O.k. I got the fact that under 10,000 feet at say an airport like KMSP speed should be kept at or under 250kts. What about an airport that's 5,000ft up. KDEN for example... Is there a higher altitude (15,000ft) for speed restrictions based on the higher elevation of the terrain??? Just thought I'd ask as I've been wondering about this for awhile now...

The 10,000 feet speed restriction is MSL (Mean Sea Level) only, not AGL (Above Ground Level), at least in the US. So even at KDEN it is 10,000ft. Tibet has probably a different setup, maybe not - good question.Pat

Thanks... :-)

Hi Chris,As Pat says, the speed restriction that you refer to, plus the FAA altitudes for mandatory supplemental oxygen requirements, and other altitudes such as the floor of the Class A airspace, remain the same here in Denver as in the rest of the US. They are MSL, or in reference to mean sea level.Other altitudes such as airspace ceilings (other than class E and A), minimum safe altitudes (MSA) and many other, that reference ground level altitude (AGL), are higher here than in most other places.Bruce.