Date & Time: Mar 5, 2011 at 1040 LT
Type of aircraft:
Antonov AN-148
Operator:
Registration:
61708
Flight Phase:
Flight
Flight Type:
Test
Survivors:
No
Site:
Plain
Schedule:
Voronezh - Voronezh
MSN:
41-03
YOM:
2010
Country:
Russia
Region:
Asia
Crew on board:
6
Crew fatalities:
6
Pax on board:
0
Pax fatalities:
0
Other fatalities:
0
Total fatalities:
6
Circumstances:
Aircraft left Voronezh-Pridacha Airport in the morning to conduct a test flight with six crew on board, two pilots from constructor, two engineers and two pilots from Myanmar Air Force to whom the aircraft should be delivered shortly. In flight, crew decided to perform an emergency descent. During this manoeuvre, aircraft lost part of its tail, stabilizer and elevator which were found later some three kilometers from the rest of the fuselage. Aircraft dove into the ground and was destroyed by impact forces and post impact fire. All six occupants were killed. Aircraft was flying for Voronezh Aircraft Production Association. (VASO - Voronezhskoye Aktsionernoye Samoletostroitelnoe Obshestvo). First accident involving an Antonov AN-148.
Causes:
The cause of the accident was the inadvertently permitted the aircraft to accelerate 110 km/h above the design limit speed during an emergency descent.
This led to low-frequency vibrations on the aircraft in all axes, an increase of alternating accelerations exceeding the margin of safety. The result was the break up of the aircraft in the air, followed by its collision with the earth.
The main factors contributing to the accident were:
1) untimely and inadequate actions of the crew to control the emergency decent
2) lack of proper coordination among the members of the crew
3) deviations from recommendations in the flight manual in executing the emergency descent
4) misleading indications on basic instruments when outside characteristic operating conditions.

Source: ASN