MAK – Interstate Aviation Committee
KBWL LP - Polish Air Incident Investigation Committee
Parts of presentation:
• First impressions
• Results of analysis:
• horizontal trajectory
• the likelihood of a roll to the left
• TAWS #38
• Possible cause: preliminary findings
Properly secured air crash investigation site?
|Two years later, March 2012 ...
|Above: April 10, 2010
Above: Wreckage unprotected from the elements.
The plane’s left horizontal stabilizer position on satellite pictures:
Above: Left horizontal stabilizer has been moved about 20 meters closer to the main part of the wreckage.
The plane’s left horizontal stabilizer position (33) in MAK Report identical to position on satellite picture from April 12, 2010
The final seconds of the flight analysis
|Photo Right: Polish KBWL Report
|Right: Photo taken by Russian amateur photographer Sergey Amelin
Flight Data Recorders:
1. Black Box MŁP-14-5 (Russia)
2. ATM-QAR Quick Access Recorder (Poland)
3. Flight Management System (FMS) (USA)
Terrain Awareness and Warning System (TAWS)
Differences between MAK and KBWL reports Angle of Attack
The angle-of-attack values are taken from a Russian and a Polish recorder, respectively. Both devices are merely data recorders and not measurement devices
The final reports of both MAK and Polish Air Incident Investigation Committee do not include any information as to the methodology of the analysis or provide any data which would make the analysis replicable.
Data recovered from some of the aircraft’s recording devices have been subject to arbitrary alterations and some of the data (FMS and TAWS logs) have not been included in the analysis.
Data Extraction conclusion:
The amount of raw binary data that was captured electronically is very large. UASC software engineering can convert additional parameters to human-readable format if they are needed for the investigation.
FMS (Flight Management System) and TAWS (Terrain Awareness and Warning System)
MAK added 3 seconds to real UTC time recorded in log files, the Polish investigating committee has added 6 seconds to most of the FMS and TAWS log times, both without releasing any further details
Horizontal Plane Trajectory Near the Birch Tree
According to TAWS #37 and #38 logs, the aircraft did not change its magnetic course 140 meters past the birch tree, which is inconsistent with information in both MAK and KBWL reports.
TAWS Alert Log #38 (Alert Type “Landing”)
Track Rate Computed rate of change of true track, in degrees/sec.
Track rate is used to determine if the aircraft is turning.
Uncontrolled Roll to the Left
Are flight parameters reported by MAK as evidence of an uncontrolled roll to the left consistent with what we know about the aerodynamics of this particular type of aircraft?
В.П.Бехтир, В.М.Ржевский, В.Г.Ципенко Практическая аэродинамика самолета Ту-154M , Мocквa 1997.
Пуминова Г.С. Практическая аэродинамика самолета Ту-154В (Ту-154М), Cанкт Петербуг 1995.
Critical flight phases of a Tu-154M aircraft in cruising configuration 
Lift coefficient (Cy), and drag coefficient (Cx) of a TU-154M aircraft in landing configuration 
Pitch angle and Roll left parameters (MAK)
Taking into account the effects of the aircraft rolling to the left as well as losing a considerable amount of airfoil surface, we can conclude that the critical angle of attack would have been exceeded one second after left wing’s impacting the birch tree.
The behavior of the aircraft after losing part of the wing has also been analyzed by a team of researchers lead by prof. Brawn of the University of Akron.
As the aircraft loses part of its left wing, drag works to counteract roll with the force equivalent to air moving at 5 meters per second, applied to the top of the right wing and to the bottom of the left wing.
|The left wing moves downwards with an initial acceleration of -23.9, which then decreases to -2.5 deg/s2 because of drag induced by the rolling motion
|The net effect is that the aircraft is being rolled to the left (3.0 to 0.55 deg/s2)
|The nose pitches down violently (1.3 to 6.1 deg/s2)
1. The horizontal plane trajectory of Tu-154M, reconstructed from TAWS alert logs, does not change 140 meters after the birch tree. Impacting the tree resulting in separation of part of the wing and an uncommanded roll would also have to result in altering the aircraft’s horizontal plane trajectory. Such change in trajectory is inconsistent with TAWS Alert Log #38
2. Flight parameters reported by MAK and KBWL describe a roll to the left event which is inconsistent with technical accounts of aerodynamic properties if this type of aircraft.
3. If Tu-154M 101 had lost part of its left wing on impact with the tree, it would have to roll to the left, pitch downwards, and impact the ground no later than one second after hitting the tree. 21
Satellite Images of the Area Where the Last TAWS Event Has Occurred (April and June 2010)
Fig. 46 of the MAK report, showing the aircraft’s trajectory base on TAWS logs #34 through #37 (purple line) as well as a reconstruction of radio altitude (blue line).
The blue line does not contain any explicit information from TAWS #38 or any of the FMS logs. We do see that the blue and purple lines cross at one point. All TAWS and FMS logs were known to both MAK and KBWL very early into their investigations.
The KBWL Report Omits TAWS #38 and FMS Logs.
This slide shows the method used by KBWL to disguise the existence of this data. The fact of this disguise suggests that KBWL is fully aware of the fact that this data is inconsistent with their final conclusions.
MAK Report, FDR Parameters (Fig. 25 and 45, English Version)
Two sudden dips in the graph of vertical acceleration (red line) appear in graphs of both MAK and KBWL reports. Neither report mentions them in the analysis.
Time correlation between peaks of vertical acceleration (MAK) and roll left KBWL
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ANALYTICAL SERVICE CO.
Report No. 456
SOME TECHNICAL AND STRUCTURAL ASPECTS
OF THE SMOLENSK PLANE CRASH
Author: Dr Gregory Szuladzinski
Independent Technical Advisor
of the Parliamentary Team of Antoni Macierewicz
|Dr Gregory SZULADZINSKI received his Masters Degree in Mechanical Engineering from Warsaw University of Technology in 1965 and Doctoral Degree in Structural Mechanics from University of Southern California in 1973. From 1981 until present, he has been working in Australia in the fields of aerospace, railway, power, offshore, automotive and process industries, as well as in rock mechanics, underground blasting and military applications. Especially since the early 90’ties he has been doing computer simulations of such violent phenomena as rock breaking with the use of explosives, fragmentation of metallic objects, shock damage to buildings, structural collapse, fluid-structure interaction, blast protection and aircraft impact protection. He has done a number of state-of-the-art studies showing explicit fragmentation of structures and other objects. He is a Fellow of the Institute of Engineers Australia, member of its Structural and Mechanical College, a member of the American Society of Mechanical Engineers and a member of the American Society of Civil Engineers.
|The left wing, view from the bottom. The parts are pieced together based on images from the day of the incident.
|The airplane change magnetic heading after TAWS #38 on baro-altitude 37.5 m.
Internal or external explosion in front of the left wing
Internal explosion in central position in airframe
The loss of the wing’s leading edge near the fuselage and the entire left-most part of the wing had two aerodynamic effects: loss of lift on the left side and increase of drag. The first effect induces roll to the left, while the second one induces a change in magnetic heading.
The rear part of the airframe with wings and vertical stabilizer rolls to the left independently of the front part which stays in its natural position
Impact with the ground: only the rear part of the fuselage is inverted.
Angular momentum about the roll axis breaks the fuselage apart completely, separating the front of the fuselage from the rear, with the rear continuing to roll to the left.
Cockpit and front part of fuselage are not inverted
Rear parts of the fuselage in inverted position
Summary of Results
The main causes of the crash were two explosions taking place just before landing.
One of them impacted the left wing near its mid-point and caused an extensive damage, effectively breaking the wing in two. The other, inside the fuselage, caused an profound damage and dismemberment of the latter, as well as loosening the connection of the left wing and fuselage. The landing in a woody area, no matter how unfortunate and at what angle, was incapable of causing the documented fragmentation of the structure.