232 establishes a threshold pitch attitude rate against which the pitch attitude rate signal q provided by pitch attitude rate information source 214 is compared to determine whether aircraft takeoff or flight conditions warrant display of warning symbology the pitch attitude rate signal q and the output of memory site 232 are applied to respective inputs 234 and 236 of a comparator 238 which provides at its output a pitch attitude rate display enable signal that appears whenever the pitch attitude rate signal represents a pitch attitude rate that reaches or exceeds 4 5 degrees per second the outputs of comparators 138 and 238 are applied to respective inputs 240 and 242 of an or gate 244 to provide alternative display enable signals to input 140 of display logic module 142 the output of or gate 244 provides display enable signals that cause a display of tail strike warning symbology whenever the pitch margin equals or exceeds 3 0 degrees or the pitch attitude rate equals or exceeds 4 5 degrees per second fig5 shows combiner 20 displaying an exemplary tailstrike warning annunciation 300 when an aircraft is on approach to landing and symbol display logic module 142 is enabled in either the first or second embodiment symbol display location module 124 displays tailstrike annunciation 300 above a flight path symbol 302 on combiner 20 flight path symbol 302 represents the instantaneous direction of the inertial velocity of the aircraft relative to its longitudinal axis positioning tailstrike warning annunciation 300 in proximity to flight path symbol 302 as a reference is intuitively appropriate because the attention of the pilot using a head up display is centered about the flight path symbol during approach to landing an altimeter reading indicating.