Analysis of Air Transportation Systems Fundamentals of Aircraft ...

Estimating Runway AccelerationUsing Newton's second law and summing forces in thehorizontal direction of motion ( x),ma x = T( V , !)– D– ( mg cos) – L)f roll – mg sin)(19)linear variations of T (tractive effort or thrust) and f roll canbe assumed to be linear with respect to airspeed for therange of speed values encountered in practice. For smallangles this equation can be expressed as,ma x = T( V , !) – D – ( mg – L)f roll(20)ma x = T( V , !)11– --! V 2 sc D – mg – --! V 2 SC L2 # % 2 $& froll(21)1a x = --- ( T(V , ! )m+1--! V 2 S( C L f roll – C D ) – mgf roll2(22)Virginia Tech - Air Transportation Systems Laboratory 31