Originally Posted by
D Bru
Have also stumbled across this one too in relation to AI171. The final report (
https://sistema.cenipa.fab.mil.br/ce...DEZ18_Ing..pdf) contains IMO interesting details re Boeing not sharing it's "777 Electrical Power Systems Safety Analysis Document" integrally with the in this case Brazilian investigation due to export policy restrictions in force of the aircraft's State of Design. This document mapped failures of the electrical system and the probability of their occurrence. According to Boeing, the said document had an electrical failure of the kind in this incident assessed as "Class II Hazardous", while its probability was calculated as 9.6x10-8 (a little bit less than 1 in a billion of hours). The Brazilian investigation assessed that taking into account the level of risk, the probability of this type of failure should be less than 1x10-7 (a failure in 10 million flight hours).
Given the "export restrictions" cited in the Brazilian 777 electrical failure incident, its IMO unlikely that the Indian AAIB will ever be able to lay its hands on Boeing's "787 Electrical Power Systems Safety Analysis Document"....
That's a common problem - some of the various documents that get produced during the certification process - System Safety Assessments and Failure Mode and Effects Analysis as examples - contain a great deal of detailed design details that are considered company proprietary and are subject to export restrictions. In fact, after reviewing the documents, the FAA is supposed to either return or destroy them.
I went to Shanghai as part of a team meeting with the Chinese CAAC regarding their approving the 747-8 for use by Chinese operators. We could show them pitch charts, and specify which documents were relevant, but we could not give them hard copies of the presentations or documents due to the export restrictions. Same thing with the Russian authorities (although they came to Seattle instead of our going to Moscow). In one case, they wanted to see a specific fault tree analysis - we were able to copy it from the document and display it on the screen, but couldn't provide them a hard copy (although I wouldn't be very surprised if someone took a discrete picture of the screen while it was being displayed.
In other another case, we provided a copy of the cert document to the Boeing cert office - they were supposed to scrub it as necessary before giving a copy to the foreign authority - but I stopped caring about it after we gave it to the cert people, so I don't know details.