Aviation accident in Sevastopol, USSR
The 1934 Tupolev ANT-27 Sevastopol crash occurred on Monday, 15 April 1934, when the MDR-4 prototype (Tupolev ANT-27) crashed in the bay of Sevastopol, killing all four airmen onboard. Some sources reported that the crash took place on 16 April near Taganrog.
Aircraft.
The aircraft was an improved version of the Chyetverikov MDR-3. Within the design bureau, it was designated as the ANT-27, while the military assigned it the designation MDR-4. Due to several delays, the construction of the first prototype was postponed by four months. On 7 March 1934, the first ANT-27 was completed, and three days later, it was delivered in disassembled form to Sevastopol for testing. On 8 April, the aircraft made its first flight, piloted by T. V. Ryabenko and A. A. Volynsky.
Crash.
On 15 April, the ANT-27 was scheduled for another test flight. Notably, pilots were accustomed to flying the heavy German-made Dornier Wal flying boat, which, due to its flat bottom, had difficulty taking off from the water's surface. To aid in takeoff, crews often used a longitudinal rocking technique. However, this technique was unnecessary for the ANT-27, which had a more keel-like bottom, yet the pilots used it out of habit. The ANT-27 responded differently from the German flying boats, prompting the designer, Andrei Tupolev, to travel from Moscow to observe the unusual behavior firsthand. He witnessed the subsequent incident.
Tupolev went ahead in a boat to observe the start of the takeoff closely and monitor the aircraft’s transition to the "step" redan. As the aircraft began its takeoff, Tupolev noticed the pilots applying the rocking technique. He attempted to warn them by waving his hands to signal them to stop, but the crew did not see him. After accelerating to high speed in Kuglaya Bay on calm water, the ANT-27 moved out of the bay and into the open sea, where high waves were present at that moment. Upon striking the first wave, the aircraft briefly lifted into the air, then lowered its nose and struck a second wave. The impact caused the struts of the central power unit to collapse, and the heavy engine fell onto the cockpit. 
The crash resulted in the deaths of KOSOS naval brigade head I. I. Pogossky, engineers G. S. Noskov and K. K. Sinelnikov, and the second pilot, A. A. Volynsky. Sources vary on who was piloting the aircraft at the time of the crash. Some indicate it was the deceased Volynsky, while others suggest that T. V. Ryabenko and D. N. Ilyinsky were also on board, piloting the aircraft and surviving the crash.
Aftermath.
After the crash, Brigade No. 2, led by A. P. Golubkov, was named in honor of Pogossky. Subsequent aircraft of this type, produced by the Tupolev design bureau, were designated ANT-27bis. A total of 16 of these machines were produced.
References.
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