Friday, February 19, 2016

SSA Convention Second Day

I missed the earliest morning session because I slept in a bit. I managed to make it to the second session to hear a very technically intense presentation about the design and building of Schempp-Hirth's newest racing glider, the Ventus 3.

The Ventus 3 had its first flight a few months ago.  The flight testing hasn't been going very well, simply because the weather hasn't been very good for flight testing in Germany.

I got into the presentation rather late, and didn't get a good seat at the front of the audience. The presentation included many graphs that described many of the design decisions they made.

Later in the afternoon, I really enjoyed the "Concordia Lessons Learned" presentation by Dick Butler. The Concordia was designed as a one-of-a-kind racing glider with the most outrageous wingspan that could ever be built.

When you design a glider that has a 55 to 1 aspect ratio (that means the wing span is 55 times as long as the chord length), you're going to have wiggly wimbly-bimbly bouncy wings, unless you do some serious engineering to solve that problem.  So they had to consider how to resist the twisting, find a way to keep the wings from bouncing around so much that they flutter in high-speed flight.  They had a really neat solution.  They sacrificed a small bit of slow speed performance to maintain the high speed performance by doing a special type of lay-up that resisted stretching on the skin of the wing.

They still have to have water ballast, in order to get the wing loading they needed to make the racing glider fast, so they had to make water ballast tanks in front of and behind the main spar.  They needed extra wing strength, so instead of using Styrofoam in their composite, they used balsa wood.  But it couldn't be any kind of balsa wood, it had to be balsa wood with a very specific mass.

They had to consider the size of the horizontal stabilizer: It couldn't be too big, because that would reduce the performance of the glider by making extra drag.  They started with a Schleicher ASW-27 horizontal stabilizer, shrunk it by 10 centimeters on each side, and ended up with a what seems to be "way too small" horizontal stabilizer.  The advantage of this is to make the empennage more efficient.  The downside of this, however, is that there is a lot more sensitivity to the center of gravity.  The center of gravity range is only 2.5 centimeters.  Everything is OK, so long as the pilot (with parachute) is exactly 85 kilograms.

The results of this amazing achievement in aeronautical engineering is a glider that can cruise with unbelievable performance.  It has a maximum glide ratio somewhere around 70 to 1.  That means for every thousand feet of altitude lost, the glider is going to go about 13.3 statute miles. My Duo Discus usually sits around 7 miles per thousand feet.

To make things even more amazing, the glider has a 50:1 glide ratio at 115 knots.  It has a better glide ratio at 115 knots than most high performance gliders have at 50 knots.   What an amazing bird!

I attended a Luncheon "SSA Focus on the Clubs".  I sat next to Mark Wilson.  The name seemed familiar.  He's the guy I bought my old LS-4 from back in 2002. After eating, Frank Whiteley hosted the discussion.  Subjects covered were things like "How does a club schedule flying operations, tow pilot, instructor availability, and glider usage?"  One club in Canada uses "Click'nGlide", a utility very popular in France.   Another discussion was how the SSA saves money by having clubs all register at the same time with their club. There was a smaller discussion about how clubs are now sharing notes on a Google Groups discussion group called "Chapters-SSA." It's an invitation-only group that shares notes similar to the discussions that were held during this meeting.
Frank Whitley shows off the Google Group Chapters-SSA  (invite only)

The next presentation that I attended was by Sean Fidler, and the topic was
How to use SeeYou for post flight analysis.  Sean has a YouTube channel, where he takes the flight traces from the winners of soaring contests and compares them to his own flying. After watching a lot of replays with the 3-D viewing function of SeeYou, he has made many observations about the mistakes he made, the successes that the winners always make. Sean has a YouTube channel where he describes what competitors did during various sailplane races.

Sean Fidler shows SeeYou for a recent National competition
Karl Striedieck had a presentation describing the different birds that you may encounter while soaring. I didn't take very good notes about this, and was too far back to get any pictures.  

The final presentation I attended today was hosted by the Soaring Safety Foundation. The topic was "Using Scenario-Based Training" to enhance flight instruction.  Sure, flight instructors do a great job teaching a student how to monkey the controls effectively to do the maneuvers.  But in many organizations, the ideas of how a student could handle a certain situation comes up a little short. Airlines use the term LOFT, and the SSF uses the term PAVE. Consider the Pilot, Aircraft, enVironment, and External pressures when presenting a scenario.  FAA Advisory Circular 61-98C mentions that the instructor should use Scenario-Based Training for the ground portion of a 61.56 flight review.  After seeing this presentation, I realize that there are some improvements to be made.  I'm going to have to have with the instructors in my flying club. 

I spent very little time on the show room floor, but managed to take enough time out of my busy schedule to get some more pictures of the gliders. But still, not nearly enough time looking at the gliders.  This is a Pipistrel Taurus motorglider. I've been fascinated with this glider, and up until now, I've never seen one in person.

Pipistrel Taurus M
 And what would an SSA convention be without a beautifully restored SGS 1-26 on the showroom floor.
The shiniest 1-26 I've ever seen
I took a picture of Shane Neitzey's flight simulator rig, that somehow didn't make it into yesterday's blog post.  So here it is:

Shane and Valerie let visitors try out the "Illudium G-36 glider flight simulator"

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