When is CG not inside the plane?
Since we are getting a few hits on this thread.... Here is another one. Since it was not my screw-up, but one I witnessed, I will change it into a teaching moment. The stuff folks usually have to pay for.
When loading a float-plane, particularly a larger one like a C-185, Beaver or Otter, you can load lots of gear into the aircraft proper and also load more than you should be able to load into the FLOAT COMPARTMENTS.
Lets say that our daring pilot supervised the loading of a lodge aircraft, but then had to return to the lodge office for a few minutes. The lodge fishing guide then hears a couple of fishing clients snivel about not taking along some more gear. So the guide, decides to load up the FLOAT COMPARTMENTS with as much junk as he can jam inside.
Now the CG has been moved downward, outside of the fuselage area.
It may even be only to one side or both... depending on how carried away our guide became with his over-loading.
Lets say that shortly after a very long take-off run, a turn is required between a couple hills covered with trees. Now the weight acts like a pendulum.
So when the pilot tries to bank the plane, the weight in the floats wants to pull it back to wings level. This causes a skidding turn at low speed and low altitude.
In more than one case it has put the plane right into the trees.
Excessive water in the float compartments from not pumping them out, or from having a disconnected pump-out hose will do the same thing.
I removed over 15 gallons of water from a local 135 pilot's floats when that pilot could not figure out why the plane took a mile to get off the lake. In that case the hoses had become disconnected and the pilot/owner had never looked into the floats to see why no water EVER came out.
I used my little Cub for the demo photos, so I don't tick off the Company owners of a wrecked Beaver.
Well I can't get the computer to let me make them large.... so you will have to click.... dang computer...
Let me know if you find this post informative.