ACN-PCN Relation and Calculation

[CURAviation]

Dear all,

I just read an archived thread about PCN values and runway usage. I saw that member Overrun had some good explanations. I'm not that active yet on this forum which is why I ask my question here again regarding PCN values.

I read that an aircraft can land on a runway with a higher ACN value compared to the runway PCN. How can this be determined? I thought that the PCN could never be exceeded by the ACN. If an aircraft lands on a runway with a higher ACN on a frequent basis, how can it be calculated how often such aircraft are allowed to land on the runway?

Overrun, can you explain this to me in more detail? Many thanks.

Edit: What do the different letters mean, such as F, B, X, U, A, W, T? I assume these letters can be used in all combinations depending on the calculation and/or condition of a runway?

Best regards,

CURAviation

[Sir George Cayley]

What ever Overrun Engineer says is gospel. Right?

But pragmatically the PCN of a runway is something ATC know nothing about, and a one off landing will only reduce the life expectancy of the pavement. So, if you want to operate a 48 ACN a/c off a 24 PCN runway just the once I woudn't worry. (Unless colleages have been doing the same foe years).

If you fly a B777 then be afraid, be very afraid.. but otherwise it's a technical foul not a life or death event.

BTW where? what and when?

Sir George Cayley

[john_tullamarine]

I thought that the PCN could never be exceeded by the ACN.

For the operator/pilot, this is true. However, if the operator obtains a concession from the airport operator, then that concession will specify a higher PCN (with whatever restrictions are appropriate) so the relationship remains correct. The only time a pilot can exceed the PCN is in an emergency type of scenario.

The subclassifications should either be described in other threads or in your AIP.

What ever Overrun Engineer says is gospel. Right?

... when it comes to airports and runway engineering .. essentially, your tongue-in-cheek comment is correct. Overrun is an airports engineer of eminent Industry standing.

the PCN of a runway is something ATC know nothing about

I would be extremely surprised if this were the case .. ATC will be more than moderately aware of all relevant restrictions in their airport of activity .. perhaps some of our ATC folk might like to comment ?

So, if you want to operate a 48 ACN a/c off a 24 PCN runway just the once I woudn't worry

Not in my technical/legal ambit so I can only offer a lay view. I would be concerned about the potential for

(a) pilot/operator regulatory penalty - this limitation has impact on both the runway (long or short term depending on the circumstances) and, perhaps, the aircraft in an event which results in some runway damage .. say, pavement spalling and aircraft damage ?

(b) insurance considerations in the event of any damage ?