FE Hoppy
Therefore if I'm at a speed lower than that required to maintain 1g flight I am by definition stalling.
That definition applies to a straight and level flight.
By definition, in the descent equation, weight is higher than the produced lift, at a reduced Cl, meaning a smaller α.
not according to the regulation by which all modern aircraft are certified.
I know exactly what you mean by the classic definition but we now have FBW systems which prevent it happening. Even before FBW if an aeroplane had stall characteristics which were no deemed appropriate a stick pusher was used to prevent the aircraft from reaching the classical "stall".
There is a difference between ”aerodynamic stall” and “stall recognition” and even more with "stall protection", of which the stick pusher is one.
3.3.2 DEFINITION OF STALL SPEED
“The stalling speed, if obtainable, or the minimum steady speed, in knots (CAS), at
which the airplane is controllable with.... (the words that follow describe the required
configuration).”
- FAR Part 23.45
“The stall speed (equivalent airspeed) at 1 g normal to the flight path is the highest
of the following:
1. The speed for steady straight flight at CLmax (the first local maximum of lift
coefficient versus which occurs as CL is increased from zero).
2. The speed at which uncommanded pitching, rolling, or yawing occurs.
3. The speed at which intolerable buffet or structural vibration is encountered.”
- MIL-STD-1797A
From a test pilot’s perspective, the task is to investigate how much lift potential can
be exploited for operational use, without compromising aircraft control in the process. The
definition of stall speed comes from that investigation.
The discussion of minimum speed includes the notion of maximum lift coefficient
(CLmax). To maintain lift in a controlled deceleration at 1 g, the lift coefficient (CL)
increases as the dynamic pressure decreases (as a function of velocity squared). This
increase in lift coefficient is provided by the steadily increasing during the deceleration.
At some point in the deceleration the airflow over the wing separates, causing a reduction
of lift. The lift coefficient is a maximum at this point, and the corresponding speed at these
conditions represents the minimum flying speed.
The speed corresponding to CLmax may not be a reasonable limit. Any other
potential limitations may prescribe a minimum useable speed which
is higher than the speed corresponding to CLmax. The higher speed may be appropriate due
to high sink rate, undesirable motions, flying qualities, or control effectiveness limits.
Influence of the separated flow on the empennage may cause instabilities, loss of control,
or intolerable buffeting. Any of these factors could present a practical minimum airspeed
limit at a lift coefficient less than the CLmax potential of the airplane. In this case, the classic
stall is not reached and a minimum useable speed is defined by another factor.