UP/Altair Glider Advisory
[ contributed by JOHN HEINEY ]
Check your gliders.
On a recent endeavor, my student Shawn and I set up at the E, a site at Lake Elsinore, California. We were the only pilots flying that day. After Shawn launched and got up 1,000 feet over, I was alone at launch. I was hooked into my Trapezoid Predator hang glider and standing at launch when I remembered that I had intended to put my pocket camera in the holster on my harness. I hesitated because I was ready to go, and if I delayed, it might blow downslope (a not uncommon occurrence at this site). I decided I wanted the camera, so I backed off launch and started rotating the glider left so it wouldn’t blow over while I got the camera out of my car. When it was about 45 degrees to the wind, I felt a pop on the rig. It felt as though the left downtube (DT) had popped off the keel. How could this be? I set the glider down and confirmed visually that indeed the top DT fitting had come off the control bar apex bolt and was pushing up against the sail. I had believed that, since the TRX hang glider days, the control bar apex bolt was secure (once appropriately installed) since the top DT fittings were designed to cage the head of the bolt and the nut. I thought there was no conceivable way that the nut could unscrew without rotating one of the fittings. However, as was just demonstrated, I was wrong about this. I had been (just seconds before) standing on 22 US H PA P I LOT
launch, ready to fly a glider that was about to fall apart. My desire to have the camera with me had delayed my flight just long enough to save me from a significant in-flight failure. It’s good to be lucky. I opened my car, got out some tools, and replaced the DT fitting and nut. As I tried to tighten the nut an extra turn, I found that the bolt was rotating in the other DT fitting. As it turns out, during the 21 years I’ve flown this glider, the steel bolt head had worn the aluminum fitting enough to allow rotation. I put the downtube back on, put the camera in the holster (which incidentally, I did not use on this flight), and went flying. I got up about 1,500 feet over in the recalcitrant thermals of the day, flew about 50 minutes, and headed out to find Shawn in the LZ. He had soared an hour while I was repairing my glider and struggling to climb out. I decided to play it conservative on this flight, so I only did one loop near the edge of the lake as I descended into the LZ. Shawn wondered why it had taken me a half hour to launch after he had departed the mountain. I told him my story as we folded our wings. Henceforth, I shall check the control-bar apex nut during my pre-flight walk-around. One person foretold this issue. When Joe Greblo started selling Predators and Saturns some