On my first "commercial" 737TNG flight, I noticed the following unexpected behaviour....I was climbing using VNAV (in the flap acceleration segment) and waiting for the speed to build up. The airplane refused to accelerate past each green flap marker (on the MASI). I had to select the next flap setting to get the airplane to accelerate. Is this normal? (I expected my speed to be limited by placcarded flap speed limits, not flap maneouvering speeds).Other problems experienced:PFD Touch Down Zone on departure from YSSY was displayed at 350feet above sea level (Sydney's runways are no more than about 20'). The FMC Departure ICAO was entered in the FMC along with the rest of the flight plan. How does one modify this data?Radio Altimeter display was showing 9 feet on the ground (previously mentioned by Tero, I think). Last time I looked on the real plane, it was reading minus 4 feet (Rad Alt Antennae are forward of the main gear on a 737 and the system is calibrated to read "0" feet when the main wheels touch the runway with the aircraft flared for landing) YMML (my destination aiport) was not in the standard database (understood), but that doesn't explain why I kept getting INSUFFICIENT FUEL msgs and a magenta line extending beyond my last waypoint (Melbourne's) "ML" stretching to the limit of the ND display.When descending using V/S, the aircraft flew through my MCP altitude. I had to use ALT HOLD to stop the aircraft's descent.Just a few more questions...Q1. When passing through transition (in climb) and upon selected STD, should the white baro setting remain in view?Q2. On the 737-700, should the ground power switch latch in the down position if the battery is on? It always seems to spring back into the centre.Thanks.Cheers.Ian.

Hi Ian,Knowing (and appreciating!) you as the resident expert on the PS1 forum I hesitate to pose as an expert in this matter myself :-)However, since I have come up with at least something from my manuals here goes nevertheless:Boeing says: VNAV may be engaged at 400 ft and will control speed appropriate to the selected flaps.Lufthansa says: Press VNAV and retract flaps on normal flap speed schedule.That isn't all that clear, is it? However, to me it at least suggest that the aircraft is accelerating on its own, which it would if VNAV commands flap placard speeds, and it's up to you to get the flaps up in an orderly fashion. So I think that at least in this respect the 737 does resemble its bigger brother! Or sister, I should say, a Queen could never be a brother, right :-)Well, there is one other aspect. As far as your question 1 goes, last Wednesday I had the privilege of spending 2 hrs in a KLM 738 sim and since I wanted to try out every knob I remember fiddling with the baro setting. The white baro setting disappears on setting it to STD and only reappears in the armed mode, as it were, when you turn the knob to set a new QNH.Finally Q2, the Boeing manual says that it is spring loaded back to neutral, so PMDG got it right! Leo Bakker

Hi, Leo.Thanks for the feedback. Just to clarify...."Boeing says: VNAV may be engaged at 400 ft and will control speed appropriate to the selected flaps.These are the manuals for the 737? Our AOM for the 747-400 says that at flap acceleration height, "VNAV will command a target speed of 250kts, Vef+100kts, or speed transition associated with the origin airport, whichever is greater. VNAV commanded speed is limited by airplane configuration. At acceleration height, VNAV commands a speed 5 kts below the flap placard speed, based on flap handle position". (I forgot to mention the buffer of 5kts in my earlier msg). The "flap placard speed" is, I believe, where the upper red bricks on the 400 start. In PMDG 737, on this particular flight, I hit an imaginary "brick wall" at the flap green marker, well short of the upper bricks. I will take your advice, however, and try to retract my flaps in an orderly manner (grin) to avoid this problem."Well, there is one other aspect. As far as your question 1 goes, last Wednesday I had the privilege of spending 2 hrs in a KLM 738 sim and since I wanted to try out every knob I remember fiddling with the baro setting. The white baro setting disappears on setting it to STD and only reappears in the armed mode, as it were, when you turn the knob to set a new QNH."Thanks for that. The 737 is not unlike our "queen", then."Finally Q2, the Boeing manual says that it is spring loaded back to neutral, so PMDG got it right! "Indeed you are right. I may have misinterpreted what I saw/heard and misunderstood a description of the switches operation given to me by a fellow engineer. I had a close look at the switch on a 737NG today, and its construction would clearly not allow it to latch. I saw one in use several days earlier, and with all the clicking of relays going on, I thought it had latched.Anyway, here's what I saw (in the cold light of day)...http://members.ozemail.com.au/~b744er/737/...PowerSwitch.jpgBTW, I've learnt more about the 737 in the last week than I have in the last few months (grin).Thanks.Cheers.Ian.

Hi Ian,About VNAV: the Boeing manual I quote is the 737 Flight Crew Training Manual and this part relates specifically to the NG. However, this was presented almost as an afterthought. In the take-off profile for the NG for instance, at acceleration height it says to select flaps up maneuvring speed and retract flaps on schedule and then to select VNAV after the flaps are up and above 3000 feet. Also during my sim ride I discussed this and they said they don't use VNAV during flap retraction, possibly because they do set climb thrust at 1500 feet but keep flying at V2+20 till 3000 feet and only start to retract at that point. In the 747 you can feed the FMC both the thrust reduction altitude and the flap retraction altitude, but with the 737 you only have the thrust reduction altitude so at that point I guess VNAV would also command a higher speed. So all in all I think the PMDG VNAV may not command the right speed during flap retraction, but in reality I'm not sure it's used all that much.Same with LNAV. You could arm it, like in the 747, and it would become active at 50 feet. Again, at KLM they use 400 feet as a minimum to select LNAV for the NG. Could be of course to maintain commonality with the classic?Leo BakkerPS. Nice pictures!

Thanks, again, Leo.... Definitely a message for my "how to..." scrapbook.Cheers.Ian.P.S. Lots more pics to come! ;-)

...and this just in from the experts....On the 737, pilot procedure is to set V2 in the MCP IAS window. When the flight director takeoff mode is engaged, the FCC FD commands are for the MCP window plus 20 knots, which is V2 + 20 as long as you set the MCP correctly. The speed set in the MCP window does not change without some crew action.The numbers displayed in the window remain at what you set until the FD takeoff mode is exited, or the MCP IAS knob is moved. If you move the knob even 1 click, the number display will have 20 knots added to it and thus then be in synch with what the FD bars are commanding. If you select LVL CHG or V/S, 20 knots is instantly added to what is displayed in the window, which also then makes the command and the window agree. If VNAV is engaged, the window blanks of course. However, note that on the 737, VNAV engagement before flap retraction is highly discouraged since the FCC does not have any knowledge of the position of leading edge devices. (placardlimiting only looks at the trailing edge flaps) Thus if a leading edge device fails to retract, there is nothing in any of the systems to prevent overspeeding the leading edge device. Once flaps are up and the crew has verified that the LE extended and transitlights are extinguished, then it is OK to engage VNAV."The pieces are slowly coming together :-)Cheers.Ian.P.S. FCC= Flight Control Computer (aka autopilot computer)

Aha! I knew there was something fishy going on here. The fact that it is so hard to find out what VNAV does during flap retraction is easy to explain now: no one dares to try :-)Thanks for the insight!Leo Bakker