Flightplan

January was not the best month for flying, with the wind, rain, snow, ice and cold temperatures.  At least we did get to fly a few times, one of which I wish I hadn't.  I was flying my Air Core trainer and decided to loop the plane.  It has done this maneuver many, many times in it's lifetime but this one was different.

As the plane came over the top and began to descend, I fed in a little more elevator then more and more until the stick was all the way back, to no avail.  The little plane came straight down and collided with the ground, boring into the earth at least six inches.  A post-mortem revealed the elevator servo had stripped it's gears but the resulting crash also ruined two others.

The plane will now undergo a face lift and hopefully be restored to service.

February came in like a lamb and we had a few good days in which to fly before the meeting.  I've been busy repairing a couple of planes but hope to fly more frequently as the weather improves.  I presently have a Sterling PT-17 and a 1/5 size Top Flite Cessna 182 nearing completion and hope to see them airborne this spring.  My 10 year-old ¼ scale L-4 should go airborne for the first time this spring.

If you have any friends who were formerly members of FMAC and dropped out for some reason, please encourage them to join the club and return to flying.  What will be your reward for doing so?  The good feeling one gets when he has made a new flying buddy and the knowledge that you have made a significant contribution to the club.  Now that our membership year has changed to begin on 1 April each year, it should be somewhat easier for folks to pay their AMA and FMAC dues.

The club has a new Contest Director...   your editor.  Our card arrived in the mail on 22 Feb and we immediately completed an Application for Sanction for the Spring Picnic.  Please e-mail suggestions for events for this Fun Fly to redleg142@hotmail.com.

Adverse Yaw, what is it?   It is an aerodynamic condition that is rarely mentioned by the model press but has caused the destruction of many full size and model aircraft.  The only mention of adverse yaw in model magazines I have read in the past 30 years was in an answer to an email by Gerry Yarrish, senior technical editor of Model Airplane News.

The question was about a rumor the writer had heard concerning a gorgeous model of a Howard Ike, a '30's racer that Yarrish built in conjunction with Henry Haffke.  This model was super-detailed but adverse yaw caught it after take-off, throwing it into power lines.

This condition affects both full size and model airplanes equally and happens in an instant, on take-off, landing, or just above stall speed.  One rarely gets a second chance to cure the problem for the usual outcome is for the plane to literally fall out of the sky.  The result is very ugly, with death for full scale pilots and destruction of the airplane in both model and full size.

When flying slowly, just above stall speed, one must apply some UP elevator to increase the angle of attack of the wing to generate sufficient lift to remain airborne.  On many full size and model aircraft, the ailerons move equal distance UP and DOWN, which is fine when flying at normal speeds but when the wing is at a greater angle of attack to the airflow while flying at a slow speed, the downward aileron produces more drag than the upward aileron.  The result is that when the right aileron is given to turn the plane to the right, the downward aileron will produce more drag and the nose will yaw LEFT.  This makes for an unsightly turn and, in extreme cases, causes a crash.

For this reason, many airplanes require use of both rudder and aileron to make a coordinated turn and most, if not all, warbirds require this.  This is also why coupled rudder ans aileron is recommended on most high wing models with a flat wing and little dihederal.  What causes airplanes to fall out of the sky?  As the plane yaws, the fuselage is angled sideways to the airflow creating more drag and the air is angled across the wing, raising the speed at which the wing stalls AND the speed drops very rapidly to the now increased stall speed and Mother Nature wins another round!

This is the principle of the side-slip approach in which an airplane can approach the runway at a steeper angle and keep the runway in view with building up excessive speed.  In this technique, almost full rudder is applied with the ailerons keeping the wings level.  In this case, the pilot, assisted by gravity, keeps the plane well above the minimum stall speed.

OK, we have discussed quite a bit but we haven't spelled out a "cure".  What is the "cure", you ask?

Aileron differential, Tiny Tim!   Make your ailerons go UP more than DOWN, either mechanically by adjusting the linkages or electronically, inside your computer radio.  Check the instruction manual that came with your radio or consult one of the several "computer radio gurus" in the club.

If you haven't been to the field lately, we seem to have acquired a pair of kittens.  Apparently someone dropped them off rather than taking the kitties to the shelter.  Several of us met at the field on 17 February to try to fly but it was just too windy.  Dwain Mayhew had arrived earlier and was playing with a kitten.   The little beast was emaciated and terribly hungry, so Walt Moore fed it a piece of crust from a McDonald's fried pie.  The beast took the crumb and ran to the shelter to eat it, growling like a vicious animal all the while.  When Bill Womble arrived with a Subway tuna sandwich, he had to feed it some so he could eat.  The little beast tried climbing his leg to get more, so Bill gave it a chunk of bread.  We gathered again on the nineteenth, again in windy weather, to find the first kittie had located his brother and brought him to the field for food.  As we drove up, Dwight Tibbets was feeding them some canned cat food which they gobbled down.   Walt Moore "just happened" to have part of a bag of cat food in his car, which he gave them.  If anyone needs a couple of kittens, go to the field!

Update: the kitties have disappeared.  Maybe a predator got the little varmints!

An inspection of the runways shows little or no damage by armadillos yet.  Hopefully we can maintain this damage-free condition, unlike last spring.  The runways do need to be rolled to smooth them some and Dwain discussed bringing his four-wheeler to pull the roller.  We will need a lot of water to put in the roller to give it enough weight to smooth out the bumps.  No date has been set for this operation but we should probably schedule a workday to prepare the field for our Spring Picnic Fun Fly in April.

Randy Tucker"s Stik suffered the same fate as my AC trainer recently.  It departed flight and impacted vertically into the swamp at the "east" end of our field, burying the nose about seven inches.  The plane received massive damage to the nose but is re-buildable.  An inspection of the remains revealed little to indicate the cause but the pin on the plastic clevis at the elevator was missing, whether from impact or during flight is unknown.

Bill Womble's Four Star Sixty is airworthy again and he has logged several flights on the plane recently.   This is an old design but it is still popular in other clubs.  One, the North Little Rock Skytigers scheduled Four Star Forty races a few years ago and it was a very popular event.  The Four Star Forty was originally designed by Bruce Tharpe while he worked for SIG Manufacturing and is still produced to this day.   A few years ago, a friend crashed his Four Star Sixty into some trees at the field, severing the right wing panel from the wing.  Upon removing the servos from the wing, he said that he wondered just how strong the wing really was, so he placed one foot on the main spar then stepped onto it with his other foot.  He stood there for a few seconds without cracking it and then bounced up and down, also without cracking the spar!

Another member of FMAC had a Four Star 60 wing and tail section but no fuselage.  Using floor underlayment (luan plywood) and plans for the plane, he fabricated the fuselage during the snowy days.  Now it's simply a matter of adding the turtleback with balsa strips, covering and it's done at a very minimal cost!  Luan is easy to work with, accepts CA and other adhesives well, and makes a strong plane.  Try it, you'll like it!