It started late one Thursday afternoon as a wave so weak, if we hadn’t expected it we wouldn’t have noticed. Next morning the lift was still light, but organized and easy to find despite no visual indications. Then wispy rotor clouds began to cycle in all the right places, soon fatter and visibly tumbling. A high thin lennie began to spread that afternoon from one end of our range to the other and by late Friday the lift was up to six knots, stronger every hour.
All night this trend continued (there was a moon and we watched). Saturday brought classic big wave, well marked, with ten-knot lift and lots of it. Yada yada.
Sunday morning’s sky was deep with dark low cloud torn by a single foehn gap positioned, conveniently, right overhead. My question at that point was whether the crosswind would shut us down before this portal slammed shut. It would.
Ordinarily at this site our primary wave forms several miles upwind of the airport, and its first harmonic much closer. But this wave had been building continuously for more than three days. After inundating the mountains, some giant disturbance from the Pacific was pushing ever deeper into the desert, making miles of airspace between us and the mountains a dense mass of churning IMC. All the awesome lift of that storm’s primary wave was now downwind of us. Goodies of this caliber smack you in the face once a year, if that, and they’re so damnably blessed you wonder if the entire remainder of your life can do them justice. Meanwhile they’re still occuring in real time…
Around noon we forced ourselves down from solid 15-knot lift meaning to land soon as we could. But a launch was staged below and waiting for a lull in the crosswind, so we loitered in rotor near pattern entry.
Sitting above, we had a better view of the whole situation and could see their time was up. The ominous dark cliff of descending wave flow was dumping bigtime sink directly onto our runway while veils of rain drifted through the closing hole. Even if a safe launch was still possible, it would be mere minutes before complete shutdown of safe VFR.
Finally they scrubbed the launch and we were clear to land – in conditions now declared too hazardous for takeoff. One thing we should all do when setting up a landing is look for trouble beforehand, and always expect more than we see. The wind aloft was forty something, at the surface twenty and gusting, all straight across the runway. Fifteen knot lift means fifteen knot sink, PLUS double the glider’s still-air sink rate (think this through or you won’t believe it). Altogether, maximum difficulty, so I followed a hunch and used one especially lusty burst of rotor to quickly double our height before giving it back to the student for some serious crosswind practice.
From there to the airport’s nearest corner was less than a mile, and a full landing pattern no more than three. But seconds into our ‘downwind’ leg it became obvious that standard procedure was out the window. “Speed up,” I told the student, “A lot!” Pushing forward on the stick lowered our nose, but the only speed we gained was vertical. Half way along our normal downwind leg we were falling so fast that reaching the airport began to look doubtful.
“I got it,” I said, turned in midfield (a mile early) and really shoved over. Still nothing. With no other option available, I held stick religiously forward while searching out the flattest patch of brush to moosh into. Eventually our weight pulled us down through all that sink and we heard the comforting rush of increased airspeed. We bottomed out in ground effect about a quarter mile downhill from the midfield fence, still in sink with a direct headwind, our airspeed well over a hundred knots (I was waaay to busy to be looking at the instruments!). Finally it felt like we were back ahead of the power curve, but holding that position caused our speed to bleed away and lowering the nose was no longer an option. The fence seemed to grow taller as we approached and I actually considered raising the gear to be sure of clearing it, but just before our energy was gone the obstacle slid behind us and we touched down softly on a part of the airport where no one ever goes.
Seconds earlier, someone watching from below saw our aircraft’s planform as if from above, nose down nearing ground level, and truly thought he was witnessing a suicide. From 2000 feet up we ‘flew’ roughly a mile and a half to touchdown – that’s an achieved glide of 4/1 in a sailplane that boasts 46/1 performance! And we never opened the spoilers except to stop.
I had flown daily with commercial soaring operations for thirty seasons at that time and explored hundreds of waves, yet never heard of or imagined such horrific sink in landing. If I don’t live long enough to see it again, that’ll be fine. But it will happen again whether I’m there or not. Next time might be your turn… BE READY!