For an aircraft with such flight envelope, the flight conditions in point
D are associated with symmetrical pitch maneuvers. So, for the combination of loads factor
n and speed
V in each of those points represents a symmetrical pitch maneuver, in which there is a certain angle of attack and certain deflexion of the elevator, both different from zero - all other control surfaces wouldn't be deflected. That comes from reports from SAE aero design competition and from
Structural Loads Analysis: Theory and Practice, Lomax
I understand the airplane can execute any maneuver so long it is inside the flight envelope, but why are the critical pitch maneuvers those "described" by points
D whereas critical rolling or yawing maneuvers have clearer definitions* regarding the most extreme conditions related to those maneuvers?
*Here's an example from
Lomax (nothing like that is said from symmetrical pitch maneuvers)
Two types of yawing maneuvers, as shown schematically in Fig. 4.1, must be considered for structural design...