Thanks for info. One never stops learning something new. Been into and out of ANC a few times in very cold winter weather, but never made any Temp corrections to QNH. Does ATC include QNH corrections when Temp goes out of ISA Barometric Altimeter envelope? I don't recall the temperature during my last approach into ANC, but the Radar Altitude and Barometric and Electric Altimeter altitudes all jived. <img src="confused.gif" border="0">