from hurricane hunter Dr. Jeffrey M. Masters' tale of Hugo 1989 as they penetrate the eye wall:
....Hugo is stronger than Emily. I am very concerned. We should not be at 1,500 feet! I fumble for the intercom switch, find it. "Winds are 135 mph, surface pressure 960 millibars," I say. "Hugo's at least a category 4."
Frank breaks in. "Lowell, Jeff, this ride is way too rough! Let's climb to 5,000 when we finish this penetration."
"Roger!" is Lowell's terse reply. Both he and Gerry must wrestle with the controls of the airplane. The turbulence is so violent that one pilot alone cannot stay in control. There is no possibility of climbing now; the pilots need the full power of the engines just to keep the airplane flying straight and level.
One minute in, one minute to go. The intercom goes silent as everyone hangs on and the pilots concentrate on getting us through the eyewall. I watch the winds and the track of the aircraft to ensure we are on course to the eye. Gerry does a great job fighting off the turbulence and keeping the airplane on track. I don't need to order any course corrections. Winds are now 155 mph, still rising. Pressure 955 millibars, dropping fast. The turbulence grows extreme. Hugo is almost a category five hurricane.
A fierce updraft wrenches the airplane, slams us into our seats with twice the force of gravity. Seconds later, we dangle weightless as a stomach-wrenching downdraft slams us downward. Clipboards, headsets, and gear bags spill loose and slide across the cabin floor.
Another updraft, much stronger, grabs the aircraft. I regret forgetting to fasten my shoulder harness, as I struggle to keep from bashing into the computer console. Seconds later, a huge downdraft blasts us, hurling the loosened gear against walls and floor. Gerry and Lowell are barely in control of the aircraft. Grimly, I hang on to my console against the violent turbulence and watch the numbers. A 20 mph updraft. A 22 mph downdraft. Sustained winds now 185 mph, gusting to 196 mph. Pressure plummeting, down to 930 millibars. Hugo is a category five hurricane, and we are in the eyewall at 1500 feet! One strong downdraft has the power to send us plunging into the ocean. We have no options other than to gut it out and make it to the eye, where we can climb to a safer altitude.
A minute and a half gone, half a minute to go. A colossal 45 mph updraft seizes the airplane. A shower of loose gear flies through the cabin as the airplane lurches violently. Gerry fights the updraft off, keeps the airplane level and headed towards the eye. We're almost there!
"Looks like it's lightening up out there!" Lowell's relieved voice breaks the intense silence. Sure enough, the sky lightens, the clouds thin, the rain abates. We are at the edge of the eyewall. A big smile of jubilation erases my anxious frown. We got away with a penetration at 1,500 feet in a category five storm!
Then, disaster.Thick dark clouds suddenly envelop the aircraft. A titanic fist of wind, three times the force of gravity, smashes us. I am thrown into the computer console, bounce off, and for one terrifying instant find myself looking DOWN at a precipitous angle at Sean across the aisle from me....
A third terrific blow, almost six times the force of gravity, staggers the airplane. Clip boards, flight bags, and headsets sail past my head as I am hurled into the console. Terrible thundering crashing sounds boom through the cabin; I hear crew members crying out. I scream inwardly. "This is what it feels like to die in battle", I think. We are going down. The final moments of the five hurricane hunter missions that never returned must have been like this......
http://www.wunderground.com/hurricane/hugo4.asp