On November 19 ,1997 at 1636 central standard time, a Cessna 310J airplane, N156SD, was destroyed upon ground impact and a post-impact fire following a loss of control after takeoff from the Jefferson County Airport, Beaumont, Texas. The commercial pilot, sole occupant of the airplane, sustained serious injuries. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 public use, post-maintenance test flight, for which no flight plan was filed. The airplane was owned and operated by the Jefferson County Sheriff Department. According to information the operator provided in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), "the flight was intended to be a local, post 100 hour inspection, test flight." The operator added that "the aircraft was preflight checked by the pilot and all checks were normal." The pilot performed an engine run-up short of runway 12 and was then cleared to taxi into position and hold on runway 12. The tower then informed the pilot that a Brazilian jet [EMB-145 regional jet] was making a low pass over the airport. The pilot reported that he had the Brazilian jet in sight, as it passed just above and a little to the right of his aircraft. Subsequently, the tower cleared N156SD for takeoff, and the pilot immediately commenced takeoff as the jet passed over. No cautions for wake turbulence were issued by tower personnel nor did the pilot request a delay for takeoff. The operator further stated that the pilot applied take-off power to the engines and the ground roll was normal. The aircraft was rotated at approximately 100 knots, and after a positive rate of climb was achieved, the landing gear was raised. Immediately upon retracting the gear, the airplane began to "roll" to the right. The pilot then applied left aileron, but "had no effect." A witness reported that, "when the airplane left the ground it seemed to go in a vertical direction and made an over revving sound." A second witness reported that the aircraft's nose pitched up and the engines made an over revving sound. The witness further reported that the aircraft rolled to the right, striking the right wing. A third witness reported that, "fire was coming from the aircraft as soon as the wing touched the ground." During a personal interview with an FAA inspector, the pilot reported that it "didn't feel like an engine problem." The pilot also indicated he reduced both throttles to idle in an attempt to land, but the plane continued to roll right. According to information reported in NTSB Form 6120.1/2, the pilot had accumulated a total of 2,100 hours, 236 hours of which was multi-engine flight time. He had a total of about 100 hours in the Cessna 310. An FAA inspector, assisted by representatives from Cessna and Teledyne Continental, examined the wreckage following the accident. The following observations were made during the examination: Evidence at the accident site showed that the right wing contacted the ground first, about 2,500 feet south of the approach end of runway 12 and 75 feet to the right of the runway. After ground contact, a fire erupted, and the aircraft rolled and skidded for about 400 feet, coming to rest inverted on the southeast side of taxiway "E." According to entries in the engine and airframe logbooks, a 100 hour inspection was completed on November 18, 1997. One of the entries of the 100 hour inspection stated the following: "replaced worn and binding bearing on control column (center bearing) with new bearing p/n BC5W10. All work done I/A/W maint. man. And AC43-13." An examination of the airframe revealed that all major parts, components and control surfaces were accounted for. The control column and yoke assembly was examined and operated freely. No binding or improper rigging was noted on the control column. Aileron control cable continuity was established to the middle of the wings. Elevator control cable continuity was confirmed. Rudder cable continuity was verified to the crushed cockpit area. The nose structure was crushed aft to the instrument panel. Both the left and right wing structures, from the engine nacelles outboard to the wing tips, were destroyed during the impact sequence. Both engines separated from the aircraft. The main landing gear and nose gear separated from the airplane. The vertical stabilizer incurred structural damage. The propellers remained attached to the engines. The propeller blades exhibited bending and twisting. Engine continuity was established from the propeller to the accessory sections in the left and right engines. Both engines produced "thumb" compression. The right engine's magnetos sparked when the engine was turned by hand. The left engine's magnetos had become dislodged from the engine and were not tested. No obstructions were observed in the fuel system. The FAA inspector reported that no evidence was found which indicated any pre-accident anomalies with the airplane, flight control system, or engines. According to some witness comments made at the airport, the EMB-145 jet that made the low pass over the runway was at about 100 feet above the ground, before turning to the right away from the airport. Therefore, the jet wake would have been in front of, and slightly to the right of the Cessna 310 during its takeoff roll. The EMB-145 is a 50 passenger, approximately 45,400 pound (certified maximum gross takeoff weight) regional jet. It is powered by two Allison AE3007A jet engines, each of which, is "rated" to produce about 7,500 pounds of thrust. The Cessna Citation model 10 is equipped with similar 3000 series Allison engines which are "rated" at about 6,400 pounds of thrust. The basic 3000 series engine is "capable" of producing about 12,000 pounds of thrust. According to a representative from Cessna, he "frequently" has received wake turbulence cautions/delays from tower personnel when he was taking off in light/small aircraft behind Citation jets at the Wichita Mid-Continent Airport, Wichita, Kansas. Pertinent excerpts contained in Chapter 7, Safety of Flight, Section 3, Wake Turbulence, of the Aeronautical Information Manual (AIM) follow: "A 3-minute interval will be provided when a small aircraft will takeoff: 1. From an intersection on the same runway (same or opposite direction) behind a departing large aircraft. 2. In the opposite direction on the same runway behind a large aircraft takeoff or low/missed approach." "NOTE - This 3-minute interval may be waived upon specific pilot request" According to the FAA's Pilot/Controller Glossary, definitions of Aircraft Classes are as follows: "For the purposes of Wake Turbulence Separation Minima, ATC classifies aircraft as heavy, Large, and Small as follows: a. Heavy - Aircraft capable of takeoff weights of more than 255,000 pounds whether or not they are operating at this weight during a particular phase of flight. b. Large - Aircraft of more than 41,000 pounds, maximum certificated takeoff weight, up to 255,000 pounds. c. Small - Aircraft of 41,000 pounds or less maximum certificated takeoff weight. (Refer to AIM)" At 1653, the weather observation at the Jefferson County Airport, reported overcast skies at 2,000 feet, visibility 10 statute miles, temperature 57 degrees Fahrenheit, dew point 54 degrees, winds from 050 degrees at 8 knots, and altimeter 30.17 inches of mercury.