Your connection with the sky

Sailplane Guy

SEL Commercial, Instrument , Glider CFI-G Began flying glider and airplanes in 1960 and ammassed about 6000 hours in each. Holds FAI Diamond Badge. Owns a 1980 Shempp-Hirth Nimbus 2C sailplane with a partner. About BillD

Off Field Landings

March 19th, 2009

All aviators face the possibility of an unplanned emergency landing and are supposed to keep options in mind. Captain Chesley "Sully" Sullenberger made the best of a very bad situation by gliding Flight 1549 to a landing in the Hudson River setting an example for all of us. Glider pilots have a special empathy for Sully and his passengers. Read More >>

Landing a Glider – “But you can’t go around”

March 12th, 2009

"How would you handle a go-around?" This is a perfectly logical question for a pilot trained in airplanes but it's likely to be met with a quizzical, "Why would you want to?" from a glider pilot. The question simply doesn't occur to a glider pilot who has been trained to land from every approach. So, how do soaring guys and gals manage to land nicely every time? Its a matter of energy management, judgment and planning - something any skateboarder or mountain bicyclist understands. Read More >>

Soaring – Sailplanes

March 5th, 2009

All aircraft are beautiful in their own way but sailplanes are arguably the most visually stunning. Because sailplanes are raced and "racing improves the breed", the pursuit of pure, uncompromising performance has resulted in objects of unsurpassed beauty. They have been refined through thousands of prototypes until designers settled on long, thin wings, a "pod and boom" fuselage and a "T" tail. The result is beautiful, fast and has superb handling qualities. Read More >>

Soaring – Surfing the Jetstream

March 3rd, 2009

boulder waveTo pilots of piston aircraft, the flight levels are usually unreachable but who hasn't looked wistfully at jet contrails. Glider pilots, with no engine or pressurization, know how to get there.

Surfers have Hawaii's North Shore, mountain climbers have Mt. Everest, and glider pilots have the Mountain Wave. You don't participate in these extreme sports without serious training, top notch equipment and the ability to manage risk. Flying a glider in a mountain wave is all that and more. For adventurous glider pilots, wave flying offers the possibility of extreme heights and record distances.

High altitude winds blowing across big mountains like the Sierras in California, the Rockies in Colorado, or the Andes in Patagonia, can form atmospheric standing waves resembling those formed in water flowing over a submerged boulder. See: http://en.wikipedia.org/wiki/Lee_waves

On January 21st, 2003, Klaus Ohlmann of Germany flew his Nimbus 4 DM glider 1870 miles in the lee waves of the Andes starting from Chapelco Apt. near San Martin de los Andes, Argentina to establish a world distance record.

What is a wave flight like? Let me describe one of mine. It was an unusually warm January morning in Colorado 30 years ago. A great "Lenticular" wave cloud floated stationary in the fast moving air at 25,000' MSL above the Continental Divide. An hour before takeoff, arrangements had been made by telephone with Denver Center for access into a "Wave Window" - an area above 18,000 feet, defined in a letter of agreement and available to glider pilots by request.

The takeoff was into a very turbulent, 20 knot west wind. I wore an insulated flight suit, boots, thick gloves and a sheepskin lined WWII leather helmet with a tight fitting oxygen mask as protection against the cold and lack of oxygen. I pulled the tow rope release knob at 11,000 feet and the tow pilot dove away with a radioed "Good Luck". The turbulence rolled and pitched the glider like a raft on the Colorado River making me work hard to maintain control - but I was climbing.

The turbulence suddenly ended as the glider entered the perfectly smooth air of the wave itself and the rate of climb increased dramatically. I could actually see the mountain peaks falling away. Denver Center granted a clearance into the wave window just before reaching FL180.

Now, facing into the jet stream climbing 2500 feet a minute, I concentrated on staying inside the assigned airspace while navigating around the upwind edge of the Lenticular cloud. In what seemed like the blink of an eye, the glider was above 30,000 feet and it was getting intensely cold. Ice was forming on the inside of the canopy as my breath froze. The outside air temperature was minus 40C and dropping but fierce sunlight provided a little warmth.

As the glider soared past 38,000 feet, I felt the "pressure demand" oxygen system automatically pushing pure oxygen into my lungs. At 42,000, the glider would go no higher. (I wasn't sure I wanted to go higher.) Jet contrails were visible BELOW my altitude. The slide rule glide calculator said I could glide more than 300 miles downwind to somewhere in Kansas. Instead, I just sat there for a few minutes taking in the view.

The cold seeping into my flight suit told me I needed to get down so I flew into the descending part of the wave which now carried the glider down even faster than it went up. As I rolled to a stop after a 40 minute flight, friends ran up with questions about how high the flight had gone. I tried to speak but my facial muscles refused to work - they were just too cold. I had surfed the jet stream at Flight Level 420 and no North Shore Kahuna could have been more satisfied.

Next time I'll write about sailplanes and their advanced technology. Meanwhile here's some great reading.

Exploring the Monster by Robert F. Whelan Amazon ISBN-10: 1891118323

http://www.inyokernairport.com/soaring_at_iyk/soaring_at_iyk.html

Soaring – The Nature of Thermals

February 26th, 2009

To pilots schooled in the meticulous care and feeding of aircraft engines, the concept of extended flight which depends on something free and invisible called "Lift" verges on the magical.

Consider the ubiquitous "thermal." Imagine a cool, clear, summer morning. The sun is warming the earth as it has for billions of years. The air is still and cool but pockets of air, perhaps over plowed field or a sun facing slope, are warming faster than the rest. These pockets of warmed air expand into bubbles which are lighter than the surrounding cooler air. Like a hot air balloons, they begin to rise.

As the sun rises, solar heating becomes more intense and the bubbles form more rapidly, ascending in a continuous stream from favored thermal generating sites. As solar heating becomes still more intense, the bubbles merge into each other forming large columns. These columns of rising air are the "thermals" glider pilots speak of reverently. On a summer day, thermals generally start around 11 AM and last until around 7 PM.

A sailplane flown at 45 knots in a 45 degree bank will fly a circle about 300 feet in diameter. That circle will easily fit inside a thermal column. A sailplane sinks at around 100 feet per minute but the thermal column can be rising at more than 1000 FPM. The glider's variometer, a glider's special, fast response, rate of climb instrument, will show a 900 FPM climb. Sailplanes are solar powered. If the atmosphere is slightly moist, the thermal will generate a fair weather cumulus cloud as it reaches the condensation level thousands of feet above the earth. These clouds are welcome signposts glider pilots use to find thermals.

There are other signs. Glider pilots know bare earth, particularly sand and rock heat up faster than vegetation as do paved parking lots. Airports are almost always good thermal generators. In the deserts, dust devils may rise thousands of feet. Strong thermals may contain bits of trash or plant matter that give them away. Soaring birds are a good thermal markers as are circling gliders. Glider pilots often find themselves in the company of a hawks and eagles who have used THEM as a thermal marker.

As a rule of thumb, thermals are five times as far apart as they are tall. In other words, if thermals are 5000 feet tall, they are likely to be five miles apart. A glider with a glide ratio of 50:1 will pass ten thermals in a glide from 5000 feet. By watching carefully for signs, an observant pilot will find many thermals, one after another.

When a glide path intercepts a thermal, the variometer will indicate a climb beeping to alert the pilot. If the decision is to accept nature's offer of free energy, the pilot will fly a circle. The first circle probably won't be centered on the strongest lift so the pilot will shift the circle until it is. The pilot will continue circling and making small corrections until the thermal weakens or the glider nears cloud base before gliding off in search of the next thermal. Where I fly, thermals often reach the base of Class A airspace at 18,000 feet. Of course, we use oxygen at those altitudes.

Spending a hot afternoon high in a cool sky cruising quietly under cumulus clouds is a indeed a magical experience.

Next time, I'll write about lift which depends on wind and the fascinating ways it behaves as it flows across the earth. Imagine the view from 40,000 feet while surfing a monster called Mountain Wave - soarings equivalent of Mt Everest.

Meanwhile, see some great videos at: http://www.youtube.com/profile?user=GlidingTV&view=favorites

Introduction to soaring – what are the possibilities?

February 20th, 2009

As flying becomes more expensive, aviation enthusiasts are taking a long look at a form of recreational flying that uses the absolute minimum of fuel and has a tiny environmental footprint.

This Blog is about Soaring. That's the "Art, Science and Sport" of flying powerless sailplanes to great heights and long distances at astonishing speed.

It's a "Sport" since we do it for fun. It's a "Science" since, like any pilot, you need to know some things about aerodynamics and meteorology. It's also an "Art" because Mother Nature keeps reminding us how little we really know.

Soaring goes back more than a hundred years - right back to the dawn of flight.

"When gliding operators have attained greater skill, they can maintain themselves in the air for hours at a time."— Wilbur Wright, 1901

"There is no sport equal to that which aviators enjoy while being carried through the air on great white wings." — Wilbur Wright, 1905

Wilbur was more than a little prophetic. In 2008, approximately 20,000 US glider pilots flew their "Great White Wings" over 60,000 hours including 1.8 million miles flown cross country. That's a lot of flying without consuming Jet A or AVGAS.

We know this is so because they submitted secure GPS logs to the Online Contest. See: www.ssa.org > "Sailplane Racing" > "Online contest" scroll down and click "here" for a list of today's flights. To see a map of a flight, click on the blue dot on the right.

I'm guessing a few of you readers are wondering how can a glider without an engine can fly cross country?

Current high performance gliders have a glide ratio of around 50:1 as compared to the typical light airplane's 7:1 glide. That means from 1 mile AGL a sailplane can silently glide nearly 50 miles - much further if the pilot can find "lift".

When flown slowly at an airspeed corresponding to the least rate of descent, these gliders will sink at less than 100 FPM. Gliding cross country there is no sensation the glider is descending.

For example, on March 27th of 2008, Jim Payne flew his German made ASW-27 1,027 miles non-stop at an average 107 MPH from Rosamond Airpark, CA to near Truckee, CA and back landing on the departure runway after a flight of over 11 hours. There were 22 other US glider flights in 2008 that exceeded 600 miles.

You might ask, "1000 miles at over 100MPH with no engine, how exactly was that done?"

Sailplanes aren't totally powerless. They have a pilot who (hopefully) knows a little about soaring weather and, in the case of soaring, that knowledge is literally power.

Soaring weather is all about finding "lift", or rising air, which can lift a glider to great heights restoring the altitude lost in long glides. It's a process of climbing and gliding again and again as you move cross country.

Jim Payne flew over California's Sierra Nevada mountain range where lift is both extremely strong and widespread. On occasion, Jim covered over 100 miles on a single glide.

In strong conditions like these the probability of finding the next source of lift after a long glide exceeds 100%. Most pilots are choosy and will pass up all but the strongest updrafts.

What about this "lift". How does it work?

If a glider sinks at 100 FPM but the air around it is rising at 1000 FPM, the glider will climb at 900 FPM as long as it stays in the rising air. The trick is to stay in "lift" and out of "sink".

I'll write more about the kinds of lift and how you find it (an how to avoid "sink") in the next installment.

Meanwhile, take a look at www.ssa.org and click "About soaring" then "Where to Fly".