For browsers that don't translate on the fly here's the most substantive section of this preliminary report.
As I was hinting in the early hours of this morning. 15 previous flights pitot and port heating recorded on. No heat for this take off. You'll find the point where they went manual and I described a bit of 'heave ho' going on.
Credit due, as usual, to our Kulverstukas.
Rob
The commission of the Interstate Aviation Committee (IAC) to investigate the crash of the An-148-100V plane RA-61704 informs that the decoding of the on-board parametric recorder data was completed in the IAC laboratory and preliminary information analysis was carried out.
A preliminary analysis of the registered parametric information showed that during the entire flight, which ended in an accident, the heating of all three full pressure receivers (PAP) was off. In all other flights on the chart recorder (15 more flights), the heating of the overflow was activated before take-off at the executive launch.
The takeoff was started around 11:21 (here and below the UTC time).
After the separation at an altitude of 130-150 m (hereinafter the height from the runway level), the autopilot was switched on. In the longitudinal channel of the autopilot, the mode of reaching the specified altitude was fulfilled, in the lateral channel - the horizontal navigation. At an altitude of 550 m the flaps were cleaned.
A special situation began to develop approximately 2 minutes 30 seconds after the separation at an altitude of about 1300 meters and an instrument speed of 465-470 km / h, when the discrepancies in the speed readings from MVP1 (air parameters module) (LPD1) of the left pilot and MVP3 , standby). The recorder does not register the speed values from the MVP2 (PPD2) of the right pilot. There were no significant differences in the altitude indication (from the same sources: MVP1 and MVP3). After ~ 25 seconds, the discrepancies reached ~ 30 km / h (the speed from MVP1 was greater) and a one-time crew appeared (message to the crew): V instrument - CF. The registration of a single command at this stage lasted about 10 seconds, after which it ceased.
After about 50 seconds, at an altitude of about 2000 meters, this one-time command was registered again, and this time the rate from MVP3 was larger and continued to grow, and the rate from MVP1 continued to fall.
After the second appearance of the said one-time command (message), the crew disconnected the autopilot. All further flight passed in a manual mode.
The speed readings from the MVP1 continued to fall and after 34 seconds the autopilot was turned off. The speed readings from the MVP3 were 540-560 km / h.
For about 50 seconds after autopilot shutdown, the flight passed at an altitude of 1700-1900 m with vertical overload changes ranging from 1.5 to 0.5 g.
After that, while maintaining the speed values from the MVP1 0 km / h, the velocity values from MVP3 (to 200 km / h and below) began to fall rapidly. In the future, the aircraft was transferred to an intensive decline with pitch angles to dive 30-35 degrees and vertical overload to 0 g.
The collision with the earth occurred around 11:27:05. Before the collision with the ground, the speed readings from the MVP3 began to increase intensively and by the time the collision amounted to about 800 km / h. The speed readings from the MVP1 continued to be equal to 0.
At the time of the collision with the ground, the angle of the pitch to the dive was about 30 degrees, 4-5 seconds before the collision, the right bank began to develop at the aircraft, which reached 25 degrees.
The analysis of the received information continues.
A preliminary analysis of the recorded information, as well as an analysis of similar cases that occurred in the past, suggest that the development of a special situation in the flight could be caused by incorrect data on the flight speed on the pilots indicators, which in turn was apparently due to icing of the PAP when the heating systems are off.
In order to determine the reasons for the shutdown of the heating state of the three PDPs by the investigation commission, the following works are planned, including:
· Decoding of the on-board sound recorder to obtain information about the actions of the crew, the performance of the Operation Technology and the response to signaling;
· Study of the Technology of crew work with the system of heating of PPD, including indication;
· Schematic analysis of the heating systems of PPD for possible malfunctions and failures;
· The laying out of the remaining fragments of the heating systems of PPD.
Specialists of the commission of inquiry also continue to work at the scene of the accident, where the description of the scene of the incident is completed and the fragments of the aircraft structure are collected for further research.
In order to prevent accidents and develop operational recommendations, a brief briefing was held today at the Interstate Aviation Committee, attended by representatives of the Ministry of Defense, the Ministry for Emergencies, Rosaviatsia, Rostransnadzor, and airlines operating this type of aircraft. At the briefing, IAC specialists presented the participants with preliminary results of the investigation to take operational measures in the field of flight safety.