EFIS PFD Altitude & Vertical Speed Displays (iFly 747-400)

This is a Training Tips Briefing on the Electronic Flight Instrument System (EFIS) Altitude and Vertical Speed Display on the Primary Flight Display (PFD). Produced by Subsonic Flight Training, Training Tips are designed to enhance knowledge to provide ultimate enjoyment of your flight simmer experience on the 747-400. Go to subsonicflighttraining.com for a full list of video briefings.

[@grumpyoldscotsman5462]

love your videos thanks for taking the time to do them. Which model do you prefer Ifly or pmdg 747?

[@subsonicflighttraining]

Thanks Grump, I like both, but I have to say the PMDG is what I fly most. While not flawless, it has less inaccuracies than the iFly model. The iFly does have some items, like CMC pages that are not modeled in the PMDG model. It depends how picky you want to get into the details, but generally PMDG wins hands down on points.

[@dawkinsm]

Hi. At 11:50 you change the altitude to 8000 and the plane starts to climb. When I tried this in the PMDG 747 I could only get it to climb if I used the dial to the left and entered a climb rate. You said you would climb using Flight Level Change, but I'm not sure what that is. Am I missing something? Thank you.

[@subsonicflighttraining]

If you look at 11:35 on, you see I changed the altitude window from 6000 to 8000 and then pushed FLCH to commence the climb. It should then start a pretty shallow climb of around 1000 fpm with thrust coming up only a small amount, well below the reference thrust of CLB 1. Now if the PMDG model did nothing after several seconds and did not climb, then that is a problem with PMDG in trying to do a small altitude change in FLCH. If you had to use V/S to climb to 8000, that would indicate a problem. I would be willing to bet if you increased the altitude to a higher value like 15,000, the jet probably would have started to climb in FLCH with the PMDG model. Most of the time during the climb phase in line operations, you will be in VNAV, sometimes for small changes in altitude V/S works fine or FLCH because you have a minimal climb rate proportional to the change in altitude. Using VNAV for a small altitude change would cause a large change in thrust as it goes to the reference thrust, similar to what you see in my video, an immediate capture of the altitude, and then a large power reduction, not very smooth or comfortable for passengers, thus the preference of using FLCH or V/S for a small change in altitude.

[@dawkinsm]

Subsonic Flight Training thanks for your response. I think the issue is with me not PMDG as I haven't done the lesson that covers FLCH yet. I've just looked through your video titles and think it will be covered in the Autoflight MCP overview video. I'll check this evening and let you know. Thanks again for the video and additional real-world insight.

[@dawkinsm]

Just tried it and it works as you say straight away. If I leave the airspeed alone and try to climb it often over shoots the target altitude if the changes are small. The engine indicator is always chowing CLB - not sure what this means - maybe in a later video or in the manual. It seems to have the exact same issue as the i-fly simulation as it doesn't take 2 minutes to change altitude - it just seems to get there as quickly as possible.

[@markcardwell]

Glad your back on the map Captain AL hope your good. Hey I have yet another question. When you were descending in vertical speed mode (1500 fpm) the throttles go to idle and even though the MCP speed was 253 you said in real life (thats one reason I love hearing your explanations your the real deal) the speed would be allowed to go up but what if there was a speed restriction, for some reason, how could you slow without reducing the 1500 foot rate? You can't just yank the speed breaks anytime you want can you??

[@subsonicflighttraining]

I think I answered this question on my iPad, but it is showing up as not answered. Looks like i need to answer on my desktop. Generally, if there was a speed restriction, V/S is not the mode I would want to be in during the descent. I would be in VNAV PTH or FLCH SPD in pitch. In VNAV, the speed constraint or restriction would be maintained as programmed in the FMC, in FLCH we would set the desired speed ourselves in the MCP. If the descent rate needed to be increased, you can use the Speedbrakes partially or fully. In the case of your example, if I am at 1500 fpm V/S, and the speed starts increasing, which it will, your only options are to reduce the vertical rate or use the Speedbrakes to maintain the speed. You can use the SB anytime you need to induce drag during the descent. "Yank" is too strong a term with PAX aboard. We would smoothly extend them, so that the pitch and buffeting would change slowly and not abruptly for pax comfort. The only time you cannot use the Speedbrakes by limitation is below 1000 feet in FLCH (Asiana accident) or beyond Flaps 20...

[@blackbirda3797]

What information does a dispatch paper contain? Do you get a dispatch paper before or after boarding?

[@subsonicflighttraining]

You normally show at a certain time before departure to your operations center and receive your papers that were prepared from your dispatch center. They will include your planned routing, detailed flight plan, weather package, Dispatch Release, Performance Information, etc. Sometime prior to departure, you will get a close out updating the load information, performance, and weight and balance. You designate one of the identical flight plans given as the Master Flight Plan and compare courses and distances on it vs what you programmed in the FMC. Then during flight, times and fuel score are calculated and checked to track you are on course and that fuel used is correct enroute...

[@blackbirda3797]

Hi Sir What i know is that FLC is to change your altitude maintaining a specific speed. Wt if you were forced to decend1500 f / minute? Does it mean that FLC won't work?

[@blackbirda3797]

I just watched some videos for landing and i noticed that FLC disconnects when activating V/S on the MCP.

[@subsonicflighttraining]

You have 2 choices, you can either use V/S mode to descend at a fixed 1500 fpm, or you can use FLCH where the modes are HOLD | LNAV | FLCH SPD in the descent. The elevator pitches to control speed and the power goes to Idle. Let’s say the descent rate is 2000 fpm and we want 1500 fpm. In HOLD power is removed from the A/T servo motor, so you can just add thrust slowly which will cause the nose to pitch up to maintain speed and the rate of descent would be reduced, you keep adding power slowly until achieving 1500 fpm. If you needed more than 2000 fpm, you have 2 choices, increase speed, or use Speedbrakes if you cannot increase the speed, like if you are at 250 below 10,000 feet and you want more descent rate...

[@subsonicflighttraining]

Yes, because the key is you have to ask WHAT is controlling speed, in V/S, the speed is controlled by A/T because pitch is controlling a specific rate of climb or descent, like 1500fpm. In FLCH, speed is controlled by pitch, and the A/T controls rate of climb or descent. So, if you are in FLCH and go to V/S, it will come out of FLCH since you are now asking V/S to control to a specific rate of climb or descent and now speed is a function of thrust...

[@criticalthinker7822]

I play FSX. How come sometimes the speed shows 000 on the PFD?

[@subsonicflighttraining]

I don’t know, the lowest the speed goes on the PFD is 30 knots which is called the park position. The ND will show GS below 30 knots for taxi...

[@TheMextremez]

May I know where is the flight path vector on the PFD?

[@subsonicflighttraining]

The Flight Path Vector (FPV) is selectable on or off from the Captain’s or FO’s EFIS Control Panel. It is a small black push button.

[@TheMextremez]

@@subsonicflighttraining thank you very much for the info. Got it :)

[@marcotokoku1898]

i guess we should set go around attitude after G/S is captured

[@subsonicflighttraining]

Yes, procedurally that’s is where we do it, at G/S Intercept on an ILS...

[@---uq1hi]

Can I use the photo in 7:13 for the report?

[@subsonicflighttraining]

Sure, just give my channel credit, what report are you doing? Thanks for asking permission...

[@---uq1hi]

@@subsonicflighttraining This is a report on aircraft electronic instruments. It is a task to describe the types of instruments that are composed of EFIS or EICAS and the contents of instruments.

[@subsonicflighttraining]

@@---uq1hi Good luck with it...

[@pitersilie1]

Thanks for your clip, please do not eat or drink anything when talking. You've always been in trouble

[@subsonicflighttraining]

You welcome, actually none of my videos was made while eating or drinking. I have a tough enough time just talking, without something in my mouth...