Friday, January 1, 2010

Chapter 24: Free as a Bird

As I pulled the yellow cable release knob there was a bang and the tow cable snaked away, dragging with it the noise of the straining L-19 pulling me up to altitude. I trimmed out the sailplane, letting the airspeed drift down to the forty-two knots which would give me the most efficient glide. Happy with the speed I then fussed with the rudder pedals to ensure that the yaw string was streaming back down the centerline of the canopy. Foolproof and cheap, the yaw string reacted to any change in airstream direction and was a good indication of whether I had been inadvertently flying with sideslip.

It was a weekend in Southern California and here I was comfortably reclining under the bubble canopy of the Grob sailplane. As the towplane spiraled away in his dive, it was very quiet in my cockpit, with only the soft hiss of the wind rushing past the Plexiglass to mark my progress through the air.

Slowly, as I became attuned to this machine again, I became aware of a familiar feeling. Unsure for a moment, I searched my memory. It had been over twenty years since I started gliding back in England. In those days we flew rather primitive wood and fabric gliders. This sleek fiberglass ship was a world apart. So it wasn’t that.

The clean lines of the Grob 103 can be seen moments after lift-off from the gravel runway at Pearblossom behind the L-19 towplane. The bubble canopy provides good all-round visibility.

The countryside slowly passing underneath was still an alien and parched landscape, punctuated with scrub and Joshua trees, upraised arms frozen in supplication. The neat English fields, green with the perennial rains and bordered by hedgerows, were half a world away from this. Then realization crept up on me. It was a case of déjà vu. Although this cockpit was lacking the usual plethora of avionics, the sensation was not unlike that of flying a modern jet fighter. The smoothness of flight, the lack of vibration and the barely sensed sound were all the same.
But here the similarity ended. Here there was no sense of urgent motion, no watching the fuel gauges sinking inexorably towards EMPTY as a thirsty jet engine gobbled up kerosene. I was not streaking across the sky, outrunning the noise. On the contrary, I was suspended over the Mojave desert, reclining comfortably in my sheepskin-lined seat, almost stationary and heading into a natural bowl on the north side of the San Gabriel mountains.

The two-seat Grob 103 sailplane is pulled to altitude at Pearblossom airport by the L-19 towplane. Once at altitude the cable will be released and the Grob pilot is on his own to look for lift.

The source of the power keeping my sailplane aloft was simply the sun shining benignly down from a winter sky in California. A few degrees of temperature difference between the desert floor and the wooded slopes of the bowl was enough to trigger a thermal, a bubble of warmer air which would break free from the ground and ascend invisibly into the sky. If I could intercept the thermal, the rising air would be enough to keep me airborne. This sleek fiberglass Grob still amazed me with its performance as I drifted slowly towards the bowl, barely losing altitude.

Two miles behind the tail of the Grob lay the tiny airport at Pearblossom, east of Palmdale. The small hut containing the Flying Club at Pearblossom had tacked on the wall a list of recent flights made from the field. Sailplane flights originating from this field had ended in such faraway places as Cedar City, Utah, Las Vegas, Nevada and Bishop in Northern California. These were destinations I normally would consider worthy of a respectable cross-country flight in a power plane. I would achieve nothing like that on this flight. In fact so far I had not located any lift at all. The sky was an unrelenting blue, with none of the haziness associated with rising air, or even a wisp of forming cloud topping a thermal. The altimeter needle was slowly and inexorably creeping downward round its dial. Disappointed, I banked around and headed back towards the field, checking for other traffic and then curving round into the pattern for landing. Airbrakes out the Grob slid down final approach, quickly losing altitude until I heard the wheel rumble on the runway.

Later in the afternoon I tried again. Others who had launched after me had managed to stay aloft, circling like a swarm of white butterflies in weak thermals away from the field. No record trips were likely, but I would try again. Checking over the sailplane again, I wheeled it into position, climbed in, tightened my straps and started my pre-takeoff drill. The L-19 towplane whooshed past me and landed, settling onto the runway, swiftly turning with a burst of power to taxi back. A helper raised my wingtip. I completed my checks and was hooked up to the towplane.

Ready to go, I waggled my rudder as a visual signal to the tow-plane pilot. A blast of exhaust fumes wafted back from the L-19, percolating through the air vents in my cockpit. The cable tightened and we accelerated away, the wheel only inches beneath my seat rumbling over the gravel runway. The controls came to life as the airspeed increased and the Grob lifted off before the tow-plane. I concentrated on keeping station, maintaining the wing of the L-19 just on the horizon as he spiraled up to altitude.

My spirits rose again as my horizons expanded. Away to the north the jagged skyline of the Sierra Nevada marched into the distance, with the white frieze of the first snows of winter matched by the white brilliance of Rogers dry lake at the foot of the mountains. At 3,000 feet above the high desert I pulled the release. Once free of the tow cable, the Grob slowly lost speed. The readings on the other instruments seemed locked into place. This sailplane with its 35:1 glide ratio did not perceptibly lose altitude for some time.

I was looking for lift. No thermals at first, then I decided to try nearer the slope. Easing the stick and rudder over to the right, I let the sailplane sidle closer to the wooded slope. The variometer quivered to show a positive climb for a moment and the right wing twitched upwards. I started turning and managed to keep in the thermal for half of a circle before sliding out of the lift.
Making another lazy circle, I hit the lift again and this time managed to center in the thermal. The variometer bounced up to show an intermittent climb and every time I glanced at the altimeter it showed the altitude had increased by a few feet. Careful now, I reminded myself, don’t stall in the turn. I pushed on the right rudder pedal, eased back on the stick, backed off on the ailerons and kept turning. The inertia of the long wings and the relatively ineffective ailerons made it hard work to keep in the thermal. I worked the lift for a couple of hundred feet before it petered out. This was just enough altitude for me to head out of the bowl and track north, over a ridge before I would have to turn back to the field.

The Grob loitered along, trimmed at its best glide of forty-two knots as I hunted for thermals. When I started flying out here in the Mojave desert, to my unpracticed eye one spot of desert looked very much like another. My instructor, Ed Green, knew the countryside around the field like the back of his hand. Whereas I saw only dirt roads and areas of rocky ground, he saw each one as a possible thermal source even this late in the year.

After another tussle with an embryo thermal I ran out of altitude and headed back to the field, setting up for an approach to the west, into the light breeze. But no, the windsock now showed that the wind had switched round and was now coming from the east. The start of a Santa Ana wind, perhaps? I could see the tow-planes taxiing about on the field, setting up to launch from the western end of the field. So I turned overhead the field and set up for an approach for a landing to the east.

This is where the good visibility from the bubble canopy was a boon. Sailplanes spend a lot of their time turning, often in close proximity to others sharing the same lift. The pattern was clear. I increased speed to guard against wind shear, and completed my downwind checks. As the Grob arced round at the end of the downwind leg my left hand eased back on the airbrake lever and the rate of descent increased. Over the runway now and I flared, a fraction too high as I forgot just how low the Grob sat to the ground, then eased it down until I heard the mainwheel rumble. I pulled the airbrakes fully open to slow our forward rush, and I pulled the lever to its most rearward position, so actuating the wheel brake. In a minor victory, I had judged it correctly and the Grob coasted to a stop next to the waiting tow-plane.

The change of wind might do the trick. I was eternally optimistic. My father, when he was fishing back in England, was always confident that his next cast would connect him with the biggest fish in the river. Similarly, I knew that there was a thermal out there, just waiting for me.

Just time for one more launch. Five minutes later I pulled the release knob and the tan-colored L-19 banked left and dropped out of my world. Once clear of the tow-rope I trimmed the Grob, settled down and eased closer to the hillside, succeeding in finding some lift coming off the rocks. Wheeling and soaring over the wooded crags in these foothills of the San Gabriel mountains, I lifted the Grob easily over ridges in an exhilarating ride before gliding silently back out over the desert again. The air trembled under my wings and I looked down over the side. A park crammed with recreational vehicles lay below. Maybe some hot air bubbling up from their barbeques? I turned a full circle over the tiny oblong shapes of the RVs but the air remained smooth. I had lost the rising air. I tried the bend of the dry river bed…nothing.

The altimeter was creeping downwards and I was still some miles away from the field. It was too late in the day for thermals, I admitted to myself as I whispered back to the field. Almost there, and with a few hundred feet of precious altitude to play with, I decided to practice a stall in the Grob. I turned and made sure the airspace around me was clear of traffic. Stalls were fun. As I eased the stick back the airspeed needle wavered off the bottom end of the scale. It got very quiet as the airspeed bled away. Under my hand the stick grew sloppy as the controls ran out of air. Eventually the wing quit flying and the nose fell below the horizon. The Grob was just another flying machine after all and I gained airspeed by lowering the nose, although I found my left hand trying to push an imaginary throttle forward.
I flew back to the field, then drifted down to my last landing of the day.

As the sun set I drove home down the crowded freeway, tired from the concentration of flying but very satisfied even though the day had produced no spectacular results. Thermals would blossom during the summer. Winds today were not high enough form mountain waves strong enough to permit climbs to stratospheric altitudes. Flying the legendary Sierra Wave would have to wait for another day.

At home almost daily I could enviously watch kestrels and red-tailed hawks circling effortlessly over grassland behind our house on the lookout for field mice. Sailplaning was the nearest I could get to that condition. It was a challenging aspect of flying.

Free as a bird…just that we humans had to work harder.

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