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Topic: Considerations For Determining Runway Length
Username: naruto38700
Posted 2012-12-31 10:41:33 and read 2034 times.

I understand there are a lot of factors taken into consideration when you are actually building a runway. Among them we have wind condition, critical aircraft, maximum stage length, aerodrome altitude etc.

The problem is, I know that those factors are there, but still no idea how they influence runway length numerical. Is there a formula to quantify the most optimum runway length using those stats?

For instance, lets say we have prevailing wind 050° at 20 knots, critical aircraft is A380 with the stage length of 13,500 km. What runway length will it be then?

Wish you all a very happy new year, gain your wings and soar higher in 2013!

Topic: RE: Considerations For Determining Runway Length
Username: tdscanuck
Posted 2012-12-31 14:36:13 and read 1995 times.

Quoting naruto38700 (Thread starter):

The problem is, I know that those factors are there, but still no idea how they influence runway length numerical. Is there a formula to quantify the most optimum runway length using those stats?

There is no formula. What you need are the lookup tables for takeoff performance.

Quoting naruto38700 (Thread starter):
For instance, lets say we have prevailing wind 050° at 20 knots, critical aircraft is A380 with the stage length of 13,500 km. What runway length will it be then?

About 9200'.

13500 km is into the part of the payload/range curve on an A380-800 where you have to take a payload restriction to carry enough fuel, so we assume you're at MTOW. MTOW on the A380-800 varies wildly depending on which specific aircraft you're talking about, but we assume 575,000 kg as the high end. At that weight, 0', ISA standard day, you need 9200' minimum (full thrust takeoff, using the whole runway). More would be better. You don't take credit for wind for runway planning because you can't count on it. If the runway is at altitude or it's a hot day, you need more length.

All the information you need for a question like this (to get a rough answer) can be found in the ACAP documents:
http://www.airbus.com/fileadmin/medi...ata/AC/Airbus-AC_A380_20121101.pdf
Tom.

Topic: RE: Considerations For Determining Runway Length
Username: UA787DEN
Posted 2012-12-31 16:15:24 and read 1968 times.

Also, Runways are often built for longest-case scenarios.
Add in Altitude, and the A380 needs more to take off.

And then with the extra built in for safety, a runway built for an A380 won't be 9200'. It will be built for MTOW on a warm day with a tad bit extra. Say 13,000' at least.

Topic: RE: Considerations For Determining Runway Length
Username: RussianJet
Posted 2012-12-31 16:33:42 and read 1958 times.

How about available space? Seems to be a pretty strong determining factor in many cases - how much land is actually available.

Topic: RE: Considerations For Determining Runway Length
Username: naruto38700
Posted 2013-01-01 06:44:44 and read 1865 times.

The available space is for me to determine, and it depends largely on the runway.
A lot of info I can get from the ACAP document.
There is a curve for the runway length needed! So I will just refer to the graph and determine the the length with some assumptions.
Thanks guys, all your answers are sincerely appreciated!


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