Archive for March, 2021

Two New Reports on MH370 Debris Suggest a High Speed Final Descent

On the 7th anniversary of the disappearance of MH370, members of the MH370 Independent Group have released separate reports that analyze two wing parts that have been recovered from East Africa. The two parts represent the first and most recent pieces of MH370 that have been found. Both reports conclude that the flight likely ended in a high speed descent.

The first report, authored by Tom Kenyon, is the culmination of several years of work of structural analysis of the right flaperon that was recovered from Reunion Island in July 2015. After performing a Finite Element Analysis (FEA) on a numerical model of the flaperon and reviewing photographs of the damaged part, Tom believes that the damage on the part is not consistent with damage expected if the flaperon was attached to the wing as it impacted water. Rather, the damage to the two hinge attachments is consistent with high cycle fatigue from torsional flutter, which likely led to separation from the aircraft while still airborne. Based on Tom’s review of simulations of uncontrolled descents for the B777, he concludes the expected airspeeds are well beyond design limits that lead to flutter and structural failure.

Local police on Reunion Island examine flaperon in July 2015.

The second report, authored by Mike Exner and Don Thompson, analyzes a part that was recovered from Jeffreys Bay, South Africa, in August 2020. Based on an evaluation of features and markings, the authors positively identify the part as either spoiler #8 or spoiler #9 from the right wing from a Boeing 777, and by extension, almost certainly from MH370.

Spoiler with annotations for identified features.

The authors observe that the spoiler detached at structures that attach the spoiler to the rear spar of the right wing. The fracture along a chord line is consistent with bending of the spar along the span of the wing. At high airspeeds, wings dynamically flex due to flutter, and the dynamic aeroelastic loads that are induced will rapidly grow until the wing structurally fails.

A visualization of wing flutter can be seen in this video of a scaled model of a B747 in a wind tunnel.

The high speed descent theorized in both reports is consistent with the final BFO values recorded by the Inmarsat Ground Earth Station (GES) on March 8, 2014, at 00:19z. Those values suggest the plane was in a 0.7g downward acceleration. Without inputs from a skilled pilot, the aircraft would have impacted the ocean shortly after reaching this condition, which would mean the debris field on the seabed is relatively close to the 7th arc.

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