A Cessna Citation 560 on a Part 91 business flight experienced severe clear air turbulence at 3 p.m. June 27 in the vicinity of Janesville, Wisconsin, after the pilot was unable to obtain air traffic control clearance to deviate. Although the twinjet was not damaged, a passenger sustained serious injuries. Anticipating turbulence along the route, the pilot briefed his three passengers and had the seat belt sign turned on.
At FL240, due to turbulence, the pilot requested a deviation from ATC on the south side of a squall line and “made several urgent requests for a clearance to deviate,” according to an NTSB preliminary report. Controllers were not able to approve the deviation and instructed the pilot to descend to FL200. During the descent, the airplane encountered four 15- to 20-second severe turbulence events, with a five- to 10-second interval between events. Again, the pilot made “several urgent requests” for deviation, but the report said ATC was not able to approve the request.
An elderly man and his caregiver were aboard the aircraft. The caregiver reported that she got out of her seat to help the man tighten his restraints. During that time, she was thrown about the cabin during the turbulence. The pilot landed the airplane as soon as possible, and the caregiver was treated at a local hospital for multiple bone fractures to her right leg.