RENO (AP) - The World War II-era plane that plummeted into an air-race crowd like a missile bore little resemblance to its original self. It was rebuilt for speed, if not for stability.
The 65-year-old "Galloping Ghost" underwent years of massive overhauls that took a full 10 feet off its wingspan. The ailerons - the back edges of the main wings used to control balance - were cut from about 60 inches to 32.
Pilot Jimmy Leeward had said the changes made the P-51 Mustang faster and more maneuverable, but in the months before Friday's crash even he wasn't certain exactly how it would perform.
"I know it'll do the speed," he said in a podcast uploaded to YouTube in June. "The systems aren't proven yet. We think they're going to be OK."
Investigators don't yet know what caused the plane to pitch sharply into the crowd at the National Championship Air Races in Reno, killing nine people, including Leeward, and injuring dozens. They have focused on the "elevator trim tab" - a piece of the tail that helps the control the aircraft's pitch and appeared to break off before the crash. While investigators did not identify the items, the NTSB released a photo late Sunday of two board officials at the crash site with items they said were part of the investigation.
In the highly competitive, bravado-filled world of air racing, pilots go for broke on the ground and in the sky, hitting speeds of 500 mph. Leeward is the 20th pilot to die at the air races since they began 47 years ago, but Friday's crash was the first in which spectators were killed.
"Pilots are a special breed of confident, intelligent, driven perfectionists," said Ken Quick, a commercial airline pilot and a crew member for one of the teams that raced Friday. "They know what they do is dangerous and demanding, and they eagerly embrace both."
Leeward's own website alludes to the dangers - and bragging rights.
"These guys are always on the edge knowing one wrong move, in one split second, could mean the end," the Leeward Air Ranch Racing Team website says. "NASCAR at 200 mph? Indy at 230 mph? Top Fuel at 300 mph? Mere Childs play. Welcome to the Big League."
Leeward had said the plane underwent several years of modifications before Friday's race, including lopping five feet off each wing, but he hadn't revealed many of the specifics. In the podcast, he called some of the changes "extremely radical," compared some to systems on the space shuttle and explained that he had increased the plane's speed capabilities to be more like those of a modern fighter jet.
"To control the airplane in the wind, and in different circumstances if anything happens, you need those types of speeds. You need jet speeds," he said.
Leeward was rounding a bend at dizzying speeds Friday when his plane took an oddly upward pitch, narrowly missing the packed grandstand. It then twirled just a few hundred feet off the ground and nose-dived into a section of VIP box seats, blasting out a 3-foot-deep, 8-foot-wide crater in a hail of metal, chairs and body parts.
Noah Joraanstad was blown off his feet as he tried to run away. Shrapnel hit his back, and he was covered in aviation fuel that burned his skin as spectators tried to wash it off.
From his bed Sunday at Northern Nevada Medical Center, where nine stitches were put in his head, Joraanstad said that when he looked back at the wreck, the plane was just gone.
"The biggest pieces I could see, it looked like just someone sprinkled Legos in every direction," said the 25-year-old, a commercial pilot from Alaska.
Officials said 69 people were treated at hospitals, including 36 who have been released. Six remained in critical condition Sunday.
Four of the spectators killed have been identified so far: George Hewitt, 60, and Wendy Hewitt, 57, a married couple from Fort Mojave, Ariz.; Greg Morcom of Washington state; and Michael Wogan, 22, of Scottsdale, Ariz.
Memory cards that may have come from the plane were found at the scene. The Galloping Ghost had a camera that faced outward, and the NTSB said the cards will be analyzed to see if there is any video.
FAA spokesman Ian Gregor said officials thoroughly vet all aircraft modifications before the planes are allowed to race. Reno Air Race Association technical experts also examine them to ensure they are air-worthy.
National Transportation Safety Board spokesman Terry Williams said his agency would look into the oversight of modifications to Leeward's plane as part of its investigation.
"We're not saying they did something right or wrong in this accident," Williams said. "We look at all angles in every accident investigation we do."
Pilot Ray Sherwood of Placerville, Calif., who raced at Reno from 1986 to 2005, said he's convinced that the crash was caused by modifications leading the trim tab to snap off. He said the same problem caused a modified P-51 Mustang to plunge into a neighborhood during the races in 1999, killing veteran pilot Gary Levitz.
Aircraft experts said losing the part could have forced Leeward to yank the plane up too fast, possibly overcorrecting and stalling, meaning the engines would be running but air breaks up over the wings, causing it to lose lift. He probably would have been able to pull out of it safely if he hadn't been at low altitude, they said.
"Assuming the aircraft had no other problems, and assuming the pilot had no problems, if he had enough altitude, you can easily get out of that no big deal ... Matter of fact, the P-51 was designed for that," said Ken Liano, a structural engineer and aircraft consultant. "But that's one of the problems with low-altitude flying: There's no time to correct."
Pilots modify their old P-51s to compete, but the alterations put additional stress on the aircraft, Sherwood said.
"If they are going to go as fast as they can, they have to modify the plane," he said.
Pilots were competing for a total of about $1 million in prize money, but Sherwood said the sport is really about the thrill. He said a P-51 like Leeward's would cost about $2.5 million.
"You can't make any money racing airplanes. It's too expensive to buy and maintain them," Sherwood said. "You do it for the love of the sport."
Leeward, 74, was a veteran racer who flew in more than 120 events and served as a Hollywood stunt pilot for movies including "Amelia" and "The Tuskegee Airmen." He has been described as a passionate pilot, a stickler for safety and an aggressive competitor.
In the June podcast, he chided a competitor to come take him on.
"I've got a standing $10,000 offer ... if he would come back, get in the airplane and fly it in the race. I'll pay him $10,000 cash on the table before he takes off just to get him in that race because when I beat that airplane, I want him in that seat," Leeward said.
Leeward's plane had a minor crash at the air races almost exactly 41 years ago. According to two websites that track P-51s that are still flying, it made a belly landing away from the Reno airport. The NTSB report on the Sept. 18, 1970, incident says the engine failed and the plane crash-landed short of the runway.
The future of the races is unclear. Joraanstad, the injured spectator, said he doesn't want to see the races end "but when you see people go through that much pain and people die, I don't know if it's worth it.
"It's just kind of that last edge - frontier of flying - where there's no limits, really, with the amount of power you can put in your plane," he added. "It's kind of the ultimate rush just to even watch these guys do what they do."
Brian Skoloff reported from Salt Lake City. Associated Press writers contributing to this report include AP Airlines Writer Joshua Freed in Minneapolis; Haven Daley, Scott Sonner and Don Thompson in Reno; Holbrook Mohr in Jackson, Miss.; and Michelle Rindels, Cristina Silva and Oskar Garcia in Las Vegas.