Ricky Craven knew something was wrong when his plane went upside down in the clouds.
Scared by the aircraft's sudden inversion, Craven began to panic until the pilot grabbed his arm and pointed to the gauges, which showed everything was normal.
As it turned out, the plane hadn't flipped at all. But Craven was suffering the after-effects of a concussion sustained in the 1997 NASCAR racing season – and he didn't tell anyone about what he'd experienced.
Watching Dale Earnhardt Jr.'s press conference on Thursday, in which Earnhardt revealed he'll be out of the car for at least Charlotte and Kansas, Craven said he could empathize with what NASCAR's biggest star was likely going through now.
And that caused the driver-turned-ESPN analyst deep concern.
"This is career-threatening," Craven said. "That's probably not a word that was used a lot today, but that's reality. That's really what it felt like for me."
While Craven said he had no insight into Earnhardt's specific situation or symptoms, his own experience made him question whether Earnhardt will be out of the car for longer than just two weeks.
"If it was serious enough to lose two weeks, I automatically start thinking, 'Is it serious enough to lose six weeks? Does it even make sense to get back in the car?'" Craven said. "... If you're 98 percent, stay out (of the car). I know that's not going to be a popular thing. I know we'd rather have him in the sport than out. But the frightening thing is the cumulative effect it has long term."
Earnhardt's involvement in a crash at Talladega gave him a second concussion in the last six weeks. In August, the driver blew a right-front tire and crashed at a Kansas tire test, but was cleared by on-side medical personnel and didn't tell anyone he was feeling ill.
Worried about pulling himself out of the car and missing the Chase, Earnhardt kept driving – but said his reactions were noticeably slower and estimated he was only at 80 or 90 percent when NASCAR's playoffs began.
He was back to normal by Talladega, he thought, but a 25-car crash on the final lap caused him to spin violently. He immediately became disoriented and knew he'd had a setback.
Craven is familiar with that story. At the start of the 1998 season, he was still racing despite the concussion. But in the fourth race of the year, at Atlanta, a competitor's motor blew up and left fluid on Craven's windshield. Suddenly, Craven couldn't get his bearings, and he dropped like a rock and finished 34th.
When he got home, he went straight to a hospital for two days of analysis and tests. During one of the tests, he became nauseous and got sick; it proved he had a severe concussion.
"That's when I knew I was in big trouble," he said. "I knew then I wasn't going to race again for awhile."
Craven missed the next four months before returning to the track. He raced another few years, then retired.
As for the active drivers, Earnhardt's current peers danced around what was clearly a sensitive topic on Thursday, with none objecting to him racing with a concussion. In fact, some said they've done the same – and even driven on public roads without being at full mental capacity.
Jimmie Johnson sustained a concussion in 2000 while racing at Watkins Glen. After the race, he said, he got on the interstate to go to the race shop but went north when he intended to go south. It scared him enough to go see a doctor, and he recovered in time to race the next week.
"While (the effects) went away after a day or two, it just goes to show you that concussions affect everyone differently," Johnson said.
NASCAR vice president Steve O'Donnell said the sport has recorded just nine concussions in the past five years. Surely, though, there are many that go unreported and undetected by officials.
Like Earnhardt, most drivers wouldn't want to get out of the car unless absolutely necessary. Craven said he couldn't criticize Earnhardt for racing after the first concussion because "I'd be a hypocrite."
"Drivers think, 'I'll be better tomorrow. I got four days. I know that's all I need to get better,'" Craven said. "If you do this long enough, I honestly believe every driver faces this."
Even knowing the risks, Earnhardt teammate Jeff Gordon said he wouldn't tell anyone about his symptoms if he were racing for a championship in one of the final races. Drivers would rather try to hide their injury and tough it out than admit a problem.
"Honestly, I hate to say this, but I wouldn't (admit it)," he said. "If I have a shot at the championship and there are two races to go and my head is hurting and I just came through a wreck...I'm not going to say anything. I'm sorry. That's the competitor in me and many other guys.
"That's to a fault. That's not the way it should be, but it's something most of us would do. I think that's what gets a lot of us in trouble."
Still, though, drivers have seen media coverage of what concussions can do to NFL players and other athletes. Why don't they recognize the need to be forthcoming about any possible head injury right away?
As Craven said, it all comes down to control.
"You put everything you have into this to get to this point," he said, becoming emotional. "And when you cross this bridge (getting out of the car due to a concussion), there may not be a way back."