Bjorn’s Corner: ET302 crash report, the first analysis

April 05, 2019, ©. Leeham News: The preliminary accident report of the ET302 crash was released yesterday. It confirmed what we wrote about earlier in the week, the pilots followed the prescribed procedure to stop MCAS. Yet they didn’t make it.

Part of why we presented Wednesday. Here follows additional analysis after studying the information in the Preliminary Crash Report.

https://leehamnews.com/wp-content/up...eral-trace.png
Figure 1. The general Flight Data Recorder trace from ET302. Source: ET302 preliminary report.

The report confirmed our assumptions

The report released by the Ethiopian Ministry of Transport is a preliminary report. It follows the structure of the Lion Air JT610 preliminary report.

It confirms what we wrote about earlier in the week, the Flight Crew followed the procedures prescribed by FAA and Boeing in AD 2018-23-51. And as predicted the Flight Crew could not trim manually, the trim wheel can’t be moved at the speeds ET302 flew.

The traces from the report is Shown in Figure 1 and 2 (click on them to make them larger).

Figure 1 shows the general Flight Information traces whereas Figure 2 shows the specific information around MCAS and the signals which affect MCAS.

https://leehamnews.com/wp-content/up...-specifics.png
Figure 2. The Flight Data Recorder trace from ET302 which deals with MCAS related data. Source: ET302 preliminary report.

etcetera