Armstrong Whitworth AW.41 Albemarle accident at Yevlakh, Azerbaijan, 26 Jun 1943 (CCCP-L403)
On June 26, 1943, an Armstrong Whitworth AW.41 Albemarle (registration CCCP-L403) operated by Aeroflot - Russian International Airlines was involved in an aviation accident near Yevlakh, Azerbaijan in flight. No fatalities were reported. Investigators recorded the probable cause as: The accident was caused by a failure in the propeller control system, which caused the propellers to spontaneously switch to a high pitch. This failure almost instantly reduced the propellers’ thrust and prevented the aircraft from reaching Yevlakh Airport. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 2 related events involving the same aircraft type or operator are linked below.
Probable cause
The accident was caused by a failure in the propeller control system, which caused the propellers to spontaneously switch to a high pitch. This failure almost instantly reduced the propellers’ thrust and prevented the aircraft from reaching Yevlakh Airport. The malfunction was attributed to a design flaw.
— NTSB Determination
Accident narrative
The airplane departed Moscow-Vnukovo Airport on a flight to Tbilisi with intermediate stops in Astrakhan and Baku, carrying three passengers and four crew members. On the last leg from Baku to Tbilisi, an oil leak on the left engine forced the crew to make an unscheduled landing at Hagiqabul Airfield located about 92 km southwest of Baku. After repairs were completed, the crew took off at 1737LT. Less than 20 minutes later, while cruising at an altitude of 1,500 metres, a second oil leak occurred on the left engine. The captain elected to divert to Yevlakh Airport but after he realized he could not make it, he attempted an emergency landing in an open field. The left wing impacted the ground first then the airplane cartwheeled and came to rest, broken in two. All seven occupants were injured.
Probable cause (official findings): The accident was caused by a failure in the propeller control system, which caused the propellers to spontaneously switch to a high pitch. This failure almost instantly reduced the propellers’ thrust and prevented the aircraft from reaching Yevlakh Airport. The malfunction was attributed to a design flaw.