VNAV UNFLYABLE! (Once more) PMDG please read!

[Guest mpauli]

JeffI can assure you that I do not only think that it will do that for me! ;)No, seriously, VNAV desends your plane as it is a pitch mode (as the other Jeff said already)!And you are right as well. While flying VOR/DME approach you use the VOR/LOC mode to capture the lateral inbound track. Lateral navigation was never a problem here. Look at the posts and you'll see that we are always talking about pitch modes either speed or path. Thanks anyway...Best regards,Martin

[Guest mpauli]

HiThank you very much for flying the approach. It's good to know that the approach works for you. How do you change the speed? Or in other words: Do you program speed constraints to get the speed down for flaps? You obviously do not use SPD INTV.The approach you mentioned is a new procedure for special weather situations. The government wants to install an ILS (about 3.5

[Guest cactuscap]

Martin,This response is with regard to your previous post, but is applicable here too. Give it a try in Zurich and see how things go.Did you also select the runway speed and altitude? Select the

[Guest HepburnUGA]

>I can

[falconno 0]

Hi MartinOn a general basis you can follow the procedures as outlined in the manual: "When flying non precision approaches, the aircraft must be in the landing configuration prior to reaching the final approach fix." Further from the manual about VNAV; "The crew should enter the required crossing altitudes and speeds in the FMC flightplan for stepdown fixes along the approach. Then, when within 15nm of the airport and operating at flaps 15 or greater, the MCP altitude will not serve to inhibit the VNAV/FMC descent according to the descent profile." Read more about it in the manual.As you also know the target speed follows the flap handle if using VNAV. I set the aircraft up to arrive at FAF in full landing config. In the procedure file I used there were some speed restrictions I deleted. The charts tell us ex. max 185 knts, I deleted that and let the FMC calculate. Now, in the FMC that will be AT 185 and not at or below. The FMC calculated lower speed anyway. I don't know how important that is but that's how I do it.My own (very)general thumb rule: downwind: flaps 1-5. base: (4-5 NM from FAF) flaps 15, at FAF: flaps 30(40).>>Have you never experienced strange VDEV bar changes during>that approach?Not during this approach no, but I have experienced it. They were not strange and not due to the AFDS, but rather to my own poor speed management. A lot of hard constraints will also take affect here. So in my opinion this has alot to do with speed and pitch management and proper settings in the FMC. Also take a look in Bulfer's 737 profiles and in Brad Marsh excellent Geezer Guide.

[zubart 5]

"If the approach is in instrument conditions, set theappropriate crossing fixes in the mode control panel and aftercrossing the final approach fix, set the MCP to

[Guest cactuscap]

Floyd,>>Some airlines may vary but this is a better way to set RNAV Minimum's using VNAV as the pitch mode.<

[Guest mpauli]

Okay GuysI thank you all for your for your answers, sugestions and ideas! I think we all look forward now for the 747-400 and what it brings to us!I hope I didn't offend some of you guys but I still see that some things aren't 100% usable at the moment or you'll need a workaround. Let's see hou it'll be with the 747. (It also costs a lot more than a 737NG ;-))All the best to all of you...Best reagrds,Martin

[Guest venquessa]

There was a recent post here about profiling the plane for landing, to aim for gear, flaps and speed to be steady at the FAF, now I don't fly IRL, and I haven't read all the 737 sites and manuals, but...1. Noise procedures.Usually the aim is to NOT fly low and slow, this brings the engines up to 70/80 N1 and makes LOTS of noise with the flaps and gear out. The aim is to come in fast, until right on or after the FAF. In some really built up areas you might have to fly well above the VREF until 1000AGL.Not a 737 but Concorde (which fair enough made more noise than 3 737s in formation) it flew at 180/190knots down to 800AGL before idling back and dropping speed to VREF (about 160). Coupled with G/S this will bring you in over the densely populated inner-cities (like runway 27L at heathrow) at idle. Only opening the throttles when you are within 4 nm of the field.2. Busy airports.ATC can quite often tell you to "Maintain 180knots until 6 miles out". This is partly I think due to noise above, but also to keep the approach queue flowing at good speed, so that another plane can be cleared in behind you. In both situations if you slow up to be established, with flap 30/40, speed 130kts at the FAF, you will take forever to get to the runway and make a shocking amount of noise at 2am! Not to mention the 747 flying behind you slowing from 240knots running in to the back of you, or having to go missed and you meet the pilot in the airport lounge and he's not too happy about it.I live on the "Direct arrivals from south east QDM arc" for Belfast City Airport. The main final approach (rnwy 22) is over sea until about 1nm before threshold. From overhead my house, they fly out into belfast lough, at about 2000 to 3000ft, descending and slowing, sounding like they are in idle. Some come in level, and make much more noise. Enough to make you look up to see what kind of plane is making that racket!Traffic is mostly 737s Airbus320s, dash-8s and BA146 whispajets.When I have spent long days fishing on the coast I have watched them fly out to the FAF, trun very sharply and allow the plane to sink on the turn, there is usually a second sudden turn, which I suspect in the LOC capture. Then they start to descend. It is only when they are at most 4 miles out that the nose rises level again and the gear drops.I have been a passenger on these flights and the engines don't rise in noise onboard until the gear drops and the last flap comes out. It's usually only 30 seconds or so before threshold.Off topic, but I have seen ATC clear the planes "under" a 1500ft cloud deck straight over my house on a night with moderate to fresh winds, rain and low vis. I have no idea why, the charts have a 4000 or above hieght restriction on them, but these planes I can see people in the windows and see in to the gear housing (yes the one I remember had the gear down when still 6 miles from the FAF!) Maybe, just maybe the cloud deck had severe turbulance and to get down under it, the pilot had to use the gear to help the retardation.

[Guest Zapper]

Gents,My apologies for my absence from an interesting debate. However a quick perusal of the FCTM would have sorted this all out ages ago. Martin, Boeing are quite clear about how to fly both Precision and Non-Precision Approaches. Forget all the ideas you have and just do it the Boeing way. Fly to the IAF in VNAV and LNAV if you like but when you are on an ILS then fly an ILS and if you are on an NPA then fly it as suggested by Boeing or at least using the method recommended by the 'Guru of All Things Boeing' - Bill Bulfer. Anything else makes a game of this sim and it is way too good for that. Bear in mind I have not read every part of all of these posts but there is a limit to what you guys can reasonably expect from a PC based sim.Regards,

[Guest patten]

Hi Per,Could you tell if you flew this in real weather or with no wind at all?because I suspect that wind might interfere.I have similar difficulties to get it right as Martin on many flights(when I use VNAV/LNAV).I use Active Sky 2004 (4.5) for the weather.Patten Dochy

[falconno 0]

Hello Patten.As far I can recall I had no real weather in these examples(the pic's doesn't show any either). But of course, winds will take effect and I think it's important to set this up both in the DES FORECAST and on the ROUTE LEG WIND as part of the pre-flight procedure.In addition changes enroute will certainly also interfere and needs to be taken care of. This also will affect the FMC's prediction of ToD and again the descend path.One other thing that seems to affect, are if many constraints are entered(both speed and alt), especially hard contraints close to each other. If you can remove them, then do so if the plane still are within the limits, and let the FMC calculate for itself. The FMS has certain limitations(as IRL and I think this is very well modelled in the PMDG), and what kind of information we feed into it will certainly make the end result. It's all about profiles...

[Guest hellogoodbye]

Bill Bulfer... Is that the guy from fmcguide.com...? Anyone here knows if his books are of any use to PMDG 737NG pilots of is his work intended for REAL pilots? And if they are of any use for PMDG pilots, does anyone know if his books are available as (legal) pdf? (The books are just a bit too expensive for me, with posting costs and all...)I'm interested in EVERYTHING that can learn me more about the 737NG, so...

[falconno 0]

Yes, that's the man. And they certainly are appliable for PMDG. I also think that there is a link on the web site to several dealers.You can download for free his 737_profiles from the website, very useful info! I also think it is a profile doc for a RNAV approach at rwy 26 Albuquerque, both available under "Pilot Support"

[Guest patten]

Hi Per,As you advised me I entered Wspd^/dir in the DES FORECAST (wich I use do do),but also in the ACT ROUTE LEGS page (what I did not before); and this seems to work for me; I didn't get any "drag req." warnings nor "VNAV disconnect" or VNAV overspeed while in LNAV/VNAV mode in DES.So thanks alot for the good advice.An other thing though: on the ROUTE LEG page there seems to be only a limited number of waypoints for entering windinfo.Any idea why not all and why those in particular ?cheers, Patten