According to the IFH, in moderate unusual attitudes, the pilot can normally reorient by establishing a level flight indication on the attitude indicator. The IFH cautions, however that “the pilot should not depend on [it] if the attitude indicator is the spillable type, because its upset limits may have been exceeded or it may have become inoperative due to mechanical malfunction.” (We note that determining this is best done on the ground. We also note that we’ve had the same AI for more than 20 years and have no clue if it’s spillable.)
Even if it is a non-spillable instrument and is operating properly, the unusual attitude itself may introduce errors of up to five degrees in pitch and bank. Further, its indications may be difficult to interpret in extreme attitudes. Unless the airplane’s POH/AFM includes recommended procedures to the contrary, recovery should be initiated by referencing airspeed, altimeter, vertical speed and turn coordination.