For Aron: What Went Wrong?
>> Tuesday, August 3, 2010
Aron asked: One more...How does my AIAA Design/Fly/Build team avoid this from happening again the plane flew before, but it got damaged during take off. What sort of tests should we do?
Sorry I've taken so long to look at this, Aron. Wow, you're expecting me to figure out a great deal from a video. I'm also not technically an aerospace engineer in that I've never designed a plane. I'm sure you have great resources there to draw from. But, since you asked me and I am nothing if not opinionated, here's what struck me.
The problem does not appear to be the landing gear unless it was broken before you tried the first run. If it was and that's why it kept going lopsided, strengthen the gear and move on.
However, if, as it seemed, it was the repeated lopsided runs that eventually damaged the landing gear, there are a few possibilities that come to mind. First and, to my mind, most likely if the wings house the fuel tanks as they do in many planes, the tanks might not have been filled equally, throwing off the center of gravity to one side. If the center of gravity was off, this would cause turning even if the thrust from the two engines were the same. Or, if the c of g was fine, it might be that the thrust from the two engines was unequal, either a deformation of a propeller perhaps or an engine problem that let one spin at a different spin than the other.
It might also have been control surfaces out of sync (say flaps on one wing, but not the other) or a rudder turned the way it shouldn't be. It might be a deformation of one wing that changed wind resistance or lift from one side to the other or an incipient imbalance in the landing gear that went unnoticed.
Without data, the fuel inequality or control surface problem might not be detectable unless they are design issues (i.e. if they were operator error). However, a problem in the fuel tank that prevents equal filling or causes a control surface to stick my be detectable with testing.
Given the dearth of data, that's the best I can offer.
@ Aron -- Indeed you should have asked an aeronautics engineer.Nice theoretical observance though Steph.Good job!
Yea, but we never did test those engine, we just assumed they where up to specs out of the box...maybe that was the problem. I'll may sure that is in the testing, but we tested CG and controls a ton.