N727JARockwell International 690B · 1977

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 the provisions of 14 Code of Federal Regulations (CFR) Part 91, as an instructional flight. Visual meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed. The local flight originated at Charleston Executive Airport (JZI), Charleston, South Carolina about 1633.

The purpose of the flight was for the pilot to accomplish a CFR Part 61.56 flight review. After takeoff from JZI, the pilots requested maneuvering airspace for airwork over the McClellanville area, at an altitude block of 13,000 to 15,000 feet above mean sea level (msl). About 1646, the air traffic controller asked the pilot to say his heading, and 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 boundary of the Francis Marion National Forest in Charleston County.

A review of recorded radar data revealed that, about 14,000 feet msl and about 3 miles southeast of the accident site, the airplane was observed in two constant-altitude 360-degree turns; the first to the right and the second to the left. The airplane then was observed on a north-northeasterly heading for about 2.5 miles, when an abrupt right turn, accompanied by a loss of altitude, occurred. At 1646:51, the radar track showed the airplane crossing U.S. Highway 17 at 12,100 feet. Concurrently, a keyed microphone could be heard on the recorded voice communications, with loud background noise that lasted for about seven seconds, and a single voice making an unintelligible sound similar to "ahhh…" The airplane was then observed entering a steep, descending left turn, losing about 7,500 feet in 28 seconds. The last radar return was at 1647:19, when the airplane was at 4,600 feet msl.

A witness, who was traveling southbound on Highway 17 at the time, observed the airplane in flight for "a couple of seconds." He observed the airplane in the left upper corner of his windshield. His car windows were up and he could not hear anything. When he saw the airplane, the belly was facing him and the nose was "completely vertical down" prior to it entering the trees. He observed both wings and the tail and he did not see anything missing from the airplane. No smoke was observed.

Another witness was working outside, at his residence, at the time of the accident. The airplane was "…either circling or looping and it did this for several minutes." The engine sounded "strained" and the "…engine speed was being changed." He then heard a "thud" and the engine noise stopped.

The private pilot, seated in the left cockpit seat, held airplane single engine land, airplane single engine sea, airplane multiengine land, and instrument airplane ratings. His personal pilot logbook(s) was not located after the accident. On his most recent FAA Class 1 medical certificate application, dated May 20, 2013, he reported 1,540 hours total time, including 106 hours in the previous six months. His total flight time in the accident airplane was not determined.

The flight instructor and airline transport pilot, seated in the right cockpit seat, held airplane single engine land, airplane single engine sea, airplane multiengine land, airplane multiengine sea, and instrument airplane ratings. He also held a flight instructor certificate for airplane single engine land, airplane multiengine land, and instrument airplane. On his most recent FAA Class 1 medical certificate application, dated May 8, 2013, he reported 22,300 hours total time, including 75 hours in the previous six months.

The flight instructor's personal pilot logbook(s) was not located after the accident; however, an undated resume of his flight experience was provided to investigators. The resume listed a variety of type ratings and formal training courses completed, including FlightSafety International training in the Turbo Commander. The resume listed more than 5,800 hours in turboprop airplanes and more than 4,100 hours as a flight instructor.

Reportedly, the flight instructor had not flown with the pilot previous to the accident flight.

The airplane was a twin engine, high-wing, retractable landing gear, turboprop airplane, serial number 11399. It was powered by two Allied Signal TPE331-10T-516K engines rated at 776 shaft horsepower each. The engines were fitted with Hartzell three-bladed adjustable pitch propellers.

A review of the aircraft maintenance records indicated that an annual inspection of the airframe and engines was performed on March 4, 2013. The aircraft total time at the time of the annual inspection was 12,192.6 hours. The annual inspection was the most recent maintenance logbook entry in the aircraft and engine records.

The 1655 surface weather observation for Mount Pleasant, South Carolina (LRO) included few clouds at 3,400 feet, scattered clouds at 4,700 feet, broken clouds at 6,000 feet, wind calm, 7 miles visibility, temperature 24 degrees C, dew point 23 degrees C, and altimeter 30.14 inches of mercury.

The review of local weather data revealed no convective activity or thunderstorms in the immediate in the area at the time of the accident.

The airplane was a twin engine, high-wing, retractable landing gear, turboprop airplane, serial number 11399. It was powered by two Allied Signal TPE331-10T-516K engines rated at 776 shaft horsepower each. The engines were fitted with Hartzell three-bladed adjustable pitch propellers.

A review of the aircraft maintenance records indicated that an annual inspection of the airframe and engines was performed on March 4, 2013. The aircraft total time at the time of the annual inspection was 12,192.6 hours. The annual inspection was the most recent maintenance logbook entry in the aircraft and engine records.

The 1655 surface weather observation for Mount Pleasant, South Carolina (LRO) included few clouds at 3,400 feet, scattered clouds at 4,700 feet, broken clouds at 6,000 feet, wind calm, 7 miles visibility, temperature 24 degrees C, dew point 23 degrees C, and altimeter 30.14 inches of mercury.

The review of local weather data revealed no convective activity or thunderstorms in the immediate in the area at the time of the accident.

The accident site was situated on level ground on the grounds of the Francis Marion National Forest. The first point of impact was trees, then the ground. The accident site consisted of a swamp. The coordinates of the first observed impact with trees were 33.06239N, 079.52365W. The coordinates of the main wreckage (cockpit area) were 33.06193N, 079.52374W. The total length of the wreckage path was about 290 feet in length and 40 feet in width. The magnetic heading from initial tree impact to the cockpit was about 190 degrees.

Measurements of the path through the trees was consistent with the airplane in a right bank of about 42 degrees and a descent angle of about 21 degrees. The wreckage was generally fragmented. There was no fire.

All aircraft fuel tanks were breached during the impact sequence. There was a strong odor of jet fuel prevalent throughout the wreckage path.

The left engine was separated from the airframe during the impact sequence and was found adjacent to the cockpit area. The right engine was located attached to the right, inboard wing section that was separated from the main wreckage and crushed against trees during the initial impact sequence.

Several smoothly-cut tree branches were found at the area of initial tree impact. The disbursement of the branches was consistent with contact by both engine propellers.

The wreckage was recovered to a storage facility at Griffin, Georgia, where a detailed examination of the wreckage was performed. All major structural components of the airframe, including all flight control surfaces, were accounted for.

Flight control cable continuity could not be completely established due to the general fragmentation of the wreckage. Cable ends that were identified exhibited overstress indications or were torn from their attachment points.

The landing gear selector handle was found in the up, or retracted, position. The physical position of the landing gear could not be determined due to impact damage. The position of the flaps at the time of the accident could not be determined due to impact damage.

An external examination of the engines was performed during the wreckage review. No evidence of uncontained failure or in-flight fire was observed. The engines were shipped to the manufacturer's facility in Phoenix, Arizona, for a teardown examination under the direction of the NTSB Investigator-in-Charge (IIC).

The propeller assemblies were examined during the wreckage review. Both propellers had similar damage. Each one had the cylinder/piston fractured off. Both propellers were missing their spinners.

The left propeller was still attached to the gearbox; however, the gearbox was separated from the engine due to a fractured engine shaft. The propeller experienced damage due to impact and a power setting or blade angle could not be established; however, slight curved tips and some rotational scoring was noted on the blades.

The right propeller was still attached to the gearbox; however, the gearbox had separated from the engine due to a fractured engine shaft. The "R3" blade was fractured off the clamp assembly. All three blades had slight twisting signatures.

No anomalies were noted with either propeller assembly that would have precluded normal operation. For additional information regarding the examination of the propellers, refer to the Hartzell Propeller Examination Reports, located in the public docket for this accident.

Pilot

A postmortem examination of the pilot was performed at the Medical University of South Carolina, Charleston, South Carolina on June 21, 2013. The autopsy report noted the cause of death as "Full body blunt trauma due to General aviation collision with ejection" and the manner of death was "Accident.".

Forensic toxicology testing was performed on specimens of the pilot by the Federal Aviation Administration (FAA) Bioaeronautical Sciences Research Laboratory (CAMI), Oklahoma City, Oklahoma. The CAMI toxicology report indicated negative for carbon monoxide, ethanol, and drugs. Testing for cyanide was not performed.

Flight Instructor

A postmortem examination of the flight instructor was performed at the Medical University of South Carolina, Charleston, South Carolina on June 22, 2013. The autopsy report noted the cause of death as "Full body blunt force trauma" and the manner of death was "Accident.".

Forensic toxicology testing was performed on specimens of the flight instructor by the Federal Aviation Administration (FAA) Bioaeronautical Sciences Research Laboratory (CAMI), Oklahoma City, Oklahoma. The CAMI toxicology report indicated negative for ethanol. Testing for carbon monoxide and cyanide was not performed. The report indicated that there was diphenhydramine in the liver and urine, pioglitazone in the liver and urine, and 47.3 ug/ml salicylate in the urine.

Diphenhydramine (Benadryl® or Sominex®) is an over-the-counter sedating antihistamine used to treat allergies and Sominex® is marketed as a non-prescription sleep aid. A determination of possible impairment was not possible since there was no blood available for testing.

Pioglitazone (Actos®) is a prescription oral antidiabetic agent that acts primarily by increasing uptake of glucose by peripheral organs and decreasing glucose production by the liver. It is used in the management of type 2 diabetes mellitus. According to CAMI, the flight instructor had diabetes that was treated and controlled with oral medications and was issued a Class 1, Restricted Medical Certificate, not valid for any class after May 31, 2014. He had also lost an eye due to an injury years ago; however, he was evaluated at 20/20 visual acuity in his remaining eye during his most recent FAA medical examination.

Salicylate is a metabolite of aspirin, an over-the-counter anti-inflammatory medication to treat aches and pains, as an antipyretic to reduce fever.

The report also noted 127 mg/dl glucose in the urine. Postmortem urine levels above 100 mg/dL are considered abnormal. No blood was available for hemoglobin A1C analysis.

Enhanced Ground Proximity Warning System

The airplane was equipped with a Honeywell Enhanced Ground Proximity Warning System (EGPWS). The outer case sustained minor damage; however, the internal memory survived the impact. The unit was sent to Honeywell for download of the data under the direction of a NTSB air safety investigator. Although the unit captured the final portion of the accident flight, the data, according to the manufacturer, was not accurate. The position data was observed in the "dead reckoning" mode, indicating that the GPS data was invalid or went out of navigation mode. This resulted in significant inaccuracies in the aircraft position data toward the end of the recording.

Engines

The engines were examined at the Honeywell facilities at Phoenix, Arizona on September 16 through 18, 2013, under the direction of the NTSB IIC.

The teardown and examination of the left engine, S/N P-79794C, revealed that the type and degree of damage was indicative of an engine that was rotating and operating at the time of impact. Numerous indicators of rotation and operation were noted, including rotational scoring, ingested and burned organic debris, and metal spray adhesion. No pre-existing condition was found that would have prevented normal operation.

The teardown and examination of the right engine, S/N P-79792C, revealed that the type and degree of damage was indicative of an engine that was rotating and operating at the time of impact. Numerous indicators of rotation and operation were noted, including rotational scoring, ingested and burned organic debris, and metal spray adhesion. No pre-existing condition was found that would have prevented normal operation.

For additional information regarding the examination of the engines, refer to the Honeywell Engine Examination Reports, located in the public docket for this accident.