Crash of a Beechcraft 200 Super King Air in Burgas: 6 killed

Date & Time: Jul 27, 1977
Operator:
Registration:
D-IBAF
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Burgas - Stuttgart
MSN:
BB-93
YOM:
1976
Location:
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
4
Pax fatalities:
Other fatalities:
Total fatalities:
6
Circumstances:
The twin engine airplane was engaged in an ambulance flight from Burgas to Stuttgart on behalf of the German Air Rescue Service (Deutsche Rettungsflugwacht - DRF), carrying one German patient aged 63, three medical staff and two pilots. During initial climb, the crew contacted ATC and reported technical problems with the automatic pilot system. Shortly later, control was lost and the airplane crashed in an open field. The airplane was totally destroyed upon impact and all six occupants were killed. The exact cause of the autopilot system failure remains unknown. Nevertheless, it was reported that both pilots were intoxicated at the time of the accident, with an alcohol level of 0,48‰ et 0,37‰ respectively.

Crash of an Antonov AN-24B in Sofia: 3 killed

Date & Time: Nov 22, 1975
Type of aircraft:
Operator:
Registration:
LZ-ANA
Flight Phase:
Survivors:
Yes
Schedule:
Sofia - Varna
MSN:
67302708
YOM:
1966
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
42
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
While parked on apron at Sofia-Vrazhdebna Airport, the airplane was deiced and the snow was removed before the crew was cleared to taxi to runway 10 for takeoff. However, the runway was closed for snow removal. When this was done, the crew was cleared for takeoff and just after liftoff from runway 10, the airplane encountered difficulties to gain height, stalled and crashed on a bank of the Iskar River located by the airport. The copilot was killed and two passengers drowned. All other occupants were rescued, some of them were injured.
Probable cause:
The hold over time (HOT) between the deicing time and the takeoff time was too long and a significant amount of snow accumulated on the fuselage, wings and all critical surfaces. In such conditions, the aircraft was unable to take off. The crew failed to request a second deicing.

Crash of an Antonov AN-24B in Sofia

Date & Time: Apr 14, 1975
Type of aircraft:
Registration:
035
Flight Phase:
Flight Type:
MSN:
87304508
YOM:
1968
Country:
Region:
Crew on board:
0
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
Crashed in unknown circumstances near Sofia Airport. Crew fate remains unknown.

Crash of an Ilyushin II-14 near Smolyan: 35 killed

Date & Time: Nov 4, 1972 at 2002 LT
Type of aircraft:
Operator:
Registration:
LZ-ILA
Survivors:
No
Site:
Schedule:
Burgas - Sofia
MSN:
1460 010 46
YOM:
1956
Location:
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
31
Pax fatalities:
Other fatalities:
Total fatalities:
35
Circumstances:
During the preflight briefing, the crew was informed about poor weather conditions in Sofia and that the visibility was below minima. The airplane departed Burgas Airport at 1901LT and en route, the captain decided to divert to Plovdiv where weather conditions were considered as better. First radio contact with approach control in Plovdiv was established at 1950LT and the crew was cleared to descent. Twelve minutes later, while descending by night and limited visibility, the airplane struck the slope of a mountain located in the Rhodopes Mountain Range, near the city Smolyan. The wreckage was found few hours later about 56 km southwest of Plovdiv Airport. All 35 occupants have been killed.
Probable cause:
It was determined that the first radio contact was established with a civilian controller at 1950LT. Four minutes later, this controller was relieved by a military controller who cleared the crew to descent without knowing the exact position of the airplane that descended below the minimum descent altitude. The lack of visibility was considered as a contributing factor.

Crash of an Ilyushin II-18V in Sofia: 28 killed

Date & Time: Dec 21, 1971 at 2332 LT
Type of aircraft:
Operator:
Registration:
LZ-BES
Flight Phase:
Survivors:
Yes
Schedule:
Sofia - Algiers
MSN:
185 0081 04
YOM:
1965
Country:
Region:
Crew on board:
11
Crew fatalities:
Pax on board:
62
Pax fatalities:
Other fatalities:
Total fatalities:
28
Circumstances:
Just after liftoff, while climbing by night to a height of 8 meters, the airplane banked left, causing the left wing to struck the runway surface. Out of control, the airplane crashed in flames in a grassy area located on the left side of the runway. Among the debris scattered on a distance of 400 meters, 45 injured people were evacuated while 28 others were killed, among them two crew members and the Bulgarian singer Pacha Hristova who was travelling to Algeria with members of the Bulgarian folklorik band 'Aura'.
Probable cause:
It was determined that the airplane was just returning into service following ground maintenance. For unknown reason, technicians failed to comply with maintenance procedure and it was determined that the aileron control cables were not properly connected.