sentences:  Both the German Air Force and the German Army placed a combined order for 428 aircraft of the "Do 27A" and "Do 27B" variants, the latter being equipped with dual controls for use as a trainer aircraft.The Do 27 was widely employed as a general purpose aircraft, frequently being used for utility transport and liaison duties.Late on in the type's production run, a modified model of the aircraft, known as the "Do 27Q-5", was developed; it had the same basic specifications but was equipped with a wider-track landing gear.