VNAV departure problems

[Guest HepburnUGA]

No actually, if you engage VNAV at 400 radio with flaps extended it will put the bug to 245 as seen on the SPD REST line of the climb page (should be 245/FLAPS -- I noticed this last night).Your procedure is dictated by your companies SOP which can be very different than others. I just think its unusual that people here are so resistant to looking at things outside of what procedures they use and instead look to see if the plane is behaving as its real world counterpart. In the end, I'm not saying whether it is or it isn't, but, instead, I am questioning an item that I think could be functioning incorrectly.Cheers

[crvm 0]

" At this moment L3 changes from 210/3000 to 245/FLAPS (speed bug to 245!!!)... " Displays XXX/FLAPS (XXX being an IAS number) if active speed rest. is lower than min speed at current flaps seting.FMC USER's GUIDE NG EDITION page 89. @Jeff, I think you are a little off on the SOP thing. SOPs ARE the way things are done, if the SOP does not cover something the BOEING FCTM will and if you can show me where BOEING states to perform a TO like you suggest then we can go further into this but as it is by you asking us to look beyond standard operations it's on you to provide the proof. The way I see it is it's not normal to fly like that so one must live with what's there and even then it looks pretty good IMO.[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | WD SATA 80 GIG | 512 DDR 400 |

[Guest HepburnUGA]

Hey Randy,My point was that SOPs are different based on company. While one company does it one way, another will do the same task differently.For example, the Continental SOP allows for the use of VNAV above 1000ft during flap retraction (see the picture I posted). However, the real NG pilot that has been participating in this thread says his company does not allow VNAV below 3,000...no exceptions.Since everyone has a slightly different approach, I simply want to know what the airplane does. Unfortunately, I don't have access to any manuals other than bulfer's and the Continental AOM. Neither of these provide information on what the plane will do. If I had the access, I wouldn't need to come on these forums because I could just look it up. The reason we come here is not to ask for proof from each other but to ask for help and get differing opinions. We come here because people are professional and courteious, and because we have pilots who do this every day give us insight.

[Guest tmetzinger]

>> I'm sorry Lee I did not mean to give you that impression. I>was in a hurry out the door and should have reviewed what that>sounded like. Once again sorry for the aburpt sounding tone.>> The 600-700 did have it the way you say and there has been>much talk about this. It was stated that flaps 5 max speed is>250 knots so it appears this was changed to mimic that>behavior. Now I have put some questions regarding the FMC>displaying flaps driven speeds on the climb page that VNAV>does not adhere to (your question) but does adhere to maximum>flap speed (i.e. 250/10000' =250 MAX flaps 5). I am confused>as to why the driven speeds are there for approach and VNAV>adheres to them and not for TO. It can be only 2 things here,>one, the flaps driven speeds for TO should not be there or>VNAV is not adhereing to them correctly. >> As it is right now VNAV will not overspeed but we need to>find out just why it is the way it is on the PMDG.>I believe that on the 600/700 the FMC set speed to match the manuevering speed for the flaps setting (green number), but now sets it to match the MAX permitted speed for a flaps setting. Not sure which behavior is correct, and perhaps it's an option (so they both are).It may also make sense that on departure the flaps are normally going up and there isn't a lot of manuevering going on, so it would be safe to accelerate to max flap speed. On approach, the "goal" is to decelerate and there is usually more movement happening.It may be that the behavior is correct and appropriate for the different phases of flight.

[Guest FattyBear]

Heh I feel dumb because I have been engaging VNAV right after departure. I always knew my take offs were too easy :-lol

[crvm 0]

Continental SOPs are unique it seems in this regard but really only proves the point that one can engage VNAV prior to flaps retraction but this we already knew. I do have many AOMS for the NG but this still is not what I base my thoughts or comments completely on. To give you another example would be the use of the A/T on approach. Here you will find varied uses and suggestions from pilots, SOPS and Boeing. Some areas are not covered in detail from the manuals and you are correct that having discussions here help to clarify these things, this is all done in a good natured way Jeff and I do not want you to think otherwise at least coming from me. At times some folks will speak with absolution on subjects that are in a grey area like " Oh I KNOW the real plane does this because.." and base this opon what they think they know insted of what is known. This is not you of course just an example. [h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | WD SATA 80 GIG | 512 DDR 400 |

[Epikk 66]

"Displays XXX/FLAPS (XXX being an IAS number) if active speed rest. is lower than min speed at current flaps seting.FMC USER's GUIDE NG EDITION page 89."Thanx!!! Didn't understand what was happening...

[Boeing_Captain 0]

Well guys, I think I must be one of many pilots who have been spoilt by PIC. I guess im just so used to engaging VNAV soon after departure and having the auto throttle system keep me from breaking through the flap retraction speeds, I probably assumed it was the same for all aircraft capable of VNAV.Am I right in guessing FLCH is the best pitch mode to use until flaps are fully retracted then ?Regards,Lee.

[zubart 5]

The airplane can remain in TOGO mode as flaps are retracted. LVL CHG is OK if you want to switch to that pitch mode retracting the flapsbut you'll have to "bug up". Engageing the autopilot will engage LVL CHG or push LVL CHG in FD mode. Floyd

[Guest Murf]

Edited to fix typos/spelling. Probably still didn't correct them all.I'm not a real pilot so I can only speak from my experience with the sim. But, it appears that VNAV is an acceptable pitch mode for departure. If you refer to this post...http://forums.avsim.net/dcboard.php?az=sho...33&page=2#50429... you will see from the AOM screen shots that VNAV is used in the real world 737s as a departure pitch mode.It does appear from the recommended settings for the climb page that VNAV does not take into consideration flap settings. By following the CLB page settings and engaging VNAV at acceleration height, it will speed up to your "clean" speed and you can retract flaps on schedule yourself. Then (depending on which method you used on the CLB page) you can acclerate to 250 kts when you are ready or after passing 3,000.I follow this method in the PMDG planes and it works fine.

[Guest Murf]

:-)Guess I should have read the whole thread first. Someone beat me to posting the AOM information.