History of Flight
On July 21, 2016, about 1114 central daylight time, a Piper PA 30 airplane, N7409Y, was destroyed following an in-flight breakup near Plainfield, Illinois. The commercial pilot was fatally injured. The airplane was registered to and operated by the pilot under 14 CFR Part 91. Day visual meteorological conditions prevailed, and no flight plan was filed. The personal flight originated from Upper Cumberland Regional Airport (SRB), Sparta, Tennessee, about 0845, and was destined for Eagle River Union Airport (EGV), Eagle River, Wisconsin.
Fueling records indicated the airplane was fueled with 73.61 gallons of 100LL aviation gasoline at SRB. After takeoff, the pilot requested VFR flight following and was issued a transponder code. At 1039, the pilot contacted Chicago ARTCC. At 1104, the controller terminated flight following, instructed a transponder code change to 1200, and provided a frequency to reinstate service. The pilot contacted the next controller at 1105, providing the previous code, but the controller could not identify the aircraft and instructed the pilot to remain clear of Class B airspace.
A radar performance study showed the airplane heading about 320° at 8,500 ft msl, groundspeed about 150 kts. About 1108:23, the airplane climbed; equivalent airspeed decreased and angle of attack increased to nearly 20° nose up. It reached 10,300 ft about 1111:10, then its lowest equivalent airspeed of about 48 kts, followed by descending turns. The final radar target at 1112:37 was at 2,200 ft and 211 kts equivalent airspeed.
Witnesses saw sections of the airplane descend. Sections impacted multiple locations in Plainfield; one caught fire and ignited a nearby building. No ground injuries were reported. Witnesses reported weather consistent with a rapidly-forming thunderstorm.
Pilot Information
The 58-year-old pilot held a FAA commercial pilot certificate with multiengine land and instrument ratings, and private pilot privileges in single-engine land airplanes. His most recent FAA third-class medical certificate was issued on May 31, 2016, with limitations requiring corrective lenses for distant and near vision. He reported 976 total flight hours on the application, and a logbook review indicated 981.1 total hours. His most recent flight review was completed on April 15, 2015.
Aircraft Information
N7409Y was a 1964 Piper PA 30 Twin Comanche, serial number 30-470, with all-metal semimonocoque construction, fully cantilevered wings, wing flaps, and retractable tricycle landing gear. It was powered by two Lycoming IO-320-B1A engines (160 hp each) driving Hartzell two-blade constant-speed propellers with feathering capability. The airplane had modifications: fuel tanks in both wing nacelles per STC SA00356WI, and tip tanks per STC SA727WE. The POH supplement for the tip tanks included limitations: auxiliary wing tip tank fuel to be used in level flight only; use tip tank fuel first; maximum gross weight 3725 lbs, with weight over 3600 lbs consisting of symmetrically loaded tip tank fuel; never exceed speed 230 MPH.
Review of maintenance records showed the most recent annual inspection on September 22, 2015. A November 1, 2015 logbook endorsement indicated repairs including replacement of left center wing leading edge skin, lower center wing skin, and left aileron skin.
Meteorological Information
The pilot did not obtain a weather briefing for the accident flight. The NTSB Senior Meteorologist produced a Weather Study. At 0753, the Storm Prediction Center issued a Convective Outlook identifying marginal risk for the accident site. At 1115, the METAR at Joliet Regional Airport (JOT) reported wind 230° at 7 kts, visibility 10 sm, broken clouds at 2,100 ft, temperature 32°C, dew point 27°C, altimeter 30.10 inHg. At 1135, conditions included wind 210° at 3 kts, visibility 10 sm, thunderstorms in the vicinity, scattered clouds at 2,100 ft, broken layers at 4,200 and 5,000 ft, temperature 31°C, dew point 27°C.
Lightning detection systems were present at local stations. Weather imagery showed relatively clear skies about 20 minutes before the accident, with cumulus clouds to the west through north at 1052; later imagery showed cumulus over the accident location. Radar identified convective features adjacent to the airplane's position. No AIRMETs were active below 25,000 ft; no convective or non-convective SIGMETs; no CWAs or MISs were active at the accident time. At 1140, a CWA was issued for an isolated thunderstorm 9 miles east-southeast of JOT. No PIREPs were made within 2 hours and 50 miles. The 1000 NAM model sounding indicated most-unstable CAPE of 4,207 J/kg, maximum vertical velocity about 92 m/s (18,100 ft/min), and DCAPE of 1,194 J/kg.
Wreckage and Impact Information
The main wreckage was located on a driveway about 2.65 nm from JOT on a heading about 315°, with a nearly vertical impact angle. The fuselage, empennage, right engine, right wing, and inboard left wing were discolored, deformed, charred, and partially consumed by fire. The empennage was inverted. The right propeller exhibited chordwise abrasion; left propeller had a separated section of crankshaft attached. Nose landing gear jackscrew position was consistent with gear retracted.
Fiberglass and aluminum fragments were found 0.82 nm from the main wreckage. An outboard left wing section was found 0.44 nm away. The left fuel tank was 0.41 nm away. The left propeller cylinder, dome, and cap were 0.36 nm away; the left propeller with attached crankshaft was 0.35 nm away; the left engine was 0.24 nm away.
Disassembly of the propellers revealed no preimpact anomalies. Right propeller blade angles suggested 37° at impact; left propeller blade angles suggested 25° at initial impact. Left engine examination showed a fractured crankcase nose; the front main bearing shells were distorted; no preimpact anomalies were found in connecting rods, camshaft, cylinders, pistons, or oil system. Fuel components contained fluid consistent with aviation gasoline. Left magneto produced spark; right magneto was fractured and did not produce spark. Sparkplugs showed normal coloration except No. 4 had reddish debris.
Right engine had impact damage, fractured crankcase, fragmented cylinders. No preimpact anomalies were noted. Fuel injector servo and flow divider were impact damaged; fuel was absent. Magnetos were fragmented. Sparkplugs showed normal condition except impact damage. Vacuum pumps in both engines were fractured.
Medical and Pathological Information
An autopsy listed the cause of death as multiple injuries. Toxicology testing identified citalopram and its metabolite desmethylcitalopram in muscle tissue, and trazodone in lung and muscle samples. Ethanol and propanol were detected in muscle, but no ethanol in kidney. The NTSB Chief Medical Officer reviewed the records and produced a Medical Factual Report. Citalopram is a prescription antidepressant; it may impair judgment, thinking, or motor skills. Major depression is associated with cognitive degradation. The FAA considers use of psychotropic drugs disqualifying, but case-by-case authorization for certain SSRIs is possible. Trazodone is another antidepressant with sedating properties.
Additional Information
Design maneuvering speed is defined as the speed below which a single flight control can be fully deflected once in smooth air without risk of damage.
Communications with Chicago TRACON were recorded. The pilot contacted ATC, was instructed to contact another frequency, and stated he was maintaining 8,500 ft. The controller could not identify his transponder code and instructed him to remain clear of Class B airspace. That was the last recorded communication.