ACN/PCN and Gross Weight

[BlueDevil2cs]

Hello everyone,

I am a civil engineering student, who currently works at a firm that specializes in airports. My question is:

How do you calculate the allowable gross weight of the runway?
And why are there different types of gross weight?

An example of the data I'm talking about:
AirportIQ 5010 (http://www.gcr1.com/5010web/airport.cfm?Site=SYR)

I know gross weight is somehow related to the PCN of the runway, but does anyone know the actual method or calculations?

Thanks in advance

- Chad

[Rigga]

BD2,

While I realise that yours is a well worded and precise question, I hope you realise that this forum is generally used by aircraft maintenance engineers & technicians who probably don't know too much of building runways.

A "PCN" on this forum normally indicates a type of qualification or grade for Non-Destructive Testing or Non-Destructive Inspection.

Try the UK CAA website for some info - they have loads of "Stuff" for airport rules and infrastructure, like this...

http://www.caa.co.uk/docs/33/CAP700.PDF

[BlueDevil2cs]

Thanks Rigga,

I guess I had not realized that. Thank you for the link. I appreciate the reply.

- Chad

[mutt]

I saw the question whilst passing :):)

Google "b747 airport characteristics" and you will find a manual that details how to calculate the actual ACN of the aircraft, this is then compared to the PCN for the actual runway.

Alternatively look at the Jeppesen Manual, it has a complete listing of aircraft ACN versus weights.

Good Luck.....

Mutt

[yowieII]

Also have a google for Californian Bearing Rating(CBR), which as I remember is the actual substrate load bearing capability that PCN and ACN are related too.

[Capot]

Yowie's post rang a bell, and then the words "Falling Plate Test" floated into mind as the actual means of measurement, which is - I think - dropping a heavy object on to the pavement from a height and measuring the echoes and ripples that the impact causes to assess the substrate's density at various depths and thus its strength. Or something like that.

Much like seismic surveys for oil-bearing strata. Perhaps it's much more sophisticated these days.

Google might help; I haven't looked yet.

[BlueDevil2cs]

Thanks everyone for the help.

I did manage to determine what the different types of gross weights were. They specify different wheel configurations. SW = Single Wheel, DW = Dual Wheel.....

Still no luck on the calculations, but i do appreciate your responses.

[BlueDevil2cs]

Alright,

We have found the solution!

After researching this for wayyyyyy too long. I found the answer while reading through the FAA Advisory cirulars. http://www.faa.gov/documentLibrary/media/Advisory_Circular/draft_150_5335_5b.pdf

The simplest method is to insert a large amount of data(including pavement design data, aircraft data, and life expectancy) into a computer program. The program is COMFAA.

Again thanks again. I sincerely appreciate it.

[BeeBopp]

Try this link for some basic info. At the bottom there is another link for calculating load data. Interesting that landing impacts are amongst the least stresses a runway or apron has to endure but pretty obvious when you read this.

Pavement Operations - Pavement Management Systems - Airfield Pavement - Technical - International Operations - Aviation Safety - Air Transportation - Transport Canda (http://www.tc.gc.ca/CivilAviation/International/Technical/Pavement/management/operations.htm)

[john_tullamarine]

You might also consider posting a similar question in Tech Log and running a search into the archives.

OverRun is a regular there and is an acknowledged expert on pavement design matters.