24 replies to this topic

[mastacheifa118]

Does anyone else here think that the 747-400DD should be nerfed a ton? Its minimum runway distance is 4,973 feet, which is shorter than the CRJ-200LR's 5,347 feet, but those "godzilla" airlines tend to spam my routes with them. I don't understand why a 747 would possibly have a minimum runway distance shorter than a CRJ.

[LATAM]

They were used by ANA (Japan) for domestic flights in a high density configuration, though I'm not much sure about the runway configurations. 

 

LATAM 

[Stevphfeniey]

Yeah I'm really curious to see the math the data collectors used to calculate that takeoff distance.

[0M4R]

You're not wrong.

 

"Minimum TORA (Take Off Run Available): 

B747-400Domestic, CFM56-80C2B1, air conditioning off, Standard day, sea level, no wind, 0° runway slope, 450,000-510,000lbs: 4800ft"

 

(source: boeing)

 

That's a minimum TORA though

 

According to another site:

\

And another

 

It varies so I can't really say for sure what is the "correct takeoff distance" but what we know is that the current data that is being used is incorrect

 

(without counting in wind, air pressure, altitude, weather, etc)

[X-Wing @Aliciousness]

Every other plane in AE has the maximum required takeoff distance as the runway requirement, why is the 747-400D using the minimum?

[LATAM]

Every other plane in AE has the maximum required takeoff distance as the runway requirement, why is the 747-400D using the minimum?

spammers within the AE Dev. corps...? 

[atnt71eb]

 

You're not wrong.

 

"Minimum TORA (Take Off Run Available): 

B747-400Domestic, CFM56-80C2B1, air conditioning off, Standard day, sea level, no wind, 0° runway slope, 450,000-510,000lbs: 4800ft"

 

(source: boeing)

 

That's a minimum TORA though

 

According to another site:

\

And another

 

It varies so I can't really say for sure what is the "correct takeoff distance" but what we know is that the current data that is being used is incorrect

 

(without counting in wind, air pressure, altitude, weather, etc)

 

 

What is the site from which you pulled the 744D's V2 speed? I've been looking for that kind of info as an amateur enthusiast.

 

You all need to keep in mind that all of the listed runway minimums are for a plane at MTOW and standard (ISA) conditions. In reality, it is extremely rare for a plane to need the full runway minimum. Most planes take off at far below their MTOW, especially for short routes. At air shows, a lightly-loaded A380 has taken off in ~4,000ft. 

 

Re the 747-400D specifically, you have to realize that it has far lower MTOW yet the same thrust and wing as a 747-400. That means it behaves like a very lightly-loaded 744; it shouldn't be at all surprising that it has a very short takeoff run. 

[Marb1]

What is the site from which you pulled the 744D's V2 speed? I've been looking for that kind of info as an amateur enthusiast.

 

You all need to keep in mind that all of the listed runway minimums are for a plane at MTOW and standard (ISA) conditions. In reality, it is extremely rare for a plane to need the full runway minimum. Most planes take off at far below their MTOW, especially for short routes. At air shows, a lightly-loaded A380 has taken off in ~4,000ft. 

 

Re the 747-400D specifically, you have to realize that it has far lower MTOW yet the same thrust and wing as a 747-400. That means it behaves like a very lightly-loaded 744; it shouldn't be at all surprising that it has a very short takeoff run. 

You are a spamliner creator. Can't believe you're now talking about realism.

[Pacific]

You know what Realism and Spamlining have in common?

 

An eye for detail with numbers, and how to use/exploit numbers effectively.

[Stevphfeniey]

The only reason why "spamlines" are as big as they are is because there is no growth cap in AE. If both the arbitrary and real world limitations to growth put on airlines were implemented on AE, those spamlines would be about as big as they are in the real world and your airline would be run into the dirt.

 

And I agree with our glorious Emperor that a 747D does have a lower overall takeoff weight, with a reduced fuel load being partially balanced with way more passengers, which with the same engines as a stock 744 would lead to a reduced takeoff roll. A C-17 under the right conditions can get off the ground with 3000 feet of runway. But "right conditions" typically means skeleton crew, no payload and bingo fuel which a 747-400D with 600+ passengers on-board definitely does not fall under.

 

The runway probably shouldn't be the 9000 or so feet takeoff roll of the stock 744 in game, but it also definitely shouldn't be 4000 feet. That would mean fully loaded 747-400Ds taking off from Chicago-Midway on the reg, which is just absurd.

 

DCs do your jobs for once and split the difference.

[WAZZ]

BTW 3320 meters is 10892.3 feet. Barely short enough for EWR.

So if the 2nd statistic is true, the 747DD will be absolute garbage.

If the 3rd statistic is true (7480.315 feet), then it will still be a semi-competent aircraft. Just not the god it currently is..

People will always spamline. It's just nature. Hell even I'm guilty of it too. Nerfing aircraft will do nothing but make the game less fun. So let people use the 747DD. It's better for all of us.

[LATAM]

You know what Realism and Spamlining have in common?

 

An eye for detail with numbers, and how to use/exploit numbers effectively.

[atnt71eb]

You are a spamliner creator. Can't believe you're now talking about realism.

 

We are THE spamline creator. Cower before us and know that your puny airline shall see no mercy.

[mastacheifa118]

Mr. Emperor Dude..... why does it say that you were in the top 10 8 times but in the top 3 10 times and in the first place 10 times?

[Jarkii]

Mr. Emperor Dude..... why does it say that you were in the top 10 8 times but in the top 3 10 times and in the first place 10 times?

A 10th place trophy isnt given out when you get top 3 - only one trophy will be given for an airline when it finishes

[mastacheifa118]

A 10th place trophy isnt given out when you get top 3 - only one trophy will be given for an airline when it finishes

Okay, thanks for clearing that up.

[Stevphfeniey]

So I did a little more digging into this today and noticed that the 744D's MTOW is something like 65% of that of the regular 744. As it turns out the runway usage of the 744D is about 60 something percent of that of a regular 744 at MTOW (which is supposedly what AE data collectors base all the takeoff run numbers from), which isn't an entirely unreasonable assumption to make except for the fact that method assumes that the takeoff run of a completely empty 744 is zero feet. So really that 65% number should be applied to the difference between a 744's takeoff run at MTOW and empty.

[zortan]

You know what Realism and Spamlining have in common?

 

An eye for detail with numbers, and how to use/exploit numbers effectively.

Good point, but not as true with realism, you're not trying to exploit as much to be honest.

 

So I did a little more digging into this today and noticed that the 744D's MTOW is something like 65% of that of the regular 744. As it turns out the runway usage of the 744D is about 60 something percent of that of a regular 744 at MTOW (which is supposedly what AE data collectors base all the takeoff run numbers from), which isn't an entirely unreasonable assumption to make except for the fact that method assumes that the takeoff run of a completely empty 744 is zero feet. So really that 65% number should be applied to the difference between a 744's takeoff run at MTOW and empty.

Fuel.

[atnt71eb]

So I did a little more digging into this today and noticed that the 744D's MTOW is something like 65% of that of the regular 744. As it turns out the runway usage of the 744D is about 60 something percent of that of a regular 744 at MTOW (which is supposedly what AE data collectors base all the takeoff run numbers from), which isn't an entirely unreasonable assumption to make except for the fact that method assumes that the takeoff run of a completely empty 744 is zero feet. So really that 65% number should be applied to the difference between a 744's takeoff run at MTOW and empty.

 

I don't quite follow you here. 

You may be assuming that there should be a linear relationship between weight and takeoff run. Not so. 

Lift is proportional to the square of speed; the dominant form of takeoff drag (induced) is proportional to the square of lift and the inverse of the square of speed. 

To solve for takeoff field length requires multiple complicated calculations, including integrating things like ground drag over the takeoff run. It's probably the single hardest thing to model when designing an airplane. By comparison, figuring out cruise drag and fuel burn is pretty easy (basically a matter of span, wetted area, weight, and engine efficiency). 

[Stevphfeniey]

Well I did my method, punched it into my Ti-84 and came out to about 7000 ft of runway usage. First I found the minimum takeoff run of a 744 which is roughly 4800 feet. Then I took AE's 744 takeoff run of 8400 feet, then subtracted 4800 from that which comes out to 3600. Then I multiplied that by 65%, then added that number back to the 4800 feet and got about 7000 feet.

 

Then somebody sent me this: