Evan Krueger, February 27th, 2009
Just like I promised, here is the plan for my first cross country with Dana. My flight will consist of Flying from Westosha in Wilmot, Wisconsin, west to Monroe Airport in Monroe , then North to Watertown Airport in Watertown, then back south to good ‘ol Westosha. Read More >>
BillD, 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
PaulT, February 25th, 2009
I've been highlighting various professional pilot paths and the profession tonight is a favorite of mine, flight instructor.
Flight instruction, by many pilots, is unfortunately seen as only a means to an end. Just a way to build flight experience before moving on to the next rung on the professional pilot ladder. But for some instructors, they realize that becoming a certified flight instructor (CFI) is much more than just another line on a resume, it is the key to sustaining general aviation as we know it today. Read More >>
BillD, 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".
Steve Tupper, February 20th, 2009
On February 8, I went up on what the Civil Air Patrol calls a “Form 5” check flight. It’s named after the CAP form that the check airman uses to check you out and sign you off. Read More >>
A Pilot's Story movie, February 18th, 2009
Wilco Films is producing the next big aviation documentary film called "A Pilot's Story". The film will feature Aviation Icons, Hollywood pilots, Astronauts, Aerobatic Champions, Commercial and Corporate pilots and a select number of General Aviation pilots. Read More >>
AndrewS, February 17th, 2009
There are few bright spots in the aviation world. Cirrus, Cessna, Piper, Diamond, and the rest of the mainstream, standard category airplane makers are all announcing production and job cuts.
But not the LSA sector. True, the LSA industry is a patch-work of family run companies that have revenue in line with the local deli. But Dan Johnson is right to say Sebring and the LSA sector is a “welcome gift to the global aviation industry. Read More >>
Evan Krueger, February 17th, 2009
Yesterday was all about the short and soft field takeoffs and landings. Although they are not used very often, its always a good idea to follow the Boy Scout's motto to "be prepared". You never know when you might have to put the plane down in a tight space or a turf strip. Having the skills to safely land the airplane at unusual airports can help in an emergency instead of creating one. I made sure to leave extra early so I could brush off the snow that had fallen the previous night. After brushing off all the snow and preflighting, we departed runway three to remain in the traffic pattern for the next hour. Read More >>
Steve Tupper, February 12th, 2009
Those who know me will not be surprised to hear that I’m a huge fan of aviation podcasts.
For those not familiar with the medium, a podcast is an audio or video show delivered over a computer network on a periodic or occasional basis. Read More >>
Jason Miller, February 12th, 2009
Many high performance singles such as the Cirrus SR22, some Diamond models, Mooney’s and the Cessna 400 feature the TKS anti-ice system as an option. The SR22 Turbo includes this feature as one of it’s many amazing safety offerings. The newest models are certified for ‘flight into known icing’ but most airplanes that feature this system are not. Without the proper education on it’s limitations, I can see pilots flying themselves into trouble or into a situation where they may not have an out ... and some of those are not so obvious. Read More >>