Wednesday, March 10, 2010

Catch a Wave

By Mark W. Danielson

The Beach Boys sang, “Catch a wave and you’re sittin’ on top of the world”, but unlike the sea waves they were referring to, air waves can literally take you there. Since air and water are both fluid, similar waves are created by disturbances at the surface. Wind currents flowing over mountains create rising air, as seen in this diagram. Mountain waves attract sailpane pilots like carcasses do buzzards.

Dan Rihn and I started flying gliders as kids. Dan soloed one on his 14th birthday. (see photo) I had my power plane license when I started flying them. In the SF Bay Area, lift was as easy to find as free gas, so we fought to stay in whatever we had. But in mountainous areas like the Sierra Nevada or Rocky Mountains, mountain waves can lift a glider in excess of 40,000 feet. (You need oxygen above 10,000 feet, and you should have a pressure suit above 25,000.)

After many years of flying aerobatic airplanes, Dan rediscovered sailplanes, and quickly learned that flying a high performance sailplane is nothing like what we flew as kids. Nowadays, he routinely flies his ASW-20 (photo below) up and down the lower Sierra Nevada, and last year climbed to 25,000 feet in a mountain wave, earning him a “Lennie” altitude award. (flight path shown on diagram)

While wind currents generally flow from the west, under the right circumstances, a strong easterly wind will flow, forming mountain waves over the ocean. I once experienced this climbing a heavy MD-11 over the ocean from Oakland to Anchorage. At 28,000 feet, my aircraft suddenly accelerated to its maximum speed of .87 mach while climbing at 7,800 feet per minute. At 33,000 feet, the wave topped out and the lift disappeared. Since the autopilot cannot handle such extremes, I manually lowered the nose twenty degrees and leveled at my cruise altitude of 35000 feet. Everything was normal after that.

Dan’s friend, Thorsten Streppel, was flying his sailplane in an easterly wave off the Santa Barbara coast where he took photos of the coastline and the Dr. Seuss-like clouds shown above. Since this wave extended along the Coastal Range, he was able to fly hundreds of miles while still gaining altitude. Everything in Dan’s and Thorsten’s flights are recorded on GPS for record and review purposes. Prior to GPS, you had to take photos and use a barograph to document such things.

The atmosphere provides us with as many challenges as it does opportunities, but with the right equipment and knowledge, sailplane pilots can get birds-eye views of the world with only the wind under their wings.


Dan said...

article Mark.
Thanks for including my adventures into your blog.
Hopefully many more to come!

take care,
(Marks life long best friend)

Mark W. Danielson said...

I wouldn't have it any other way, Dan:)

Jean Henry Mead said...

Closest thing to flying like an eagle. Have you or Dan flown above 25,000 ft. in a sail plane?

Beth Terrell said...

I have never been in a sailplane, but I must have one in a book sometime.

Thanks, Mark, for letting me live vicariously through your posts.

Mark W. Danielson said...

Dan's high altitude flight is diagramed on the graph. It's hard to read because of its size, but Dan actually climbed above 20,000 feet twice on the same flight. Since he didn't release on the first time until 7,000 feet, his altitude gain wasn't enough to qualify for a Lennie award, so he descended to six thousand feet and then climbed back to 25,000 feet, which earned him the award.

I was flying a sailplane in Arizona and had a near-hit because of my altitude, but that was working thermal lift versus a mountain wave. I may have had the right of way, but it's a moot point if you collide.

In Colorado, I once towed a glider to 20,000 feet, which is probably close to a record, and after his release in the mountain wave, the glider pilot climbed to 40,600 feet, which is way higher than I'd care to go. The FAA sets airspace aside for these high altitude flights to ensure airliners and sailplanes do not mix.

A lot of gliderports offer introductory rides and I encourage anyone who wants to experience flying like a bird to take a flight.

Dan said...

The flight I made was just over 25,000 feet above sea level. I actually got two awards for this flight. One was for what is known as a Diamond award. For that I had to have a gain of altitude of 16,404 feet (5,000 meters) and the other was a "Lennie" award named after the Lenticular clouds formed by these waves. I earned a single Lennie by going to 25,000 feet. A double is 35,000, tripple is 45,000. I'm very happy with my single Lennie and have no desire to go any higher or do that again. This is extreme glider flying which take a lot of planning prepartion and proper equipment.
There are Three Diamond awards in Soaring; Altitude gain of 16,404 feet , distance to a pre planned (declared) goal, 186 miles and total distnce greater than 310 miles. Since this altitude flight completed all three diamonds. One of my distance flights was just over 400 miles.

Jean Henry Mead said...

Congratulations, Dan, on the awards. That's impressive sailing!

Mark W. Danielson said...

I'd like to emphasize that flights like Dan's award-winning flight are the result of skill, understanding aerodynamics, and stick-and-rudder application. Not everyone can accomplish such feats, which is why the Soaring Society of America rewards these accomplishments.

While towing gliders in Arizona, there was one pilot who was in a cross-country competition flying sailplanes from Phoenix to San Diego who never got it right. I towed him three times, and on his third attempt, every other competitor was already half way to their destination. Unfortunately, this pilot never made it away from the airport. His failure wasn't the result of bad luck, but rather bad skills.

Congratulations, Dan