Crash of an Antonov AN-24RV in Cherkessk: 50 killed

Date & Time: Mar 18, 1997 at 1003 LT
Type of aircraft:
Registration:
RA-46516
Flight Phase:
Survivors:
No
Schedule:
Stavropol - Trabzon
MSN:
3 73 085 02
YOM:
1973
Flight number:
SVL1023
Country:
Region:
Crew on board:
6
Crew fatalities:
Pax on board:
44
Pax fatalities:
Other fatalities:
Total fatalities:
50
Captain / Total flying hours:
12641
Captain / Total hours on type:
11600.00
Copilot / Total flying hours:
4563
Copilot / Total hours on type:
2657
Aircraft flight hours:
41181
Aircraft flight cycles:
27628
Circumstances:
While cruising at an altitude of 6,000 metres, the aircraft suffered a structural failure when the tail separated. The aircraft entered an uncontrolled descent and crashed in a wooded area located about one km from Cherkessk. The aircraft was totally destroyed upon impact and all 50 occupants were killed. The tail was found about 1,600 metres from the main wreckage. It was reported during investigations that the tail separated due to corrosion after the aircraft was operated in humid environment in Zimbabwe and DRC from 15 August 1994 till 28 December 1995.
Probable cause:
The accident was caused by the combination of the following factors:
1.Surface, without the use of instrumental control methods, by the commission's assessment of the technical condition of the An-24 RA 46516 aircraft and the subsequent unjustified issuance of a conclusion and a decision on the possibility of extending its MTO and service life;
2. Violation of the requirements of the current documents when extending the overhaul life for the An-24 RA 46516 aircraft and extending the established overhaul life without taking into account its long-term operation in a humid and hot climate;
3. Inconsistency of the regulatory documents governing the organization of work to establish and extend the resources and service life of civil aircraft (Regulation 1994) with the requirements of flight safety in modern conditions;
4. Violation of the requirements of the technology for repairing aircraft and household equipment during repairs in ARZ conditions;
5. Imperfection of technological documentation for periodic maintenance in terms of determining the corrosion and corrosion-fatigue state of the aircraft structure in hard-to-reach areas;
6. Insufficient control in the operation of hard-to-reach areas of the underground part of the fuselage in terms of determining the state of structural elements and the presence of corrosion lesions;
7. Failure to comply with the prescribed anti-corrosion measures for the structure of the aircraft during repairs at the ARP and in operation.
Final Report:

Crash of a PZL-Mielec AN-2 in Krasnyy: 5 killed

Date & Time: Jul 31, 1976 at 1519 LT
Type of aircraft:
Operator:
Registration:
CCCP-70255
Flight Phase:
Survivors:
Yes
Schedule:
Anapa – Maykop – Cherkessk – Kislovodsk
MSN:
1G139-14
YOM:
1972
Flight number:
SU470
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
7
Pax fatalities:
Other fatalities:
Total fatalities:
5
Circumstances:
En route, the crew encountered marginal weather conditions and was forced to modify his altitude several times between 400 and 800 metres. Approaching Labinsk, the crew was informed about thunderstorm activity on the route but decided to continue. The airplane entered the thunderstorm area at 1503LT, lost speed and altitude. Eventually, it went out of control and crashed in a cornfield located in Krasnyy, about 35 km southeast of Labinsk. The aircraft was destroyed upon impact. While four passengers were seriously injured, all five other occupants were killed.
Probable cause:
The decision of the crew to continue the flight into thunderstorm activity and adverse weather conditions, and failed to return. Thunderstorm activity and altitude turbulences caused the aircraft to lose speed and height and to become uncontrollable. Information transmitted to the crew regarding weather briefing were inaccurate, which was considered as concomitant.