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Guest Stanner1953

PMDG 747 Autopilot VNAV and speed problems

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The far left one is the Autothrottle mode. If you set TO/TO for takeoff and hit the TOGA switch, then you will get THR REF annunciated... until 65kts. Then it will go to HOLD. If you had VNAV armed, then the annunciation should return to THR REF until top of climb.Cheers.Q>

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Stanner-First go into the PMDG menu and assign Key strokes to the individual door commands.Then save and exit the menu. Now whenever you want to open a particular door, you just press that key/key combination and the door opens. Just remember with the nose (400F) power must be established and AVAILABLE on BOTH sides of the a/c.I.E.- L & R sides have ground power OR APU running with at least one side ON and the other available.Hope this helps-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png


Best-

Carl Avari-Cooper

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Guest D17S

Q, Let them do it.

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Guest c210_cvs

>Thanks. That tells me about the center FMA. What about the>LEFT one?Like Qavion said, left is field is speed, center is lateral and right is vertical. If there is nothing displayed in those fields at any one time then the auto pilot is not managing that particular mode, ie if the left side is blank the autopilot is not managing speed.FRED

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Guest D17S

Thanks. That helps. Let's go with that for now because it appears that Stanner had his problem in cruise. He still needs to tell us what was annunciated in that LEFT FMA when he had the problem. Was there anything in there at all? Stanner, are you starting to focus on that LEFT FMA when buzzin' 'round with the autopilot engaged? Why? Stanner, . . . Come in Stanner!

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Guest Stanner1953

Gentlemen:The PMDG rep felt I had a corrupt file and suggested that I reinstall the sim. I did, and now all my autopilot problems are GONE!Thanks for your help.Stanner

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Guest shogun007

G'day Stanner, I am a having exactly the same problems as you.VNAV won't operate correctly, the speed window doesn't close like it should and is dropping the selected speed back to 100 kts after takeoff. The red bricks form a continous line along the speed tape and the sim has become a waste of time to operate.I Uninstalled the sound update and the 744 base program, reinstalled the Base program and didn't worry about the sound update, and all the problems are fixed. It works just like the real thing now. I have a 747-400 endorsement and operate them for Qantas so trust me when I say it's all good. Regarding some of the replies that you were given regarding system modes they are partly incorrect. For us, the use of VNAV and LNAV for takeoff are the preferedmeans of automation modes. The correct way of conducting the takeoff (RR engines)is to raise the thrust till you have 1.10 EPR on all four engines and they are stable, then press either or both TOGA switches. The auopilot can be engaged above 250ft with LNAV becoming active through 50ft and VNAV becoming active through 400ft. The idea of using VS for a climb is not good as you can put the aircraft into a situation where you are asking it for a rate of climb that is in excess of its thrust available which ultimately leads to a stall. The flap retraction schedule will be much easier if you use VNAV for the climb as the speed will increase to 10 knots below the maximum speed or Flap Limit Speed for the selected flap. This means that you won't overspeed the aircraft and you will be climbing at an optimum speed and profile for your configuration.The reply about the red bricks is interesting as the red bricks will display under the following conditions:From the Boeing 747-400 Operations manual:Maximum SpeedIndicates maximum airspeed limited by lowest of the following:

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Guest D17S

Since you're here for a moment, we had a question a while back. In that initial VNAV/THRREF climb, at flap Vref-10 (flap limit speed) will the AFS control speed by 1) Reducing thrust, thus maintaining a (somehow?) defined ROC, or 2) Will it just start pulling the nose up (speed on pitch) to keep the flaps on-board? Maybe next time you're in the sim ...? Vnav has proven to be the hardest part. I'm gonna be facing a whole pilot group that will grandfathered from entire careers on 741-2 airplanes into a spanking new fleet type of 744s. For some very old timers, this will be their very first experience with an FMC. There's not going to be anybody in the left seat to show the new guy what is what. They will all be new. Lnav's pretty straight forward. The INS has been doing this basic function all along, just without the pretty pictures. But Vnav is a whole new ballgame. The new airplanes will be equipped with EFB (electronic flight bags) and ADS_B systems. CDA (continious descent approaches) are all the rage these days. (Hey, how about the PMDG 744X with the EFB/ADS-B to interact with AI? I like it!) The guys are already using TCAS for arrival lineups to jamb more airplanes into busy arrival windows. And now they want to do it without touching the throttles? Yup. These new guys are gonna have a hand full getting up to speed on all this in a single gulp. This PMDG airplane has given a few of us ground -types a real head start. This is going to be fun.

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Guest shogun007

Give me a few minutes and I'll pull out some notes on the flap limit question. Cheers Steve

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Guest shogun007

I am sorry to say that I cannot find any documentation in any of the suite of manuals that I have in front of me that discusses speed limiting to Flap Limit speed -10kts or VMO/MMO limits.From memory when we did our training we looked at it and with the A/T engaged it will reduce thrust to maintain the 10 knot buffer so as not to induce an overspeed situation. It will not be guaranteed to give you that protection if you are descending rapidly though as the A/T reduces thrust slowly when it senses an increase in speed above the Commanded speed. The A/T won't give any overspeed protection with the gear extended either, so it is possible to overspeed the gear if you are not paying attention to what is going on.Hope this helps, sorry I can't give you a definite answer from a manual, I will ask the guys on the way home tomorrow night and see if they can shed some light on the subject. Regards Steve PowerS/O 744

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Guest D17S

My (undocumented) impression has been that the AT mode THRREF might not be just referencing thrust to the prevailing thrust limit. Seems to me the name might infer that this AT mode is a bit more aware . . . or not. We'll see. And to stay on topic jut a bit, this is all about the nuances going on in that left FMA. Fun Facts. That autothrottle (the left FMA) is an critical component of the AutoFlight team.

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