PPRuNe Forums - View Single Post - Plane of singer Jenni Rivera missing in Mexico
Old 13th Dec 2012, 04:18
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Machinbird
 
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Originally Posted by bubbers44
Unless the Lear had black boxes in it that is all you have and I don't think they did. If that is the case they can only calculate descent rate and speed when it it hit the mountain. Measure the hole it hit and how far it skidded. End of investigation.
Bubbers, the wreckage, even if badly fragmented, can tell you a lot. I was part of the team that recovered the wreckage of an aircraft that flew into the water 50 degrees nose down at 550 knots.
From the damage to the compressor blades and inlet guide vane positions we could evaluate power setting. From the way the Mach dial draped over the IAS dial, we could validate airspeed and Mach number. From the way the all attitude indicator draped over the rest of the instrument internals, we could evaluate attitude and heading at impact. Since we understood the context of the accident, this was sufficient information to write the accident report.

There is generally a lot more information that can be obtained if you have a complete set of wreckage. Reading the wreckage gives you the aircraft final configuration at the instant of impact. More violent impacts probably are better at preserving the final configuration since when everything distorts so quickly, it doesn't have time to move from crash forces before it is marked by items in its vicinity. The worst situation though is probably when components are thoroughly shattered down to the component part level.

You have to take this configuration data and figure out what it means. This particular accident will have a lot of data available to the trained eye.
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