the wing-fuselage join and radiators, retractable wind generators. TB-3 4AM-34RD A series of long-range demonstration aircraft with streamlined fuselages and wheel brakes. Some aircraft had single main gear wheels in diameter and three-blade metal propellers. Used for flights to Warsaw, Paris, and Rome in 1933–1934. TB-3 4AM-34RN High-altitude version with AM-34RN engines, four-blade propellers on inboard engines and two-blade on outboard, single main wheels, turrets upgraded to ShKAS machine guns, top speed at , service ceiling . Tested in August–October 1935 but did not enter production as the basic TB-3 design was becoming obsolete. TB-3 4AM-34FRN/FRNV AM-34FRN/FRNV engines with increased power output and four-blade propellers, aerodynamic refinements including streamlined turrets, main wheels with brakes, top speed over . TB-3D Proposed variant with Charomsky AN-1 diesel engines of and projected range of , did not enter production as other performance characteristics were inferior to TB-3 4AM-34RN. G-2 Retired TB-3s with M-17 and M-34 engines converted for freight duties with Aeroflot ANT-6-4M-34R "Aviaarktika" TB-3 modified for the 1937 expedition to the North Pole with enclosed cockpit, single main wheels, three-blade metal propellers. Operators Nationalist China Air Force Aeroflot Soviet Air Force Soviet Naval Aviation Accidents and incidents 17 March 1938 A Polyarnaya Aviatsiya G-2 (CCCP-N210) crashed on landing at Bukhta Teplits; ground fog forced the crew to perform a go-around. As a result of poor CRM the aircraft re-entered the fog. Descent was continued until the left landing ski struck snow, ripping off the landing gear and causing the aircraft to crash; all seven on board survived, but the aircraft was written off. 14 March 1941 An Aeroflot G-2 (CCCP-L1496) stalled and crashed near Begovat, Uzbekistan after the pilot attempted to climb following a loss of altitude caused by severe turbulence, killing the six crew. The aircraft was operating a Tashkent–Fergana cargo service. 27 August 1941 An Aeroflot G-2 (CCCP-L1996) struck a hill near Kizyl-Arvat, Turkmenistan while attempting to make a forced landing after the crew failed to locate their destination, killing six of nine on board. The aircraft was operating a Tashkent–Ashgabat cargo service. 26 December 1941 An Aeroflot G-2 (CCCP-L3043) crashed near Dmitriyevka (now Bayserke), Kazakhstan after the aircraft lost altitude while turning, killing 26 of 34 on board. The aircraft was operating an Alma-Ata (now Almaty)–Karaganda–Kazan passenger service with high-ranking Kazakh party and state officials. This crash is the deadliest involving the G-2. 29 December 1941 An Aeroflot G-2