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707 max weight/TO weigt problems: to climb, speedup, range

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707 max weight/TO weigt problems: to climb, speedup, range

Postby Sarith » Tue Jul 25, 2017 11:25 am

Hey I realy like the 707, but no I had some porblems with this old lady. I wanted to fly form KORD - EDDF cause I look up the long range in the internet and it should fit for the 707. I set standart passengers in the fuelmenu and add about 60t kg fuel. After starting I had the problem at like around 10t ft that the 707 was realy hard to climb with. My planned flightlevel was 350 but i never get ther after 1/4 of the rout all main tanks where empty so is their a trik to speed up and climb with the heavy old lady ;-) And How I should fly long distances with Passengers without running out of fuel cause of the hard climbing.
I ll be happy for any help !
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby legoboyvdlp » Tue Jul 25, 2017 11:57 am

Well, "heavy old lady" means just that: heavy :)


You should level out at about level 300, fly for about an hour there, then climb about 2000 feet more, then fly for an hour more there. That avoids that problem. Also, you probably added 60000 lb of fuel by accident instead of kgs!
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby Sarith » Tue Jul 25, 2017 12:24 pm

ok thanks but with the fuel im sure it was 60t kg
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby wkitty42 » Fri Jul 28, 2017 5:13 pm

i just noticed that the fuel truck dialog only measures in kgs and it isn't an "add X kgs fuel to the tanks" but "make a total of X kgs in the tanks"... in this instance, "add" is the wrong word because we're not adding 60000kgs to the fuel but we're filling the tanks up to 60000kgs total on-board fuel... it threw me off, too...

so after the fill up, i have the following on board:
60018.6kgs fuel
17772kgs pax and bags

301308lbs gross weight
311000lbs max TO weight

[edit]
i do have a question, though... what's the sound that sounds like cards being shuffled kinda slowly? we're climbing to 25000 now and then on to 35000 in another 2 or 3 steps... is it something to do with the throttle, maybe? some kind of warning?
[/edit]
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby wkitty42 » Fri Jul 28, 2017 11:15 pm

well, that really sucked... apparently i lost two engines while just short of YLK by about 50nms... how do you restart the engines in the air? even the autostart failed after it first shut off the other two! good grief :(
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby legoboyvdlp » Sat Jul 29, 2017 11:42 am

wikitty,
You probably don't have enough fuel in the feed tanks and had to open crossfeed valves or something?
And that sound is the trim as far as I know :)
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby wkitty42 » Sat Jul 29, 2017 6:35 pm

according to the checklists, everything was right... i didn't mess with the crossfeeds after getting the engines started... fuel was being pulled from all the tanks when i looked at the fuel and passengers dialog... you could see the fuel counting down in all the tanks... maybe i'll try it again with fuel freeze turned back on and see what happens...

i'm guessing i should see the trim wheels moving when i hear the sound? she was flying with her nose up... yoke all the way back and trim all the way back, too... she was really working it to go higher :lol: even had to cut the speed back to ~175 so the engines weren't full throttle all the time...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby asr » Mon Jul 31, 2017 9:51 am

Hi wkitty42,

The 707 is a bit overwhelming to manage until you get used to it. I haven't done any long flights recently, but have flown ~10hr trips in the past without trouble.

Make sure you are following proper procedures for T/O and climb, its crucial for having decent climb performance:

During take off, full throttle, then release brakes.
During take off run, When you get past 100kias, reduce throttle out of the "yellow" range for N1 (This isn't strictly necessary in the sim).
Below FL100, don't exceed 250 kias (again, regulation, not strictly necessary).

Now the important:

After FL100, reduce pitch to achieve 300kt IAS. Maintain 300kts at all times either by reducing pitch as you climb or increasing throttle.

In a heavy loaded aircraft, you'll probably have to settle at some point past FL200 and before FL300. I do it when I can no longer climb at least 1000fpm. Cruise at this altitude until you feel you've burned enough fuel to climb some thousands feet more.

At some point around FL290, Mach speed reaches M0.78. At this point, ignore the 300kt IAS rule and instead maintain M.78 (The mach speed indicator is in the lower left corner of the panel).

My ideal target for cruise is FL330. Find it a waste of time to go higher than that.

In cruise, you shouldn't have any trouble holding M.82-M.83, that's the speed I usually cruise. You'll have to constantly monitor the speed as the 707 has no autothrottle. Be careful not to overspeed as you may lose some engines, presurization and A/P if you get close to M.90.

- The noise you're hearing all the time is the trim wheel being moved by the A/P. I have a patch to reduce this effect's volume because it gets really annoying

Other than that if you need more help with the 707, I would love to do a dual pilot flight. You can find me in the discord server or mumble.
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby Isaak » Mon Jul 31, 2017 1:25 pm

wkitty42 wrote in Sat Jul 29, 2017 6:35 pm:according to the checklists, everything was right... i didn't mess with the crossfeeds after getting the engines started... fuel was being pulled from all the tanks when i looked at the fuel and passengers dialog... you could see the fuel counting down in all the tanks... maybe i'll try it again with fuel freeze turned back on and see what happens...

i'm guessing i should see the trim wheels moving when i hear the sound? she was flying with her nose up... yoke all the way back and trim all the way back, too... she was really working it to go higher :lol: even had to cut the speed back to ~175 so the engines weren't full throttle all the time...


When I read this, I would guess you hear the yoke shaker because you are stalling. (it 's been a while since I last flew the 707 so don't shoot me if I 'm wrong) The yoke and trim way back mean that your autopilot is desperately trying to keep the current altitude but can only barely manage to maintain it. I guess this contributes to your bad fuel management because you would need full power to maintain altitude and speed in such a bad nose up attitude (invoking way more drag than necessary). Try to maintain speed as ASR suggested, so you don't get in an infinite near-stall condition.
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Re: 707 max weight/TO weigt problems: to climb, speedup, ran

Postby wkitty42 » Mon Jul 31, 2017 6:15 pm

i appreciate the comments, folks... i can see and understand what you are saying... i turn off the yokes so i can see things easier so i would not have been able to see the yoke shaking because of this... no autothrottle?? really? i set the speed value in the F11 dialog and watched the throttles move back and forth on the HUD as well as the center console... on the yoke and trim being all the way back, i figured it was because it was trying to do several things... mainly to gain altitude which is was doing but rather slowly... when i reduced the throttle to maybe level out and hold the current altitude, she would drop but i'm guessing that was because of not correcting the yoke and trim for level flight but then again, nose up was holding altitude and climbing... until the two engines went...

so anyway, based on this information, i may try again and see hos high i can get her to go... as noted previously, it was my first time in the craft and i went full on with no documentation other than the checklists to get the engines started and what to do once airborne...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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wkitty42
 
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