As I had mentioned in the
previous post, and the one
two years ago, adding 200 additional pounds to the gross weight of the airplane, without adding much of anything to the empty weight of the airplane seems like a simple task, but the reality is that it is quite difficult. Three years, numerous tests, hours of analysis, and over 40 reports were all required for this project.
We knew there were a lot of details that needed to be looked at, so we started looking at those areas quite a while ago. It started with making a list of all the structures and systems in the airplane and then going through them one by one to verify they were good for the new higher weight.
We started with the structure of the airplane. We needed a good safe structure to support all the systems level changes that would be required later in the project. Detailed loads reports were re-written for all the structures on the airplane. Fuselage, wing, vertical tail, horizontal tail. With new loads reports, that meant we had to go through all the structural analysis for all of those structures as well and publish new structural analysis reports. Physically, this meant changes to the wing spar, and some changes to the fuselage structure.
With the structural analysis changes, it also meant having to redo the flutter analysis, and a report documenting that. A significant amount of work also went into the fatigue and damage tolerance analysis to keep the current 12,000 hour life limit.
So you can begin to sense a theme of cascading design and analysis changes. How looking at or changing one area, leads to the need to look at and change another area. It is a theme that we would see in a couple different areas of the airplane, and I will describe in future posts.
