Friday, March 1, 2013

787: design change for dummies

787: design change for dummies:
As Boeing prepares to test, implement and certificate what it hopes will be an FAA-approved fix for its 787 battery problem, the company has issued a kind of ‘design change for dummies’ overview to aid understanding of the processes involved. The info includes examples of previous design changes on the 787 ranging from the minor (a rain gutter positional change over main deck passenger doors) to the major (the side of body, wing root redesign that delayed first flight in 2009). It also differentiates between those modifications made before and after aircraft-level certification, citing the aft fuselage longeron shimming change as another example of the latter. Click here to view the design change guide.
Boeing clearly lays out the steps involved in the design change process, from developing the change proposal and obtaining program approval to developing the plan, executing the change and finally certifying. What remains unanswered by Boeing for the moment is where exactly the 787 battery change proposal is in the flow, as well as whether or not the change would be incorporated under a supplementary type certificate (STC), the usual approval timeframe for which can be up to six months.
On the surface, it would appear the battery change is roughly somewhere in the midway stage of the process flow. This step involves developing the actual design change plan and follows approval from Boeing’s change control board, as well as - it would seem in this case - the FAA and other parties. This phase involves initiating a change notice, developing an engineering statement of work, collecting quotes from affected production sites and committing to a production plan.
Implementation of the change itself would follow. The final step assesses the impact to the type design, submitting the certification plan and review by the FAA.

An interesting graphic of the components making up the current battery configuration (Boeing)

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