For main gear oleo strut servicing, when we charging it with nitrogen, The dimension of oleo extension would increase or decrease.As wat i understand, the pressure of strut may remain constant as it reflect the weight of aircraft acting on it. Any idea about the construction and theory of b777 strut. the damping action is by its oleo fluid or compress gas in the strut? Question 2: How the aircraft calculate the EPR of the day(max epr) ; when aircraft is power up eventho engine EEC is not powered, the value is still showing on the EICAS. Does it mean it do nothing with the EEC?