Three basic enquiries

[WTE_Galway]

Originally Posted by AndyJWest

The maximum speed for an aircraft is usually attained at a medium-high altitude. It is measured in level flight, but note the speedbar and instruments give indicated airspeed (IAS), rather than the true airspeed (TAS) - instruments of the time couldn't give accurate TAS, and for many purposes, IAS is more relevant, but IAS gets relatively slower than TAS with increasing altitude. If you shitch to 'no cockpit' view (ctrl-F1 toggles this, I think), you will get a dial showing TAS (or more correctly, groundspeed, though without wind TAS = groundspeed anyway), this is in Km/h.

Where it really matters you should be working with CAS or EAS not IAS.

In terms of speeds at sea level ... CAS=TAS=GS at standard temp and pressure with no wind.