AEG R.I

The AEG R.I (Riesenflugzeug - giant aircraft) was a four-engined biplane bomber aircraft of World War I.

Design and development
The R.I was unusual for a multi-engined aircraft in that rather than mounting propellers directly to the engines and mounting these in nacelles, the R.I carried all its engines within the fuselage and turned its propellers via a system of drive shafts. A single prototype was completed and flew in 1916. Initial flights were quite successful, the aircraft being considered very manoeuvrable, but on 3 September 1918, a newly assembled propeller, which had not been given sufficient time for glue to cure, disintegrated. The vibrations resulting from that failure caused the complex transmissions and shafting connecting all four engines to both propellers to tear loose, which then cut a center section strut, resulting in the break up of the aircraft, killing all seven crew on board. Of the seven further AEG R-1's planned or under production when the war ended (R.21, R.22, R.59, R.60, R.61, R.62, R.63 and R.64) only the R.21 was finished and R.22 partially complete.