[wingspan33]

Paraglider
One large step for man . . .

One giant leap backwards for mankind!




In addition,

Girls Having Fun ? ! In that kind of "Big Air" wouldn't you expect your fellow collapsible canopy occupants to know how to coordinate and clear their turns?

[Rick Masters]

They may have been texting.

But seriously, how many close calls - defined as being suddenly startled by someone you never saw zipping by, way too close - have you had in your flying career?

Me, zero. But I only had to worry about other hang gliders.

PRICE OF ADMISSION

U.S. Hawks: admit one.

[wingspan33]

. . . But seriously, how many close calls - defined as being suddenly startled by someone you never saw zipping by, way too close - have you had in your flying career?

Me, zero. But I only had to worry about other hang gliders . . .

I am ashamed to say that once in Telluride, CO I failed to see another pilot who was flying TANDEM! It wasn't an extreme close call, but it did startle me. I wondered for quite some time why I didn't see the other glider coming. But several hundred previous and later hours of flying with no close calls more or less restored my confidence - but seeing everything within 360 degrees is CRITICAL!

[AirNut]

This touches on the rather woolly concept of 'airmanship'. Although somewhat tenuous to define, we all know it when we see it, and rather alarmingly, when we don't see it.

Maintaining a good look out is certainly one of the planks of good airmanship. In sailplanes (and general aviation) flying, for example, this is emphasised, even harped upon. You're trained to keep up a continual scan across the horizon, above and below. The sailplane manuals even give a worked-out formula for how to scan, how long to rest your eyes in one spot before moving to the next and so on. In other words, they treat maintaining a look out as a very serious business that should be taught thoroughly and hammered in to students until their eyes bleed. In HG/PG, the emphasis on this seems to be somewhat less, usually just vague advice to "clear your turns" and "keep looking around". I think that's probably fair enough for HG/PG, because with sailplanes, the closing speed is a lot higher and it only takes several seconds for an on-coming sailplane to grow from a speck to a wind-shield-filling surprise .

From what I've observed, the general level of airmanship exhibited by PGers seems to rather less than that of HG pilots. My guess is that this has a lot to do with the short time between a student being a complete newbie and sharing a ridge with other pilots. The same progression generally takes longer for a HG pilot, and there's more time to absorb the vital lessons that contribute towards good airmanship. But there may also be less emphasis on airmanship by PG instructors generally. I did a (short) PG course very many years ago (until I ran in the other direction) and certainly in that case there was no treatment of airmanship at all, everything was just about technique and the mechanics of getting the collapsible thingy to fly.

[Bob Kuczewski]

Maintaining a good look out is certainly one of the planks of good airmanship. In sailplanes (and general aviation) flying, for example, this is emphasised, even harped upon.

When I was getting my Private Pilot's license, my instructors always used the phrase "keep your head on a swivel". Just like you said, it was hammered into our heads over and over.

In HG/PG, the emphasis on this seems to be somewhat less, usually just vague advice to "clear your turns" and "keep looking around". I think that's probably fair enough for HG/PG, because with sailplanes, the closing speed is a lot higher and it only takes several seconds for an on-coming sailplane to grow from a speck to a wind-shield-filling surprise .

This is a very good observation. Potential closing speed sets the "timer" in the back of our minds as to how many seconds we can fly before getting nervous. The interesting thing is that we tend to set that timer length based on our own speed with the assumption that others are moving at a similar rate (human nature). That becomes a problem when we mix aircraft of differing speeds.

At sites like Torrey Pines where we have many different kinds of aircraft flying, I've always felt it would be helpful for every pilot to at least get some experience flying in other aircraft (maybe a tandem or RC "buddy box"). I believe it enhances safety to be able to understand and appreciate all perspectives.

[Bill Cummings]

# 1) While scratching east along the rim of South Face Point of the Mountain
I failed to see a hang gliding tandem pilot which caused him to yield his/their right of way to avoid a collision that would have been my fault.

Further to the east behind this tandem glider a mountain rose higher than the South Face rim.
Due to a wet summer the vegetation on the side of the mountain was green and the color of the tandem glider was also green.

When the tandem pilot with passenger turned away from the South Face rim to avoid me it was just as though he had turned off his cloaking device.

It was upsetting to me that if he too had not seen me we would definitely have had a midair collision.

Our paths directly toward each other would have had me motionless against the sky behind me from his vantage point. I would think that it was easier for the tandem pilot to spot me.

The tandem pilot, had I noticed, would probably have appeared motionless against the side of the mountain.

# 2) John Q. Olson was my instructor for flying N - numbered Sport Pilot Aircraft.
With several reminders he got me in the habit of looking to my right before turning left onto final. This of course would give me a chance to see faster General Aviation Aircraft that might also be on final.

#3)

[AirNut]

Maintaining a good look out is certainly one of the planks of good airmanship. In sailplanes (and general aviation) flying, for example, this is emphasised, even harped upon.

When I was getting my Private Pilot's license, my instructors always used the phrase "keep your head on a swivel". Just like you said, it was hammered into our heads over and over.

In HG/PG, the emphasis on this seems to be somewhat less, usually just vague advice to "clear your turns" and "keep looking around". I think that's probably fair enough for HG/PG, because with sailplanes, the closing speed is a lot higher and it only takes several seconds for an on-coming sailplane to grow from a speck to a wind-shield-filling surprise .

This is a very good observation. Potential closing speed sets the "timer" in the back of our minds as to how many seconds we can fly before getting nervous. The interesting thing is that we tend to set that timer length based on our own speed with the assumption that others are moving at a similar rate (human nature). That becomes a problem when we mix aircraft of differing speeds.

At sites like Torrey Pines where we have many different kinds of aircraft flying, I've always felt it would be helpful for every pilot to at least get some experience flying in other aircraft (maybe a tandem or RC "buddy box"). I believe it enhances safety to be able to understand and appreciate all perspectives.

And when HGs and PGs (nylon pyons) mix, there is even a bit more going on than just the speed differential. There is also different turning behaviour (PGs pendulate), different pitch behaviour (HGs can dive), and different blind spots (HGs can't see well above, PGs can't see well below). Put all that together and the need for a good lookout at mixed sites becomes paramount.

[Bob Kuczewski]

And when HGs and PGs (nylon pyons) mix, there is even a bit more going on than just the speed differential. There is also different turning behaviour (PGs pendulate), different pitch behaviour (HGs can dive), and different blind spots (HGs can't see well above, PGs can't see well below). Put all that together and the need for a good lookout at mixed sites becomes paramount.

Well said!!!

Bill, your story about the South Point of the Mountain is very good warning that we can't be vigilant enough when flying.

By the way, in January of 2012 I wrote a Java program to generate an almost identical illusion:

optical_illusion.gif (234.39 KiB) Viewed 4734 times

Here's the source code:

Code: Select all

import java.awt.*;
import java.util.StringTokenizer;
import java.util.Random;
import java.util.Vector;

// import java.awt.*;
import java.awt.image.*;
import javax.imageio.ImageIO;
import java.io.File;



class gdata {
  // static Color bg = new Color(141,199,253);
  static Color bg = new Color(0,0,0);
  static int x_offset_for_screen = 330;
  static double delta_angle = Math.PI/128; // Math.PI/128; // / 32; //  /128  Math.PI/32   Math.PI / 10; // was 0.01;
  static int pause_time_ms = 10; // 1000;  // was 5
  static int file_num = 1;
  static boolean create_files = true;
}


class ExitFrame extends Frame {
  public ExitFrame ( String s ) {
    super ( s );
    setBackground ( gdata.bg );
  }
  public boolean handleEvent(Event evt) {
    if (evt.id == Event.WINDOW_DESTROY) {
      System.exit ( 0 );
    }
    return super.handleEvent(evt);
  }
 
}



class plusses {
  double current_angle = 0;
  int spacing = 143-95;
  int length = 112-80;
 
  double ct=0;
  double st=0;

  double rot_x ( double x, double y ) {
      return ( (x * ct) + (y * st) );
  }
 
  double rot_y ( double x, double y ) {
      return ( (x * st) - (y * ct) );
  }
 
  public void rotate ( double angle ) {
    current_angle += angle;
  }

  public void draw ( Graphics g, int w, int h ) {
 
    int num_plusses = 7;
    int border = w / 8;
    int pw = ( w - (2*border) ) / num_plusses;
    int pwc = pw / 2;
    pw = 2 * pwc;
    double pct = 0.3;
    double hlx, hly, hrx, hry, vtx, vty, vbx, vby;
    double tmp = 0;
   
    g.setColor ( new Color(0, 0, 255) );
    for (int row=-3; row<4; row++) {
      for (int col=-3; col<4; col++) {
        // Start with the normal coordinates for this plus sign
        hlx = (col * pw) - (pw * pct);
        hly = (row * pw);
        hrx = (col * pw) + (pw * pct);
        hry = (row * pw);
        vtx = (col * pw);
        vty = (row * pw) - (pw * pct);
        vbx = (col * pw);
        vby = (row * pw) + (pw * pct);
       
        // Rotate by the angle
         ct = Math.cos(current_angle);
         st = Math.sin(current_angle);
        
         tmp = rot_x ( hlx, hly );
         hly = rot_y ( hlx, hly );
         hlx = tmp;
       
         tmp = rot_x ( hrx, hry );
         hry = rot_y ( hrx, hry );
         hrx = tmp;
       
         tmp = rot_x ( vtx, vty );
         vty = rot_y ( vtx, vty );
         vtx = tmp;
       
         tmp = rot_x ( vbx, vby );
         vby = rot_y ( vbx, vby );
         vbx = tmp;
       
        // Offset to center of screen
        hlx += (w/2);
        hly += (w/2);
        hrx += (w/2);
        hry += (w/2);
        vtx += (w/2);
        vty += (w/2);
        vbx += (w/2);
        vby += (w/2);
       
        for (int xoffset=-1; xoffset<=0; xoffset++) {
          for (int yoffset=-1; yoffset<=0; yoffset++) {
            // Draw the plus sign at this row and column
            g.drawLine ( xoffset+(int)hlx, yoffset+(int)hly, xoffset+(int)hrx, yoffset+(int)hry );
            g.drawLine ( xoffset+(int)vtx, yoffset+(int)vty, xoffset+(int)vbx, yoffset+(int)vby );
          }
        }
      }
    }
   
    // Draw the dots last
   
    g.setColor ( new Color(0, 255, 0) );
    g.fillOval ( (w/2)-4, (w/2)-4, 8, 8 );
    g.setColor ( new Color(255, 255, 0) );
    g.fillOval ( (w/2)-4, (3*w/4)-4, 8, 8 );
    g.fillOval ( (w/3)-4, (w/3)-4, 8, 8 );
    g.fillOval ( (2*w/3)-4, (w/3)-4, 8, 8 );
   
  }
}



public class Optical_Plusses_001 extends java.applet.Applet implements Runnable {

      public Optical_Plusses_001 () {
         super();
      }

      public boolean handleEvent(Event e) {
         // if (e.id != 503) System.out.println ( "Got an event: " + e );
         if (e.id == 501) {
            if (current_delta_angle == 0) {
               current_delta_angle = delta_angle;
            } else {
               current_delta_angle = 0;
            }
         }
         return super.handleEvent(e);
      }

    boolean is_applet = true;

    Thread update_thread;
    boolean moved = false;
    int delay = 1; // This will be changed in init!!

    double angle = 3 * Math.PI / 2;
    double delta_angle = gdata.delta_angle;  // Math.PI / 10; // was 0.01;
    double current_delta_angle = delta_angle;
    double altitude = 0;
   
      plusses illusion = new plusses();

    public void paint_frame(Graphics g) {
      Dimension window_size = size();
      int w = window_size.width;
      int h = window_size.height;
     
         illusion.rotate ( current_delta_angle );
         illusion.draw ( g, w, h );
     
      if (moved) {
        moved = false;
        angle = angle - current_delta_angle;
        // altitude = altitude + 0.5;
        // if (altitude > h) altitude = -50;
        int N = 2;
        altitude = ( -h * (angle / (N * 2 * Math.PI))) % h;
       
        if (gdata.create_files) {
            String fname = "plus_frame" + gdata.file_num + ".png";
            System.out.println ( "Opening " + fname );
            File imgFile = new File( fname );
            // ImageIO.write(new BufferedImage(img_buffer), "png", imgFile);
            try {
               ImageIO.write(img_buffer, "png", imgFile);
            } catch ( Exception e ) {
               System.out.println ( "Error writing to file!!" );
               }
            gdata.file_num++;
          }
      }
     
    }

    public void init() {
      // font = new java.awt.Font("TimesRoman", Font.PLAIN, 24);
      String param;
      if (is_applet) {
        param = getParameter("delay");
      } else {
        param = null;
      }
      if (param == null) {
        delay = gdata.pause_time_ms; // 1000;  // was 5
      } else {
        delay = Integer.valueOf(param).intValue();
      }
      System.out.println ( "Delay = " + delay );
      // init_gbuffer();
    }


    // Image img_buffer = null;
    BufferedImage img_buffer = null;
    Graphics g_buffer = null;
    Color bg_color = gdata.bg;

    void init_gbuffer() {
      if ( (img_buffer == null) || (g_buffer == null) || (size().width != img_buffer.getWidth(this)) || (size().height != img_buffer.getHeight(this)) ) {
        // img_buffer = createImage ( size().width, size().height );
        img_buffer = new BufferedImage ( size().width, size().height, BufferedImage.TYPE_INT_RGB );
        g_buffer = img_buffer.getGraphics();
        g_buffer.setColor ( bg_color );
        g_buffer.fillRect (0,0,size().width, size().height);
      }
    }

    public void init_frame() {
      // img_buffer = createImage ( size().width, size().height );
      img_buffer = new BufferedImage ( size().width, size().height, BufferedImage.TYPE_INT_RGB );
      g_buffer = img_buffer.getGraphics();
      g_buffer.setColor ( bg_color );
      g_buffer.fillRect (0,0,size().width, size().height);
      init_gbuffer();
    }

    public void update(Graphics g) {
      init_gbuffer();
      g_buffer.setColor ( bg_color );
      g_buffer.clearRect (0,0,size().width, size().height);
      g_buffer.fillRect (0,0,size().width, size().height);
      paint ( g );
    }

    public void paint(Graphics g) {
      init_gbuffer();

      paint_frame ( g_buffer );
      g.drawImage ( img_buffer, 0, 0, this );
    }

   
    public void start() {
      update_thread = new Thread(this);
      update_thread.start();
    }
    public void stop() {
      update_thread.stop();
    }
    public void run() {
      while (true) {
        try {
          Thread.currentThread().sleep(delay, 0);
          moved = true;
        } catch (InterruptedException e) {
        }
        repaint();
      }
    }
   
    public static void main ( String args[] ) {
      System.out.print ( "Running: blink " );

      String jv="1.0.2";
      String jcv="45.3";

      if (System.getProperty("java.version").compareTo(jv) != 0) {
        System.out.println( "Warning: This program is designed to run with java.version " + jv );
        System.out.println( "    You are currently running with " + System.getProperty("java.version") + "\n" );
      }
      if (System.getProperty("java.class.version").compareTo(jcv) != 0) {
        System.out.println( "Warning: This program is designed to run with java.class.version " + jcv );
        System.out.println( "    You are currently running with " + System.getProperty("java.class.version") + "\n" );
      }

         String format_names[] = ImageIO.getReaderFormatNames();
         System.out.println ( "ImageIO understands the following format types:" );
         for (int i=0; i<format_names.length; i++) {
            System.out.println ( "  " + format_names[i] );
         }

      Optical_Plusses_001 app = new Optical_Plusses_001();
      app.is_applet = false;
      app.init();


      ExitFrame f = new ExitFrame ( "Optical Illusion" );


      f.add("Center", app);
      f.resize(492,508);
      app.start();
      f.show();

    }
   
}

[Rick Masters]

01/09/2013 Paraglider collapse in thermal at takeoff (Brasil)

“Ele só caiu porque pegou uma corrente de vento, que dobrou o parapente."
"He fell because he caught a thermal which collapsed the paraglider." [my translation]
Intensive care. Bleeding in lung. Internal injuries.

[Merlin]

This touches on the rather woolly concept of 'airmanship'. Although somewhat tenuous to define, we all know it when we see it, and rather alarmingly, when we don't see it.

Beautiful.

In fairness, there are simply ruthless soaring pilots that pursue lift with little concern with the consequences to those around them. They seem oblivious to the havoc they create.