Aug 29, 2009

4th Annual Ojai XC/Thermal Clinic Sept 19th-23rd 2009

We are returning to the beautiful Ojai Valley again for our 4th annual Ojai Thermal and XC Clinic! The flying in Ojai is spectacular and offers ample opportunities for finding and using thermals, and easy XC flights. Every year we have seen new personal bests for altitude, duration, and distance. The primary site we'll be using will again be Chief's Peak which offers fun and safe flying from first thermal flights, through advanced XC. We can cater to your particular needs and goals. Depending on conditions, there are 16 other launch sites within 45 minutes of downtown Ojai that we can explore as well, including beach soaring on the coast, or mountain flying in Santa Barbara.

This year Jeff Farrell will be joining us. Jeff is the co-owner of Superfly and ran the mentoring program and XC clinics at the RatRace this year. He is a fountain of knowledge! Since the trip is now being led through Superfly, you will not only have the opportunity to pick Jeff's brain, but also demo various gliders if requested in advance.

Like the last few years we're keeping the logistics simple. We provide rides to launch, weather briefings, and thermal & XC tactics before, during and after flying. Ojai offers a wide range of places to stay, so you can decide how much you want to spend, and how close you want to be to downtown. Everything from tent camping, to 5 star hotels are available. Most pilots fly into LAX or Burbank and rent a small car for the short drive to Ojai. Ojai is family friendly and there's no shortage of things to do for non-pilots.

The cost this year is $625 for 5 days. You must be a P2 or higher, have a DHV/CEN rated glider, a harness with a reserve, and a 2 meter radio. We recommend having a GPS and vario to get the most out of the clinic but they're not required. We'll be sending out a list of "incidentals" that would be wise to have, like water, energy bars, etc to those who sign up.

For some short video of previous Ojai XC/Thermal Clinics click here.


To sign up, contact Chris Grantham at (805) 368-3543 or destinyaltitude@gmail.com. You can also contact Jeff Farrell at (801) 671-8357 or jeff@superflyinc.com.


We have a limited number of seats so sign up early!

Aug 19, 2009

2009 US Paragliding Nationals SLC

The 2009 US Paragliding Nationals are in full swing here in SLC. Superfly team pilot Andy Macrae has been keeping us up to date on his blog, complete with photos, results, and spectacular video.

Jun 9, 2009

Garmin BaseCamp

Garmin has released BaseCamp for OS X, "a 3D mapping application that allows you to transfer waypoints, tracks, and routes between your Mac and Garmin device and manage your data using topographic Garmin maps that include digital elevation model(DEM) data." It's like a TOPO Google Earth built to work with your GPS.

Apr 28, 2009

Performance By The Numbers

I’ve never bought into the idea that adding 20 lbs of ballast, or flying a glider at the top of the weight range will suddenly have you whizzing past your buddies at mind-bending speeds. Or even less likely, that doing either of the above will suddenly make un-flyable conditions flyable. And glide ratios? Not so much. Or rather, I don’t buy the rationale for getting excited about 0.5:1 differences. David Dagault mentioned the tiny differences in glide ratio in the February issue and his deductions about the compromise between safety and performance are spot on. But what are the advantages of adding weight, how do the numbers really work out and how do we get that 100% performance out of our gliders? This article will attempt to examine the mathematical realities, the huge effect that a little speed can have, and what that extra 0.5:1 glide really does for you. As a kid who nearly failed high school math I’ll try to make it as painless as possible. If, like me, a string of numbers makes your head hurt and you care more about the color of your glider than it’s glide ratio, skip it! If you’re still with me, I’ll try to pull back the curtain on the wizardry we call performance with a few examples and a bunch of numbers. Hopefully you’ll walk away from it relatively un-molested by numerology and with a new appreciation for your speed-bar.

Weight
It’s common knowledge that adding weight to an aircraft increases all the speeds including stall, min-sink, trim, and 100% speed-bar. Sailplane pilots commonly carry ballast during competitions or XC flights, small airplane pilots calculate extra weight into their takeoff and cruise speeds, competition HG/PG pilots have been known to toss on 10Kg, etc. The point is, speed increases with weight. For the examples I’ll concentrate on trim speed in a paraglider because it’s where most pilots fly their gliders most of the time and will illustrate the advantages and disadvantages with minimal trauma to the frontal cortex.
So, how much do we get? Adding weight increases the speed % by the square root of the % change in weight. If your weight doubles (2X weight increase) your speed increases by the square root of 2 or 41%. Sounds like a lot! Yes, but that was a tandem with a solo glider. Not terribly realistic unless you live in Europe and don’t mind getting wiped across the landing zone. For the rest of us, the reality is somewhat less astounding. If a 176Lb (80Kg) pilot adds 22Lb (10Kg) they’re going to increase their airspeed from 37 Km/H, to 39.2 Km/H. That’s about a 6% increase and it’s not exactly going to blow your buddies away at the local ridge site. It can add up but we’ll get to that later. I don’t know about you, but carrying around 22 Lbs of ballast gets old pretty quickly anyway. However, flying the next size smaller would put you higher in the weight range. The difference between flying at the top of the weight range, and the bottom is about 2.9 MPH or 4.6 Km/H assuming the weight range is 20Kg. That might be a deciding factor in choosing your next glider, but keep in mind that there’s also a performance disadvantage when flying a smaller glider. Your glider, you know, that thing providing lift, is smaller but your drag, mostly from lines and the pilot, remains nearly the same. Your Lift/Drag ratio takes a hit and you lose around .2 on your glide ratio (we’ll talk about what that means later too). As a general rule, for every 22 lbs you add, you can add about 2.25 Km/H or 1.4 MPH to your trim speed. The other speeds on your polar curve will increase by less toward the stall, and more toward 100% speed-bar, but always by the same percentage.
Your forward speed with extra weight, or by flying high in the weight range, isn’t the whole story though. Your vertical speeds will also increase. Not by much, but to use the same 22Lbs the vertical descent rate would increase by 6% or (assuming the glide ratio is 8.3) 30 fpm. It’s not a huge difference until you find yourself scratching for that weak chunk of lift that’s going to get you out of a tough spot or you’re ridge soaring on a light day. How often you find yourself in those situations is up to you. Interestingly, the amount you increase your sink rate is smaller at the top and bottom end of your speed range, but again, always by 6%. The result is a slightly flatter polar curve with extra weight. If the climb rates are good, and lift is aplenty the added 30 fpm is inconsequential to the vast majority of us.
To calculate your own speed with added ballast take the Square root of (New Wt./Old Wt.). Then multiply the result by your old speed. You can substitute your New Wt. for your current weight, and the Old Wt. for the middle of the gliders weight range which is where many manufacturers measure the published trim speed. Your old speed then becomes the published trim speed which will give you a good idea of how much you’ll gain by flying at various points in the weight range.

Glide Ratio
It’s not uncommon to hear aspiring XC pilots talk of stepping up to a “higher performance” glider. The oft quoted figure and rationale for a new bag-o-joy is the glide ratio. But is that really where we’re going to see the biggest advantage? Certainly it makes some difference but how much and in what conditions?
Since most of us fly DHV 1 through DHV 2 gliders we can generalize and use glide ratios of 8.0:1 through 9.0:1. Let’s start with the typical transition between a DHV 1 and a 1-2 and assume our DHV 1 gets an 8.0:1 while our 1-2 gets an 8.5:1 glide ratio. The speed is irrelevant at this point because we’re not dealing with wind or time. The arrival height difference between the two gliders, after a 1 Km glide, is 24 feet (or about 6%). That’s a distance you can make up for in about 7 seconds with a very light 200fpm climb. For reference, the distance between you and your glider is about 20 feet. If you’re worried about 24 feet after a one Km glide, a bad decision was made about 1 Km ago.
Most pilots don’t go cross-country. The vast majority of us are content to boat around with friends, enjoy the scenery, make it to the LZ, and have a beer. As such, most of us will never see more than a hundred foot difference between an 8:1 and an 8.5:1 glide. We shouldn’t be using “I just barely cleared those power lines in front of the LZ” as a rationale for a higher performance glider. There are other reasons for that new toy.
Cross-country pilots have to decide whether that 24 feet could make a difference. Are you already flying long XC flights with a 1 or 1-2? How close together are your connection points and how strong is the lift when you get there? If the lift is strong, and the connection points are close together, the arrival altitude will be of minimal importance and isn’t going to keep you from long XC flights. If the connection points are 10 Km apart, you’re now arriving 241 feet lower than your buddy on the 1-2. Still not that significant if the lift is strong, but it does start to add up. Over the course of a 40 Km flight you’d lose an extra 965 feet below the 1-2 but, be honest now, how often do most of us get the opportunity to put down 40 Km or more and would an extra 965 ft have gotten us there or was it a bad decision that put us on the deck?
As we step from the DHV 1-2 to a typical DHV 2 (9:1) our performance advantage is even less. We’re down to a 22 foot difference and that will continue to decrease as glider performance increases. As we stride into the next few decades, when gliders that most of us can fly reach 11.5:1, 12:1 and beyond we’ll be getting excited about arriving only 12 feet higher, or less!
This doesn’t mean that all gliders are created equal but in the small jumps we typically make between gliders, the performance differences aren’t going to blow your socks off. The difference between a DHV 1 (8:1) and a Competition level glider (10:1) is 82 feet after that same 1 Km glide. After 10 Km it’s 820 feet. Of course, if you’re not ready to fly a comp glider, you’re chances of making it past the first strong thermal with clean shorts is slim and your performance won’t matter much after that. So please don’t think I’m advising you to jump to a competition glider to get the most performance!

Speeeeeeed!
Speed is the oft overlooked performance figure and will bring us back to the weight relationship. How often have you heard “I’m stepping up to a glider with a 1 MPH faster trim speed”? Not very often. In fact, that’s where most of us are going to get most of our useful performance and can in some situations make up for a significantly lesser glide ratio. Some of you are now asking yourselves: “Isn’t this speed-to-fly?” Yes, but don’t spoil the surprise for everyone else!
For the first example, let’s look at 4 gliders, all of which get 8.5:1, which is irrelevant for this example but I include it to assure you that every glider arrives at the same altitude. There is no wind and the gliders are flying at trim. Glider A trims at 32 Km/H (20 MPH), B at 33.7 Km/H (21 MPH), C at 35.4 Km/H (22 MPH), and D at 37 MPH (23 MPH), which at the low end are modest speeds for most gliders but useful for this example. Glider A takes 1:52 minutes to fly a 1 Km course. Glider B takes 1:46, C does it in 1:41 and D in 1:37. Glider D is arriving a full 15 seconds before glider A over a paltry 1 Km course. That’s 13.4% faster. Over a 10 Km course it’s 2:33 minutes faster and over a 40 Km course, just over 10 minutes! This is why some competition pilots carry ballast. If you can increase your speed by adding 10Kg and picking up 2.2 Km/H from 35.7Km/H to 37 Km/H, you’ll arrive 3 minutes faster through a 40 Km course. On task 4 of the 2009 PWC, with a 84 Km course, 7 minutes made the difference between 1st, and 16th place. Certainly pilot skill and speed-bar use had a great deal to do with it, but gaining even 2 Km/H over the distances flown in an arena like the PWC can’t hurt. As a general rule, you can decrease your arrival time by about 4.5% for every 1.6 Km/H or 1 MPH you increase your speed.
Factoring wind into the equation makes the performance advantages of a faster glider even more apparent. Let’s now assume there’s a 16 Km/H (10 MPH) headwind. Those same gliders, A, B, C, D, are traveling the same 1 Km course, at trim and into the wind. Glider D is now arriving a full 0:54 before glider A and 92 feet higher because while the sink rate hasn’t changed, the amount of time glider A has been sinking at that rate is longer. This is where the numbers get interesting! If Glider B, rather than getting an 8:5:1 glide now only gets an 8.1:1 it will arrive at the same height as Glider A but do it 22 seconds faster. Glider C could get a 7.8:1 glide ratio and achieve the same altitude but 0:40 before glider A. Glider D could get a 7.5:1, arrive at the same altitude, and still do it 0:54 faster! That is the essence of Speed-To-Fly, and why a little speed-bar can make a big difference despite the sink rate/glide ratio hit.
To bring this full circle and back to the advantages/disadvantages of adding weight, let’s revisit that .2 you lose off your glide ratio by flying a smaller glider in order to be at the top of the weight range. You have the glider you want all picked out. It’s the PERFECT color but you can’t decide which size to fly. The small weight range is 60-80Kg and the medium runs from 80-100Kg. Naturally your all-up weight is 80Kg. Why does it always work out that way? The published speeds are 37 Km/H and 8.5:1 at trim for both sizes, but you know you’re going to lose .2 off your glide by flying the smaller size. You’ll be flying the small at 107% of it’s published speed, and the medium at 94% meaning that you’ll arrive at your destination 1 Km away 12 seconds earlier on the small. Because of the slightly lower glide ratio you’ll also arrive 9 feet lower. However, with just a 6 Km (3.7 MPH) headwind, you will begin to arrive higher than the medium, and 17 seconds earlier. Those performance gains will increase with greater headwind. The small glider, in those conditions or into any headwind greater than 6 Km/H, will perform better.
To be clear, none of these numbers are a reason to get a tiny glider so you can fly a ridge site when it’s blowing 20+ MPH. It’s essential to consider your safety margins and those margins should be large enough that the difference in speed between the top and bottom of the weight range is inconsequential to the conditions you’re flying in.

Density Altitude
We know from our basic training that the atmospheric density decreases with altitude and barometric pressure, and with an increase in temperature. By factoring in those three components we can get our Density Altitude or the altitude at which it FEELS like we’re flying. For the purposes of our example I’ll leave the standard atmospheric pressure at 29.92 and the temperature at the standard 15ºC. At 10,000 ft, in standard conditions, it feels like we’re at 10,000 ft but If the temperature rose, or the barometric pressure dropped, we’d feel like we were at some altitude higher than 10,000 ft. But why do we care? Because speed increases with higher density altitudes! In small aircraft the Density Altitude is used to calculate takeoff distances, speeds, cruise performance, etc. and the same applies to us. Anyone who has flown Aspen or Telluride can tell you that takeoff is longer, speeds are higher and we can calculate by exactly how much. For every 1,000 ft in Density Altitude, we increase our speed by roughly 1.5%. Doesn’t sound like much until you’re at 10,000 ft in the Owens, Aspen, Snowbird, Valle De Bravo etc. and you’re tripping along 15% faster than you were at sea level (horizontally and vertically). You’ve heard the adage “get high, stay high”? This is one of the reasons why, aside from the fact that you have options at altitude. A 15% increase in speed is nothing to scoff at. If you trimmed at 37 Km/H at sea level, you’re now trimming at 43 Km/H! Remember how even a relatively small difference in speed can make a significant difference in arrival times? Now you hit the mother-load in the Owens and get the wild ride to 17,999, right to the floor of Class A airspace. That’s a 28% increase and you’re trimming at 49 Km/H true airspeed (not indicated). Alternatively, if you’re flying a glider that trims 1.6 Km/H (1 MPH) slower than your buddy, you’d have to fly ~3000 feet higher just to keep up. So for those of you who get high and go far, staying high has advantages well beyond options and the view.
To calculate the Density Altitude, ignoring moisture content which has a relatively small impact, you can use the equation: Altitude + ((29.92 - Baro Pressure)*1000) - ((15 - Temp ºC) * 120).

Drag
Since most glider manufacturers measure performance with aerodynamic harnesses, the rest of us are forced to wonder what exactly the drag off an upright harness is costing us. The answer is pretty simple. An upright harness will typically cost you 2.4 Km/H and 0.9:1 off your glide ratio or 7 seconds and 46 feet over a 1 Km course. That’s an altitude difference you can make up for in 14 seconds with a 200fpm climb, but you’ll never be able to make up for those 7 seconds and that 14 seconds you had to waste getting your altitude back will catch up with you if you’re going cross-country in a race against the sun. All accounted for you’ll be 21 seconds behind your buddy with the same glider but an aerodynamic harness after just 1 Km.
While we’re on the topic of how manufacturers measure performance, most of them gather polar data at 1,500 Meters or 4,921 feet above sea level. You can knock roughly 2.7 Km/H or 1.7 MPH off your speeds if you’re boating around at the beach.

Reality
But enough of this hypothetical stuff. Let’s look at the full range of gliders from Advance in the 28 sq meter size with an all-up weight of 97.5Kg. Their current range consists of the Alpha, Epsilon, Sigma, and Omega. Gotta hand it to the Swiss for being consistent with the their naming schemes. I chose Advance for the example because most of their gliders have been refreshed within the last year, they were very generous with polar curve data, and they have a nifty Speed Performance Indicator right on the back of their risers that will help pilots get the most performance. They know how much speed matters and they want us to know too. Kudos to them for making it easy for us.

Table A

Table A shows polar curve data for 4 points for all 4 gliders (min-sink, trim, 50% bar, 100% bar), their weight range, the pilot’s weight, the polar curve data corrected for a 97.5Kg pilot, the weight range and the percentage of the published speed you’ll get from the glider at 97.5Kg. I left out the range between min-sink and stall because nobody interested in performance, or self-preservation for that matter, flies around that slow. Table B shows the test distance, the published L/D ratio of each glider, the weight-corrected trim speed, and the glide ratio corrected for wind which is 0 for this example. It also shows the altitude lost along the test distance, the altitude above the lowest glider after the test distance, the time to complete the test distance, and the speed & glide % advantage over the glider that had the lowest respective altitude, or greatest time at the end of the test distance. I’ve left the numbers uncorrected for Density Altitude to keep things simple. What we can glean from the pile of numbers is that we’d be flying the Alpha at 103% of it’s published speed, and the Epsilon at 100% of it’s published speed. The result is that the Alpha arrives at goal 1 Km away 2 seconds before the Epsilon, but 26 feet lower. Not bad for a glider with a 0.6:1 glide ratio deficit! Most of us would swoon over picking up 0.6:1 on our glide. As we step up to the Sigma we see that we will arrive 2 seconds before the Epsilon, and 10 feet higher. The Omega will arrive another 2 seconds earlier and 26 feet higher than the Sigma but we’re only flying it at 97% of it’s published speed so we’re not getting all the speed we could out of it. As I’ve mentioned before, these values do add up, sometimes significantly over greater distances or into a headwind, but most of us are not reaching those distances anyway, due either to lack of desire, skill, or conditions and if we’re attempting to lay down some miles we’re not going to try to do it into the wind. With a tailwind the performance differences decrease to a point where, with a 30 Km/H tailwind, 34 feet separates the Omega from the Alpha instead of the 62 foot separation in nil-wind conditions.

Table B

We could go on to compare gliders with 0.5 MPH speed differences and 0.2:1 glide ratio differences, but we already know how small the differences are with larger numbers. Calculating your own arrival time is easy enough. Time=Distance/Speed. Calculating the altitude lost is equally straight forward. Altitude Lost=(Km Flown*3280.8)/Glide Ratio. Plugging in your weight-compensated speed might help you decide whether you want to be heavy on the small, or light on the medium.
To wrap up the performance examples, let’s look at a short cross-country flight of 20 Km, with a 500fpm climb at the end. Both gliders get 8.5:1 but glider A trims at 37 Km/H and glider B trims at 39 Km/H. Glider A arrives 1:39 seconds behind glider B but at the same altitude. Glider B can use that extra time to climb 832 feet before glider A has even arrived.
Now we can do the same flight with 2 different gliders that have the same trim speed of 24.25 but glider C has an 8:1 glide ratio instead of the 8.5:1 that glider D gets. At the 20 Km mark glider D arrives 482 feet higher which would take glider C 58 seconds to catch up to in a 500 fpm climb
Finally we can do the flight again with gliders that have different trim and glide ratios. Glider E trims at 39 Km/H but has a glide ratio of 8:1 while glider F trims at 37 Km/H and gets 8.5:1. After the same 20 Km glider F arrives 482 feet higher, but 1:39 behind. That's time that glider E can use to climb 825 feet giving it a 350 foot altitude advantage by the time glider F arrives. Suddenly thinking about using that speed-bar more often? Me too.
Remember that all three examples were over 20 Km and the difference we’re talking about is still relatively small.

Up until now, we’ve completely ignored pilot skill, glider handling when heavily loaded vs. lightly loaded, and the associated difference in DHV/EN test results. We’ll keep it that way. Those are differences that get hashed out in places like Valle De Bravo, the Owens Valley, and the Alps by pilots with names like Russell, Torsten, Christian, Alex, and Jean-Marc. I won’t pretend to be able to tell you which glider to fly, where in the weight range or in what DHV category. Those are decisions you’ll have to make based on the conditions you fly in, the kind of flying you’re doing and the amount of passive safety you want from your glider. Hopefully the numbers have convinced you that you don’t absolutely need a hot-ship to go places and that a little speed-bar can make a big difference in your performance, even when you’re taking a typical DHV 1-2 up against a typical DHV 2. Don’t let the small differences in performance on paper discourage you from a new glider either. Newer gliders do have better performance, they’re generally safer and if you like the handling, you will fly better. The equation for calculating the performance of a glider you actually enjoy is: ((Speed/Glide)^fun) + pretty colors.

For the spreadsheet that was used to generate all the figures, go here. Using Apple Numbers 2.0 you can enter your own polar curves, altitudes, weights, and compare performance figures. It will also generate a Hoisington Chart (so dubbed after Zach’s 2005 Woodrat Speed-To-Fly presentation) that can be used in flight to maximize performance.

Hoisington Chart

(Red gliders and helmets with flames on the side will increase your speeds by roughly 5%.)

Apr 6, 2009

New Tests

Just a heads up for USHPA Instructors. New P1 and P2 tests are available online at the USHPA website. Apparently they were updated some time ago but we weren't notified.

Mar 25, 2009

Digifly Flyer 2 Software Update

Digifly has quietly released new firmware for the Flyer 2 vario. The new firmware makes the Flyer 2 functionally identical to the Archimede, but without the new labels on the buttons. There are several useful improvements and if you have a Flyer 2 this shouldn't be passed up. The new software is here. Manuals and VLTools for the Flyer 2 and other models are available here.

Mar 24, 2009

CompetitionPilot


For those of you with old Palm Pilots sitting in the closet collecting dust, Vincenzo Piazza has created a great piece of software that, when coupled with your GPS, turns it into a fully fledged competition-grade flight instrument. Very cool. Check it out here.

Mar 22, 2009

Tini Tutorial

This is an attempt to consolidate the instructions for compiling and running Tom Payne's Tini utility for OS X. It's designed for people who have little or no experience with the OS X Terminal. Tini is a small application for downloading logs from Flytec and Brauniger flight instruments.

First, make sure you have the OS X Developer tools (XCode) installed. It comes with every copy of OS X but may not be installed by default. Just run the installer again to make sure XCode is installed.

Second, download the Tini source code, not the "OS X Binary". The latest version is always available here. Once it's downloaded, unzip the archive, and put the resulting folder on your Desktop.

Third, make sure your OS X Root account is enabled.
  1. From the Finder's Go menu, choose Utilities.
  2. Open Directory Utility.
  3. Click the lock in the Directory Utility window.
  4. Enter an administrator account name and password, then click OK.
  5. Choose Enable Root User from the Edit menu.
  6. Enter the root password you wish to use in both the Password and Verify fields, then click OK.
Fourth, open the Terminal. It's in your Utilities folder which resides inside your Application folder.
  1. Type 'su' and hit return. At the password prompt enter the password you set for your Root User.
  2. Type 'cd ' (with a space after 'cd'). Find the Tini folder on your desktop and drag it to your terminal window. It should enter the full path to that folder in the Terminal. Back in the Terminal, hit return.
  3. Type 'make' and hit return. It'll list a few files, then give you the # prompt again.
  4. Type 'make install' and return. It should be successfully installed!
If you would like to avoid some typing later, follow the directions below. They will replace step 3 above. This is optional!
  • If you're using a Keyspan USA-19HS (most of us are, it's written on the back of the adapter) it's easy. Replace 'make' in step 3 with 'make DEVICE=/dev/cu.USA19H3d1P1.1' and hit return. That will set the Keyspan adapter as the default every time you run Tini.
  • If you're not using an adapter, and have a Compeo+ or 6030, replace 'make' in step 3 with 'make DEVICE=/dev/ttyUSB0' and hit return.
Fifth, it's time to set up your serial port adapter because the default probably won't work. You'll have to do this every time you run Tini unless you followed the italicized directions above when installing Tini.
  • If you're using a Keyspan USA-19HS (most of us are, it's written on the back of the adapter) it's easy. At the # prompt type 'export TINI_DEVICE=/dev/cu.USA19H3d1P1.1' and hit return.
  • If you're not using an adapter, and have a Compeo+ or 6030, type 'export TINI_DEVICE=/dev/ttyUSB0' and hit return.
You should be ready to rock-n-roll! Before downloading type 'cd /' and return to set your current directory to the top level of your Hard Drive. Now type 'tini' and it should download all the tracks to the current directory, or in this case, the top level of your HD. For tini help type 'tini -h' and it will list additional commands.

Tini

Tom Payne has produced a nifty command-line tool for downloading tracklogs from Brauniger and Flytec instruments that runs on OS X, Linux, and the BSDs. Many of us have been waiting for this for a long time (no more booting into BootCamp or having to use Parallels!) and somehow his work has gone mostly unnoticed. You can find it here!

Mar 11, 2009

Site Guides


I'm posting the site guides that I usually hand to students or visiting pilots with the hope that more pilots visiting Ojai/Santa Barbara see the guides, and understand that renegading on these sites poses a risk to themselves and the site. These three guides only cover Chief's Peak in Ojai, and Alternator and Skyport in Santa Barbara but more will be forthcoming. I have purposely left the coordinates of all the launch sites OFF the guide to discourage pilots from showing up unguided.

Mar 9, 2009

Performance Calculator v.2.6.2

2.6.2 makes a few big changes. I've added S2F Gain to the arrival altitude chart. It shows how much higher you would arrive if you flew at the proper Speed-To-Fly. The Time chart also shows times for S2F. The Polar curve graph now no longer allows the S2F indicator dot to exceed the 100% speed-bar value. That applies to the S2F table as well. The Polar Curves Table and Input tables have been changed to allow for different weights for each glider. That will allow two pilots to compare two different gliders, rather than one pilot looking at what their performance would be on each of the 4 gliders.

Feb 19, 2009

Why Can't We Get a Handle On This Safety Thing


This article was written by Mike Meier many years ago, and still stands true today. I don't think anyone has ever put it more clearly or concisely. This should be required reading for all P2s and an annual refresher for all instructors.

Why Can't We Get a Handle On This Safety Thing

Jan 28, 2009

Jan 19, 2009

Closet Cleaning for Summer!

We're doing a little closet cleaning for the Summer season so we have some gear that MUST go!
The following are still available as of 10/28/09

UP Makalu 2 - Small 65-85 kg - Red/Grey
Kited in a field 3 times but otherwise brand new! Stellar gliders for brand new through intermediate pilots! This is one of my favorite beginner gliders.
$2100
Makalu 2

Windtech WINDSOS Reserve - Small (31) - Max Weight 105 Kg.
Brand new. It's been sitting in a closet for 2 years so it's time to go!
These are great, reliable reserves. I've repacked a number of these for people and those that have used them haven't had any complaints!
$500
WINDSOS

Give us a call or send us an email if you have an interest in any of these things!

Jan 18, 2009

Big Ears: Rethinking Our Rationale

An article I wrote in '08 after seeing several "enlightening" events involving Big-Ears.

We've all been there. We've all done it. We've all wanted or needed to get down, preferably 5 minutes ago, for any number of imaginable reasons and an equally vast number of unimaginable ones. We have all, at some point in our time as pilots, thought "If I make my glider the size of a marmot pelt, I should pick up a few extra miles per hour and get down faster!" The logic works doesn't it? Smaller surface area, increased wing loading, speed increases with wing loading...just what we were looking for! We all remember that stuff from our training...Right? As an added bonus our gliders feel more stable in turbulence and we don't have to worry about the bumps! This is the part where you should hear a little voice that sounds suspiciously like Scooby-Do saying "RUH-ROH!"
To understand the problems, and why big-ears are so commonly used in inappropriate circumstances we have to understand the up-side to big-ears and what happens while they’re installed. Increased descent rate without compromising speed? Check. We can see it on our instruments and it's quantifiable. This is, after all, the primary reason we use big-ears. Increased wing loading? Check. Make your glider smaller and you're suspending the same weight from a smaller wing. We could measure it with the right instruments but we shouldn't need to. Increased angle of attack? Absolutely, and like an increase in wing loading, it's a byproduct of big-ears. You can't have one without the other. Without increasing your horizontal speed the angle at which the air is intersecting the chord increases. It's debatable as to whether the angle increases to a dangerous level, but it does happen to some degree and could, in some conditions, be an important factor.
But how do we get ourselves into trouble with such a common, useful, and if used properly, safe maneuver? Unfortunately it often goes all the way back to our training, where we learned that increasing the wing loading, however we choose to do it, increases all our speeds, makes our glider less susceptible to deflations, and that big-ears is one way of increasing our wing loading. It's an explanation that leaves out a myriad of variables. As eager students we instantly deduce that big-ears are the perfect method for getting into tight landing zones, dealing with turbulence that makes us uncomfortable, often on approach to a landing zone, or escaping "park-out" where our ground speed is 0 or negative. We like to think of big-ears positively. "What can they do for me?" rather than "What does it cost me?"
The reality is that using big-ears to descend lower on a windy ridge may put us in a position with less wind and thus increase our ground speed, but no matter how much we wish they did, big-ears do not increase our airspeed. The extra drag from all that limp fabric flapping in the breeze conveniently negates any increase in speed we would have gained through higher wing loading. Some high performance gliders may actually lose air-speed while in big-ears. Using speed-bar in conjunction with big-ears (big-ears first, then speed-bar) would clearly help our penetration and decrease our angle of attack, but using an appreciable amount of speed-bar close to the ground isn't recommended. I wouldn't want to give anyone the impression that descending below 500 feet AGL with speed-bar applied in turbulent conditions is a good idea. It's most definitely not.
What about getting into tight landing zones or dealing with turbulence? Tight landing zones are often tight because they're surrounded by trees, buildings, and an assortment of other turbulence inducing nuisances. By using big-ears to descend steeply into a landing zone you are gambling that the amount of turbulence behind the obstacles will be less than the turbulence required to disfigure your glider in its highly loaded state. Remember that you already have a higher angle of attack and while holding onto the outside A-lines it's utterly impossible to be an active pilot. For those unfamiliar with the term active piloting, it's what we do when we sense the glider through the brake toggles and harness, and translate those senses into properly timed inputs that keep the glider flying the way we want it to. With big-ears installed you have no surge control or feedback from the glider through the brake lines not to mention diminished directional control. It's like driving a 4WD road with both hands on the dashboard. One should always be an active pilot, but of all the times to be especially vigilant, flight close to the ground should rank high. To add to the complexity of landing, if you did suffer an unexpected glider disfigurement or surge while in big ears and you released the outside A-lines to apply brake, you're now dealing with high wing loading, an increased stall speed and a bunch of brake to stop the surge. Messy.
Very, very tiny big ears don’t solve the problem! By using very small ears you gain none of the advantages and all of the disadvantages. Your descent rate wont increase much, your hands are occupied with something other than active piloting, and you don't gain any real increase in stability through wing loading. You'd be better off yelling to someone on the ground to throw you a rope or some lead bricks.
Wouldn't the turbulence required to disfigure a glider in big-ears be greater than the turbulence required to disfigure a glider without big-ears? Not if you're being an active pilot. Be a pilot! Fly the glider and take command of your aircraft. Active piloting is much better at preventing glider disfigurement than passively hoping that big-ears will. Remember, big-ears are a descent maneuver, not a deflation prevention maneuver. By using big-ears as a band-aid for poor planning, fear, lack of skill, or lack of knowledge, you are taking yourself out of the equation and placing your fate in the hands of your environment. Planet earth is hard, and the atmosphere has no pity. If you have the altitude for it, and you no longer want to be involved in piloting your aircraft, come up with another descent maneuver. I'm a big fan of B-Line stalls and spirals. In a B-Line stall your glider is no longer flying and is significantly less likely to require inputs from you. As with most maneuvers, get training at a maneuvers course before doing a B-line stall. Once you've descended to within 500-1000 feet of the ground, exit your descent maneuver of choice and actively pilot your glider to the ground. Obviously any horizontal wind component will be a deciding factor since in a B-Line stall or spiral you will drift downwind at at whatever rate the wind speed happens to be.
So why do we bother learning how to do big-ears? Is there any appropriate place to use them? Absolutely! We learn how to do them because they're a handy tool for escaping clouds or descending at a moderate speed in reasonably smooth air (your bump tolerance may vary). Big-ears is also the only descent method that doesn't compromise our progress toward a goal. You can install ears and still be zipping along at or at least near trim speed which make it a great method for escaping cloud suck or getting down to 1000ft AGL over a buoyant landing zone. When nearing cloud-base, and think you may be unable to make it to the edge before whiting out, toss in big-ears, pick a direction and make a quick exit. It's a band-aid for poor planning but is still better than illegally entering a cloud. If the cloud suck is extremely strong, use a faster descent method, lose some altitude, then go back to big-ears.
Used in the right situations big-ears can be a safe and useful descent method. Used inappropriately it's a sloppy band-aid for poor planning, or fear, and is significantly riskier than actively piloting your glider.

Chris Grantham is an advanced nomadic instructor, and a nomadic advanced instructor. He is also extremely handsome and charming and expects to gain fame and fortune through the cunning use of chap-stick, hazel nuts, and small woodland creatures.

Jan 16, 2009

Wind Speed Probes


In another response to a question about Wind Probes I put together this short explanation on why cheaper is better!

If you absolutely MUST have one, get a simple Hall Airspeed Indicator. The usual anemometers you see folks holding up at your local ridge are impeller driven (with a little propeller) and what they're measuring is the speed of the air molecules as they pass through the impeller. However, they do not compensate for air temperature or density (density altitude) and so have little bearing on how flyable or unflyable it is unless you happen to be at sea level and the temp is 59ºF. The Hall airspeed indicators will compensate for pressure, temperature, etc. The reason that's important, especially in places where you're likely to be launching at high altitude, is that if you measure the wind speed with an impeller at 10,000 ft you'll get a 15% faster reading than if you measure it with a Hall meter. To better illustrate my muddled explanation, here's an example:

You have a hall meter and an impeller attached to your toes, in clean air flow. You launch from sea level at 59ºF and go hands up on your glider. Both wind probes read 22mph. As you climb, the impeller driven meter will begin to read faster because your glider is moving through less dense air and your true airspeed increases (it has to move faster through the air in order to generate the same lift with fewer molecules). However, the Hall meter will continue to read 22 mph because the pressure being exerted on it remains the same, as it does on your glider.

If you are already stuck with one of those battery eating, propeller spinning, whizzbang wind-gadgets you can do a quick recalculation to get close to the results of a Hall probe. For every 3k feet above sea level subtract 1 Mph from your indicated wind speed. So, for example, you're standing on a 10,000 ft mountain and are getting a reading of 20 Mph. Subtract ~3.3 Mph to get a reading of 16.7 Mph which is what the wind should feel like anyway.

Hall meters are about half the price and don't require batteries!

Performance, Speed-To-Fly & Instability Calculator



I was reminded recently that I had created a Performance, IAS & Atmospheric Instability calculator to satisfy my own curiosity and it was collecting dust in a long forgotten folder. So here it is, unleashed upon the public in Apple Numbers '09. It calculates:
  • True Airspeed at Altitude
  • Lapse Rate/Thermal Index
  • Polar Curves based on 4 points corrected for weight and Density Altitude
  • Altitude lost along course compensated for wind & weight
  • Time to goal compensated for wind & weight
  • Relative Altitude lost for comparing up to 4 gliders
  • Altitude advantages compensated for early arrival time with an X climb rate along course
  • Speed-To-Fly based on polar curve, wind, sink along course, and expected climb rate
  • Scoring penalty percentage to handicap high performance gliders. Used this at Tater Hill '08 to level the field. DHV 1 gliders were scored evenly with 2-3 ships.
  • Speed-To-Fly chart (Hoisington Chart) that can be printed and used in flight.
2/20/09- The Performance Calculator has been in constant development for the last few days and it now calculates Speed-To-Fly automatically! Still Apple Numbers 2.0 only but if someone wants to convert it to Excel, please do and send me the results! Email me if you find any bugs. I'm always curious about who is using it so if you do, send me an email!

2/21/09-Fixed a bug that relates to Speed-To-Fly calculations. New version is 2.5.1.

2/23/09-Updated to 2.5.2. Fixed a few bugs, added instructions, and the sinking air along the route is now included in the "altitude lost" along route. No idea why I didn't do that sooner.

3/5/09-2.5.4 is out. It fixes a few bugs, and adds a new sheet for generating a Speed-To-Fly chart that can be used in flight. It's an almost exact duplicate of the chart Zach Hoisington used for his Speed-To-Fly lecture at Woodrat a few years ago. This one you can customize to your gliders polar curve, wing loading, etc. Currently you have to enter some values manually, but I'll be working on an automatic solution for 2.5.5.

3/5/09-2.5.5 is out. It fixes a few more bugs, streamlines a few calculations, and makes the Speed-To-Fly values a little more accurate, now to the nearest .25 rather than the nearest .5. An automatic method for generating the Speed-To-Fly chart doesn't seem to be possible at the moment which is why 2.5.5 is so close on the heels of 2.5.4. It just isn't going to happen.

3/7/09-2.6 is done. A bunch of bug fixes to the Hoisington Chart in 2.5.5. Streamlined all the calculations to make future updates easier, and...*drumroll*...The calculations for the Hoisington Chart are now almost completely automatic AND you can choose which glider you want it to chart! The defaults should be fine but if you want to adjust it for slightly more accurate readings you can. The steps for generating the chart are now infinitely simpler. The ONLY known bug left is an artifact of how gliders are tested, and small errors in the Density Altitude calculations. The problem lies in the fact that most gliders are tested at 4,921 ft but are entered into the tables as if they were tested at sea level. So to get real sea level speeds for gliders the altitude has to be adjusted to -4,921 ft. Entering the gliders as if they were tested at sea level (slower speeds) results in an error of ~1.5 km/hr when the altitude is raised to 4921 ft. Treating 4,921 ft as your baseline altitude (entered as 0 in the chart) solves the problem, at least mentally.

For folks who don't have Apple Numbers 2.0 (part of iWork '09) and want to know what all this is all about, I've created a PDF of the default gliders. Calculator.PDF

3/9/09-2.6.1 is done. New life lesson, never declare all your bugs fixed. There's always one lurking in the shadows and this one was so obvious it's embarrassing to admit that I missed it the last 4 versions. So, the Expected Climb rate no longer affects the glide ratio in the Speed-To-Fly table above and beyond what the required speed bar would do to your glide ratio. Previously a 200 fpm expected climb would cut your glide ratio value in half....oopse. I've also cleaned up the layout a bit, removed some redundant stuff, etc. It should now also fit on a 13" widescreen monitor without scrolling.

3/17/09-2.6.2 makes a few big changes. I've added S2F Gain to the arrival altitude chart. It shows how much higher you would arrive if you flew at the proper Speed-To-Fly. The Time chart also shows times for S2F. The Polar curve graph now no longer allows the S2F indicator dot to exceed the 100% speed-bar value. That applies to the S2F table as well. The Polar Curves Table and Input tables have been changed to allow for different weights for each glider. That will allow two pilots to compare two different gliders, rather than one pilot looking at what their performance would be on each of the 4 gliders.

Jan 15, 2009

Ruminations on Surviving as an Instructor

This is a short post I made to the paraglidingforum.com in response to a relatively new pilot's request for information on turning paragliding into a career. Despite being a bit of a disjointed brain-dump it received a good response so I thought I'd archive it here for anyone who is interested.

In my experience there are 3 ways to survive. Run your own school, with a base, a safe and consistent place to fly and be a dealer for 2 or more brands. You work your back end off but you do it because you like being outside all day with cool people.

You can get hooked up with a tandem operation in one of the "hot spots" like Sun Valley, Aspen, Queenstown, British Columbia, or almost anywhere in Europe. You have to have the Tandem gig down to a science. If you've blown a bunch of solo launches in the last 12 months, don't even think about it. It's good work but tougher to form those bonds with students/passengers that are so rewarding.

Finally, the route I've taken. I've been roaming the country working for lots of different schools which has been extremely educational. If it's consistent/year-round, with someone who treats you well, it can be a lot of fun and pay the bills. Unfortunately the seasons change and Winters are slow so you'll often find yourself in conservation mode. What you make in the good season, pays for thumb-twiddling or traveling in the off season. Some instructors will head south of the equator for the Winter and get year-round work that way.

A couple tips: Don't do it halfway. Immerse yourself in it, research everything, and find the best possible information. Don't settle for being a mediocre instructor. Work for the best possible schools, especially early in your career. You'll learn more from them in a season than you will at any 3 day clinic. Don't compromise your ethics or principles, even if it costs you some work. If a school owner or "more experienced" instructor asks (or tells you!) to do something that you know is wrong, don't do it! The best piece of advice I've ever been given was at Doug and Denise's up in Eastern Washington (Aerial Paragliding): "If I have to write an accident report about this am I going to look stupid?" Don't bother working for people who won't treat you well or are going to put a black mark on your safety record. It's not worth the stress, money, or your reputation. It's not an easy lifestyle so the people you work with should be fun, treat you well, and make it worthwhile. It's not necessary, but makes it much more fun when you have new information/skills to offer the school, and vise versa. Obviously the school should place an appropriate value on the information/skils you bring to the program, and if they don't you're being used. You're not just getting paid in cash, you're getting paid in experience and information. It's a little less interesting when they don't have any experience relevant to your teaching career left to offer. The more places you've taught, and the more you know about tandems, PPG, towing, XC, mountain flying, flatland flying, different equipment, etc etc, the more valuable and desirable you are as an instructor.

If it's going well, treat your employer well, have fun, and soak up as much info as possible. There will be times where you botch something up, do something differently than the way your employer does it, etc and you take a blow to the ego. It's not personal. If what they're saying makes sense (it doesn't always but be open minded), do it!

If it's not going well, get out! I lost a good bit of money getting to an operation south of the equator, where I worked for 9 days before realizing that carnage was imminent and I didn't want to watch it happen. It was an expensive waste of time but had I stayed it would have cost a lot more. My suspicions were confirmed when I later met another instructor who worked for the same operation and stuck it out for the Winter.

Write a syllabus! It's something you can hand to your students, and a way to show schools you'd like to work for that you know what you're doing. Start it as a sort of notebook of tips, tricks, techniques etc. Then write your syllabus based on that. If an instructor that has one gives you permission you can adapt yours from theirs. Keep it up to date with the latest info! It'll also help you after the Winter season to refresh on how, what, and in what order you want to teach a course. It's invaluable during ground schools because every student gets the same information in the same way, every time.

Get comfortable leading students through ground school and know the information! I was one of those shy kids in school and the thought of standing up in front of a group and taking control of a classroom gave me dry-mouth and sweaty palms. When it came to teaching ground school it took me a long time to really feel comfortable but practice makes perfect and having confidence that the information you have is 100% spot-on will make a huge difference. I find that most instructors who are uncomfortable teaching ground school either don't know the information inside and out, or aren't sure why the information they have is correct and are worried that they're going to be asked a question that they can't answer.

As for expectations; eat cheap, work hard, have fun! You're not going to get rich, but it's worth it! The perks are good and many schools will include you as an instructor on their trips so you get to travel, usually with some of the same students you've been teaching during the past year.

Jan 6, 2009

Bell Drop Helmets


We have a limited supply of Bell Drop helmets in stock! We like these helmets because they provide significantly more protection than even the best paragliding helmets while still being light, with great visibility. They conform to the new ASTM DownHill mountain bike standard which far exceeds the protection of the CPSC bicycle helmet standard and the EN 966 Free Flight helmet standard. The visor is completely removable to avoid snagging on your lines and the liner can be removed for washing. $130 for all sizes with free shipping! Give us a call to order yours today!