Go to the FAA Type Certificate database at:
http://www.airweb.faa.gov/Regulatory...e?OpenFrameSet

Each type certificate lists the maximum operating airspeed and Mach
number. The airspeed is the limit until an altitude is reached at which
the Mach number listed equals the airspeed. Then, the Mach number
limits the aircraft. Be careful - some type certificates list the
airspeed in Knots Indicated Airspeed (KIAS), some in Knots Calibrated
Airspeed (KCAS), some in Knots Equivalent Airspeed (KEAS) and some in
Knots True Airspeed (KTAS).