December 18, 2010

Calcuating Trigger Time

The last post covered the process of calculate trigger temperature and the mechanics of the atmosphere that are underway as the day heats up and thermals start. Today's post will cover how to estimate what time the surface temperature will reach trigger temperature and will also cover a few other tips related to trigger temperature.

To find the estimated trigger time first recall this plot from the last post:
It turns out that the heat required to eliminate the ground inversion is proportional to the area of the triangle formed by the temperature profile (shown above as the area shaded with dashed lines). So, first calculate the area under the temperature profile, this can be done by copying the plot onto graph paper and counting the squares or by simple geometry; the area of a triangle is 1/2 * base * height. For plots of this type the y axis might be in milibars, you will want to convert milibars into feet. The x axis is temperature. That means the area calculation you have done will result in units of (degree*ft). Which is handy because the chart below, which shows the available heating from the sun just happens to be in degree*ft!

This chart is for a latitude of 45deg, if your latitude is greater/less move/down up 1/2 hour for every 5deg difference in latitude. This chart allows us to predict when the air will have been heated enough to over power the ground inversion. Note that the above chart is for clear skies, cirrus, fog, smoke or any other sun blocker can reduce the about of energy reaching the ground and should be accounted for.

The other method, which is much more user friendly is to rely on your local weather station predictions for the temperature as throughout the day. You can always supplement this information with temperature readings of you own. I glued a thermometer to my wing wheel so when i'm waiting to launch I can monitor the rise in temperature and know if it is rising faster or slower than predicted and adjust my launch time accordingly.

All of these methods help you become more aware of how the soaring day starts and how to position yourself to start your flight on time and get the most of the soaring day for those long tasks. Until next time...

Keep soaring,

December 10, 2010

Calculating Trigger Temperature

If you want to fly long distances you need to get going early. The best way to make that happen is to be ready when the thermals start to pop; but how do you know when that will be? Today's post will address how to determine Trigger temperature. My next post will cover how to estimate when trigger temperature will be reached. Like my previous post, the information for this post comes from Dennis Pagen's book, "Understanding the Sky" which is required reading for anyone serious about soaring XC.

The first step to this process is to find the skew-T for the location you plan on launching from. The easiest way to get a skew-T is thought XCSkies point forecast tool or use the tools provided by Dr Jack.To find the trigger temperature you will need to determine the height of the ground inversion layer and the lapse rate of the air layer above it. In the figure below, taken from Understanding the Sky, a notional skew-T chart is shown with only the relevant information displayed.

The ground inversion layer, usually about 1000'-2000' thick, is caused by the relatively cold temperature of the ground at night cooling the air layer closest to the ground. This is the same mechanism that forms the superadiabatic layer near the ground when the surface heats up and warms the lower layer of air. It isn't until the ground inversion layer is warmed to match the lapse rate of the air above it that thermals will escape the ground inversion layer; this warming process is shown in the figure above as the dashed lines. To find trigger temperature, draw a line starting where the temperature profile begins to decrease and follow the dry adiabatic lapse rate (DALR) lines on the skew-T to ground level. The temperature where the DALR line intersects ground level is trigger temperature, represented in the figure as the far right dashed line.

We now know that for trigger temperature to be reached the early morning solar heating must eliminate the cold ground inversion layer, this means that on days following cold clear nights where the ground inversion is thick trigger temperature will occur later in the day.

Hopefully this helps take the mystery out of calculating trigger temperature. Until next time..

Keep soaring,

December 5, 2010

My Six Month Leave is Over, and Unvailing a New Posting Formatt

Gosh, has it really been 6 months since my last post? It's been a busy 6 months at work and with my flying. The end of the soaring season left me wanting a little bit more; the weather just didn't stack up this year like it did last year so to get my fix I started paragliding. I know, not the safest decision but it really has brought to light a new understating of low level wind and thermal development phenomena and a strong desire to study more about micro-meteorology. It also means I can get my feet off the ground more often, even if it's only for half an hour after work.

The major challenge I faced with my blog over the last 6 months is that I rarely had time to put forth the effort to collate information for one of my longer posts. However as winter sets in and any hope of flying - glider, paraglider, or otherwise - gets covered over with snow I have once again re-dedicated myself to studying all topics of Soaring. This means I can continue to share what I am learning in hopes that others can benefit. In a effort to have a more consistent presence and give all my dedicated readers (or soon to be dedicated readers) a reason to stop in regularly I will be posting shorter articles covering some of the details of the work I'm doing with longer more detailed post when I have the time. In this spirit, below is a short snippet of of information gleaned from an amazing book recently purchased called, "Understanding the Sky" by Dennis Pagen.

In Chapter 7 Local Winds, Dennis addresses a phenomenon common to pilots in the North West US and on the East Coast; Sea Breeze Fronts. Here are some of the more important notes. If we imagine we are on the east coast with a north/south coast line, for winds coming from the south west the sea breeze front is most likely to push far inland. Winds from northwest will promote a sea breeze front which will likely form off shore and slowly push inland as heating increases. Winds from the north east likely means a high pressure inland which my set up a sea breeze later in the day but will be dependent on heating and will not push as far inland as general off shore winds. South east winds are indicative of a low over land increasing the onshore component of the wind and driving cool stable air far inland; No traditional sea breeze will be present. This is also the least favorable for soaring conditions. A more detailed explanation of why this is the case is covered in the book and worth a detailed read if you fly near a large body of water.

Also addressed in Chapter 7 is the effect of a sea breeze. For a soaring pilot sea breezes bring various different kinds of lift. Stable on shore winds bring smooth ridge lift to coastal sites and sea breezes flow around mountains and through passes colliding on the other side to create convergence lift bands familiar to the folks flying out of Hollister in nor-cal and Lake Elsinore in so-cal. Additional the formation of sea breeze fronts forms lift bands ahead of the cool airmass much like pre-frontal lift found ahead of an arriving cold front. Sea breeze frontal lift is characterized by a small band of good lift marked by good clouds with dying cu on the far side. Pilots are advised to stay ahead of the front to not suffer the same fate. The lift associated with the sea breeze front usually tops out around 3000', for inland covection levels below that the sea breeze front will be weak, convection levels greater will likly cause over development and localized showers and thunderstorms.

Hopefully you learned a little bit about sea breeze winds and front and are encourages to go out and get a great weather resource in the form of Dennis Pagen's book, "Understanding the Sky."

I'll take any comments or advice on the new format or anything else I've written about.

Keep soaring, even when you're close to the beach,

May 23, 2010

Biennial Flight Review - A Review of 2 Years of Mistakes

On May 3rd 2008, I finally achieved the goal I had been dreaming about since I was very young, I became a pilot. It was a rainy day at Arlington Municipal Airport just north of Seattle, Wa. My flight examiner was Neil Karman, we went through the oral exam and then went outside to check the weather. My first decision as a de-facto rated pilot was the go/no go decision to fly; "Lets Fly!", I said, and we got the tow pilot and my trusty trainer, a Blanik L-13, and we were dodging clouds in no time. 3 flights later I was set free as a rated glider pilot.

Fast forward two years and now it's time for my Biennial Flight Review. The actual BFR was straightforward; with 200 hours in the last 2 years my stick and rudder skills are sharp, I'm current on my FARs, and flying at the local airport I knew every inch of the pattern and runway. What I have found more valuable was a review of all the stupid mistakes I have made in the last 2 years that have eaten into the acceptable safety margin I like to maintain. Below are the top 3 (or should I say bottom 3) mistakes I have made. Sadly there are many more than 3, but by stepping up and acknowledging all of them to myself I have recognized a few aspects of my flying that need to be kept in-check and identified situations and thought patters I need to be aware of.

When flying someplace new, question your level of comfort and confidence.

I had 3 flights under my belt flying out of California City, Ca, my longest just short of 200km, but I still hadn't done my planned out and return flight for my silver badge. Feeling anxious to get it out of the way, I took a tow on March 27th. With consistent thermals to 5000' agl near the airport I felt comfortable to push towards the mountains. Why not? I had gone cross country at 2500' agl flying out of Arlington and been successful, what can prevent me from repeating that success here? Before not too long I got low and had to back track to get a climb, again up to 5500' agl I pushed north, undeterred, into higher terrain on the other side of a ridge. A short glider later, and after lots of sink, I was below the required glider to get back over the ridge, and I was in the middle of nowhere! I was targeting a landout field on my PDA that I had never seen nor had conformation that it was landable. When I arrived at the spot, which was a 500' long dirt area on the side of the highway, I discovered a truck was parked right in the middle. I found a few thermals to give him time to move along and for me to make a run at going over the ridge. My attempts didn't work and I begrudgingly returned to land on the side of the highway. I should note that this was way first landout. The gider and myself were unhurt and I was quickly picked up by my crew; quickly because I had only made it 20 miles. At this point, if you were counting my mistakes on you fingers and toes, you would have both shoes off. Fundamentally, what really got me in trouble was a strong desire to achieve my goal coupled with a rational for my in-flight decisions based on a lot of experience from a completely different soaring site. Not everything transfers from site to site. Always question your own decisions! Here is the flight.

Don't ever outsource in-flight decisions to someone outside the cockpit.

Reading this one it is difficult to imagine a situation where this would ever happen, yet it has happened to me and it almost ended very poorly; in fact it's the closest I have come to crashing my glider. I was flying the practice day of Region 12 last year and I had identified a pilot who I knew was very good, and my plan was to flollow him around the course and try to learn as much as I could. I would go where he went, leave when he left, and thermal with him; taking notes the whole time. Well at the start I was a little lower that he was and he was soon off leaving me in the dust, I had set a minimum altitude from which I would leave the start gate and at that point I was below that altitude. I tried to find a better thermal but in the process fell lower. There was a lot of internal pressure to leave so that I could execute my plan, how could I complete the task if I didn't follow this other pilot around? So, I left the start gate well below my minimum altitude and spear chucked into a field 10 miles further on. I committed to land way too late, failed to see the power lines running across the field, failed to notice how long the grass was, and failed to notice the nicer fields 1 mile behind me. I finally picked up the power line on short final, luckily they were not a factor, but no off field landing story should ever use the expression, 'luckily'. Once I touched down I caught a wingtip in the grass and ground looped. I thought for sure the boom was coming off but it didn't and glider and pilot once again escaped damage. All because I delegated my success of the flight outside the cockpit. Check the flight here.

Know the point of no return.

This one has happened to me a few times, most notably early in this flight. Out on course there were amazing Cu's popping, but not in the direction I usually leave the Tehachapi Valley. There were more to the west in an area that is very far out of the way and only has was very non desirable land-out option. I got as high as a I could and made a B-line straigh for the clouds. About 10 miles into that glide, when I realized the clouds were out of reach I should have turned to the east to make my escape, but I didn't, I had made my decision and a was fat, dumb, and happy. About 5 more miles and I could have made an escape to better terrain and much better landing options, but again i had made my decision, the clouds were still there and they were getting better, but at this point I should have realized they were out of reach If I were to maintain escape options. I had crossed the point of return and hadn't yet noticed. It was just a little further on that I realized I was going to have to make it work if I wanted to escape the valley, so I got down low and close into the rocks and finally got the thermal I was looking for. I should have never been in the situation in the first place; low, in a valley with only one very poor land-out option, and no escape routs.

So that's the short list of the mistakes I have made in the last 2 years of flying. Soaring is challenging and dangerous, that's why I like it, but there is no reason to make it any more dangerous that it needs to be. If you asses your mistakes and understand how events transpired you're more likely to fill your bag of experience before you bag of luck runs out!

Keep flying, and making good decisions,
Michael 'BK'

February 23, 2010

Current Projects

I just wanted to provide a status of what I'm working on and apologize for missing last few weeks worth of posts, there is a great post in the works based on an interview with Chip Garner; so stay tuned for that.

My current projects:
1) I'm sanding the wings of my Libelle, fixing some poor repairs previously done, sealing aileron gaps, sealing aileron root holes, improving spoiler fit, replacing all spoiler springs, making tip wheel fairings, improving the canopy seal, fixing some fuselage scratches, adding tabulator tape to the rudder, making a tail skid, fixing some trailer issues, and making some improvements to the cockpit to increase comfort.

2) Developing a detailed simulation of an ASW-20 to evaluate different digital vario filtering schemes.

3) Planning for the upcoming season's contests - US Sports Class Nationals, Avenal season opener

And there are always a million other things on the back burner. In an upcoming post I will detail all the mods I made to my Libelle, and talk about the season goal sheet I'm developing for myself.

Keep soaring,

February 13, 2010

Changing Gears - Continued

Last week I posed the question, "Why would you need to change gears while flying?" and provided a list of reasons why I though you would have to. Tony Condon, a Cherokee II pilot (who's soaring blog can be read here) also provided his own reasons for changing gears. Below I address a few of those reasons and provide anecdotal evidence from my own flying.

Good Reasons for changing gears:

The sky ahead is blue.

I imagine this is the most common reason for changing gears during flight, and the easiest to see coming. It happened to me on a 500km triangle task on my way to the first turn point; the last 50km was out in the blue after a leg under good cloud development and reliable lift. The approach was simple because it was easy to see the problem coming, which is important to realize in addressing the other reasons for changing gears - if you are aware of the changes ahead you can start to plan early. In this instance, the solution was to climb as high as possible before heading out into the blue and switch from flying cloud references to following ground references. Dial back the MacCready and turn around and retreat before you are too low to make it back into an area of known good lift. Keep in mind when flying into the blue there are three reasons why the sky is blue; 1) the lift doesn't go as high as it did in the area of clouds, 2) the dew point is lower and the lift goes just as high, 3) there is little or no lift. On my flight, it turned out that the lift was just stopping 500' lower than in the area of clouds. That portion of the leg was still slower but I made the turnpoint.

The last thermal was broken at 8000'.

This one came form a very interesting learning experience; it required connecting a lot of different information together to develop a good reason to change gears and slow down. The sky was clearly rocking, good cu all over with good vertical development but no hint at over development. The cloud tops were leaning to the north east but I was showing wind more out of the north west. Cloud base appeared to be at 9500'-10,000', but climbing through 8000' the lift was broken and weak, about 2-3 knots below the rest of the climb. I realized, after ignoring the sings for an hour, that there was a shear layer at 8000' and if I could break through 8000' the lift would be much better and as an added bonus the wind would be better aligned with my leg. So I changed gears by slowing down and struggling through the shear layer, once above 8000' the lift picked up markedly. I was then forced to shrink my working band so that I would not drop below 8000'.

I am nervous.

Death Valley has an intimidating name which conjures up images of a very formidable place for a glider pilot to fly over. When your landing options are Furnace Creek or Stove Pipe Wells you consider all other options seriously. On a straight out flight from Tehachapi, Ca for the 2010 Dust Devil Dash, I had to make an even more difficult decision. I needed to cross the valley north east of Death Valley - 35 miles of inaccessible desert with the retrieve option being a helicopter for you and a 3 day expedition for the glider on ATVs and 4 wheel drive trucks. In this situation, no matter how good the clouds look are how strong the lift is, it's reasonable to change gears, slow down and stay high.

Bad reasons for changing gears:

I needed to make up lost time.

This happens to me more than I would like to admit. If you set a goal for your flight, and maybe it's a bit reaching or an over call for the day, it easy to blame yourself for falling behind and try to make up for it by doing the completely wrong thing in poor conditions; change gears and fly faster. There is only one optimal speed for every condition, and that speed doesn't change because you are flying poorly or because you need to fly faster to make your turnpoint or goal.

The final point is that there are good and bad reasons to change gears - good reasons are based on lots of information gathered from all resources available, bad reasons often come from internal emotions or rational independent of all the information available to the pilot. If you only eliminate all the bad reasons for changing gears from your flying you will be making a significant improvement.

Keep soaring, no matter what gear you're in!

February 7, 2010

Changing Gears - Community Comments Requested!

I'm trying something different this week. I would like to ask all the great pilots who have been reading my blog to help contribute. Below is a list of all the good and bad reasons I can think of that a pilot would change gears while soaring. By change gears I mean, fling more or less aggressively, staying high or pushing low, increasing or decreasing MacCready, keep flying or land. I don't imagine that my list is complete, so I would like you to add a comment below with all the ones I have missed. During the week I'll collect the comments and amend the list with your thoughts then select a few to provide anecdotes for from my own flying or from flights I have read about. If you are feeling ambitious, provide an anecdote as well! Note that there is a list of good reasons, and a list of bad reasons; I'll comment on that later.

Good reasons for changing gears:
The sky ahead is showing:
  1. More clouds
  2. Fewer clouds
  3. No clouds
  4. Cloud bases rising
  5. Cloud bases lowering
  6. Thunderstorms building
  7. Thunderstorm blow-off
  8. Cloud streeting
The wind is:
  1. A greater headwind/tailwind
  2. more/less favorable for ridge/wave/thermal-ridge/thermal-wave
  3. Showing a gust front
Last thermal was:
  1. Weaker than expected
  2. Stronger than expected
  3. Broken
  4. Broken above/below/at altitude x
  5. The next thermal is expected to be:
  6. Weaker than expected
  7. Stronger than expected
  8. Broken above/below/at altitude x
  9. Unknown
  1. Hasn’t started yet
  2. Is about to stop
  3. Has changed, i.e. shear line at end of day, ridge to thermal, thermal to wave, etc.
The sun:
  1. Has changed angles, i.e. high to low, east facing to west facing
  2. Will/Has become blocked
  3. Is about to set
Your altitude is:
  1. Too low for comfort
  2. Too high to use
  3. Above/in/below the working band
The Terrain:
  1. Will/Has become unlandable
  2. Will/Has changed, i.e. mountains/ plains, grasslands/forest, dry/wet
You are:
  1. Lost
  2. Tired
  3. Daydreaming
  4. Nervous
  5. Uncomfortable
Other gliders are:
  1. Reporting weak/booming lift
  2. Appear lower/higher ahead
  3. Returning lower/higher
  4. Deviating from course
  5. On the ground
  6. Gaggling
  7. Easy to see
Bad reasons for changing gears:
  1. Make up lost time
  2. Make more distance
  3. Fly further/faster than competitor
  4. Recover from a mistake
  5. Frustration
  6. Impatience

February 3, 2010

New Resource for Importing Existing Turnpoint Files to Google Maps

There was a questions that came up at the convention I hadn't answered yet, that I would like to address now:

Q) I have a number of turnpoint/waypoint/landout files used in flight on my PDA, how do I get them into my Google My Maps?

A) Prior to my discovery of this tool, I was only able to do this with tools I have developed that wouldn't share well. But, thanks to Lynn Alley and his website there is now a tool for everyone to use, and better yet it's free and it's online! Here is how to take data you already have and map it in Google My Maps.

1) Start by downloading this file from the World Wide Turnpoint Exchange, saving it to your desktop for easy access later. I have chosen a .cup file but other waypoint formats will work. Read this for more info.
2) Go to in the first box, click on the words "this link".
3) Use the Browse button and open the .cup file saved in step 1.
4) Select, "Include only turnpoints in the output" and/or "Use FAA/NASR aiport names" if you want.
***I believe the website has a small error so the next steps are a work around to be able to select, ".KML (for Google Earth)" in Box 4, which at this step should still be unselectable***
5.a) Input a local airport identifier in Box 1. If you downloaded the .cup from step 1, try using L94 (Mountain Valley Airport in Tehachapi, CA)
5.b) Select a maximum waypoint count of 5 (doesn't really matter)
*** At this point the ".KML (for Google Earth)" in Box 4 should be a selectable option***
5) Select ".KML (for Google Earth)" in Box 4
6) Type in "Soar" in option 5 and select Submit
7) You will get a popup that prompts you to save a .zip file; save it to your desktop. Once the download is complete, unzip the .kml file.
8) Go to Google Maps and Select My Maps and create a new map or open an existing map you want to add to (see my Feb 1st post for details) Then select the Import option, and brows to the .kml file and select OK.

In just a few seconds all your waypoints/landouts/airports will be imported into your map. You are 90% of the way to a great soaring resource for your local club. Here is an example map that should look just like the one you created following the steps above.

View US Airports from NASR Data in a larger map

As always, I'm available for questions.

Keep soaring,

February 1, 2010

Using Google My Maps for Soaring

My presentation at the SSA convention was a big success, thanks to all the pilots who were able to attend and provide support by asking questions and creating a good discussion. As promised I have embedded the presentation below; scroll over the edge of the presentation and click to change pages and all the links work, so feel free to click away.
SSA Convention Presentation - Google Maps Tools

A few questions came up during the presentation that I would like to address here:

Q1) Can I overlay sectional maps on Google Maps?

A1) Yes, but it's not easy. At the time I didn't know if it could be done, but after a little research I have discovered that yes it can be done, but the complexity is very limiting. The best description I have found is here. Note that you would need an image of the sectional you want to overlay. Then you need to create a .kml file that contained a link to the image and the geotag information on where the image should be placed on the earth. What I would suggest is to use your map in conjunction with other online tools, like the website skyvector or RunwayFinder to view sectionals online and make notes on your soaring map.

Q2) Can I embed a video into my map?

A2) Yes, and it can be very helpful. A description on how to add video to the map can be found here. As an example I have added a video to the Evergreen Soaring - Local Spots of a local pilot, Brad Hill, digging himself out of a hole behind Higgins that is a good example of how to fly the local conditions. Select the light blue thermal marker.

After the presentation I had a number of people asking me how to find the maps I showed during the presentation. Prior to the convention I had been relying on providing direct links to my maps via email, however it became clear that a more universal solution is needed. So I am working on getting the 2 maps I have been working on linked in the Worldwide Soaring Turnpoint Exchange. Stay tuned for an update. Until then use the search option and hope for the best.

There were also a lot of comments about specifications for the format of the maps I have made and the maps I hope everyone else will make. I have put a fair amount of thought into what the maps should look like so I would like to suggest a standard that everyone should follow here:

1) Good thermal generators or ridges that generate lift should be marked with yellow balloons, yellow lines, or yellow polygons. Try to give detailed information on the lift source.

2) Airports should be marked with a Blue line showing the approximate runway heading and length.

3) Landout fields should be marked in purple showing the usable landing area.

4) Danger areas, caution areas, or areas that consistently lack lift should be marked with red balloons, red lines, or red polygons.

5) Try to add as many pictures from the air and on ground as possible.

6) Since this map is intended to be studied, not used in flight feel, free to add as much information as possible.

I hope that this helps everyone set up a map of their local soaring site! As always, if you have questions please post them and I'll get an answer out as soon as I can.

Keep soaring,

January 28, 2010

Day One of the 2010 SSA Convention

The first day of the 2010 SSA convention was a resounding success. Thanks to everyone who was able to stop by my presentation. There were lots of great questions and I'll be spending the next few days tracking down the answers. If you have any questions or have comments please post them here.

For those who are looking, here are the links to the maps i showed during the presentation:
Evergreen Soaring
Tehachapi Soaring

Keep soaring,

January 24, 2010

Cross Country Planning Tool - Google Maps

This week's post is inspired by my upcoming visit to Little Rock, AR for the SSA Convention where I will be giving a presentation Thursday at 10:00 in Ballroom C on the topic of Using Google Maps for cross country planning.

I started flying cross country the weekend after I became a licensed glider pilot. It was always my goal, fly beyond glide of the airport. Luckily where I learned to fly cloud bases we always very low so I didn't need to go far to get out of glide. The issue was, as soon as I lost sight of the airport I lost sight of my confidence as well. I realized early on that to fly like the experienced pilots in my club I needed the knowledge of their experiences, but being wet behind the ears I didn't want to wait to gain it. At the time there was an old topo map in the clubhouse that provided some information - local airports, names of local mountains and ridges, etc - but it was in the club house and I couldn't study it every night. What I needed was an online map that contained all the local knowledge that I could gather from club members that could also support future soaring pilots looking to go cross country from our home field or the airports we visit throughout the year. What was developed is shown below; using Google's My Maps utility I employed all the members in my club to add a few bits of information to a map so that their knowledge would be available to all.

View Evergreen Soaring - Local Spots in a larger map

What I ended up with was a great repository for all the local knowledge that I gained on each flight along with what all the other pilots flying with me learned. Immediately we had a place to post pictures, information, and details about a new land out field; the same day someone lands out! It was easy to add markers for the local house thermals, the local ridge with the name that we call it - which doesn't appear on any map I have ever seen, land out fields were quickly populated, areas in the mountains where no glider pilot should willingly go, and hints on how to connect from one ridge to the next. When the winter wave season came around it became a great place to report wave entry points with wind directions to start a build a picture of the wave cross country possibilities. And for those who want to do more post flight analysis, the map can be exported along with any .klm file downloaded from the OLC to see if the pilot took advantage of any of the information presented on the map.

Here is my impression of why every club and airport should start a soaring map online -
  • A lot of people doing a little work creates something big
  • Search for mountain peaks, lakes, other geographic points of navigation
  • The map is available to everyone, everywhere, all the time (iPhone app)
  • Glider specific airport information, i.e. Landing patters, glider staging
  • Local and distant Landout options, where and where not to land
  • Ability to add photos to landout descriptions
  • Accurate terrain features, enough detail to recognize peaks and topo overlays are available
  • Each user input has a date and a link to the editor to verify currency of data
  • How to make crossings, how to connect lift, when and where to start
  • Publish dimensions and locations of wave windows and wave procedure
  • Location specific safety procedures; Procedure alpha, VOR locations for Reno ops, high traffic areas, etc.
  • Current weather overlays, links to webcams, Google webcams, other utilities
  • Local backup copy can be saved
  • Map the story of great flight – Alby’s Voyage
If you are attending the SSA convention and would like to learn more please stop by Convention Center Ballroom C at 10:00am on Thursday, January 28th. If you can't make it, I will be posting the presentation here next weekend.

Keep Soaring, but only if you know where you're going

January 10, 2010

Developing a Soaring Model in Flight

This post was inspired by an email from a local pilot that files out of Mountain Valley Airport here in Tehachapi, Ca. An excerpt is provide below.

Mark Grubb says:
You need to build a model of the airmass + wind +
terrain + sun angle and then test the model by putting your airplane
in the regions you define (based on your model) as good energy lines.
Based on the evidence you collect, you adjust the model and re-test.
Do this efficiently for 8 hours and you have flown 1000 km.

The most dangerous place to get into, IMO, is bumbling along, having
no idea of what is going on around you. Most of those "I flew into
massive sink / turbulence/Hand of God" are completely predictable if
one is acute enough to pick up on the many signals the world gives us.
Secondly, one must be skeptical and constantly testing the model.
Complacency is what has almost killed me twice. You must have
evidence that your model reflects reality or you are living in a

The concept is easy to describe but very difficult to master. I have been thinking about it more and more because I recently read this article by Gavin Wills on page 16 of Soaring-August 2002 (SSA membership required to access the article). The article wasn't written with the same intent as the quote from Mark, however the basic idea of building a picture of the sky ahead is at the crux of the article. Reading the article in this way has allowed me to extract a specific method for building a model accompanied by a very nice case study of it's implementation.

To build an atmospheric model you need to ask yourself a series of questions covering 3 basic topics: (I use the acronym ATE)

The state of the Airmass
The nature of the Terrain ahead
Where is the Energy going to be

To understand the airmass you are flying in you need to know the wind at all altitudes, and the height, stability and moisture content of the boundary layer. Here are some examples of questions you might be asking while determining the state of the air mass.

What indications do I have for wind?
What has been the height of my past 3 thermals?
Is the day building or dying?
Is it a pre-frontal or post-frontal day?
How long until the day dies?
Are there Cu's ahead?

Terrain is more critical in mountain flying than for a day of flying in the plains, but it is always important to search for order in the chaos of a cu riddled sky, or worse yet a blue sky, over a flat seaming featureless surface. Here are a few examples of questions you should be asking to understand the terrain (hopefully) far below you.

What is the general direction of the most predominate terrain features (along track/cross track)?
Are there tall peaks, low ridges or a mix?
What is the surface like (Read Reichmann pg 4 - different heating rates of cereal crops vs trees etc)?
Are there options on you route (high ground vs low ground)?
Are there wind shelters to collect warm air on windy days?

Knowing where the atmosphere will have more or less energy is really the end goal of developing our model. The following questions require some additional information gathering but more so synthesis of the data collected in the Airmass and Terrain sections. Here are the questions you should be asking when thinking about Energy.

Where has the sun been hitting the ground?
Are there obvious thermal triggers around (peaks, rocks, tractors, etc)?
is there Ridge lift, wave lift?
Can you stay up wind?
Can you stay to the high ground?
Are there large bodies of water near that such energy?
Is there smoke that will limit solar heating and energy reaching the atmosphere?

You should be able to get to the point where this process takes only 30 seconds and requires minimum effort and minimum additional information gathering; because presumably you should have been paying attention to these things all along. I use the term, "you" collectively because this is specifically something I need to work on. Once you have built your atmospheric model use the tricks (stay up wind, run ridge lift, etc) you have learned previously to exploit the energy available in the air. And continuously recheck you model to make sure things haven't changed.

The next post will be to support my presentation at the SSA convention in Little Rock, Arkansas. I will be presenting on using Google Maps as a tool for cross country prep and also how to share tribal knowledge with the My Map utility. Until then...

Keep soaring,

January 5, 2010

Soaring While Still on the Ground

Soaring is one of those activities where the anticipation is so great that it's hard not to spend your days daydreaming about it. On a recent trip from Harrisburgh, Pa to Binghamton, Ny I had an opportunity to do just that and I learn a lot in the process.

I left Harrisburgh at 11:15 on December 27th, had I been soaring it would have been a sled ride; but the air was crisp and clear and seasonably warm. I didn't think much about soaring until I saw the fist hints of convention around 12:15 near Pine Grove, Pa. This is where we introduce Weather Underground's historic data for the 27th in Scranton, Pa (the middle point of my journey). The data shows that the winds were between 6 and 16 mph, and the high was 43F with a dew point of 30F. At 12:15, when I spotted the first Cu, the temperature was about 39F. it was low, about 2500' agl appropriate for the temp-dew point spread. What was interesting was how fast the day developed. Here is a sequence of photos for the 1.5 hours following the first Cu spotting.

Pine Grove, Pa - looking north at 12:15

Minersville, Pa - Looking west at 12:45

Hazleton, Pa - Looking north at 1:30

Looking at the photos, it is interesting to see how quickly the day developed, and how much development there turned out the be. The south west wind formed streets on the predominately SW to NE running Appalachian mountains helped by the low sun angle all day. What is missing from the photo sequence is how quickly the day ended. The historical data shows the peak temperature of 42F at 1:00pm with a quick drop after that. By the time i arrived at my destination of Binghamton, Ny the day was well over.

While I was watching the clouds, I used the opportunity to run a number of different experiments. The results were obviously difficult to verify but by not having to worry about flying the airplane (only driving the car) I was able to spend to time thinking what I should be thinking while flying. Here is an example: in the second picture, how would you get from your current position to the best cloud, which is the best cloud, and what is the expected thermal strength under that cloud? These are all questions that the best pilots will know how to answer, using this light workload time to think about how to answer them is time on the ground that is time well spent.

If you are interested like me, there were only 7 flights in the US on December 27th, 6 were in California/Nevada and 1 in North Carolina.

Keep soaring - even if it's on the ground,