1. Hurricane Hugo, 1989
The NOAA Hurricane Hunters, including Weather Underground's Dr. Jeff Masters, were expecting to fly into a 130-mph hurricane in 1989. What they actually flew into was a 185-mph major hurricane with extreme turbulence and gusts nearing 200 mph.
This P-3 flight penetrated the eyewall 3,500 feet lower than recommended for a hurricane of Hugo's intensity. Intense downdrafts pushed the plane down to 880 feet, took out one engine and nearly took out another engine on the same wing.
It looked like a Category 5 on the inside of the plane when the crew finally reached Hugo's calm center. Everything that was even remotely loose was tossed across the cabin, landing in piles knee- to waist-deep. A 200-pound life raft was thrown around like a missile, putting a 1-inch dent into a steel handrail.
Masters wrote in his blog at the time:
"The cockpit G-meter shows we took five-and-a-half Gs up and three-and-a-half Gs down," continues Lowell, now sounding really concerned. "The P-3 is only rated to plus three and minus two Gs, so we may have some serious structural damage. We'll have to climb as high as we can and find a part of the eyewall to exit through with a minimum of turbulence.
"Five-and-a-half Gs!" I exclaim, looking at Pete in amazement and trepidation. No hurricane hunter aircraft has ever taken more than three Gs. We are lucky to be alive."
A "G" is the force of gravity, with positive or up Gs meaning you are being pulled toward the ground, and negative or down Gs being the feeling of weightlessness. The topic of Gs is usually brought up with roller coasters or space launches. Extreme Gs can be deadly to humans and extremely destructive to aircraft.
It took two additional aircraft and some brave crew members to get the battered plane, one engine down, out of Hugo's eye. Luckily, the team found a weak spot at 7,000 feet in the immense eye wall and returned to Barbados safely.