Land Sailing Upwind
Direct Upwind and Downwind Record Attempts



DownindRecord

 


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This page contains Information and links to information about attempts to sail a wind-powered craft directly down wind (and now directly up wind) at the highest speed possible. If, as has occurred, that speed exceeds the wind speed, there will undoubtedly be a controversy since many people believe that both common sense and basic physics* say that going faster than the wind in the direction of the wind is impossible.
NALSA's interactive Yahoo Group webpage might be a good place to have a discussion about this. Please keep it civil and meaningful. If there is a flaw in the rules or some indication that the rules have not been followed, obviously changes will need to be made.
Please note: This is not a joke  or an intentional hoax; everyone involved is taking this seriously. The Blackbird is not claiming to be a perpetual motion machine, it is using energy from the wind; if the wind stops so does Blackbird. They just seem to have figured out a way to turn the wind's energy into forward motion in a way that is more efficient than a parachute, tumbleweed or conventional sail or wing. As far as NALSA can tell the Thin Air folks aren't "cheating."
Rules
NALSA Speed record regulations  ( including Directly Up Wind and Directly Down Wind )(rev 4, 2012)(PDF)
Current Records


July 16, 2012 
Upwind Record ( this is directly upwind, "dead into the wind," not tacking.)
Set by Rick Cavallaro at the New Jeruslem Airport near Tracy California with a slightly modified version of the same Blackbird that set the downwind record in 2010. They were able to achieve a recorded and verified run directly into the wind at 2.1 times the speed of the wind (10 mph wind) and on a separate run achieved a record speed of 22.9 mph, again directly into the wind. The big difference in the two crafts is that in the upwind version the **turbine  actually powers the wheels while in the downwind version the wheels power the **propeller. In neither case is there any motor, battery or flywheel used for storage. 
As of August 11, 2012 NALSA has ratified a category C3, propeller mode, speed record of 51.4 mph by the rotor powered craft Blackbird, sailed by Rick Cavallaro on July 2, 2010 on El Mirage Dry Lake.  This record was made viable by the latest revision of the NALSA Regulations for Speed Record Attempts.  The wind at the time was in the low 20 mph range and blackbird was sailing close to directly down wind.  Links to detailed reports can be found below. 
2012, rev. 4, Speed record rules (PDF) | July 2012, NALSA Submission Report (PDF) | July 2012, Observer's Report (PDF)
July 2, 2010.
  Set by Blackbird, an unconventional sailing craft designed and operated by Rick Cavallaro and John Borton of Thin Air Designs. The Blackbird, piloted by Rick Cavallaro sailed "directly downwind" at 27.7 mph in a sustained 10 mph wind, setting a record for ratio of "boat" speed to true wind speed of nearly 2.8.
  
  *It is possible that the author of this page underestimates the "common" understanding of sailing, and aerodynamics. People experienced with landsailers and iceboats have reported continuing acceleration for at least a short time after turning downwind at high speed which makes it difficult to proclaim "impossible!" in relation to the record published here. See the "faster than the wind" link below for an explanation of the physics involved. Once one gets propellers or turbines involved, the physics that apply to sails just don't apply. 
**turbine vs. propeller: these could be the same object; it is a matter of function. A turbine is spun by the wind and transfers the energy to something else (in this case the rear wheels of the Blackbird). A propeller is powered by something  (in this case the rear wheels of the Blackbird) and moves the vehicle by pulling or pushing it through the air.
Documentation
Upwind: June 2012
  NALSA Submission Report (PDF)
Observer's Report (PDF)  

Downwind: July 2010
  NALSA Submission Report (PDF)
  Observer's Report (PDF)
  Observer's report Appendix 1 (XLS) 

Links
Inhabit article
*Faster than the wind (Wikipedia)
Thin Air Designs Website
Downwind Noir


Last Modified
  May 16, 2013



