Albatros D IV

The D.IV was developed essentially to test the geared version of the 160hp Mercedes engine (this having reduced the 1400rpm of the engine crankshaft to 900rpm at the propeller). It was based on the D.II cellule, but substantially enlarged, and three D.IVs were ordered in November 1916. It is believed that only one of these was completed and flown. It was tested with two-, three- and four-bladed propellers until April 1918, but excessive vibration led to the discontinuation of the programme.