Originally Posted by
aajones
"Speed" isn't really a technical term in aviation...there are several types of speed that all mean different things. What you most likely experienced is a large difference between indicated airspeed and speed over ground. Indicated airspeed is the speed of the plane moving through the atmosphere--which is the forward speed of the plane plus any atmospheric factors, like wind. Speed over ground is the speed the plane is moving relative to the ground.
What you say is only half true. Indicated airspeed is NOT the speed of the plane moving through the atmosphere however. It is the speed at which an aircraft flying under standard conditions at sea level would be going to create the same difference between total pressure and static pressure. (ouch... that's technical
)
The speed of the plane through the atmosphere is the true airspeed. And in Denver, in particular, true airspeed is higher than indicated airspeed. Roughly speaking, for a given indicated airspeed, the true airspeed increases as the altitude increases.
To the pilot however, indicated airspeed is the important one, because the stall speed is always at the same indicated airspeed independently of the altitude (for a given weight).