777-200LR Flight Test Journal: Archives

30 November 2005

Certified from nose to tail

Bob Buchholz, Chief Engineer, 777 Safety, Certification and Performance

Catherine Weaver, 777-200LR Certification Project Lead

Certification regulations created by governmental aviation organizations around the world - most notably the Federal Aviation Administration (FAA) and European Aviation Safety Agency -- help ensure airplane safety. If we comply with those regulations, in their eyes we have a safe airplane. The whole point of certification is proving that the airplane meets the regulations that have been spelled out and is therefore safe.

First, we have to tell these agencies how we plan to meet the regulations, and that's called a certification plan, or what we like to call a "cert" plan. It's an agreement between Boeing and the certifying agency, in this case primarily the FAA, about how we plan to demonstrate compliance to their regulations. Once we agree on that, Boeing can start collecting the information: the analyses, the ground tests, the qualification tests, the flight tests that all have to be documented and approved.

Certification is kind of a rollup of data. We have substantive data, which comes from the testing, and the collection of drawings that is the descriptive data portion. All that together actually defines the type-design data for this new minor model (derivative), but it also presents the entire certification package on which the certification is based - the Type Certification.

On this program, we have approximately 90 to 95 cert plans: avionics has 15 to 20, electrical has 15, propulsion has 10 and so on. All the different areas have many, many cert plans, because the plane has to be certified from nose to tail. Every part of that new minor model - everything - has to show compliance to the rules. And in the end that's the point that they're focused on.

In any case, once the cert plans are in place, we start actually working on compliance. We typically try to have all the certification plans completed well in advance, certainly by the beginning of flight test, because we have to be able to assure the FAA that the airplane is sufficiently airworthy for their people to get aboard. Once we have all the certification plans essentially complete and have done a certain amount of Boeing flying, we submit data prior to Type Inspection Authorization (TIA). The TIA brings the FAA personnel on board the airplane to conduct the certification testing.

The other thing that comes into play here is conformity: conformity means that we have sufficiently defined and described, and it has been verified that it's been built as described, the pieces of the airplane that are used to define compliance data. The airplane may not be in final configuration, but what we're assuring the FAA and ourselves is that the airplane as tested on a given date is in a configuration that will match the final configuration. That way, the FAA is guaranteed that we actually tested everything that we're ultimately going to build.

The regulatory agencies have delegated approval or the finding of compliance of two-thirds of the data collected in the 777-200LR program to Authorized Representatives (ARs). ARs are Boeing engineers who know what is required to show compliance to the regulations. The FAA recognizes this skill and experience and grants ARs the right to act in same capacity as an FAA employee in finding compliance. So, we are able to submit the data already approved. But the other third, which includes some significant items and much of what remains in this program, has to be approved by the FAA. Just because we submit it doesn't mean it will be accepted. So we send it in and hope that they will respond in a timely fashion. We hope that they will send then a formal approval back to us. But until we get the Type Certificate, we're on the hook.