In the ole ATPL(H) material Hydraulic Lock is described as different to Jack Stall- which if I remember correctly is a hydraulic force overload. Hydraulic Lock as I understood it from the ATPL(H) studies is a failure (design or mechanical) in which the hydraulic pressure gets around the back of the relevant actuator(s) and the controls become hydraulically 'locked'.
Definition of mourn - feel or show sorrow for the death of (someone), typically by following conventions such as the wearing of black clothes Definition of mourn - feel or show sorrow for the death of (someone), typically by following conventions such as the wearing of black clothes dictionary thesaurus
diurnal - of or belonging to or active during the day; diurnal animals are active during the day; diurnal flowers are open during the day and closed at night; diurnal and nocturnal offices. 1  biological science, biology - the science that studies living organisms.