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trisho0

PMDG 747-400 question

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The flight plan OAKB - OPIS is about 217nm. For every 100nm I should set approx. 8200 lbs. right? Also, adding Reserve Fuel of 20500 lbs. So, total to enter in FMC Fuel would be 369. Am I right? I have to mention never used Fuel Planner, started learning about. So, now is clear the climbing issues is due to overweight.

But, if any other flight plan is over than 200nm journey like 800nm then the plane Take-Off will fail again?.


Patricio Valdes

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Can you explain how you get from 2 x 8200 lbs plus 20500 lbs to 369 ? 

Maybe you mean 36.9 tons ? 

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Watched the video. You're very heavy, trying to take off from an airfield that is at 6000ft above sea level. You loaded 173.6 tons of fuel (= 382722 lbs), that is a lot. Please give more details about the route you want to fly. If you wanted to fly from OAKB to OPIS like the video description suggets, 20 tons of fuel should be totally fine, so I don't know why you loaded as much fuel as possible.

Anyway, I tried calculating some take-off performance date using TOPCAT (RWY 29 at OAKB), but even if I go as "light" as possible in regards to weights, take-off isn't authorized in a 747-400 from RWY 29 due to obstacle limits.. I guess you should use Runway 11 instead.

Okay, even if we ignore all of this (exceeding MTOW, etc.), there are several "oddities" that happen after take-off. Running almost out of runway, you raise the gear before you get even an indication of positive rate (even rotating before reaching Vr), way too early (imagine your plane is still on the ground, you just lifted your nose, main gear is still on the runway..). Then, you pitch up to 20(!) degrees nose up and while your speed is dropping and dropping (why? Speed is now in the yellow speed band and way below manouvering speed - if you see the speed dropping, you should lower the nose (push), don't pull or even bank), you even raise the flaps from 20 to 10 (why? You don't want to retract the flaps until reaching maneuvering speed for your desired setting, indicated on the speed tape of your PFD), stick shaker goes off and you bank into the turn (why? Banking increases your AoA / Angle of Attack even more))? Uhm.

I hope you don't get this wrong, no offense - but I can only recommend that you read the tutorial that comes with this plane and try to recreate the tutorial flight. Because.. yeah, somebody could start explaining what went wrong and why, but for me it looks like there are still some issues with basic concepts of flying such aircraft type.

Like I said, even if this take-off would not be "allowed" IRL, you still could have made it without stalling.

Edit:

I made a screenshot, video stopped at the moment you raise the flaps from 20 to 10. Your speed is 160kts (dropping, indicated with this little green arrow, called speed trend vector), while the flaps 10 maneuvering speed is about 195kts, as far as I can see it on your video. Maybe it's easier for you to see what I try to tell you if you can see it on a picture.

 

747toswkqm.png

Edited by roesti
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1 hour ago, roesti said:

I made a screenshot, video stopped at the moment you raise the flaps from 20 to 10. Your speed is 160kts (dropping, indicated with this little green arrow, called speed trend vector), while the flaps 10 maneuvering speed is about 195kts, as far as I can see it on your video. Maybe it's easier for you to see what I try to tell you if you can see it on a picture.

 

747toswkqm.png

I realized that and learned the FD is showing the flaps 10 still busy. I should raise the flaps 10 when it moved to the middle of the FD.


Patricio Valdes

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Okay, the amount of fuel for this route makes much more sense now, good! 🙂

Now you rotated a little bit late, just begin slowly rotating when you reach Vr on your speed tape.

Yeah, then the stick shaker came in again.. The reason is your "confusing" flap retraction schedule. Aside from this "extreme" turn right after-take off you're trying to do, you instantly retract all of your flaps. You're in VNAV SPD, which commands 169 kts (below acceleration height). You simply cannot retract all of your flaps with this low airspeed (look up the flap maneuvering speeds of the 747-400), thats why you're almost stalling again.

Watch your speed tape (left on your PFD). You see this green little numbers. At first, there's a little green 10. This is your flaps 10 maneuvering speed, so when your airspeed goes above this speed, you can retract your flaps to 10. You will then see a litte green 5 afterwards. If your airspeed goes above this little green five, you retract the flaps to 5, I think you get the idea ("1" and "UP" are the remaining indications following after 5).. I won't go further into detail here, because there are so many tutorials out there (including a written one coming right with this plane), explaining the procedures and the reasons behind all of this. In my opinion, this is even basic flying stuff as it doesn't matter if you ride on a 747 or a Cessna 172, you should know such numbers on every plane you're flying. So I hope you will read a little bit more about it - believe me, it will make your life easier 🙂

 

20 minutes ago, trisho0 said:

I realized that and learned the FD is showing the flaps 10 still busy. I should raise the flaps 10 when it moved to the middle of the FD.

- Just watch this video - this should answer all questions (they're flying flaps 20 until reaching acceleration height (it's called out in the video, timestamp 2:55 after reaching 3000ft+), then you see how VNAV command 230kts and they start with the retraction schedule)

Edited by roesti

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You just need to study a lot, first you need to understand what is v1, vr, v2, when to retract the flaps...

There is so much missing here and from what I see you really need a basic flight course before you get involved in this airplane.

Just try to follow the tutorials that you have with this software, even find some videos on line and watch closely how they take off etc.

The good news is that you have a somewhat understanding about the FMC and that will make it easier but unfortunately what you really need to learn is impossible to achieve it with just a few messages.

I'm sorry, I'm not looking to discourage you but there is so much to be worked on. 

  • Like 1

Br,

Vlad Tepes

I9-10900K CPU @ 5.0GHz, 64 GB RAM @ 3600MHz, NVIDIA RTX 3090

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2 hours ago, roesti said:

Okay, the amount of fuel for this route makes much more sense now, good! 🙂

Now you rotated a little bit late, just begin slowly rotating when you reach Vr on your speed tape.

Yeah, then the stick shaker came in again.. The reason is your "confusing" flap retraction schedule. Aside from this "extreme" turn right after-take off you're trying to do, you instantly retract all of your flaps. You're in VNAV SPD, which commands 169 kts (below acceleration height). You simply cannot retract all of your flaps with this low airspeed (look up the flap maneuvering speeds of the 747-400), thats why you're almost stalling again.

Watch your speed tape (left on your PFD). You see this green little numbers. At first, there's a little green 10. This is your flaps 10 maneuvering speed, so when your airspeed goes above this speed, you can retract your flaps to 10. You will then see a litte green 5 afterwards. If your airspeed goes above this little green five, you retract the flaps to 5, I think you get the idea ("1" and "UP" are the remaining indications following after 5).. I won't go further into detail here, because there are so many tutorials out there (including a written one coming right with this plane), explaining the procedures and the reasons behind all of this. In my opinion, this is even basic flying stuff as it doesn't matter if you ride on a 747 or a Cessna 172, you should know such numbers on every plane you're flying. So I hope you will read a little bit more about it - believe me, it will make your life easier 🙂 

- Just watch this video - this should answer all questions (they're flying flaps 20 until reaching acceleration height (it's called out in the video, timestamp 2:55 after reaching 3000ft+), then you see how VNAV command 230kts and they start with the retraction schedule

OK I will repeat the flight. I can say I learned about the flaps retraction schedule much better. I will try to takeoff from the other runway side. Before, I used to turn left to be more safe not going to the mountains (too close). Your video is a very good tutorial about flaps retraction but altitude at 5,000 instead of 17,000 from mine. I will proceed with your guidance, cool. Thanks again.


Patricio Valdes

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2 hours ago, killthespam said:

You just need to study a lot, first you need to understand what is v1, vr, v2, when to retract the flaps...

There is so much missing here and from what I see you really need a basic flight course before you get involved in this airplane.

Just try to follow the tutorials that you have with this software, even find some videos on line and watch closely how they take off etc.

The good news is that you have a somewhat understanding about the FMC and that will make it easier but unfortunately what you really need to learn is impossible to achieve it with just a few messages.

I'm sorry, I'm not looking to discourage you but there is so much to be worked on. 

Thanks for your comments I appreciate that. I am not perfect on V1, VR and V2 but I can handle them. 


Patricio Valdes

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Everyone is going on about the plane being overweight/too low flaps reduction speed, but surely the take off direction was wrong for the flightplan indicated on the ND?

Edited by Christopher Low

Christopher Low

UK2000 Beta Tester

FSBetaTesters3.png

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3 hours ago, Christopher Low said:

Everyone is going on about the plane being overweight/too low flaps reduction speed, but surely the take off direction was wrong for the flightplan indicated on the ND?

I think the take-off direction doesn't matter if from FMC the ILS is setup properly. Once Autopilot is engaged the plane will follow the magenta line of ND. I might be wrong ...

Edited by trisho0
n/a

Patricio Valdes

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Gents,

The are many issues here, I want to be very clear here to Patricio that I'm not trying to discourage you from this hobby.

Contrary, I urge you first to study (a very tedious process) and understand the basics of flying a smaller airplane (start with the basics first).

Again, this is the wrong airplane to jump in when there is so much to be learned about flying, as a side note people flying these airplanes have thousands of hours in other equipment before they get to be trained to fly this one.

 

Now regarding the first take-off (forget about the direction of t.o.), even is 11520 rwy at that elevation of 5877 ft a max t.o. wt (396.7 or 396.4) is unrealistic based on day to day operations more so without performance data and trying to use a D-TO.

 

His speeds are V1 162 Vr 175 and V2 182 when I mentioned the understanding of V speeds he said that he's got them under control but is rotating at 164 instead of 175 or taking off at 175 when V2 is actually at 182 makes me ask the question of what is under control.

 

Unfortunately, not familiar with the proper deck angels and pulls a direct 20 degrees nose up putting himself in a worse situation where is losing energy and speed (forget about the FD which is showing him to lower the nose to gain some speed) .

It was not enough that he ran out of speed and energy during t.o. and is behind the power curve, now is pulling the nose up to an unrealistic deck angle for that weight and elevation.

While it can be noted his speed is constantly decreasing and he's still pulling the nose up and banking more, even the speed is low he starts retracting flaps way below the proper speeds getting close to a stall.

 

Next, if someone is paying attention his entering CRZ ALT of 17000 while MSA for that area is 17,500.....

 
On the second attempt, V1 119 Vr 129 V2 144 he is still on the rwy at 160 and starts rotating at about 165...................

 

Unfortunately, there is so much wrong here and misunderstanding that it cannot be fixed over a web-board and that statement of

"I think the take-off direction doesn't matter if from FMC the ILS is setup properly" says it all.

 

Also, there is indeed a SID for both runways it's just the matter of choosing the right one with proper ( or close to) t.o. computations.


Br,

Vlad Tepes

I9-10900K CPU @ 5.0GHz, 64 GB RAM @ 3600MHz, NVIDIA RTX 3090

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and now I can't even takeoff due to the EICAS messages in red:

>Config Park Brk

>Config Stab

with consistent beep sound I had to stop. I was be able to fly this 747 v3 before and not experienced issues with fs9 and FSX. With P3Dv4.5 I started with problems. Even though, joystick profile changed by itself. PMDG 737 and 777 all good.

Is there a way to leave 747 back to defaults or I do have to reinstall in order to get 747 default back as original? 

Edited by trisho0
n/a

Patricio Valdes

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