Pinpoint Location - Above the Speed of Sound
Two-time motorcycle landspeed record holder Valerie Thompson of Scottsdale, Ariz., is obviously no stranger to going fast. But in early May 2012, when she sat in the cockpit during an engine test on the North American Eagle--a jet-powered car converted from a Lockheed F-104 Starfighter airplane and featuring a Topcon Positioning Systems Euro 160T mobile control board among its high-tech performance data collection equipment--Thompson caught a glimpse into a whole new world of power.
While the car was restrained to the ground by chains, both engines and the afterburners were tested. “I had the opportunity to familiarize myself with the very complicated cockpit and learn all the startup/shutdown procedures,” Thompson says.
The car’s owners hope to conduct test runs in the Alvord Desert in Oregon sometime this year. Incidentally, the current female landspeed record is held by Kitty O’Neil, who established it with a 512-miles-per-hour average in the Alvord Desert in 1976. The team plans to conduct a few “shakedown” runs to ensure that all systems are operating properly and then give Thompson some “seat time” in the cockpit. If she feels comfortable on the big day, the plan is to make an attempt at the record.
The North American Eagle’s all-volunteer team of 40-plus, led by Seattle-area aerospace and computer experts, wants to attempt to break the overall world land speed record of 763 miles per hour that was established by British entrepreneur Richard Noble in 1997--who exceeded the supersonic threshold by 2 mph. Co-owners Keith Zanghi, a manager at The Boeing Co.’s Skin & Spar (wing components fabrication) Division in Frederickson, Wash., and the main driver and the team’s project manager, Ed Shadle of Spanaway, Wash.--a retired IBM project and system management specialist and field engineer--have kept their goal in mind since Noble broke the record. They converted the F-104 because it features a durable windshield and a General Electric J-79 engine capable of propelling the car well over 800 mph.
The 56-foot-long, 13,000-pound car had its first test run at a small rural airport near Mount St. Helens in western Washington state in November 2005. Before and since, the crew has steadily increased the car’s technological sophistication and continually tinkered with its components on weekends to get ready for an eventual attempt to attain its stated 800-mph goal. The expertise brought to bear utilizes many of the same practices as aeronautical component testing at Boeing.
To ensure maximum efficiency and safe operation, the crew captures huge volumes of performance data from as many as 70 sensors mounted on the car’s body and a GNSS. The captured data allows for sophisticated analyses of the car’s exterior components under realistic simulated conditions.
The Euro 160T mobile control board mounted in the vehicle that stores the data is designed according to the Eurocard standard format, i.e., its interface is designed as a rugged, industry-standard adapter for computing products that withstands acceleration up to 30 G-forces. The board withstands operating and storage temperatures of -40 degrees C (-104 degrees F) to 75 degrees C (167 degrees F). Wallace uses a flash drive to transfer data from the board, which has a total storage capacity of 1 gigabyte, to a personal computer. Wallace uses Topcon Tools software to correlate the time and location data. Then he exports the data to a Microsoft Excel spreadsheet.
Each row of data in the spreadsheet reveals the interval as time-stamped by the data-acquisition system 20 times every second for the car to reach a GNSS coordinate within a three-dimensional Cartesian coordinate system. Elapsed time is converted into mph for each dimension, and then the data is merged into “three-vector velocity” showing the car’s direction and speed. Wallace can use the data to generate charts showing acceleration, which may indicate how numerous components and systems on the car are performing. Measuring speed according to time-stamped geospatial position is extremely accurate, he notes, whereas another reliable method--measuring airspeed--is not a bad way to do it, but the data requires a lot of smoothing and averaging.
Wallace has enough experience with using GNSS that he has approached the Southern California Timing Association (SCTA), one of the world’s oldest automotive racing sanctioning bodies and recordkeeping organizations, about approving the North American Eagle’s timing method. During the 2010 Speed Week event at the Bonneville Salt Flats in Utah, Wallace compared a GNSS-based timing system with the SCTA’s tried-and-true conventional timing method on the Original Fast Guys II lakester owned by Dave Green from Abbottsford, British Columbia, Canada.
Wallace’s data and the SCTA’s data on the car’s speed were nearly identical to within thousandths of a second. He said that he respects SCTA’s timing method so much that he wanted to make sure that his method correlates fairly closely as a validation of the system and the methods he uses to derive the results. The experiment was a rousing success.
The recent North American Eagle engine test at Sanderson Field in Shelton, Wash., was a success, too--for both the car and the driver. Thompson says she is impressed with the team and is excited to be a part of it. “They have experts on every system in the vehicle, which is very reassuring. Being chosen to test pilot the North American Eagle is a true honor for which I am very grateful.”
All told, the car has been tested more than 30 times in 14 years. Currently, the team is trying to gain approval from the Bureau of Land Management and environmental groups to conduct the next test, which the team hopes will take place this fall.
“Our use of the Topcon technology has really been good for our project because we can measure not only our speeds but also the range of speeds on runs, so it gives us the dynamics of the entire event,” Shadle points out. “If you use any other kind of measurement, you’re only measuring from point to point--we need to know variations in speed and stability and control. Stability and control are really the keys to setting this record.” As of mid-2012, the team was providing evidence to verify the accuracy of its timing method for Guinness World Records.
More details about North American Eagle are at www.landspeed.com. For more information about Topcon GNSS technology, visit www.topconpositioning.com.