An improved model of the standard engine , referred to as the Reanault 12Ff , appeared in Summer 1918 .
An improved model of the standard engine , referred to as the Reanault 12Ff , was used on some later - built aircraft .
An improved model of the standard engine , referred to as the Reanault 12Ff , appeared in Summer 1918 and was used on some later - built aircraft .