Re: Thickness of Runways

From: (Jeff Berton)
Date:         01 Dec 93 20:47:28 PST
References:   1
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In article <airliners.1993.758@ohare.Chicago.COM>, (Philip Papadopoulos) writes:

> How thick is the average concrete runway that is capable of handling
> "heavies" (e.g. 747,767, MD-11, L1011, AB300, etc.)?   

The stress imparted to a runway is a function of, among others, strut load,
number of tires per strut, tire spacing, tire size, and even tire pressure.  

Here are some numbers from Lockheed's "Landing Gear Design Handbook" (1982):

Aircraft       Gross Weight     Concrete Thickness at Static Load
  Type            (lbs)            for Unlimited Operation (in)

  747            775000                        12.8
  C-5            769000                        10.0               
 L1011           410000                        11.9
 C-141           316000                        12.3
  707            297000                        11.3

An interesting comparison involves the 747 vs the C-5.  Both have similar gross
weights, but the unusual gear arrangement of the C-5 allows nearly 3 inches
less runway thickness.  And the C-141, at four-tenths the weight of the 747,
requires nearly the same runway thickness.
Jeff Berton, Aeropropulsion Analysis Office, NASA Lewis Research Center