FRESNO, Calif. (KFSN) --A deadly Fresno plane crash could change national policies for pilots. Tim Farmer crashed his Cessna 172 Skyhawk in December 2013. He and his 9-year-old nephew, Finn Thompson, both died.
Farmer tried to land at Chandler Airport on a pretty clear and calm night, but on his third pass, he clipped a tree. Investigators now believe the 72-year-old had a health issue that's common as people get older, but one that gets no mention in FAA safety brochures.
As the NTSB took Tim Farmer's Cessna away from Chandler in pieces, the plane's wreckage gave away little as to why it went down the day after Christmas. But as they dug into Farmer's medical history, they found the clue they needed.
"At night, he would've had difficulty seeing the runway and making out the runway and he had demonstrated that three weeks prior," said Dr. Nicholas Webster of the NTSB.
Earlier that month, investigators say Farmer couldn't see well enough to taxi off the runway at his home airport until someone lit it up with his truck's headlights. Farmer's corrected vision was still 20/20, but his optometrist documented a four-year progression of cataracts.
"It's a clouding of the natural lens in the eye, so instead of looking through a clear glass of water, think about a glass of milk," said Dr. Richard Moors, an ophthalmologist at Eye-Q in Fresno who's also a pilot.
The condition affects more than 20-percent of Americans older than 65, and half of everyone over 75. That means about 12,000 active pilots may have cataracts making flight riskier, especially at night.
It's a big enough concern for the National Highway Traffic Safety Administration to put out a brochure about driving with cataracts. But FAA safety brochures never bring it up. Because of Farmer's crash, the NTSB now says they should because flying with a cataract is even more dangerous than driving with one.
"There's a minimum speed they have to maintain while flying and slowing down may not be an option," said Dr. Webster. "Pulling off to the side of the road may not be an option."
A representative from the FAA tells us they take these recommendations seriously and they'll have a response within the next two months. He said pilots have periodic medical exams and should be aware of any conditions that could make flying riskier, including cataracts.