I lost my Giant Scale Planes/CMP P-40 last fall. It should never have happened. The reason - unexpected failure due to fuel starvation. This story hurts.
My engine was a YS-1.20 FS, which is very quiet at idle. I had fueled the model as usual. Fuel it until it runs out of the overflow vent, and plug the vents (It's a pressure fuel system).
I took off and had flown maybe five minutes when I decided to make an approach. I lowered flaps on downwind and reduced power and turned base.
When I made my turn to final, it went out of control (tip stalled actually) and went in. I thought I had a radio failure. In any case the model was a total loss.
As I tore into it back in the pits, I noticed my fuel tank was empty. The tank was not damaged in the crash, so I couldn't figure it out. I know I had filled it to overflow. Back home I removed the tank from the remains of the nose section. I had a rattle in the tank and it was not the clunk......That's weird...... The brass vent line going to the top of the tank had broken off, so I only had a half tank of furl instead of a full tank.. Another guy was flying his much louder model, so I had not heard my engine quit. When I pulled a little up to make the turn to final, it stall and spun in.
That was a hard one to lose considering the way it happened. The model was about nine or ten years old, so the brass had corroded in the bend due to the nitro (so I've been told). If you are flying an older model using glow fuel with a high nitro content (the YS calls for 20%), it might save you a model if you check the condition of your tank and plumbing.
Joe