ACN vs. PCN vs. Tyre Pressure
 

Help needed with ACN vs. PCN

Now I know that ACN has to be less than PCN, so long as tyre pressure is at or below limit of runway, you're good to go. My question is around the B777-300ER and B777F...

Both have a standard tyre pressure of 221 psi, yet many of the airports it operates into/out of have a PCN containing the restriction of 217 psi (or X - medium tyre pressure category).

Im a little confused...

So how is this allowed? Is this just a recommendation? Do the aircraft operators have to lower tyre pressures? Do the aircraft operators have to have prior agreement with airport operator?

Any help would be awesome, thanks :ok:

Somewhere in the theory there is a frequency effect. This means you can go over the PCN limit as long as you don't do it too often. If you operate daily then the ACN/PCN limits are enforced more.

Aircraft classification number - Wikipedia, the free encyclopedia

Thanks for the response.

Sydney and Melbourne airport have max tyre pressure limits of 217 psi, so would operators that fly daily to these airports in the B777-300ER have weight restrictions? As the B777-300ER has a standard tyre pressure of 221...

FWIW "we" operate a 777-300ER into SYD daily with no additional weight restrictions above and beyond the normal airframe limits.

Thanks for the response Wiggy, still a little confused by the whole thing, airport companies are no help either...

I think 1.1.3.9 on page 3-10 of ICAO DOC 9157 (edition 2 in 1983) can answer your question.