Unreliable Airspeed B767 specific procedure
 

Hi ! Can someone explain-
in the Qrh explanations for unreliable airspeed-
it says that Rudder ratio fault is an indication of UAS , how is it correlated ?

It doesn’t say RUDDER RATIO is an indication of unreliable airspeed. It says:

“Display of one or more of the following EICAS messages may be evidence of unreliable airspeed/Mach indication:
•AILERON LOCKOUT
•ALT DISAGREE
•CAPT PITOT
•F/O PITOT
•IAS DISAGREE
•L AUX PITOT
•OVERSPEED
•PROBE HEAT
•R AUX PITOT
•RUDDER RATIO”

Basically, faults that may corrupt the input to the ADCs such as PROBE HEAT or failure of systems that have an ADC input such as RUDDER RATIO, may be an indication or confirmation of unreliable airspeed.