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View Full Version : Tire Loading


joepilot
08-31-2017, 11:00 AM
A question came up that I don't know how to find data on.

What aircraft had the highest tire loading? Also what aircraft had the highest PSI tire loading on its footprint, excluding fighters, which had ridiculously high loadings.

Joe


galaxy flyer
08-31-2017, 04:15 PM
You could look it up here:

https://www.scribd.com/mobile/document/21956554/ACN-s-Tables-Aircrafts-Classification-Numbers

The Sabreliner was right up there at 265 psi on the mains.





GF

tomgoodman
08-31-2017, 06:12 PM
I think LGA used to have a B-727 weight limit for the runway piers, but heavier aircraft (with more tires) were not restricted.


HIFLYR
08-31-2017, 06:54 PM
A question came up that I don't know how to find data on.

What aircraft had the highest tire loading? Also what aircraft had the highest PSI tire loading on its footprint, excluding fighters, which had ridiculously high loadings.

Joe

Are you talking PSI or runway PCN?

badflaps
08-31-2017, 06:55 PM
A 727 main tire won't fit in a DC-9 cargo bay. I'm glad we were close to ATL for delivery purposes.

galaxy flyer
09-01-2017, 07:33 AM
Actually ACN, Aircraft Classification Number which must be less than or equal to the Pavement Classification Number (PCN)

GF

joepilot
09-01-2017, 03:34 PM
Are you talking PSI or runway PCN?

I'm looking for two numbers.

First is highest weight borne by any one wheel of a max gross weight airplane.

The second is the highest PSI exerted by an aircraft tire on an airport surface by a properly inflated tire of a max gross weight aircraft.

I am not concerned with the actual inflation PSI of the tire, except that it conforms to the manufacturers specification.

Joe

galaxy flyer
09-01-2017, 04:27 PM
Because you have to consider the interaction of the pavement type, subgrade, and tire pressure, it's not as simple as you make it. Look at the chart I posted and search for highest ACN.

Here's a good intro

http://code7700.com/acn_v_pcn.htm

This from wiki
The aircraft classification number (ACN) is a number expressing the relative effect of an aircraft on the runway pavement for a specified standard subgrade category, using a method defined by the International Civil Aviation Organization (ICAO).

The ACN is a single unique number expressing the relative effect of an aircraft on a pavement for a specified subgrade strength specifying a particular pavement thickness. It consists of a number on a continuous scale, ranging from 0 on the lower end and with no upper limit, that is computed between two pavement types (rigid or flexible), and the subgrade support strength category. ACN values for civil aircraft have been published in ICAOís Aerodrome Design Manual and in FAA Circular 150/5335-5.

Using the ACN method, it is possible to express the effect of individual aircraft on different pavements by a single unique number, which varies according to pavement type and subgrade strength, without specifying a particular pavement thickness.

The ACN is twice the derived single-wheel load expressed in thousands of kilograms, with single-wheel tire pressure standardized at 1.25 megapascals (= 181 psi). Additionally, the derived single-wheel load is a function of the sub-grade strength.

The ACN of an airplane is a function of not only its weight but also the design parameters of its landing gear such as the distances between the wheels of a multiple-wheel landing gear assembly.

The pavementís strength is denoted by its pavement classification number (PCN).

The load exerted on a pavement by the landing gear of an airplane is denoted as its ACN, or airplane classification number. The ACN is not permitted to exceed the PCN of the runway to be used, in order to prolong pavement life and prevent possible pavement damage.

The ACN is defined for only four subgrade categories (high, medium, low, and ultra low).


GF

sailingfun
09-02-2017, 03:37 AM
The A321 has operational restrictions at LGA due to its wheel loading. It is probably one of the highest loading for current aircraft however the MAX may give it a run for its money.

PerfInit
09-02-2017, 06:12 AM
Chart Supplement (formerly A/FD) specifies the weight bearing limits of the pavement.