The no speed restriction option on the controller menu is greyed out for US airspace. Is this true to life?Any info would be appreciated.TIA

Yes, this is correct. Elsewhere, pilots can ask for cancellation of speed, and traffic permitting, it will be granted. But in FAA airspace this is a big no-no, and I believe controllers do not have the option to authorise higher than 250kts below 10,000ft even if they wanted to. So RC has been developed with this in mind.Interesting to note though in r/l here in Australia, I often hear controllers actively approving high speed climb, without the pilot even asking for it. It is such a big contrast to FAA, (probably due to the difference of traffic density).Subs

Hi Ulysese,That is the rule for FAA airspace. The option was provided for non-FAA airspace where the restriction is often lifted in real-world ops.Come over and fly in Europe where the speedcops don't give you any grief :-lolCheers,

Not 100% sure, but I believe the 250kt speed restriction can be waived in the US for a "heavy" aircraft. Doug or one of the otherr/l controllers can confirm or deny.

I don't live in the states but I also thought the 250kt rule could be waved for heavies, the reason why escapes me at this present moment thoughAlan

So, in some situations a heavy 747 could climb to FL100 with flaps deployed as the clean speed would be greather than 250!Thanks,

I've authorized this once in 25yr. A loaded b747 from KHSV to Euro, at about 2:30a local. States authorization (let alone the request itself) is almost unheard of.