During 1916 AEG received an order for two R.I Giant four engine heavy bombers. R was an abbreviation of "Riesenflugzeug" (giant aircraft). All four engines were grouped inside the fuselage and drove four blade propellors at 750 rpm via shafts and gearboxes; a combination leather cone and dog clutch. Two blade propellors were installed later.
One R.I was completed (R.I 21/16) and made its first flight in 1916. During a trial night flight on 3 September 1916 this aircraft broke up in the air with a loss of all seven crew. This crashed was caused by propellor delaminating because of insufficient hardening of the glues. A second machine, R.I 22/16, was still incomplete at the end of World War 1 and eventually scrapped.
Engine: 4 x Mercedes D.IVa, 260 hp
Wing span: 118 ft 1.5 in
Length: 63 ft 11.5 in
Empty weight: 19845 lb / 9000 kg
Loaded weight: 28,003 lb / 12,500 kg