History of Flight
On June 20, 2013, about 1648 eastern daylight time, a Rockwell International 690B, N727JA, was destroyed following a collision with terrain after an in-flight loss of control near McClellanville, South Carolina. The private pilot and the flight instructor were fatally injured. The airplane was registered to a corporation and was operated by the pilot under 14 CFR Part 91 as an instructional flight. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed. The flight originated at Charleston Executive Airport (JZI) about 1633.
The purpose of the flight was for the pilot to complete a 14 CFR Part 61.56 flight review. After takeoff, the pilots requested maneuvering airspace for airwork over the McClellanville area at an altitude block of 13,000 to 15,000 feet msl. About 1646, the air traffic controller asked the pilot to state his heading, but there was no response. Radar contact was lost, and search and rescue operations were initiated. Based on a witness report, local responders found the wreckage within the Francis Marion National Forest in Charleston County.
Radar data revealed that, about 14,000 feet msl and about 3 miles southeast of the accident site, the airplane made two constant-altitude 360-degree turns—first right, then left. Then it flew north-northeast for about 2.5 miles, followed by an abrupt right turn with altitude loss. At 1646:51, the track showed the airplane crossing U.S. Highway 17 at 12,100 feet. Concurrently, a keyed microphone recorded loud background noise for about seven seconds and a single unintelligible sound like "ahhh…". The airplane then entered a steep, descending left turn, losing about 7,500 feet in 28 seconds. The last radar return was at 1647:19 at 4,600 feet msl.
A witness traveling southbound on Highway 17 observed the airplane for a couple of seconds. He saw the belly facing him and the nose vertical down before it entered trees. He observed both wings and the tail, with nothing missing. No smoke was seen. Another witness working outside heard the engine sound strained and changing speed for several minutes, then a thud and engine noise stopped.
Personnel Information
The private pilot, seated in the left seat, held single-engine land and sea, multiengine land, and instrument ratings. His most recent FAA medical application (May 20, 2013) reported 1,540 total hours, with 106 hours in the previous six months. His time in the accident airplane was not determined.
The flight instructor, seated in the right seat, held airline transport pilot and flight instructor certificates with various ratings. His most recent medical application (May 8, 2013) reported 22,300 total hours, with 75 hours in the previous six months. An undated resume listed more than 5,800 hours in turboprop airplanes and more than 4,100 hours as a flight instructor, including FlightSafety training in the Turbo Commander. He had not flown with the pilot before.
Aircraft Information
The airplane was a twin-engine, high-wing, retractable landing gear turboprop, serial number 11399, powered by two Allied Signal TPE331-10T-516K engines rated at 776 shaft horsepower each, with Hartzell three-bladed adjustable pitch propellers. An annual inspection was performed on March 4, 2013, at a total airframe time of 12,192.6 hours. No subsequent maintenance entries were found.
Meteorological Information
The 1655 surface observation at Mount Pleasant, South Carolina (LRO) reported few clouds at 3,400 feet, scattered at 4,700 feet, broken at 6,000 feet, wind calm, 7 miles visibility, temperature 24°C, dew point 23°C, altimeter 30.14 inches of mercury. No convective activity or thunderstorms were in the area.
Wreckage and Impact Information
The accident site was on level ground in the Francis Marion National Forest. Initial tree impact was at 33.06239N, 079.52365W; main wreckage (cockpit) at 33.06193N, 079.52374W. The wreckage path was about 290 feet long and 40 feet wide. The heading from initial tree impact to cockpit was about 190 degrees. Impact marks indicated the airplane was in a right bank of about 42 degrees and descent angle of about 21 degrees. The wreckage was generally fragmented. No fire occurred. All fuel tanks were breached, with a strong odor of jet fuel.
The left engine separated and was found near the cockpit; the right engine remained attached to the inboard right wing section, which was crushed against trees. Smoothly cut branches were found at initial tree impact, consistent with propeller contact. All major structural components and flight controls were accounted for. Flight control cable continuity could not be fully established due to fragmentation; cable ends showed overstress or were torn. The landing gear selector was in the up position; gear and flap positions could not be determined due to damage.
Engine examinations showed no evidence of uncontained failure or in-flight fire. Both propellers had similar damage: cylinder/piston fractured off, spinners missing. The left propeller was attached to the gearbox, which separated due to a fractured engine shaft. The right propeller was also attached to the gearbox with similar separation. Both propellers had rotational scoring and slight twisting; no pre-existing anomalies were found.
Medical and Pathological Information
Postmortem examinations of the pilot and flight instructor were performed. The pilot’s cause of death was "Full body blunt trauma due to General aviation collision with ejection," manner accidental. Toxicology was negative for carbon monoxide, ethanol, and drugs; cyanide not tested. The flight instructor’s cause of death was "Full body blunt force trauma," manner accidental. Toxicology was negative for ethanol; carbon monoxide and cyanide not tested. Diphenhydramine, pioglitazone, and salicylate were found in the instructor's liver or urine. A determination of impairment was not possible due to lack of blood. The instructor had diabetes treated with oral medication and a restricted medical certificate. He had lost an eye but had 20/20 vision in the remaining eye. Urine glucose was 127 mg/dL, considered abnormal.
Tests and Research
The Enhanced Ground Proximity Warning System (EGPWS) survived impact. Data from the unit captured the final portion but was inaccurate due to GPS signal loss, with position data in dead-reckoning mode.
Teardown of both engines at Honeywell indicated they were rotating and operating at impact, with rotational scoring, ingested debris, and metal spray. No pre-existing conditions were found that would have prevented normal operation.