The most stupid and dangerous thing I ever did in a plane was as a 20 hour student. My instructor at the school I was at quit to go to another school. I decided to go with him as he had soloed me and I had already been through 2 or3 other instructors. The day was 9-10-2001. He had warned me that the planes were old but said nothing of their condition. The 172 was old ,had poor paint, and a low tire. When I checked the oil, I found that there was only 3 1/2 quarts. I’m ashamed to this day that I didn’t leave at that point without any discussion. However, I was anxious to get on with my training. I added another 2 quarts with the instructors knowledge and had them put air in the tire. I rechecked the oil and we had about 5 1/2 quarts. He insisted that this was Okay. However, I put another 1 1/2 quarts in. We went flying and I did about 1 1/2 hours of hood time. We returned and landed on a parallel runway aside an airliner. I taxied back and parked the plane. It was getting dark when I went to tie the tail down. What I found was oil dripping down the belly to the ring. I checked the oil level and there was only a drop of oil on the stick. I had very little to say to the instructor as the implication was obvious. I nearly quit flying for good that day, but the next day was 9-11-2001. Several days later I called the school to see what was wrong with the plane. Apparently there was a blown gasket that resulted in the oil leak.
Well, where was the mistake? The mistake was clearly in not questioning why an engine would only have 3 1/2 quarts of oil in the first place. As a pathology instructor once taught me in medical school “always think dirty”. You alone are PIC and make the final decision, not the instructor.
Now I always get a standard briefing, even for a short flight. I always check fuel quality and quantity carefully. Never let anyone fill the tanks without watching. Always check the oil, and if it’s down more than a quart or even just a quart in a short time, ask why, don’t fly. Also, I always look at the belly for oil.
If anyone would like to share a stupid mistake they made please do so.