. That pretty much answers your question about how to extend the flaps periodically, and set VREF to your MCP SPD. Why your plane goes up and down I can't tell, but at least I answered your question about the flaps and MCP speed. If you've already read this somewhere and don't want anyone to repeat it, then don't ask it!

Nico,If you follow the tutorial to the "T", it should work perfectly. I have flown it at least a dozen times without any problems at all. I believe that the responder to your original post was trying to make you aware of this. You'll be hard pressed to get a lot of response when you lash out at someone for trying to help you.George Stoddard

>Nico,>If you follow the tutorial to the "T", it should work>perfectly. I have flown it at least a dozen times without any>problems at all. I believe that the responder to your original>post was trying to make you aware of this. You'll be hard>pressed to get a lot of response when you lash out at someone>for trying to help you.>George Stoddard Correct.The tutorial does call out for speed decreases by changing the MCP speed to Vref, lowering the gear, and setting flaps 30 before GS intercept. (page 52).So you have to MANUALLY dial down the speed to around 140 before you start your glideslope descent.

Thank you for drawing my attention to this part of your tutorial. I knew that you would be the one to understand how all of us can overlook an important detail - One finds it obvious, while another does not. Then it is good that we can all help each other with giving hints in the right direction.I am very happy with your tutorial, and I look foreward to future issues. It has been helping me a great deal understanding the FMC and made my Flight Simulator experience much more enjoyable.Once again thank you very much, Timothy.Nico

Ahem..(a) That's Vref + 5 (NEVER exactly vref) if landing is planned to be executed with autothrottle ON or (:( The maximum between Vref+5, VRef + 1/2 headwind + full gust component (no correction for tailwind) if landing is planned to be executed with AT off at any stage during approach. If approach speed exceeds Vref+20 use this value. If approach speed exceeds flap placard then use flap placard limit - 5 knots (flap limit shown by red zipper). If you plan to land overweight you need to think ahead for speed/conifguration management.If you don't know what Vref is, because you never initialised the FMC then Vref+5 at flaps 30 will give you 3.5 degs pitch up. In general this is the correct approach pitch.As replied elsewhere if at any stage you exeed flap structural limits or approach speeds are too low so that a stall condition is imminent the automatic fligt system will revert to LVLCHG and try to save the situation.Best Regards,VangelisPS. That's the trouble with realistic models. Sorry...===================================== E. M. Vaos Precision Manuals Development Group www.precisionmanuals.com=====================================

>Ahem..>>(a) That's Vref + 5 (NEVER exactly vref) if landing is planned>to be executed with autothrottle ON or >I believe that this will vary by airline, as my training so far has talked about adjusting final approach speed around Vref as needed, and hasn't mentioned any prohibition of setting speed target=Vref.In calm wind conditions, Vref can be an appropriate speed as it provides adequate protection against a stall. As the environment changes, it becomes necessary to add a speed cushion to Vref. Since the goal is to safely land with the minimum energy (to save wear on the brakes), and to make minimal configuration changes during the final approach segment, we don't want to carry any unnecessary extra speed during the approach. The biggest cause of problems on an approach is carrying too much energy.

Tim,I just quoted from the Boeing Flight Crew Training Manual for this aircraft (Section Landing page 1.15). As you correctly point out different airlines have different SOP's (extending safety margins at will). Safety would have you increase speed as much as possible --- think of a run-away-stabiliser or a sudden wind gust. In general though Vref is essentially the threshold cross-over speed not the approach speed. You never do a CAT II ILS with MCP at vref+0 --- never.Best Regards,Vangelis===================================== E. M. Vaos Precision Manuals Development Group www.precisionmanuals.com=====================================

I have to agree with EV here too. Tim, the real FMC *defaults* to VREF + 5 for app vref, even in calm conditions one can get a unexpected gust and + 5 gives you a slight advantage..[h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-5/196432/winglets_lg.jpg

>> I have to agree with EV here too. Tim, the real FMC>*defaults* to VREF + 5 for app vref, even in calm conditions>one can get a unexpected gust and + 5 gives you a slight>advantage..>>>[h4]Best Wishes,>Randy J. SmithI think that's the confusion - are you saying the speed displayed in the FMC and set on the bug is actually = VRef(1.3Vs0) +5?.If so, then we're agreeing all along - I'm saying that you set the MCP speed to the REF bug.If not then I don't understand what you said in your previous post.

>I think that's the confusion - are you saying the speed>displayed in the FMC and set on the bug is actually =>VRef(1.3Vs0) +5?.>>If so, then we're agreeing all along - I'm saying that you set>the MCP speed to the REF bug.>>If not then I don't understand what you said in your previous>post.I'll apologize here - we've been apparently using Vref in two different ways, and I've been using the wrong one for this contextIn Part 25, Vref is defined as landing speed, and the airspeed should be stabilized here (or greater) for at least the last 50 vertical feet of the approach. The AC for FMS in transport category aircraft does call for the FMS setting an approach speed equal to 1.3Vs0 +XX knots.In Part 91 flying in small airplanes, we use Vref to refer to the stall speed of the aircraft in the landing configuration +30%. And approaches are flown using this speed as a minimum. Usually we fly the approach faster to the final approach fix and then set power/gear/flaps at the fix so that the airplane stabilizes in the descent at the speed we want, usually Vref with a cushion for the winds (one half the gust factor). Little airplanes decelerate and accelerate a lot faster than the transports, and we can get away with a somewhat smaller margin.I think, however, that the speed you want to carry on approach in the NG is the FMC set speed on the INIT REF page (because this should be Vref+ a factor), plus any cushion you choose to add.So I will stand by my original advice - set the MCP speed to match the FMC-set bug on the ASI, and add a cushion for gusts if you need it.

Timothy,OOOOKKK see what you mean. No the INIT REF page shows you the let us say "uncorrected" VRef i.e. the minimum approach speed and suggests a "standard" wind correction factor of +5 (in addition to VRef shown) right underneath. So if you see 127 in the FMC you set 132 in the MCP, if repeat if, the approach is planned to be flown using AT ON until touchdown. Else you add wind corrections etc as above.Good to clear this (Hey I like these discussions very much)Best Regards,Vangelis===================================== E. M. Vaos Precision Manuals Development Group www.precisionmanuals.com=====================================

>>Good to clear this (Hey I like these discussions very much)>>Best Regards,>>VangelisI like these too... here's one more... when I press a flap setting, it sets a little REF bug on the ASI tape.What's that bug set to? VRef? or is it set to something else?