An additional 15 Do 17 U-1 Pathfinder model were built, as was the S-0. A renovated front fuselage was introduced that increased the height of the cabin, allowing a crew of five men (two radio/operators) and a machine gun installed in a lower hemisphere. Twelve production aircraft, target markers, Daimler-Benz 600A engines. First flight in early 1938.

The U models are used to fly ahead of other bombers on night missions using radio equipment. The measure was personally requested by KG 100 as experimental models for this function. The U-1 had a maximum speed of 424 km/h and a combat ceiling of 4,500 m . The U-1 had a cruising speed of 384 km/h  and a maximum attainable altitude of 5,700 m , due to the lower performance of the Bramo 323 A-1s. The three prototypes (U-01 – U-03) and twelve production aircraft were built in 1938. In total only fifteen Do 17-U were built.
Type 5-seat Pathfinder
Engine 2 BMW Bramo 323A  with 3-bladed VDM variable pitch propellers, dia 3,6 m
Dimensions Length 15,8 m , height 4,6 m ,  span 18,0 m , wing area  55,0 m2 ,
Weights Empty 5775 kg, loaded 8505 kg , max. take off weight   fuel 2 x 700 l + 2 extra tanks. Total capacity 2660 l
Performance Max.. speed 417 km/h sea level , , range 2945 km at sea level endurance  , service ceiling  6000 m , climb to 4000 m 18  min.
Armament 1 7,92 mm MG 15
Type Werk.Nr Registration History
U-01
U-02
U-03
U-1