but i didn't mean it...

So on my last heli lesson, everything was okay over all except for the fact that one, i messed up on my last two radio calls, and two, i inadvertently called my instructor 'fat' during out ground school session. GRR. I'm pretty sure he was teasing me, but i was innocent! I wasn't even thinking that! He's about my dads height, and is just as skinny and fit! He is not fat or large in anyway, he's just heavier than me, AS MOST PEOPLE ARE LOL. that's all i meant. I was innocent!

It was accused from a very poor, awkward context too. we were talking about the way the semi rigid (dual) rotor systems were built at a slight angle of THREE degrees to the left to help counteract the Translating Tendency (i believe its called, more notes will be present later this weekend). Because of the way the rotor system is built and how this affects the helicopter's flight behavior, the left skid, no matter how heavy that side is literally, is always the LAST to lift off the ground.

before i learned this i thought it was just the weight factor involved. all my previous instructors weren't fat, they're just big and/or weight heavier than me--im SMALL! Since the instructor typically sits on the left side, it obviously weighs more and would pick up first from the start! My assumptions were innocent! But still terrible LOL.

I can't believe I did that. I know my instructor understood and teased me about it (only because he knew it would, i partially deserved it regardless, and people love teasing me -_-*cough*), but i still can't help but find it embarrassing and amusing at the same time. Yeah, silly I know. Oh well.

I guess all I can hope for now is that he doesn't bring it up.

aerodynamics pt 1

Along with the types of drag, here's some notes I've saved from reviewing aerodynamics. It's not complete. There will be more later. Mind you I've already learned about this stuff in the past here and there, but lets just say now I'm really cracking down on the material and additionally, refreshing my memory further. Yay. I hope its simple enough to understand.

AERODYNAMICS

R22 gross weight is 1370 lbs, has a governor, symmetrical semi rigid rotor system, asymmetrical tail rotor and airfoils.

Properties:

3^rd law of motion: for every action there is an equal and opposite reaction

Bernoulli’s principal: generation of lift resultant of wind moving faster over the curve of an airfoil (low pressure created).

Solidity ratio: ratio of total blade area vs. total disc area—this measures potential for thrust.

Coriolis Effect: the rotation of an object moving clockwise will make it drift to the right while in motion.

Gyroscopic Precession: when a force is applied to a spinning gyro, the max reaction occurs about 90 degrees to the direction of rotation (R22-counter clockwise).

4 forces of flight:

Lift: lifting force

Lift=area X Wind X (velocity)^2 X CoL(AoA) X 1/2

Weight: opposing force of lift

Thrust: speed/acceleration/power

T/R: pedals required to counteract torque made by rotors

In hovering, thrust also acts as lift until you push the cyclic forward.

Drag: opposing force of thrust

Three types of drag:

Parasite: drag resulted from surfaces NOT involved with creating lift (airframe, skids)

Profile:

- form: drag created from skin/sfc roughness of airfoils

-skin friction: drag created from sfc’s on airframe-sfc’s not involved with creating lift.

Induced: (means to produce, lead/move by influence, assert or establish)

-is an additional, aft result of relative wind flowing over airfoil.

-Drag is always perpendicular to lift, and

-in forward flight, all forces are perpendicular to reference plane

AERODYNAMIC FLIGHT BEHAVIOR

1.) R22 rotors rotate counter clockwise. Drifting tendency is to the right,, so use left pedal and a little left cyclic to counter act, and, these three other ways. the most important thing is just to remember how the mast is built and what control units you use to counter act the drifting.

2.) Translating Tendency--This is when the helicopter will tend to drift in the same direction as anti torque rotor thrust—in R22’s case it is to the left.

3.) Gyroscopic Precession

4.) The initial aerodynamic conditions apply too.

Ways to help control translating tendency: rig rotor mast, Flt control rigging, mix in hover

1.) Rig rotor mast--the rotor mast is built to have opposite tail thrust, and angled THREE DEGREES to the left. The left skid will tend to pick up after the right skid.

2.) Flight Control Rigging--Opposite t/r thrust when CYCLIC is centered.

3.) A mix of both can be made possible if in hover.

Center of Mass on each rotor will move closer to or away from rotor hub, but will never go past it; this is affected by the Coriolis Effect.

Flaps up: CM moves closer to hub

Flaps down: CM moves away from hub.

1.) The R22’s rotors are symmetrical. T/R blades, etc, are asymmetrical to generate more thrust.

2.) Asymmetrical airfoils’ Center of Mass change quicker than symmetrical airfoils.

Centrifugal force: the apparent force of an object moving along a circular path exerts on body constraining the object will move INwardly and outwardly (simultaneously) from the center of rotation. This apparent force and dampers keep the rotor system from coning too much.

Centripetal Force: the horizontal component of lift. In a turn, centrifugal force is apparent in the direction away from the path of the turn, while centripetal force pulls in towards the vertical component of lift, stabilizing the turn.

*Centrifugal force is always present in flight, while centripetal force may only be present during turns.

*When moving into forward flight, push nose down (apply forward cyclic), use pedals and collective if needed.

IN GROUND EFFECT

When hovering, stay in ground effect, lift vector is better for both the main rotor system and tail rotor.

*When the helicopter shifts in Ground Effect (after about half the diameter of the rotors above the ground), drag will increase, more thrust will be needed. Adjust unless moving into forward flight.

The pitch angle is different from the angle of attack: AoA involves angle of chord line to relative wind. Pitch angle is the angle between the reference plane and chord line.

Out of ground effect

Vector for tail rotor becomes more efficient

More power is needed.

Translational Lift

a. t/r affected as it moves out of ground effect and accelerates.

b. Thrust shifts forward

c. ETL

d. Loses a little alt. as thrust is applied

e. Condition: rises up and may roll to right if not caught.

f. Correct by: lower collective, right pedal may be needed to.

5 Induced flow: max displacement of rotors is 90 degrees of rotation

a. Rotor blades generate rotational relative wind

b. Flow parallel and opposite rotor leading edge.

c. Air projected downward as lift is produced and rotors spin.

d. Large masses of air—resultant relative wind, generate extra lift.

6 Transverse Flow Effect

a. In forward flight induced flow drops to near zero and angle of attack increases in the aft disc area, because of torque and acceleration, it will roll to the right.

b. Happens around 20 knots

c. Cyclic correction needs to be made.

7 Dissymmetry of Lift: (an existing but not major behavior)

a. Advanced blade has more relative wind (and lift) than retreating.

b. Due to flapping and retreating the lift generated equalizes as the rotors spin.

c. For and aft positions of reference plane are balanced.

8 Retreating blade stall:

a. Reduced lift from flapping and effect from Gyroscopic Precession behavior in retreating blade area risks retreating blade stall, may pitch up and roll to left.

b. Also avoid Vne speed.

Rotorhead

So my mom came back from new Hampshire with a t-shirt for me from my Uncle Steven. He knows I love helicopters and as a thanks for willingly giving away one of my cat beany buddies to my grandma who i sadly don't get to see much any more, gave me a t-shirt that says "Rotorhead" on the front. It's a little big, but it's awesome! I can't wait to wear it this week! though the shirt is quite simple, as is its color and font, i have to say that's one of the coolest shirts I've received in a long time. i normally don't get too excited when i receive gifts of something from friends or family, but this one i was particularly very excited about--i was all like: "OMG! This has to be the coolest shirt ever! It's awesome!" I must have been in one of my weird moods, but my eyes even got a little watery!

XD so yeah I'm pretty happy about that. I'll have to send thanks to my uncle sometime soon.

Oh and next up, I'll be writing about the different types of drag (regarding aerodynamics). So if you thought there is only one type of drag, you're wrong. For study/memory refreshing purposes I'm going to explain each type as best as I can--and with out over doing it, straight to the point I mean LOL.

The Secrets of Life and Flight ((an old essay))

This was from my first semester of college in 2007. While there are a few errors that I STILL haven't caught in this essay, it is being published in a UAA article. Yipee!
Date: October 2, 2007

Secrets of Life and flight

When I first lifted off the ground in that helicopter, hearing the rotors spinning above my instructor and I, I got my first unexpected spiritual reminder that I am alive. It felt good to be in the air, and to be in that helicopter while it was hovering. I was anxious to learn. That day I didn’t have an idea just yet how that day was the first of a turn in events for the rest of my life, but much, much later, I would. Since then, I began to learn that there are many things that keep a helicopter aloft. Not just one. A part of a helicopter cannot operate without the help of something else. As my life improved and changed, I very gradually learned (up to this day) a human has to live life the same way. One dream doesn’t have to keep a person going. Many can, just as the four forces of flight keep an aircraft up in the air. A human reacts to life similar to how a helicopter operates and behaves while in flight. Most importantly, a helicopter is useless sitting on the ground without its engine running, its rotors spinning and the governor on controlling the Rotor RPM. Several things are needed to keep it going…

Obviously, a helicopter can take no action unless the engine is running and the rotors are spinning. A helicopter needs fuel, a pilot, and lift to fly, like a human needs water, air, and a dream or two to keep them going. A helicopter prefers balance as a human likes order and control. A helicopter reacts to weight and drag as a person relates to stress and consequences. Lift is equal to weight as thrust is equal to drag. Of course, drag and weight are negative, but they belong just as lift and thrust do. If a helicopter doesn’t have the forces of flight, fuel, a pilot and its tail rotor to counteract torque, it becomes unstable. For every action there is an equal and opposite reaction-there wouldn’t be much of a world if the world itself didn’t have consequence.

From the first day I had my introductory flight that one summer when I was a freshman, a whole new world was revealed to me. This world was strange to me, intriguing. I wanted to know what this was all about, anything I could about this amazing aircraft. Not only was I curious about this, at the same time, I wondered what else my own life would be about. Was I already at a dead end, or would there be more things to come like the things I was going to learn about with this chopper? I had a simple idea of what kept this helicopter going, but not what kept me going.

All these strange ideas grew on me as the weeks progressed and the more I got into the chopper. The more I learned and improved, more secrets about life and flight were revealed simultaneously. It has been this way and still is this way as I continued to learn.

The helicopter was insanely mysterious when I first saw it on screen at the iMax theatre in Dallas, and later when was able to get a tour during a trip to Canada with my family. Eventually, I got a lesson in New Hampshire. I remember marveling over how smoothly the helicopter ran. I was stumped at how a person was to manage hovering. It was something I wanted to accomplish that seemed twice as hard as it looked. One way or another I was going to get it right. Grapevine and Dallas had no helicopter schools close to where we lived. Life was dull in Texas. It was hot, lonely, and claustrophobic. I hated it. I felt like there was nothing to do, and I felt different from my friends. Without money, fuel, and a pilot to operate the helicopter, it remains still. Trapped and unused, collecting dust. I felt unused and dusty. I needed out. I needed to fly.

Later, my dad got an offer from the oil business he still works for (called Pioneer) to move to Alaska. “What do you think of moving to Alaska?” he had asked. I never thought I would have a chance to move, let alone a place like Alaska. “I guess it wouldn’t hurt.” I remember saying something like that. Some lifting force told me it wouldn’t be so bad. I missed my friends, but not for long. Later on after we settled in, July fourth of 2004, I found Alpine Air, also known as Alyeska Helicopters. My mom and I did a glacier tour with them, and after the flight was over, we discovered they were also a school.

Things would get in the way from that point forward. But where there were problems, like money for lessons. And, later on after we became best friends, my current boy friend moved because of his dad being in the military, working on C130’s. From that point forward, I discovered a new kind of love, and the costs and consequences have been worth the effort since the day I met him. Weight is the opposing force of lift. I would start to learn what stress and determination was all about, and continued to learn even after he moved. Pain and grief are the worst form of weight and drag. Even after numerous struggles, I was thankful to realize he’s still there. When it came to straight and level flight, as long as I kept the helicopter balanced, it would remain stable. I eventually learned we were like this as well.

The engine is the heart. The carburetor heat scoop is the mouth. The throttle is the lungs. The collective is the leg. The skids are the feet. The fuselage is the body. The main rotor system the veins, the pulse-for they are constantly spinning and supply lift. Without the rotors to produce lift, the helicopter is lifeless. The arms are the cyclic. The rotor hub and swash plate are the neck and spine. The governor is the brain. The cockpit is the head. The pilot is the soul. Once we completed the checklist and crank the throttle, things got moving. It’s still interesting to me, how after that lesson, everything seemed to change.

Think ahead of the helicopter. Make tiny, steady movements with the cyclic. Don’t over react. Keep opposite pressure so the helicopter doesn’t drift when in a hover. I learned I couldn’t use my whole arm to raise or lower the collective at my left side. Lesson after lesson, I began to learn I had to gently nudge or pull the collective with the muscles in my fingers! When one hovers, it doesn’t take much arm power at all. It used to be I’d over correct all my movements, and the helicopter would swing about randomly while I tried to adjust until my instructor regained control. Gradually I was able to keep it at a fairly stable hover, and now it seems I’ve improved even further. I couldn’t let myself drift too far off course! I’m still working on getting my license, at mastering these things. It’s slow progress. Then again, so is my life, and waiting for him to move back to Alaska.

It took me a while to figure it all out. Memories containing bits and pieces of emotion and information here and there started to fit together like a giant puzzle in my mind. Now I have it. Just as a helicopter will have some amount of weight for it to have structure, we ourselves are made this way. Another form of weight (or drag, depending on how you look at it), is cost. And with structure, drag is always present. Drag and weight work hand in hand. They affect a person’s esteem, but it builds personality. You have to feel some amount of stress to be determined and accelerate, to produce enough thrust to move forward. It seemed to me (and still does) that life is costly, as a helicopter is costly. That I’m certain is true. There is no way around it. Nevertheless, we adapt and persevere. We accelerate. I had it a while ago, only it came in bits and pieces: tidbits of love, grief, pain and pleasure.

In one of my more recent lessons this year, I improved with setting down the helicopter, which is harder than it looks. It was a little bumpy, but I could do it. I could pick it up without it drifting to the right or left too much (though there was still room for improvement), and I could hover above the numbers on the runway much better than I could a few weeks before that. In the past, I didn’t realize all these things about life, love, and myself. However, I began to understand the things I didn’t learn right away. There are three things I’m passionate about have kept me going, my source of fuel. I never gave them up since he moved and have yet to. I concluded some outside force brought me to all these conclusions and my first love. Not me or helicopters. Something more like God Himself, if He exists. Through Him, helicopters have opened my eyes and mind to a new dimension of life.