I spent three weeks at the Naval Air Station in Corpus Christi, Texas, as a second-class ROTC midshipman receiving an introduction to Naval aviation. We would eventually go up in trainer planes, but we began with ground school: a crash course in engines, flight plans, flaps, propellers, wings, and, above all, instruments. In the classroom, the ''artificial horizon,'' a floating sphere bisected by a bold horizontal line, impressed me in particular. This instrument portrayed the aircraft's attitude in the air: If the line was horizontal, the plane was flying parallel to the ground, an attitude I considered highly desirable. There were really only three important instruments on the plane: the altimeter - to know your height, the fuel gauge, and the artificial horizon. With these three tools, even I could fly a plane. How hard could it be? Our flight instructors were young Navy pilots who embraced their duties with savage glee, using every trick and play they knew to frighten and disorient us in flight as they took us up in the two-seater aircraft. We went into turns, stalls, and tailspins, every maneuver they could imagine to unseat our stomachs. Finally, the time came for my first assisted flight - where I'd take control of the aircraft. My instructor for this flight was Lieutenant Meredith, a gruff combat veteran out of Vietnam. ''Come here,'' he growled, pulling the pre-flight checklist from his flight suit. We proceeded to complete the endless mechanical and informational checks required before taking up an aircraft. Finally, he examined me. He went over my flight suit and equipment. He punctuated every item he checked with a contemptuous snarl as he tightened this, loosened that, rearranged my straps. He finished by thrusting his face inches from mine. ''Listen to me, middie. We're going up there,'' and he pointed to the sky. ''You make mistakes up there and you're history. Got it?'' ''Yes, sir,'' I said. ''All right,'' he said, ''just don't mess this up.'' We taxied down the runway, bumping on the asphalt until he pulled the nose up and I felt that drooping sag in my stomach that said we were airborne. I looked below and saw the Corpus Christi Naval Air Station sprawled below me in the harsh July sun. As we arrived at our training altitude, Lieutenant Meredith's voice came over the internal radio. ''You ready to take it?'' My mouth went dry, and I nodded quickly, then realized he couldn't see the nod from his seat ahead of me in the cockpit. ''Ready, sir!'' ''OK, you've got control. Now see if you can keep it straight and level for a while.'' A man after my own heart. I focused my attention on the artificial horizon. The plane was perfectly parallel with the ground below. No sooner had I verified this, however, when the line began to waver, then to tilt gradually to one side. Concentrating harder, I adjusted the flaps to bring the artificial horizon back in line. No good. The line drifted farther off kilter. ''I said straight and level. Now do it!'' the voice barked at me over the phones. ''I'm trying,'' I whispered as I narrowed my focus down to the rudder controls and the artificial horizon. Despite my efforts, the line continued to drift away from the horizontal. ''If you don't get this aircraft level in the next 30 seconds, I'm taking control,'' spat the mike. ''I've got control,'' I said. ''I've got control.'' Nothing existed in the world except the artificial horizon and me. I adjusted and trimmed the flaps until, by sheer determination, I brought the bold line into perfect parallel position. I held my breath, but the line stayed there, as solid and firm as Earth itself. ''How's that?'' I crowed. No problem here. There was real laughter in his reply. ''Not bad,'' he said. ''One of the more impressive flights I've seen. I have one suggestion, though.'' ''What's that?'' I asked. ''Look up,'' he said. I did. It took me a moment to recognize what it was. The entire Corpus Christi Naval Air Station covered the sky from horizon to horizon. I had brought the aircraft to a perfect horizontal flight - upside down. I suddenly realized I was hanging in my straps 10,000 feet above Texas. ''Would you like to take control now?'' I asked. He laughed again. ''Not a chance. You got us into this, middie. You get us out.'' We landed 10 minutes later on the Corpus Christi runway. The other midshipmen crowded around us as we came off the flight line, fierce in their competition to determine who was the best pilot among us. ''How'd he do?'' they asked. ''Did he blow it?'' Lieutenant Meredith frowned a bit. ''Nahh, he didn't blow it,'' he said. ''I think he'll make a pilot. Just needs to use these a little more.'' He pointed to the most important instrument in the cockpit, his eyes. ''I'll say this, he maintained a whole different attitude up there than everybody else.'' He laughed as he walked away, ''Man, what an attitude!'' I strutted to the group, preened my flight suit, and let the lieutenant's words stand on their own. Sometimes attitude is everything.