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here VISITORS IN 2018

Newsletter January 2018.

Previous Newsletter December  2017

Next meeting Thursday January 11.

7:30pm, Blair Field Clubhouse.

Please note:

I went up to the airstrip on January 4.  It was minus 4 degrees.  I wanted to ensure that the trailer door can be opened; it can! So, no problem there.

Next, the furnace. It was slow to start, but then it produced lots of heat. I let it run for 15 minutes.

Then the generator did not want to start right away, but finally did and I let it run for 15 minutes too.

Some of the snow has been cleared, so we have parking space.

So: we have access, heat and light. I will get there early to make sure it is comfortable for the meeting.

See you there!

In the meantime, if there is a big snowfall making it impossible to go, I will try to let you know.

Counters

I installed counters to see how many visitors were looking at this website. In December we averaged over 200 visits per day on the Buy&Sell section, not too bad!  For the past week we are already at 1280.

Cam

By Dan Thomas

Angle of Attack

     One of the most important aspects of aerodynamics is also one of the most misunderstood or underemphasized in flight training. This lack of knowledge leads to numerous accidents, many of them fatal. Let's review Angle of Attack and how it can cause grief to the unwary.

     Angle of Attack (AoA) is the angle at which the oncoming airflow meets the chordline of an airfoil. It governs the amount of lift a wing generates at any given speed: more AoA means more lift, but only up to a certain angle, beyond which the airfoil stalls and the lift largely disappears. You know that in level slow flight the nose of the airplane is high, indicating that the wing is at a much higher AoA than it was when you were in level cruise and the nose was much lower. The wing needs both airspeed and AoA to generate lift, and if we have less speed we need more AoA. This is simple enough, right? Until, of course, we ask for too much AoA and the air can no longer make the turn downward over the top of the wing and it breaks free and turbulates and the low pressure is lost. We've stalled it. 

     One of the ways we get into trouble is when we start adding load factor, or G -loading. Students are taught that load factor increases in a turn, as centrifugal force is added to gravitational force. The normal 1G turns into 1.06G in a 20-degree bank, 1.31 at 40 degrees, 2.0 at 60, and 5.75 at 80 degrees. You can see that it isn't a linear relationship. The stall speed goes up by the square root of the increase in load factor: a 40-degree bank will increase the stall speed by 1.144 and a 60 degree bank by 1.41. An airplane that stalls at 55 will stall at 63 at 40 degrees and 78 at 60. This is the reason why your training taught you that you should bank at no more than 30 degrees in the circuit, where the stall increases by about 1.08. Your stall speed of 55 increases to a little over 59, safe enough if you're doing 80.

     But we can add load factor in other ways. Almost every manoeuver we make will increase AoA and therefore load factor. The one that lowers it is pushing forward on the stick, as you change the flight path downward with respect to the airplane. And that's a temporary change; the loading returns to normal once the airplane is established in straight-line flight again, whether that is climbing or descending or level. A steady descent is essentially 1G, contrary to many opinions. So is a steady climb.

      Newton's First Law of Motion: Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. It takes force to change the flight path of an airplane, and the more rapid the change, the more force required. In an airplane, that force comes from the wing.

      Picture the guy that buzzes his friend's place and pulls up hard to get that impressive climb. All too often this turns into an accident. The airplane is seen to pull up and rather suddenly dive into the ground, sometimes dropping a wing as it goes. The pilot pulled hard enough to get a load factor that increased the stall speed to something beyond his airspeed and got an accelerated stall.  Those tend to be violent. If he was doing 90 and pulled hard enough to get 3Gs, his stall speed of 55 went to 95 and the wing suddenly gave up. If he introduced a turn as he pulled up, he added that into it, too, and even some speed over 100 wasn't good enough. The yaw will also add a spin. Don’t forget that airspeed immediately starts dropping in such a maneuver, too, bringing the stall closer.

      The usual comment recorded after such an accident: "I don't understand. He was such a good pilot!" No, he wasn’t that good. His knowledge was deficient.

      One more: The dreaded base-to-final stall/spin. This one happens at or near 1G, but another AoA factor is at fault. Remember the definition of chordline: it's the line that runs though the leading and trailing edges of an airfoil. If we lower a flap or aileron, we have moved the aft end of that line downward. Moving it downward changes the AoA, which is why the airplane flies nose-low when the flaps are down--we need to keep the AoA at a safe angle. Moving an aileron down increases the AoA over the span of wing associated with the aileron; remember the instructor's admonition to keep the ailerons level when recovering for a stall, using rudder only? Many Cessnas are somewhat tolerant of aileron misuse in that situation due to their washout and differential aileron movement, but go buy an older design and it won't forgive you so easily. If you are turning base to final and see that you are overshooting the runway centreline, DO NOT add rudder while holding up the inside wing with opposite aileron. Keep the turn coordinated and get back on centreline, or add full power and abort the approach. Adding rudder to tighten the turn and using opposite aileron is causing a skid, and there are several factors there that can quickly lead to the stall-spin, one of them being that lowered aileron increasing the AoA to stall angle when the airplane got too slow, and it will get slow because of the drag of the skid and the nose will want to drop. The pilot will pull back to lift it, and now we have all the ingredients for a nasty stall/spin: yaw, skid, and low airspeed.

      When I was an instructor I most enjoyed the taildragger checkouts in the Citabrias. It was fun to see the students, who usually had a fresh PPL and were thinking pretty highly of thir skills, suddenly find out that their feet weren't so smart. Anyway, if I saw them start skidding the turns in the circuit, we'd break off and go out to a safe altitude and skid a couple of descending turns, letting the airspeed decay some. It would suddenly drop the inside wing and roll over into a spin and we'd need 800 feet to recover even though we knew it was coming and used the right control inputs to recover. Doing it at 400 feet in the circuit while neither expecting nor recognizing it results in a large, painful and expensive hole in the ground. My students didn’t skid their turns anymore after seeing what could happen.

From Dan Oldridge

Hello fellow KWRAA members and friends,

The January issue of The Leading Edge is now available on the KWRAA website... www.kwraa.net
In this issue I have included a number of photos taken by Lee Coulman and a description of a visit Lee and I had to the Rotax distributor, Rotech Research in Vernon, BC in December. There is also a copy of a Letter to the Editor Lee sent to COPA in regard to ADS-B and the direction currently being taken by COPA, Nav Can and Transport Canada.
You can access the newsletter directly at: https://kwraa.weebly.com/uploads/4/3/1/8/43188173/leading_edge_-_january_2018.pdf

From Paul Parsons

You can always go around!

https://www.youtube.com/watch?v=lr5d3sGxSXQ

From Jan Nademlejnsky

181. Short Cold Flight over South Ridge and Sandbars, Kamloops, Dec 23, 2017

 

It was cold, -12C, but beautiful and sunny day. Had to hand shovel snow to get from the hangar to taxiway. I used to fly down to -25C, but my ultralights were slow to max 50 km/h.  -12C at 110 km/h feels very cold especially on the face and my fingers. There is an opening in the front bottom of the pod to accommodate the steerable front wheel. This creates serious and concentrated draft directly into the face, which is very unpleasant. Even the microphone wind screen sponge froze solid from my steamy breath. I had to raise my voice to penetrate the ice.

Overall it was very good flight. Actually, by default, the flying in winter is more pleasant then in summer, because usually there is no turbulence to worry about. 

Video     Photos

New in the Buy&Sell in the last month

Note that I re-arranged this page and placed all the ads together, aircraft and parts. I also removed all the ads that had been there for over a year and the owners had not asked me to renew.

  PARAMOTOR WITH WING    $7,000.  

SALE PENDING

I am selling my black devil Corsair powered paramotor wing accessories and wing. The motor is 25HP and has about 52 hours on the motor.  The wing is a vitamin 30. Excellent wing for no wind take off. Crisp and clean wing.  Will include spare prop and belt and some other extras.  Registered with transport Canada  Call/text: 403-872-9220  Email: piecowye@gmail.com

 171215-BS659

WANTED

WANTED- The Canadian Museum of flight is looking for a Lycoming 0-235 for one of our Sopwith pups. Were also looking for a couple of props close to 74-76 X 44, we would prefer wood over metal if possible.

171215-BS658

1973 Citabria 7ECA     $42,000.

1973 Citabria 7ECA  TTSN 6420 SMOH 1785 STOH 323, New wood spars and polyfibre covering 2001,  Fuselage recovered 1981,  New toe brakes, New adjustable front seat, New engine mounts, baffling and interior 2016, Icom 200, intercom, wheel pants and federal skis. Hangared. Asking $42,000cdn Home 306-928-4505 cell: 306-482-8119 gerrybarbm@yahoo.ca

 171212-BS657

14' Kevlar floats     $4,000.

Kevlar 14 foot straight  floats. ...never used....c/w custom alum: ...toe-behind trailer $4,000.   Lost medical  !!       ALLEN.     250-247-7440 svsolstice@shaw.ca

171211-BS656 

CESSNA 172L     $72,000.

CESSNA AIRCRAFT 172L FOR SALE  Price: $72,000.00   Total Time Since New: 1475 hours  Looking for an amphibious ultralight trade. Dian Brown <dianbrownbellabella@gmail.com>

171211-BS655

Wheel Skis     $10,000.

Wheel Skis for Cessna 180.  Hydraulic Federal 2500, Teflon Bottoms 10/10. As new.   Jon Sarver   250-395-6659.  

171208-BS654

(For more ads, click here.)

  Newsletter Editor: Cam at  villeneuve@shaw.ca