Volume 7 Issue 2
February 2001

Calendar of Events

Soaring in February...

What's Happening with those Blaniks?

Blanik N99950 and the Pawnee are both due for annual inspection, which will be accomplished by Bill Stukenholtz at Loup City.  The AD, due on both Blaniks, is in the works, as the tester required is enroute from the manufacturer. We also have another option should getting the equipment become a problem.

Blanik America has stated that there have been no L-13's in the US that have been found to have the defect mentioned in the Airworthiness Directive, but as you know, the test must be conducted before the glider is flown.

Comments from Flight Operations

Jaime Alexander

The Safety Seminar was in my mind a great success.  The roster showed 17 in attendance and I recieved 17 quizzes and can report that everyone did well and "passed."  I would be happy to review the quiz with anyone so desiring.

The most commonly missed question had to do with a decreasing wind gradient.  I don't find this unexpected because when I reviewed the video tape I noticed I skipped over that material.  I am surprixed that no one asked me about it however!  The subject is not well covered in the SFM but is addressed in both the "Joy of Soaring" and Tom Knauf's "Solo to License."  Here is a scenario.   Assume a ground level wind of 10 Kts and the pilot selects an approach speed of 55 Kts.  So far so good.  Now unknown to the pilot the winds at the altitude are 25 Kts.  Let us also assume that the wind changes quickly from the 25 Kts to 10 Kts at, say, 200ft AGL.  Above 200ft the glider is indicating 55 Kts and has a ground speed of about 30 Kts.  As the glider descends through the "decreasing gradient" the IAS will decrease 15 Kts quickly.  i.e., The ground speed will remain at 30 Kts momentarily because of the gliders inertia while the headwind drops to 10 Kts.  The resulting 40 Kts IAS is 15 Kts below the chosen approach speed.  The glider will tend to drop its nose and regain the trim speed, but will increase the rate of descent to do so, hence the land short possibility.  Or the pilot can resist the descent with back pressure o the stick with the resilt being a continuation of the low speed or even a stall entry.  The answer I was looking for is "to make the glider slow and/or land short."  Wind gradients and wind shear situations are easy to analyze from a desk, but can cause serious problems when confronted from the cockpit.  Keep in mind that we need to keep sufficientenergy in the glider to handle the problem.  When the wind is blowing or varies a lot with altitude it is a good idea to stay up in the higher part of the "cone of possibilities" so spoilers are well extended and don't get slow untill the landing is assured.

The next most missed question (by only a few) dealt with entering a thermal with another glider.  The common asnwer not circled was "keep the extablished glider in sight."  Everyone agreed to circle the same way as the established glider.

Let me thank everyone in attendance for making it out on a not so good day.  Also my special thanks to Bob Dyer for the ground handling presentation Bob Moser for the insights from the tow pilot, and Bob Craig for his thermal and get home comments.   Lastly, special, special, thanks to John Seigel and NP Dodge for making the room available.

I have sent the video to Terry Glaze in Kearney who will make us several copies.   I expect to have them available to those who missed the seminar by the march meetin. Remember that we all need the Seminar, the Ops Quiz, and Safety flight by June 1, so jump in with a CFI!  I highly recommend that as many as possible accomplish this on your first flights as you work on regaining landing currency.