O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Oertz V4
   The Oertz V4 (100 hp 14-cylinder Gnome rotary) first flew on March 31, 1912, flown by Henri Wijnmalen. Owing to speed of 172 km/hour that the machine attained on a flight from Bremen to Hamburg (with tailwind !). Wijnmalen got the idea to make a racing variant and to participate in the Gordon Bennett Race in September 1912 in Chicago. Unfortunately there was not enouigh money for the journey to the USA. So the machine never participated.
   The machine was offered to the Preussian Fliegertruppe, but was not bought with the rreason that 'the machine was too fast for normal flyers'.
   In Chicago Jules Vedrines won the race with a speed of 174 km/hour.
   There is a note that one Oertz Eindecker (unknown) type was bought by Krupp for a price of 25,000 DM.

   Oertz V5
   This machine is designated Max Oertz V5. Machine was powered by a 14-cylinder rotary enhgine (Gnome) of 100 hp. The first flight of the machine was made in January 1913, piloted by Marchal.
   The pictures presented were taken on the flying field Schneverdingen, south of Hamburg in the summer of 1913.
   Span: 12,5 meter Lenght: 10 meter Max. speed: 135 - 170 km/hr
   Range: 400 - 500 km Climb with fuel for four hours: 15 minutes to 540 meter.

Jane's All The World Aircraft 1913

OERTZ. Max Oertz, Yachtwerft, Reiherstieg b. Hamburg. Famous yacht builder. Commenced aeroplane construction in 1911. Existing models as below. Capacity about 25 machines a year.

   M 1911-12. M 1912-13.
   Monoplane. Monoplane.

Length......feet(m.) 29? (9) 30? (9.2)
Span........feet(m.) 41? (12.75) 41? (12.75)
Area...sq.feet (m?.) 247 (23) 263 (24.5)
Weight,
   total...lbs.(kgs.) 948 (430) 1212 (550)
   useful..lbs.(kgs.) ... ...
Motor...........h.p. 70 Gnome 70 Gnome
Speed,
   max....m.p.h.(km.) 69 (110) 75 (120)
   min....m.p.h.(km.) ... ...
Endurance.......hrs. 3 4
Number built
   during 1912....... 3 1