What is the Process for Re-certifying Flight Hardware?

Question

I was reading about how we reused the water tanks because they were still within their certified life-time and had two questions:

• When would a certification become VOID?
  • I'd assume if the water tanks accidentally took a fall they'd not be certified still.
  • What are some other examples of events that can void a certification?
• When an event occurs altering the suitability of flight hardware how is it re-certified?
  • I'd assume there's some sort of inspection, could someone outline what it'd be?
  • You may use the example of the water tanks being dropped, what would NASA do?

You may also consider the toppled NOA satellite as a case study too if you wish. I'd like to know what all they had to do to consider it as "certified" again after the incident.

Answer 1

From what I've observed, the general process works like this:

1. A Non-Conformance Report (NCR) is generated. These are applicable for everything from an unexpected scratch or tool mark on a surface to a system-level failure. The NCR identifies the "is" vs. "should be" state of a component.

2. A Material Review Board (MRB) convenes. This is a group of engineers and managers who make decisions in a structured way regarding NCRs. From here, it's case-dependent. It may involve specific analysis, or it may just be a series of discussions. It all depends on the specific nonconformance.

3. The NCR is dispositioned. Again, case dependent. The disposition is determined by the MRB. Typical disposition outcomes:

   • Use as is. Analysis shows the nonconformance does not affect safety or mission success -- no corrective action is necessary to certify the part for flight.
   • Rework the part. Case dependent. Could be as simple as redrilling a hole in the right location, buffing out scratches, etc.
   • Use as is, issue drawing rev. In the case of a misdrilled hole, for example, create a drawing rev showing where the hole was drilled so that there is traceability between the drawing and what was manufactured.
   • Scrap. The component is too far gone. Toss it out and build a new one. Depending on the source of the NCR, it may be a build to print, or there may be a redesign.