Update: Marc Arnold, the pilot for Rocky Mountain Jet who flew the Eclipse 500 against the Lexus LFA, was kind enough to give us detailed information on the race. Rather than leaving his insight as a comment, we thought it more relevant to include it in the body of the original story. Thanks go to Marc for providing his response, seen in its entirety on pages two and three.
A few days back, Lexus announced an interesting-if-not-uncommon showdown between its LFA supercar, equipped with the Nürburgring package, and an Eclipse 500 corporate jet at an airfield in Longmont, Colorado.
Since a showdown from a standing start would clearly go to the LFA, the contest allowed a flying start for the jet versus a standing start for the LFA. As the jet crossed the start / finish line, Scott Pruett would launch the LFA, travel the 4,800 feet length of the runway, turn around and repeat the process.
The jet, already traveling at 150 knots (about 173 mph), would need to bank at the end of the runway before completing the two-way run, with the honors going to the first vehicle to cross the start / finish line. The video below explains the details, and we're fairly sure Lexus will follow up with a video of the race.
Since the stunt was sponsored by Lexus, it’s really no surprise that the LFA beat the Eclipse 500 by some two seconds, which has us asking all sorts of questions. We know that Pruett was going flat out in the LFA, but we doubt that the Eclipse 500 had its throttles to the firewall and probably wasn’t banked at the limits of the airframe.
Could a more aggressive pilot (flying at a higher altitude for safety) have made up the winning two second gap? Is the Eclipse 500 capable of faster speeds and tighter banking? We can’t answer those questions, but we’d sure love to hear from readers who can.
Marc Arnold's response:
Thanks for your comments and interest in the LFA vs Eclipse Jet Shoot Out. I was the pilot of the jet and am pleased to respond to your suspicion that a more aggressive pilot could have won.
As you might guess, a longer race circuit would have resulted in a shut out in favor of the jet. Conversely, a shorter course would have favored the car. During the planning stages, we predicted staging the race at Longmont Airport with its relatively short 4,800 foot runway would be a close race. As it turned out, it was extremely close. Since you are a techie, here’s the behind the scenes scoop on how the flying part was handled….
I practiced the maneuver about 50 times over the prior four months (but not at low altitude over the runway since that required a special waiver from the FAA that was only valid on race day). Together with another experienced acrobatic pilot to enhance safety and record data, we tested a wide range of variables to determine how best to shave seconds off the time. To my knowledge, no other business jet has participated in a race quite like this one. On the day of the race, I flew alone. Needless to say, there are many ways to accomplish this maneuver and we methodically varied each one to determine its effects. On race day, I pushed every one of the relevant limits.
First, I approached the start line in a steady 3 degree descent at 110 KEAS (Equivalent Airspeed). Jet engines take some time to spool up. Three seconds before crossing the start line, I slammed the throttles to the stops. The FADEC’s (Full Authority Digital Engine Controls) are in direct control of the engines and feed in as much fuel as possible without exceeding temperature, thrust or rev limits given the atmospheric conditions present. Had I stayed level with full power on, I would have screamed past 150 mph in a few seconds, but instead, I crossed the start-line just a shade below the agreed upon maximum of 150, then immediately turned left and pulled up hard to minimize the radius and gain the altitude. I knew from practice that I would need every foot of altitude for the return dive and race to the finish. Had the starting speed been slower, I wouldn’t have been able to get the altitude needed for the diving high speed, high G turn back to the finish line. Any faster, and the radius of my left 90 / right 270 would have been greater… again, a slower start/finish elapsed time. Which leads to the second limit.
The initial pull-up and hard left turn was done with flaps partially down (this is just barely visible in some of the photos) to minimize the turn radius. The aircraft is limited to 2 G’s with flaps down. My G meter recorded 1.93G’s. Airplanes stall at a given angle of attack, NOT at a fixed airspeed. This means the harder you pull in a steep turn, the higher the stalling speed. Turning first left, then right at 115 KEAS and nearly 2G’s put the plane very close to an accelerated stall. Stalling at low altitude is fatal. Fortunately, the Eclipse has an advanced ADHRS (Air Data and Attitude Heading and Reference System) which analyzes actual angle of attack in realtime. I rode that indication to stay 5 knots away from the automatic stick pusher which would have automatically pushed the nose down with 45 pounds of stick force (also a really bad thing to do at low altitude).
Then at the top of the right 270 degree turn, I selected flaps UP, but it takes 15 seconds. While waiting for the flaps to retract, I pushed the nose down past the horizon to 60 degrees down. The top of the turn was only 1,500 feet above the ground which is pretty low (and 60 degrees down feels like you’re pointed straight down) with the engines producing full take off power. Every instinct says “PULL”, but I had to wait until the flaps were fully stowed. (Remember the Star Wars scene, “Stay on target…. Stay on target…”?) Once the green flaps UP indicator flashed, I could pull out of the dive using the full certificated G load limit of 3.62G’s.
Level at 100 feet above the ground, I saw Scott Pruitt in the LFA almost half way down the runway and headed for the finish line, but I was gaining fast. I was doing 300+ and came within 2 seconds of catching him at the finish. The only thing left for me to do to win the race was lean forward and once I get a chance to see the race photos, it wouldn’t surprise me to find that I did that too!
A great deal of effort went into organizing the event and we wanted a close finish, but we had no idea it would end up being THAT close. We were extremely diligent to be sure that every aspect of the race was safe and legal. Within those constraints, you can be sure I did everything possible to win.
Bottomline: The limits of aircraft are finite. We carefully calculated the maximum possible speeds and forces that could be reached during the complex maneuver and compared those against the technical limits of the aircraft specifications. I practiced & performed the race as close to those limits as safety and legality permitted. Another, more "aggressive" pilot could only have gone faster by busting those limits.