Date: 201512
Local time of day: 0601-1200
Location: GPT.Airport, MS
Weather elements / visibility: Turbulence
Light: Daylight
Aircraft: Epic LT
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Cruise
Airspace: Class A ZHU
ATC / advisory: Center ZHU
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; General Maintenance Action
Contributing factors: Aircraft; Weather
Primary problem: Weather

Narrative: Just prior to the flight I got a weather brief from Flight Service.  They suggested flying further down the coast to an area that appeared to have light precipitation (GPT) in order to get on the back side of a broken line of thunderstorms.  I re-filed with ATC to the recommended fix just prior to departure.  As we approached the area; the onboard Garmin XM weather showed only light precipitation (green and light green) and no lightning in the area we wanted to fly through.  We were in cruise flight and at 28;000 feet.  As we got close to the clouds I call Houston center and reconfirmed with them my line and direction of travel.  Center commented it looked good with only light to moderate precipitation returns.  After we got into the clouds we started to experience heavy turbulence for 3-4 minutes followed by about 5 minutes of relative calm with another 3-4 of heavy turbulence during which we saw flashes of lightning.  We were in the clouds about 10 minutes and after getting out we called Houston center and reported heavy to severe turbulence so they could warn others.  They asked if there were any injuries and we replied no. As we continued flying; we noticed that the pitch and rudder trim were not working but as the plane was already trimmed for level flight; we continued to destination.  We flew an approach and the plane was somewhat difficult to keep on line but all systems worked (flaps; gear; etc).  Upon landing and exiting the airplane; we noticed several carbon fiber 'blowouts' on the trailing edges of the rudder; wings and horizontal stabilizer.  Also we noticed that the rudder cable had either broken or was very loose.  We had the [plane towed] into a hangar to start looking at the extent of the damage.  I was amazed at the amount of turbulence and lighting we experienced given the rather innocuous XM satellite picture at the time of the occurrence.

Callback: The reporter stated that the autopilot; which had remained engaged throughout the ordeal; was having difficulty flying the approach and was disconnected. The reporter also found the aircraft difficult to control but was able to continue to a safe landing. Post flight revealed the reported damage to the flight controls and also that the rudder cable had been completely sheared. The engine and propeller were also found to have damage requiring maintenance.



Synopsis: An Epic pilot reported refiling prior to departure to avoid severe weather over Mississippi. XM radar is used to navigate around the southern end of a line of thunderstorms; through weather that appeared as green and light green on the XM image. ZHU agreed that the intended route was good showing no severe weather. The weather turned out to be anything but benign with two separate periods of severe turbulence with lightning. The autopilot remained engaged throughout the incident and the reporter continued to his destination.