March 2006
March 2006 RidgeDancer Print
  1. President's Report
  2. Editor's Note
  3. Flying in the Huaraz Valley in Peru
  4. Safety Director's Report
  5. Meeting Minutes
  6. Mount Diablo Site Introduction
  7. Common Wind Shear Pattern
  8. Annual Anderson Flat Fly-in
President's Report
Written by Ann Sasaki   
Thursday, 23 March 2006

President’s Report for March 2006

Ann Sasaki

After a brief warm spell in February, we have had some really inclement weather in March! The recent storms brought much snow to the East Bay hills and mountains, creating a beautiful view framed with big, puffy cumulus clouds.

The second Saturday in March was a fabulous flying day with great instability. It was incredibly cold which meant the air was dense and lifty. I got as high as I’ve ever gotten at the coast after thermalling up along Walker Ridge. The view was fantastic - I could see several sections of Crystal Springs reservoir to the SE, the runways at SFO, the snow-covered range in the East Bay and all the way to the base of the Golden Gate Bridge.

Meanwhile Dave Cherne took one of the photos accompanying this article as he benched up to 3500’ over launch at Mission. He said it was great and I imagine he was freezing up there.

Photo by Lori Teichert-Smyth
Arnel & Nova soar. Photo by Lori Teichert-Smyth
 

A few notes on winter flying. First, weather conditions can change rapidly around storm fronts. As a number of folks found recently on a day between the fronts, you can be boating around in sunny, benign-seeming conditions and then find that the wind is quickly picking up and you need to land as soon as possible. It’s a good idea to read the National Weather Service forecast (Discussion, Zone and Marine) carefully in the winter. If the day seems fine but the forecast is for stronger, gusty winds, or an approaching front, you will want to factor that in to your flight plan. You’ll want to keep an eye on the water, not get too high and too far back, watch for wind lines, whitecaps, cloud changes, squalls out on the ocean and so forth. If you are at Mission, you’ll check the texture on the Bay and the ponds and monitor the development of the clouds and the strength of the wind.

 

Photo by Dave Cherne
Dave's boots over Mission on a snowy day. Photo by Dave Cherne

In addition, for those flying at the coast, the new slide that developed earlier this winter right around the corner of Westlake could be an issue on a NW (such as post-frontal) day. What used to be a slightly concave cliff face has now become a big dirt slide that really cuts into the hillside. Pilots should be careful not to carve too far into this area if the wind is NW because you may hit a rotor from the north edge of the slide and the air may be swirling around close to the slide. On a NW day, it’s tempting to go in and hug that first lip of the slide but watch out for possible rotor off the north edge. In addition, you really don’t want to land on the new slide or the older slide just to the north. Both are now so steep and unforgiving. No trace of the old highway 1 roadbed remains in this area.

And finally, a general note – we usually get less local flying during the winter than in other seasons. This means two things – first, we are less current in our skills and second, we may be more eager to fly than usual. This can be a somewhat undesirable combination of factors. When you go flying in the winter, try to use good judgment and realize that if the conditions are really not good, it’s better to wait until you have more favorable weather.

I would like to mention a few upcoming events of note as Spring rolls around –

March 25 and April 1 – Jill Nephew will lead discussions of weather conditions. See Wally Anderson’s announcement for details.

April 16 – Get your HAM license on Easter! See James Smyth’s announcement for details.

April 22 – Jody Lucas Fly-in and Picnic at Ed Levin – Hike and Huck, food at 1:00 p.m., door prizes, soarable flights guaranteed. See the BAPA calendar for details and don’t forget to RSVP to James Smyth.

April 28-30 – Elk Mountain Spring Fly-in – Big bonfire, possible beer drinking, soarable flights, serious 4WD excitement. See the BAPA calendar.

May 6-7 – Anderson Flat Fly-in – Beautiful wildflowers and soarable flights with incredible views of the mountains close to Yosemite. See the BAPA calendar for details.

Fly often and fly safely.

Last Updated ( Sunday, 02 April 2006 )
 
Editor's Note
Written by Richard Hammer   
Thursday, 23 March 2006

Hello Pilots!

Dang...It's COLD in them thar hills!  

Well hopefully it will warm up soon! There have been some good flying days sparsely intertwined between the recent rash of winter storms plowing through the region.

This month we have a robust Ridge dancer for you. A great interview of Dan Foust by Ann regarding his wonderful trip to Peru. We also have an site introduction for you P4s wanting to fly the mystical Mt. Diablo. To top it off Jeff Greenbaum has contributed an article about Coastal Wind Shear.

I know that some pilots have been asking when we will have a downloadable, printable version of the Ridagedancer. We are working on this...really we are. Since the engne that drives this newsletter is based off of an Open Source product (that simply means FREE to us non-geeks) we basically have to search for the modules that allow us to perform magic in the site. One of those modules are for printing the whole newsletter at once.

You can print article by article now but we want to make easier to print the whole shabang at once. In the mean time I am going to put the document in PDF format manually so those of us wanting to print the RD may do so. I will do it for the issues I have been editor of. I will let you know when I have that done. 

As usual, I close with a request for more articles and or photos! Send them please!!!! We welcome any comments or suggestions as well!!!

Take care, get high and stay high!

Rich 

Last Updated ( Sunday, 02 April 2006 )
 
Flying in the Huaraz Valley in Peru
Written by Dan Foust   
Thursday, 23 March 2006
Ann Sasaki interviews Dan Foust

AS: I heard that you had a fascinating trip to the Huaraz Valley in Peru with Jeff Cristol of Adventure Tour Productions, based in Colorado. In a few sentences, how would you describe the overall trip?

DF: From cultural perspective it was wonderful. The Quechua people have obviously lived in this valley for a very long time and they still farm their small terraces and tend their animals pretty much the way they always have. They seem to have a strong sense of identity and to be very comfortable with who they are. It was great to see that.

I would say the flying was pretty intense - at least for me. I guess it was the combination of an overwhelming mountain environment, high altitude sites, XC landings, big verticals and a new unfamiliar site almost every day. It was an amazing place to fly but I will admit that on more than one occasion I was, well... scared. Now that I’m back, I am feeling much braver and would love to go again.

AS: How would you characterize the flying conditions in general at the sites you visited?

DF: It’s a little difficult to generalize because we were there in November, at the beginning of the rainy season. The more obvious flying season would be May – September. However, weather and flying conditions were surprisingly good.

On many days there was considerable buildup over the Blanca, but invariably the Negra remained flyable. Several times we launched from sites in the Negra, under partly cloudy skies while, just across the valley the Blanca was completely socked in with heavy rain and snow. Maybe we were just lucky, but we flew every day, except for one blowing-over-the-back day in the Blanca.


Photo by Dan Foust
Jeff Cristol sets up at one of the Cordillera Negra sites. Photo by Dan Foust
 

I would say thermal conditions, at least while we were there, were similar to many sites in California – you had to look for them. There certainly wasn’t soft easy lift everywhere. However, we were able to get up most of the time and that was at sites we usually flew only once.

Cloud bases are extraordinarily high - always above the Negra (16k +) and usually above the Blanca (23k +). I would assume that conditions could be much stronger during the “summer” season.

Oxygen is a good idea. Most of the launches are above 14k and, if you climb out at all, you are getting pretty high. You will also need 2 – 3 days of acclimatization before doing the higher launches.

The valley has potential for epic XC flying. Both the Negra and Blanca run virtually unbroken for 120 kilometers on either side of the valley. Obvious routes would be either along the crest of the Negra or along the front of the Blanca (flying over the peaks of the Blanca may be asking a little too much).

Jeff and I often discussed the Negra route. It would start at my favorite site above Caraz and ride the valley winds south along the entire length of the Negra, ending in the stunningly beautiful high pampas near the Cordillera Huayhuash. I never had near the nerve to try it. 

Photo by Dan Foust
Tim Jackson from the U.K. greets a local resident. Photo by Dan Foust

AS: How many different paragliding sites did you visits and what was your favorite site? Are these sites well-established or are some places that Jeff has pioneered?

DF: It was a new site every day for the first 10 days. Jeff had flown about half of them. A couple others he had heard about and the rest we scouted and flew on our own. The Cordillera Negra is such a great place to fly that, if you can find a road that reaches the upper ridges, you can certainly find a place to launch and to land. There are no local pilots, none of these are official sites and you will certainly not see other pilots.

One of the really great things about this area is that you are free to launch and land virtually anywhere you like. There are no gates. No fences. No closed roads. And best of all, no "No Trespassing" signs. The entire valley is intensely cultivated and we often launched from farm terraces in the mountains and landed in fields in the valley. However, the land is communally owned and, although the farm plots are individually worked, they are not considered private property. Everyone is apparently free to pass through, linger about or even launch a paraglider. Several times we launched from farm terraces directly behind the farmer's little adobe house while he and his family watched.

Jeff once landed in a local school yard. From the air it looked like he was leading a school pep rally. The reaction from the local municipal official? “We are quite happy to have you participate in your sport here in our town”. 

Favorite site? That’s a tough one. We did a couple of sites in the Blanca, both in spectacular settings; 16,000 feet, glaciers just above us, ice walls and 22,000 foot peaks all around, clouds scudding in over from the Amazon side. Awesome!..., and seriously scary. However, I think my favorite was on the other side of the valley in the Negra above Caraz. It was also close to 16,000 feet but instead of glaciers and peaks it is rounded grassy mountain tops, giant cacti, old Inca terraces and Quechua herders..., and 7,000 feet to the river! 

Photo by Dan Foust
Jeff flying in front of the Ranrapalca glacier. Photo by Dan Foust
 

AS: Please describe your most memorable flight of the trip.

DF: I guess the most memorable flight (maybe for some of the wrong reasons) was the one flight we managed to get off in the Blanca, at Puertachuelo de Llanganuco. We had tried a very similar site a few days earlier and had not been able to launch due to high-altitude winds blowing over the back of the Blanca. It was obvious from the clouds moving over the peaks, that we had the same issue again at this site.

However, we had some things going for us. The backside winds didn’t seem as strong and, although we were launching at 15,000 feet, we were a full 5,000 feet below the peaks. Also there was intermittent sun and light upslope thermals. Glide out didn’t seem to be a problem; We were looking almost straight down at a long alpine lake with a huge meadow at one end. I thought about rotors and downdrafts but figured with the peaks that far above us, it would be ok... should have thought about it a little harder. 

Anyway, I launched and got away from the slope. When I hit the first big downdraft, my wing didn’t ball up, it just quite flying. It felt like I dropped 500 feet. There was air moving in all sorts of directions and I just tried to concentrate on keeping my wing open and away from the canyon walls. With all that air moving down into the canyon, the flight didn’t last long. As I got close to lake level, the downdrafts turned into a horizontal wind blowing down the lake. I landed on full speed bar slowing moving backward toward the lakeshore. I was absolutely thrilled to be on the ground!

AS: How would you characterize the landscape and the people in the Huaraz Valley?

DF: The local people are almost entirely native Quechua Indians and have lived in this valley since long before the Inca era. For the most part they are subsistence farmers and live very traditional lives. The valley floor is at 10,000 feet but much of the farming and many of the villages are on terraces as high as 14,000 feet. We saw old terraces and often met locals herding their animals at launch sites as high as 16,000 feet. All the field work is done by hand or with oxen. They are wonderful people, open, honest and charming.

The valley runs north and south with the Cordillera Blanca on the east and the Cordillera Negra on the west. The Blanca is one of the great mountain ranges of the world, with more than 25 peaks over 6,000 meters. The upper half of the Blanca is entirely glaciated and so launches are limited to just a few (very intimidating) sites just below glacier level at about 5,000 meters. 

The Negra is a thousand meters lower and in the rain shadow of the Blanca. Consequently, although the crest is still over 16,000 feet, the ridges and mountain tops are grassy and rounded... perfect places to launch. It is possible to launch from virtually anywhere along the 120 kilometers of the Negra and it is always an easy glide out to the river and main road. The only thing that is required is road access, of which there is a surprising amount. The views of the Blanca just across the valley are breathtaking.

AS: Was there a quintessential moment or experience that kind of summed up the uniqueness of the trip?

DF: Some of the most quintessential experiences had more to do with getting to and from the flying sites than actually flying. Riding in the little colectivo vans with the farmers and their animals; coming down out of Corderilla Blanca in the back of a truck with a wonderful mix of farmers, climbers, trekkers and local women with their babies or just hiking down a mountain road with a couple of local kids and their burro.

One of my favorites was a colectivo van ride to a launch in the Cordillera Negra at Pamparomas. As usual the van was jammed with locals and top-heavy with our paragliders and farm produce. The dirt road (hardly wider than a cow trail) seemed to wind endlessly up the steep face of the Negra. We rounded a blind corner to find a woman and her burros plastered up against the road cut. A few switchbacks later, it was a young boy and his small flock of sheep, diving over the side onto the nearly vertical slope.

All I could see out the side window was thousands of feet of airspace. I tried not to think about blowouts and rollovers. It was comforting that the local women were sleeping and nursing their babies. We got out at the pass at 16,000 feet and the colectivo drove on to Pomparomas. After looking at the map, Jeff wasn’t sure this was the right road. It was going to be a long walk if we couldn’t fly. The altitude was making me breathless and dizzy and I was nervous.

Not sure why this one sticks in my head - it was fairly typical morning.

AS: Where did you stay and what was the food like?

DF: We stayed in Huaraz most of the time, which made a good base for all of the sites at the southern end of the valley. However, one of the very best sites was about 70 kilometers down the valley in the Negra above Caraz. We flew that site twice and stayed in Caraz each time to catch the early morning colectivo to the pass. 

Huaraz is not a pretty town. It was completely destroyed by a quake in 1971 and has been rebuilt with adobe brick and rebar. However, it has a reasonably good visitor infrastructure, mostly catering to climbers and trekkers. There are several good hostels and guest houses that are quite adequate and very reasonable. The guest house, where I stayed, was run by friends of Jeff. I had my own room with en suite bath, maid service, use of a nice lounge upstairs and a lovely breakfast served each morning on the rooftop terrace - with a stunning view of the Blanca. I paid $148 for 11 days.

I liked Caraz better than Huaraz. It is a smaller town with more atmosphere and even fewer visitors. (I think we were the only gringos in town.) I’m not sure about accommodations for a longer term visit. The place we stayed was pretty basic and came outfitted with a “gringo fryer” in the shower and its own parrot.

It is hard to pay more than $2 or $3 for a meal. There are plenty of places to choose from, some of dubious quality and hygiene. (We avoided the sidewalk vendors unless it was well cooked in front of us.) Most are pretty basic but the food is generally good. Ceviche (raw fish marinated in lime juice with cilantro and peppers) is a local/Peruvian favorite and is very good.

AS: Would you recommend this trip to other pilots? Do you have any advice on who might enjoy it the most?

DF: If you are looking to fly really high altitude sites (up to 16k), around really big mountains (up to 23k), there probably isn’t a better place. It is certainly unstructured and there is lots of opportunity to pioneer new sites and XC routes. It wouldn’t be a good place to get yourself hurt.

Don’t expect a resort atmosphere. There are no quaint sidewalk cafes or trendy bars. The local people are still relatively traditional and can be very charming but they are poor and you will find yourself appalled as often as charmed. Things can be a bit gritty.

AS: Thanks for giving us all that information Dan and for submitting your beautiful photographs. This seems like a great trip for pilots who want an adventure set amid spectacular scenery. However, it’s obvious that you would want to go with someone like Jeff Cristol who is familiar with the area and the flying sites.

Photo By Jeff Cristol
Dan Foust at Pamparomas above the town of Caraz. Photo By Dan Foust
 

Last Updated ( Monday, 05 June 2006 )
 
Safety Director's Report
Written by Wally Anderson   
Thursday, 23 March 2006
I would like to talk about a condition that happens at Ed Levin in the wintertime. When high pressure sets in the winds tend to blow off-shore (NE). The velocity & direction depend on the position & strength of the high pressure system. This creates wind over the back at the top of Ed Levin. Often the lower hills are still flyable in this condition & this happens so often that folks, especially new pilots don’t pay attention to the wind at the top. What is happening is that the warm inverted lower level air mass is diverting the upper level wind over the top of the LZ and out towards San Jose. This is all fine & good, but at some point the cold NE valley wind will overcome the inverted air mass and suddenly avalanche down the hill. This happens suddenly & with little or no warning. In my experience it can occur with as little as 15 mph velocity & is very likely when the wind aloft gets in the 20’s or above. This event is extremely dangerous & can literally slam a glider back down to the ground.

I was down at Ed teaching earlier last month. Early in the day the wind talker was indicating 10-15mph but was increasing throughout the day & eventually peaked at an average of 27mph with gusts to 37mph. a mixture of  hg’s & pg’s were flying from the 300’ hill. I launched a couple of my critters but stopped when I saw the 600’ wind sock switch down. We waited a while & had a sudden 15mph gust come through, roll up the laid out pg’s from the back & tumble a couple of parked hg’s. While we were waiting I explained the condition to my students with hg pilots listening in. What scared me about this incident was even though my group bundled up & rode down the hill. The hg crowd did not. Upon reaching the LZ I was amazed to see hang gliders launching off the 300’ hill! I don’t know what they were thinking as the wind sock on the 600’ hill was pointing towards the lake & standing out stiff. Fortunately they got away with it, got away with it  being the operative words here. I was relieved when the last pilot made it safely down, but that wasn’t all. I noticed a pilot walking back up the hill. At this point I conferred w/a WOR senior pilot suggesting that we should close the launch & he agreed. As quick as I could I drove up the hill to talk to this person. The only reason the pilot hadn’t launched was that the glider had sustained a broken batten when it had previously rolled over. The pilot was apparently thinking of fixing the batten & flying. While I was explaining that the site was closed & why a sudden strong dust devil ripped through the set-up area & as it left the wind switched down at 15 or so, this all happened in less than 3 seconds. 

Ed Levin and Slide Mountain are the only two sites in our area that I can think of where we launch on the lee side of the mountain. It is extremely important that you are aware of the conditions above you. Also realize they can change so your last observation may be outdated. I have seen a couple of incredibly scary flights off of slide when the pilots launched too late in the summer time & got rotored all the way into no-mans-land at the base of the mountain. 

Be sure to be aware of the big picture not jus the wind sock in front of you. It’s wise to check the winds aloft forecast, the position & strength of the highs & lows, the closeness of the isobars & of course the wind talkers before deciding  when & where to go flying. In winter it’s common for us to be starved for airtime & willing to accept less than ideal conditions & accept more than normal risk to get a flight, any flight. 

May your spirits soar (even if your bodies sometimes can’t)! 

Wally

Last Updated ( Sunday, 02 April 2006 )
 
Meeting Minutes
Written by Alex Koorkoff   
Thursday, 23 March 2006

SFBAPA meeting minutes – March 1st, 2006

(held at Summit Pointe Golf Club in Milpitas)

By Alex Koorkoff, the Secretary 

Officers in attendance

Ann, Tom, Atta and Alex 

The meeting was called to order by Ann Sasaki at 7:17. 

Total 27 members attended, of which 4 were BAPA officers.

Members attending the meeting for the first time:

Curt, George Morford, Patrick Hajek and Daniel Curylo (the latter two from Vancouver, BC) and Peter Jennings.

Officer reports

Ann Sasaki – the President

  • Updated members on the GGNRA meeting she attended recently regarding Mori Point flying site – a North-facing ridge. BAPA had a permit for a survey team for a one-year period, which was over in July 2005. Since then the GGNRA has not wanted to move forward with the permit process. About two months ago they asked pilots to stop flying at Mori while the Environmental Analysis was being complete. At the GGNRA meeting on 2/28, the GGNRA said that they had built two small ponds in the "Bowl" area which is the LZ for paragliders. The Bowl is a habitat for two endangered species - the SF garter snake and the red-legged frog. Dave Sondergeld and Dan Byrne will suggest feedback that pilots may want to give the GGNRA before the end of the public comment period on March 31, 2006.  Ann will send a message to BAPA members soon.
  • Ann again reminded all members to renew membership.
  • Ann notified members that WOR paid the $1400 Mission tax fee discussed at the February meeting. New pilots and students who fly at Ed Levin are encouraged to join WOR because club dues go toward site insurance, maintenance and now, taxes such as the one at Mission.
  • On Saturday, April 22, BAPA is organizing the Jody Lucas picnic. The Hike and Huck starts at 9:00 a.m. and the picnic is at 1:00 p.m. Please see the BAPA calendar for details and do not forget to RSVP by April 15.
  • Elk Mountain fly-in is on April 28th – April 30th.
  • Anderson Flat fly-in is on May 6th – May 7th.

Atta Pilram – the Treasurer

  • As of last week, our balance is $4850
  • Out of 159 BAPA members only two thirds have paid their dues as of now. 52 people still haven’t.

Old Business

  • Ann proposed to approve meeting minutes for February 2006. Motion passes.
  • Jug distributed the remaining calendars to those who ordered but hasn’t received them yet. He will contact individuals who sent emails regarding missing calendars.

New Business

  • Motion to allocate money for Judy Lucas fly-in as follows: $250 for food, $120 for prizes. Motion passes.
  • As a way to obtain better liability insurance for its members (especially during competitions), Jug proposed looking into a possibility of BAPA becoming an LLC. Atta needs to get more information, and seek legal advice.
  • Wayne volunteered to prepare 3D-software tracks for the XC league.

Entertainment

  • Following the officer reports, Jugdeep Aggarwal made a presentation about the XC League, the competition rules and how to use your GPS in the comps.
  • Raffle

Meeting was adjourned at 7:55PM.

Last Updated ( Friday, 24 March 2006 )
 
Mount Diablo Site Introduction
Written by Bob Clem   
Thursday, 23 March 2006
      Welcome to Mount Diablo, the Bay Area’s premier flying site.  This site introduction document will cover: assessing flying conditions, launches, LZ’s, a typical flight, soaring opportunities, common weather patterns, lee-side winds, land-outs, radio use, flying with hang gliders, X-C, restricted airspace/aircraft traffic, and surface hazards. It is mostly site-specific, so it doesn’t discuss standard thermal site principles, though these certainly apply here as much as at any other thermal site.  It is not a replacement for an in-person site intro, but a supplement.  It will not cover the PG flying regulations, which are contained in a separate document and which all fliers should abide by.   

Assessing Flying Conditions

      Mt. Diablo, elevation 3,849 ft., is the highest mountain in the Bay Area.  The park includes thousands of acres of high terrain surrounding the peak.  This geography creates a lot of its own weather in addition to both the marine air influence from the nearby sea and the large scale weather pattern in effect.  When the three weather sources (local, marine, and large-scale) combine it can be confusing and difficult to assess the flying conditions.  Moreover, one weather phenomenon may be dominant at lower altitudes and another at higher altitudes.  A good practice is to observe the weather conditions (winds and temps mainly) during the whole drive up the mountain, including above launch elevation if in doubt.  Particularly, note conditions at the Northgate Road park entrance (elev. 350 ft.), main LZ (elev. 1,000 ft.), alternate LZ (elev. 1,750 ft.), Junction sign-in box (elev. 2,150 ft.), main launch (elev. 2,900 ft.), and appropriate pull-outs along the road above that if there’s any question about the upper level winds.  Only the alternate LZ stop is additional, the others you would generally need to stop at anyway.  Each stop allows you to feel ground-level winds, see foliage and cloud movement from the wind, and see how the “locals” (hawks and vultures) are faring in the nearby air.  And once at launch, it is usually a good idea to eyeball conditions there for at least 10-15 minutes before you commit to flight.

      The wind talker, ph. # (925) 838-9225, is located at the top of the mountain, some 900 ft. above launch, so it can give only an approximation of winds at launch.  Generally, the wind at the peak is a few mph faster and more north than the wind at launch.  However, if the peak is in cloud and launch is below cloud base, the wind speed and direction can be quite different in these two locations.  Another common exception occurs mainly on interfrontal/higher pressure days, when winds at the top can register strong and northerly on the wind talker during the night and into mid-morning, then with solar heating during mid-day the registered winds subside to single-digit levels and become more westerly.  Sometimes this low wind reading is real and represents the prevailing wind, allowing mid-day flying.  But often there is an actual stronger lee-side base wind, apparent only after you’re at the mountain or even in the air, which tells us that the peak (where the wind talker is located) is in a local “thermal calm” while the true prevailing wind (N to E usually) is blowing all around it.  This is another reason not always to trust the wind talker to give the true general prevailing winds.  In fact, you cannot necessarily trust the wind you’re feeling at launch to represent the general prevailing wind; on a strong lee-side day, it can feel almost calm at launch, even with some light cycles coming up.  But a glance at nearby foliage reveals much higher local winds, over-the-back, while launch itself is in a wind shadow or near the center of a rotor where it is calmer.

      An important resource is the Concord Airport ATIS (Automatic Terminal Information Service), 11 mi. NW at near sea level, ph. # (925) 685-4567.  This is recorded weather information for the airport that is updated at approximately 50 min. past the hour.  Of importance to us, it gives cloud cover, visibility, temperature in Celsius, barometric pressure (as an altimeter setting), and winds.  Convert Celsius to Fahrenheit mentally in 3 easy steps: 1.) double the Celsius, 2.) subtract 10%, 3.) add 32.  Example: 16 degrees C. would double to 32, subtract 3.2 (10%) = 29 approx., add 32 = 61 degrees F.  For our purposes, a general rule is that if the difference between the airport temp and the wind talker temp is 10-16 degrees F. we can expect good soaring, depending on winds, ground moisture, cloud cover, time of day, season, and the presence of inversion(s).  A 6-10 degree difference gives marginal soaring.  Over 16 degrees can mean too much convection and associated turbulence. 

      There are web sites for Mt. Diablo and nearby locations that give wind/weather info to help paint the “big picture” for you.  The Mt. Diablo site itself is:  http://cdec.water.ca.gov/cgi-progs/queryFx?MTDhttp://cdec2.water.ca.gov/cgi-progs/queryFx?s=MLR.  A third is Las Trampas, 8 mi. WSW, elev. 1,760 ft., http://cdec2.water.ca.gov/cgi-progs/queryFx?s=ltr.  All three of these and some other Bay Area locations can also be viewed at once as current readings only; just move the cursor over the ones you need and a table with all the current info appears for each one: http://www.wrh.noaa.gov/mesowest/mwmap.php?map=mtr&limit=1.  A good soaring forecast site for Mt. Diablo is: http://home.san.rr.com/tadhurst/Mt_Diablo.htm.  Of course, there are countless web sites for assessing general weather and soaring potential for specific areas, but they won’t be covered here.  You will eventually find and use those which fulfill your needs best.  and it shows winds, temps and solar heating over the preceding several hours.  It is useful not only for assessing a proposed flying day, but also for reviewing its data on a day you have flown there and relate those data to your actual flying conditions.  This helps refine your interpretation of the data in the future.  A similar web site is Mallory Ridge, 7 miles ESE, elev. 2,040 ft.,

      Think of the wind talker, airport ATIS, your own weather observations at the site, your knowledge of the site, online weather info, etc., as each just a single piece of the big picture which you see clearly only when you put them all together correctly. 

Launches

      There are four sanctioned launches.  The main launch at Juniper Campground is at 2,900 ft. elevation.  It faces WSW.  The direct course to the main LZ is close to due west, which is where you see Mt. Tam on the distant horizon.  Appropriate winds are S to WNW.  Very light prevailing winds averaging no more than 5 mph from other directions are usually OK as long as you have favorable wind conditions for launching.  The launch has plenty of open space to either side and several hundred feet down, making it ideal for kiting practice and making top- and side-hill landings. 

      A second launch, at 3,200 ft. elevation, is on top of the main ridge next to Juniper and requires a short hike to reach.  Appropriate winds are SW-WNW, except when there are light N to NE winds; then you can launch off the back side.  In that case you fly to the left and over the gap to the main LZ.  You should not do this in N winds over about 10 mph due to lee-side turbulence and sink.  Yet you need at least 6-8 mph winds for launching because of limited run-out space.  The N side of this ridge is sketchy for soaring and has more potential for turbulence, so it is infrequently used. 

      The third launch, facing SE, is at the big parking lot just below the peak, elev. 3,700 ft.  It is not maintained and has some low brush on it making it difficult to lay out and inflate your canopy without line entanglements.  There is very little run-out space and there are utility lines about 400 ft. below launch, though they are easy to avoid.  Desirable winds are ESE-SSE between 6 mph and 12 mph. This area can be soared in the correct conditions, which are not very common.  If unsoarable after launch, you would turn right and follow the terrain heading toward the Juniper launch, then to the main or alt LZ.

      A fourth launch, the RDS tower, is technically open to PG’s but is not advisable for PG use.  It is at about 3,650 ft. elev. and faces NNW, toward terrain with no bail-out LZ’s; the nearest regular LZ is too far away to be easily reachable in a PG.  The terrain in this area of the mountain also generates greater turbulence because it has a lot more exposed dark rock.  This launch is essentially exclusive to HG’s.

      Ninety-nine percent of launches are from Juniper, and about 95% of landings are at the 1,000 ft. LZ, so the route between the two represents the standard flight plan. 

Landing Zones

      There are three sanctioned LZ’s.  The main LZ is 2.9 miles in from the North Gate entrance on North Gate Road.  There is a “1,000 Ft.” elevation sign just above the LZ parking pull-out.  This LZ is a large gently-sloped ridge that has enough space to land on easily.  We try to keep one or two wind streamer poles on the ridge top.  It is 1,900’ vertical below launch, and a 4.5:1 glide out, which means there is a greater risk of landing short than at most sites. 

      The alternate LZ is on the left/northwest side of the road about ¼ mile past the two ranches you will see on the drive up.  It has no markings or wind streamers.  Its main function is as a bail-out on north wind days when you cannot make the main LZ due to sink and/or headwind.  If you approach it in the usual direction, flying west, it has a slight down slope to it, so make S-turns or use big ears if necessary to get on the ground in the available space rather than float off the W end.

      The third sanctioned LZ is the helicopter LZ on South Gate Road.  It might be used if you’re trying to fly in the infrequent SE wind, launching from the SE launch near the peak.  It is rarely used by PG’s because they generally would not fly with a SE wind, and because there may be more turbulence at that LZ. 

Typical Flight

      Let’s look at a typical flight from Juniper launch.  The following is what you would encounter in sequence unless/until you find Your Big Thermal that takes you above it all.  The main ridge (Moses Rock Ridge), immediately to the right of launch, is usually the first place we look for lift.  Past that is a low gap or saddle which can harbor stronger venturi winds that can lead to a blowback, so be cautious about getting back in there too far with stronger winds.  Past this gap and farther west is a S-facing bowl that can sustain you in a S wind.  Alternatively, from the far end of the main ridge you might head WSW, over a low ridge that has weak thermals at both its upper and lower ends.  From there you might proceed NW across a narrow ravine (which often harbors sink and turbulence in WNW-N winds) into the West Bowls, located about 1/3 of the way down and to the right of a direct course to the LZ.  They are grass-covered slopes/bowls with almost no trees or high brush.  With patience you can often gain enough altitude there to make it back to launch for a top-landing.  However, if you’re still sinking you can fly SW to Poker Table Flat, a long ridge that roughly parallels much of the lower direct flight path from launch to the LZ.  Since it slopes down very little until just before reaching the LZ, it is a common land-out area.

      At some point after launch, especially in NW winds, you may find yourself in sink and/or headwind and unable to make the main LZ.  You must decide early to “bail” to the alternate LZ which is to the WSW from launch, or make a side-hill landing near launch.  Not doing so can easily lead to a land-out in the lower terrain which is usually safe but requires a lengthy hike out.  There is some brush/tree-covered terrain that must be crossed enroute to the alt LZ, a hazard mainly if you delay the decision to bail. 

Soaring Opportunities 

      Launch itself is a thermal source, and upslope winds move up the launch face and typically break free at or near launch.  This is why dust devils are occasionally seen at launch on active days.  The main ridge to the right (NW) of launch is usually the first place we try to soar.  The near end is foliage-covered and late in the day, with W winds, it often provides lift.  The far end is a steep spine that often harbors upslope winds that break free at some point to become a regular thermal.  On S-SW wind days, this far end also provides some ridge lift.  The terrain to the left (S) of launch is often soarable but is less steep and not as consistent as the main ridge to the right.  From this area it is easy to land sidehill or make it to the alternate LZ if necessary.  If you can climb a little from this area you can move back to a point over the big parking lot at the entrance to the Juniper campground; this is a thermal source.  The low ridge to the WNW of launch on the way to the LZ has thermal sources at the near (high) end and the far (low) end.  There are variable and inconsistent thermal sources in the West Bowls and they seem to work best in W-NW winds.  Poker Table Flat has thermal sources, especially the upper end adjoining the West Bowls and the higher of two knobs at the far end, near the LZ.  Once you’ve gained a few hundred feet over launch, there is lift over the main ridge next to launch, and at the top of the West Bowls.  Your on-site intro can point out these important landmarks to you. 

Common Weather Patterns 

      1.) Prefrontal conditions can bring smooth S-SW winds, sometimes with low cloud bases.  The lift can be widespread making it difficult to stay below a low cloud base.  If that happens, try to fly out away from launch and search for sink, as well as use descent techniques.  Depending on the strength and direction of the wind and its associated lift, you should fly only with adequate cloud base clearance, perhaps 200-300 ft. minimum over launch in light winds of 6-8 mph, and perhaps 1,000 ft. over launch in winds in the 12-14 mph range.  Be aware that the wind can increase rapidly in prefrontal conditions so land before risking a blow-back by high winds.  2.) Postfrontal conditions bring scattered cu’s, northerly winds and cold air. If the N base wind is low enough, i.e., under 5mph, there can be excellent soaring.  If convection cycles are too strong at launch during mid-day, wait until later when solar heating is less and cycle strength is lower.  3.) Interfrontal high pressure systems bring stable air masses, lighter winds and good weather.  Soaring is usually marginal, depending on the lapse rate at the moment.  It might be necessary to forward-launch.  In the colder months on stable days, fog often forms over the lowest terrain, so be sure to land before descending into it and losing your orientation.  On stable days in any season it is best to fly mid-day to take advantage of the maximum thermal strength from solar heating.

      Stable days are also known for inversions; sometimes there is a high inversion, say near launch level, and the soaring beneath it can be OK.  Other times, the inversion is low, near LZ, and you can find good soaring above it.  Generally, though, once you drop below the inversion you will likely sink out to the LZ.  Some weaker inversions can be “punched through”, especially when, as the day wears on, convection below an inversion increases, even as the inversion rises and dissipates, enabling a low save and a welcome climb back to launch, so it can pay off to try to stick with scratchy lift at the lower elevations.

        Sometimes a strong interfrontal high pressure center sets up somewhere over the far western states and  produces N to E winds of 30-60 mph at the peak, lasting 2-3 days, and shutting down PG flying for the duration.

      During the warmer months of the year, the marine air mass often makes its way inland to Mt. Diablo as an advection process driven by onshore wind.  It is a stratus deck usually based at 1,000-3,000’ msl and several hundred feet thick.  At the edge of this deck it is too windy to fly, but if this edge recedes back toward the coast during the day, the wind goes with it, often leaving good flying conditions, though the mixing of thermal action with marine air influence can be complex and a little chaotic.  When the edge of this stratus deck is between the Oakland/Berkeley hills and Las Trampas Ridge, conditions are frequently optimal for PG’s.      

Lee-side Winds

      Most lee winds are from WNW to ENE and we have a fair amount of experience with these winds.  Lee winds from E to SSE are less common, so we do not have much experience with those.  The following applies to the commoner first category, WNW-ENE. 

      It is OK to fly in lee-side conditions if you can reliably determine that these over-the-back winds are 5 mph or less.  You will likely not notice winds that low at launch or in the air.  In lee winds of 5-10 mph you may find launch to have upslope cycles that seem fine, but once in the air you may find areas of sink, turbulence, and disorganized thermals, often leading to a quick trip to the alternate LZ.  Lee winds over 10 mph are obvious enough at launch to indicate to most any pilot that it’s unflyable.

      If you find yourself in excessive lee-side turbulence after launch, fly away from the mountain toward the LZ’s where the turbulence and sink are less.

       

Land-outs

      At some point you will need to land out, despite your best efforts to follow the park rules and use only sanctioned LZ’s.  Land-outs should be made when you cannot confidently make an LZ, and to avoid landing in trees, high brush, rough terrain, or fog.  Land-outs are more common when the wind is in the WNW-N range because that’s what generates sink and/or headwind on the route to the LZ.  If you become familiar with the park trails and fire roads you can more easily choose a practical land-out spot with a mind to the subsequent hike out. 

Radio Use 

      Radio communication is more important at this site than most others because of the large area available for flying and the higher likelihood of landing out somewhere in this vast space.  If you land out, you can be difficult to locate just by sight, either from the air by other fliers, or from the ground.  Without radio contact and no visual confirmation of your status, no one can tell if you’re OK, and search efforts would have to be initiated.  Obviously, if your radio becomes inoperational while on-site, you could continue flying that day, but it would be advisable to apprise others so they can keep a special look-out for you.  Just do not make it a routine to fly without a radio. 

Flying With Hang Gliders  

      Hang gliders pioneered our site, starting in January, 1984.  Since PG’s came along around 1991 there have been no problems integrating the two, primarily because a.) we don’t often use the same launches or airspace, b.) there is such a large flying area available at the site, and c.) the overall number of both types is small compared to the number at other Bay Area sites.  Occasionally HG’s use the Juniper Launch when winds are SW.  They generally set up on the back part of launch (nearest the parking area) so there’s still plenty of room for PG’s to launch and top land on the front part of launch.  When PG’s approach to top-land, it is often necessary to pass close to HG’s setting up or in position to launch so allow plenty of clearance from them.  If possible, delay a top-landing when a HG is about to launch.  Otherwise, land sidehill away from the HG.  If the main ridge is working, then PG’s and HG’s will be flying close together there.  Many of the HG’s at Mt. Diablo are high-performance, with speeds about twice ours, or more, so maintaining separation is more of a challenge.  Ridge rules apply, and constant visual contact is vital, especially considering each other’s blind spots. 

X-C

      Occasionally conditions will be favorable for X-C.  Generally, these would include a light W wind and thermal tops at 5,000’ or more.  After you climb above 5,000’ a typical route would be to the SSE toward Blackhawk Ridge, then SE along the high terrain toward Windy Peak, Brushy Peak, and finally out toward Tracy.  If you fly south, avoid Livermore Airport’s Class D airspace and a Restricted Area between Livermore and Tracy.  Also stay above 800’ agl near the Livermore Lab.  Be sure to review and carry an aircraft sectional so you can locate and avoid these special airspaces.  If, as you’re just about to leave the park on this SE route and you are sinking out, the helicopter LZ is an appropriate place to land.  A second X-C route is directly over-the-back, to the E toward Discovery Bay or Byron Airport.     

      The park is surrounded by mostly private land, and the owners often do not want HG’s or PG’s on their property, complaining to the park staff when they spot us there.  Perhaps the best advice here is to land as discreetly as possible, and close to a road; then get off the property and onto the road with your gear immediately.

      You should have a dedicated retrieve driver or make some other arrangement for your vehicle since, after your X-C, you will likely not be able to get back into the park to get it before the park closes for the day, and it is a violation to leave it there overnight. 

      Before attempting X-C from Mt. Diablo connect up with someone who has experience with this when you can both be on-site. 

Restricted Airspace and Aircraft Traffic 

      The only restricted airspace within the Mount Diablo State Park borders is the outer ring of the San Francisco Class B airspace, the floor of which is at 6,000’ msl.  Its lateral boundary is about ½ mile E of the LZ and is oriented NW to SE at our site.  The airspace to the SW of this line and over 6,000’ msl is the no-fly area.  It is not a concern except on the rare days that you climb above that altitude and you are close to the main LZ. 

      Although Mt. Diablo is not close enough to the Concord Airport for paragliders to be at risk of penetrating its airspace (Class D, 2,500’ agl and 5 statute miles radius from the center of the airport), there is a lot of light airplane traffic to and from this airport passing near Mt. Diablo, so keep a good lookout to avoid these aircraft as best you can.

      If, while in the air, you hear sirens on the ground, there could be an evolving emergency, with a rescue helicopter soon to follow.  You should watch/listen for it, and if you detect it in the distance, land immediately.  Stay on the ground until it departs the area.    

      There are occasional sailplanes around Mt. Diablo and they usually operate from the Byron Airport which is 16 miles ESE of the peak. 

Surface Hazards 

      Spectators are numerous on week ends and when the weather is good.  They will often spread out and occupy much of the launch area to fly kites, throw Frisbees, watch HG’s/PG’s, etc.  Obviously, launching and top-landing pose a collision hazard to them and us.  When launching, politely advise spectators to stand well to the side in case a gust pulls you out of position.  Top-landing can be difficult and hazardous when launch is covered with spectators, so plan on a side-hill landing just below the top of launch to avoid a possible collision with them.  From the air on short final you can give a shout (e.g., “heads up!”) to alert nearby persons that you’re about to land.  Incidentally, try to be cordial to spectators and answer their questions. 

      Occasionally there are horseback riders passing through the launch area, and since horses can be spooked (possibly throwing the rider) by a launching/top-landing PG, you should delay operations until they’re out of the area.

      During much of the year, poison oak abounds, so be sure you can identify it so as to avoid contact with this plant while on foot.  Another obnoxious but non-toxic plant is tar weed, between mid-summer and late fall.  Its sticky residue gums up whatever it touches.  Fortunately, a couple of flying days after it abates for the season there is little to remind you of it on your equipment.  If you lay out your wing on the barren part of launch, you’ll avoid it there.  

      Rattlesnakes are also very common, including at launch and in the LZ’s, but they are a hazard mainly when you mess with them intentionally. 

      While driving, please be on the look-out for wildlife on the roads, including deer, coyotes, ground squirrels, snakes, lizards, and tarantulas, to avoid running over them.   

      Try to avoid flying near paved roads because of possible driver distraction. 

Conclusion

      Hopefully, this document will give you a good start in understanding Mt. Diablo, though the real learning comes from actually flying there.  Conditions at this site are variable enough to make almost every flight a learning experience, especially during your first couple of years.  Regular fliers there will acquire a wider range of knowledge and experience, making them feel more comfortable flying at other sites. 

      You should expand your range of self-allowed flight conditions very gradually.  For example, once you feel confident flying in winds of 6-8 mph near straight in at launch, try 10 mph next rather than jump right to 12-14 mph.  The same goes for less-favorable wind directions, lower cloud bases, restricted visibilities, stronger convection, and other challenging variables. 

      All of us who fly there agree that our mountain deserves respect, and if we always keep that in mind it will reward us with many memorable flights. 

      -Bob Clem, (email: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it ) with helpful review and suggestions from Rick Conger, Juan Laos, Robert Moore, Ann Sasaki, and Greg Thomas.  Relevant material for this document from other fliers will be considered for inclusion in future editions.

Last Updated ( Thursday, 23 March 2006 )
 
Common Wind Shear Pattern
Written by Jeff Greenbum   
Thursday, 23 March 2006
Observations for the Bay Area coastal areas

A wind shear happens when two air masses intersect and overlap each other. The air masses can be either moving in different directions or at different velocities. Among the most violent versions of a wind shear is the micro burst that occurs preceding a Thunder Shower. These are extremely violent downward blasts of air that hit the earth and radiate outward causing very high winds and hazards to pilots of any craft. Other wind shears happen in a horizontal fashion. The term shear defines the fact that one air mass is shearing off of the other. This happens because of the directional or velocity difference. Faster moving aircraft like planes and jets, will transition through the two air masses in an instant and this can be extremely hazardous. With the speed of a paraglider, we actually sometimes fly in the zone where the two air masses meet and mix.

In some locations, when the shear is of a horizontal nature, one air mass rises above the other. Sometimes the result of such an overlap can create soarable conditions much like the dynamic lift related to ridge soaring. One year, several Hang Gliding pilots got as high as 4,500 ft after getting in a wind shear and heading north of Fort Funston. The Class B airspace above Mussel Rock begins at 1,500 ft. then jumps up to 2,100 ft beginning near the Canyon of Westlake and to the North. Since the Jets from SFO depart right above us, any pilot that gets up in a shear above Mussel Rock could become a bug on a Jet’s window should they go into the Class B airspace. Even a near miss could jeopardize our beloved flying site. If you learn anything from this article, it should be that you need to stay below 1,500 ft at Mussel Rock if you get into a shear.

Looking North at a Shear that moved in over San Francisco.

Photo Credit to Geoff Rutledge - Full Gallery

 

This article is not being written to encourage Paragliding Pilots to try to fly in wind shears. There are many days when an approaching Wind Shear is visible and pilots can avoid the hazards by seeing such before it arrives. Knowing the symptoms that identify a shear can help you to avoid putting yourself in harm's way. There are some very advanced pilots that have had great flights in wind shears, but for each successful venture into a shear there are as many stories of pilots fearing for their lives and safety.

I have flown in wind shears since about 1986 in Hang Gliders and occasionally in Paragliders since the early 90s. I have learned a quite a bit from each experience but mostly have learned that predicting the good from the bad ones is very difficult. Shears are less threatening to Hang Gliders than Paragliders because of their greater flying speeds. Occasionally, shears can happen with winds that are manageable by very experienced paraglider pilots, but only with knowledge of the nature and hazards of shears should this be attempted at all.

The coastal wind shears that we see near Mussel Rock and Fort Funston can often be predicted as they approach, but not always. When visible, there are specific conditions that can be observed and watched as a shear approaches. The Northern California shears in this area are most common in the Spring and Fall, but can happen any time of year. Mostly, they involve a northwest wind or west / northwest wind overlapping a southwest or west / southwest wind. I have seen some, however that were southwest over northwest.

 

Pacifica in Background, Shear Cloud shows the curve of the NW wind 
as it overlaps the W or SW. When the whitecaps approach, even on  
a blue shear day, you will see a curve like this. 
Photo Credit to Geoff Rutledge - Full Gallery

Some shears seem to have a solid overlap of the two air masses. When you get above the mixing zone, the air smooths out. In others, it seems that the mixing layer does not end and the air can be choppy to the point of creating collapses to the paraglider.

When the shear has cloud form (shears other than blue shears), the cloud forms behind the overlap area. The cloud is like a lenticular cloud that one sees in waves. On blue days there is not a solid cloud, but sometimes you can see tiny wisps of clouds form and then disintegrate in the mixing zone. Occasionally other pilots and I flying in a shear have soared slightly above this cloud. Getting too far back in relation to this cloud would be very dangerous, as once you get behind the overlap, laminar and even descending and choppy air is often there. The cloud can be used to demark the shear location and XC flights can be done. Dave Ellers set the local site distance record using such a cloud (not documented, but it occurred) for Mussel Rock by flying to Montara in a wind shear. A few Hang Gliders have made it a bit to Half Moon Bay.

 

View from above the Cloud Form, noting where the overlap is. 
Photo Credit to Geoff Rutledge - Full Gallery

 
 

Looking North at a Shear that moved in over San Francisco.

Shear Cloud - likely moving slowly back toward SE,  but sometimes they just remain stationary...

 
 


Another shear cloud above Daly City.  
The little wisps at bottom left are all you see in a Blue Shear.  
Imagine only the faint wisps and that would be a Blue Shear.

 
The following are all common observations when a wind shear is present or approaching:

• A horseshoe shaped band of whitecaps is approaching (the band of whitecaps bows toward the coast like the shape of the curved part of a horseshoe). This can be well defined and easy to see. Whitecaps can be harder to see in some lighting, especially when there is cloud cover.

• Above the coast may be coastal low clouds and fog, but the horseshoe indent moves in with the whitecaps. When this occurs, this is the easiest way to recognize and see the shear coming. On other days, the whitecaps approach, but the sky remains blue. This is commonly called a “Blue Shear” by the locals.

• The winds will often get very switchy and gusty as a shear approaches. Occasionally, it can remain soarable until just before the shear arrives, but usually the wind will die and start to gust in varying directions as it gets close. The wind direction can become extremely switchy and there can be a lot of gustiness. Sometimes the wind will almost die for a while. The only rule that is consistent with regards to wind shears is that they are not predictable.

• When a shear arrives at the coast, pilots trying to get into them work their way up through the mixing layer to get to the upper level. The air in the mixing layers is often described as “holey” (like Swiss Cheese) meaning the air feels like there are chunks taken out of the wind. It is like flying along and suddenly the wind dies and lift disappears, then you hit some lift like a small thermal bubble. The wind drop-offs feel like holes in the air.

• Above the mixing/chop layer, the lift can increase quickly and the velocity too. In some shears, it seems like there is no layer above the chop. In others, the air becomes smooth and strong above the chopped section where the air masses overlap.

• In some shears, the wind seems to continually increase as you move up into it. In some, the wind will level off with altitude gains. If you are ever in a shear, have your guard up at all times.

The following two days occurred in the Spring of 2005 back to back. I wrote up a description of this and posted it to the local Bay Area Paragliding Group. I believe it helps to emphasize both the hazards of flying in shears and how unpredictable they are. Day 1 was a shear that was super docile and some of the pilots did not even realize what was occurring. The next day, a stronger shear approached and the gustiness and switching winds got all of the pilots out of the air. After it set in all the way, I decided to test it to see how strong it was and if it might have turned out to be like Day 1’s version. The wind on Day 2 was standard at the bottom layer, but once I got above the chop, it got stronger and stronger, faster than any shear I have ever been in.

 
Good Shear - Day 1

About 10 of us enjoyed one of the best Wind Shears ever at Mussel Rock. It did not move in with the normal obvious horseshoe wind lines and it was a Blue Shear (no cloud form behind it). Instead the winds built slightly and pilots entered it without much effort. Winds were about 18 or so (you could penetrate upwind at a slow pace at trim) in perfectly and glassy smooth lift that took us to 1000 ft or so way out in front (1/4 or 1/2 mile for some) of the Westlake Cliffs. I came down giddy after 45 minutes in this great shear with a perfectly clear blue sky and sharing the air with some great friends.

 
Nasty Shear - Day 2

Myself, Brad Smith and Nova Dasalla all saw the shear form and come in to usable level late in the day. Pilots had been flying earlier, but the air got choppy and switchy as the shear approached. All stopped flying, it was late in the day and most left other than us. We were excited, but also a little cautious about it because the white caps were bigger. I launched at Tomcat, flew to just below Lemmings and could not bridge across, so landed at Gusto Launch (the flat pad area below Lemmings). The air had been quite chopped on the flight across, but manageable for experienced pilots.

I launched at Lemmings and jumped across to the corner of Westlake and worked the lift portions of the Shear up the South end of the Westlake Cliffs. I had a radio on and was communicating with Nova and Brad at Tomcat. I talked Nova out of flying and decided to be the air testing technician (aka Wind Dummy). I was able to climb pretty quickly to about 3/4ths of the way up the cliff and the air was still choppy. I hit the biggest of the chop at about cliff-top, but then got into the shear layer. Up until this point, the winds were pretty manageable (less than 16 or so). Once I surfaced into the main shear layer, it jumped up to 18 or so, for a few seconds I was cautiously optimistic. The wind then began to get above 20. I was climbing very quickly and veered a little toward the west/southwest to penetrate and head a little to the south. It was increasing fast, so got on the speed bar around then, straight out in front of Walker. I got pretty far out, above the breakers and water's edge. I was able to penetrate, just slightly, but as I was ascending, I could tell that it was getting stronger. I was about 300 ft over the top of Westlake, so about 900 MSL. This was less than 2 minutes after the launch at Lemmings!

I made the decision that this one was just too strong, so engaged speed bar fully and did big ears. I was now still able to penetrate, drifting south toward Tomcat but not going down. I was still going up slightly with full speed bar and big ears, my adrenaline glands became active. I also stopped penetrating and started to go back. This all happened unbelievably fast. Within 2.5 - 3 minutes from launching, I was in this situation. I had climbed incredibly quick and the winds and lift rose steadily as I had ascended. I thought about either B lining or a spiral to try to drop below the shear level. It took me less than 2 seconds to think this out and chose the spiral. I did 3 high banked corkscrew 360s rapidly and dropped as I drifted back over the mesa. It did not seem like I was dropping much, but it was in fact pretty significant (guesstimate of about 250 ft or so). At the same time, I drifted about 70 percent of the way to the cliffs at the south corner of the Westlake cliffs ( I had started in front of Tomcat and over the water's edge (in winds like this you drift very quick). I could not continue to spiral as I would have gone back over the houses and back of the cliff, I was about 50 - 75 yards in front of the rear SE corner of the Westlake Cliffs. I exited the spiral and got on full speed bar with big ears. When I first checked, I could tell I was not penetrating with the big ears / full speed bar combo, then I notice that I was descending slowly. Within about 15 seconds, I descended about 50 more feet and began to penetrate forward. I flew forward to Tomcat and as quickly as I could get out of my harness, literally kissed the ground.

Lessons from this story:

I tell this story to raise awareness of the dangers of Wind Shears at Mussel Rock. I have been flying here for 18 years and this was the closest I have ever been to a blowback. I survived this, but I am so glad that I was the wind dummy on this day and had the right mind set to deal with it when it became critical.

Beware of shears until you have lots of coastal experience. This was one of the strongest and rapidly accelerating ones I have encountered and will be more cautious next time. Yes, I will fly in shears again, but will pick them a little more carefully in the future. If the white caps are as big as Day 2, I will likely leave it alone. They did not look that big to me, I was guessing 15 - 20. I guessed wrong and was able to survive this. On Day 1, there were white caps, but very few. It did not look like 18 or 20 on the water, but the winds were around there up in the shear. There were some new P2s flying in the shear on Day 1, most were aware of what was going on, a few were not fully aware. All of the P2 pilots did really well, using speed bars and big ears when it got stronger, and also staying way out in front of the cliffs. The two shears on consecutive days were entirely different in nature. I had really hoped Day 2 was going to be similar to the shear on Day 1, but it was way stronger than we anticipated when I decided to fly.

When a shear is approaching, if there are advanced pilots around that want to take a crack at it, watch and learn. If you are an advanced pilot and decide to try flying in a shear, know that the air will be very choppy in front of it. Know also that the wind can increase rapidly once you enter one. Look for the most experienced pilots around when a shear is present and begin to learn what is going on by asking lots of questions.
Last Updated ( Saturday, 25 March 2006 )
 
Annual Anderson Flat Fly-in
Written by Gene Pfeiffer   
Thursday, 23 March 2006

Anderson Flat Fly-in May 6 – 7th weekend. 

   This year’s Fly-in will be held on May 6 – 7th weekend.  This is the prime time for Anderson Flat flying.  The mountains and meadows are green and the thermals are working.  If you are a P2, you should have some mountain thermal experience.  For information about flying at Anderson Flat, see Kim and Mike’s excellent web site for Anderson Flat at:

http://www.flyzephyr.com/aflats.htm

Photo courtesy Gene Pfieffer
Anderson Flat Fly-In 05/01/05 Photo courtesy Gene Pfieffer
 

   Again our cabin will be open to you.  Email me at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it for directions to the cabin and to save a bed. Bring your own sheets or sleeping bag. We now have a cleaning person to clean up after we leave.  Please donate $10.00 per person for the cleaning costs. Saturday night will be pot luck, so bring your favorite dish.  Some pilots may camp in the campground LZ, but the launch is only 25 minutes from the cabin.  Bring your fishing pole, mountain bike, kayak, or hiking boots for alternate activities if the flying is questionable.  I hope you can make it for a fun weekend.  The picture is of one of last year’s pilots landing at the LZ in Anderson Flat. 

Gene Pfeiffer

 

Photo courtesy of Gene Pfeiffer
Anderson Flat Fly-in 04/30/05 Photo courtesy of Gene Pfeiffer

Last Updated ( Saturday, 25 March 2006 )
 
 
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