Aeroflot Flight U-505

Aeroflot

Industry	Airline
Founded	1923 (1923)
Headquarters	Moscow , Soviet Union
Products	Passenger and cargo air transport

Aeroflot Flight U-505 crashed shortly after departing from Tashkent on 16 January 1987. This early morning service was operating between Tashkent and Shahrisabz, both located within the Uzbek Soviet Socialist Republic (now the Republic of Uzbekistan). The flight took off only one minute and 28 seconds following an Ilyushin Il-76, resulting in the Yakovlev Yak-40 encountering the Il-76’s wake vortex. The aircraft then abruptly banked to the right, impacted the terrain, and ignited. All nine occupants were fatally injured.

Aircraft and crew

The airplane involved was a Yakovlev Yak-40 with construction number 9131918, registered as CCCP-87618 under Aeroflot. It was produced on 22 July 1971. At the time of the accident, it had accumulated 17,132 flight hours and completed 20,927 cycles (each cycle representing one takeoff and landing).

The flight crew comprised:

• Captain T. Yunusbek (Юнусбеков Т.)
• First Officer Valery Strunin (Струнин Валерий Александрович)
• Flight Engineer R. F. Davydov (Давыдов Р. Ф.)

Sequence of events

This flight was tasked with transporting cargo from Tashkent to Shakhrisabz. Onboard were approximately 1,200 kg (2,600 lb) of mail and 35 kilograms of personal effects, along with four passengers in the cabin. The takeoff weight was recorded at 14.4 tons, which was within permissible limits. Due to a delayed cargo loading that began at 6:00 local time—after the scheduled departure at 5:55—the crew expedited their preflight checklist, completing it in under a minute instead of the typical five minutes. The aircraft taxied via taxiway three toward Runway 8L. At 6:09:40, an Il-76 (tail number CCCP-76482) initiated its takeoff roll from the runway. The Yak-40 crew immediately contacted air traffic control requesting clearance for departure. After receiving permission to enter the runway, they commenced takeoff at 6:10:58 without explicit clearance to lift off, breaching standard procedures. The engines were set to maximum thrust, accelerating to 124.2 knots; however, at approximately 20 meters altitude and at 6:11:04, the aircraft suddenly banked sharply rightward and subsequently crashed at 6:11:15, resulting in total loss of life for all nine onboard.

Cause

CCCP-76482, the aircraft responsible for generating the wake turbulence.

The Yak-40 departed 66 seconds following an Ilyushin Il-76. During the investigation into the incident, the commission determined that despite the Il-76's position, it would have still produced significant wake turbulence. With wind speeds measured at merely 1 mph, investigators concluded that the Yak-40's erratic behavior resulted solely from encountering the wake vortices created by the much larger Il-76, which had taken off from the identical runway just 75 seconds earlier. At Tashkent Airport, the mandated minimum takeoff separation was only one minute for all aircraft types, a regulation that contributed to the smaller Yak-40 losing control rapidly and crashing after passing through the wake turbulence.

See also

• Aeroflot accidents and incidents
• Aeroflot accidents and incidents in the 1980s