N2584NPiper PA-38-112 · 1979

On August 15, 2011, about 1130 mountain daylight time, a Piper PA-38-112, N2584N, sustained substantial damage when it impacted terrain near Silver Bow, Montana. The airplane was registered to and operated by JJ Aviation, Butte, Montana, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. The certified flight instructor (CFI) and student pilot sustained fatal injuries. Visual meteorological conditions prevailed and no flight plan was filed for the instructional flight. The local flight originated from the Bert Mooney Airport (BTM), Butte, Montana, about 1030.

A witness who was traveling east on Interstate 90 (I-90), about one-half mile north of the accident site, reported observing the accident airplane flying in a clockwise horizontal circle with the wings almost vertical, while losing altitude slowly. The witness stated that during the second turn, the airplane appeared to be attempting to straighten out and climb, however, went straight down. The witness said that the airplane nosedived, spiraled twice and “fell fast.” The witness further stated that prior to losing site of the airplane, “the nose came up out of the dive.”

A second witness, driving west on I-90, reported that they observed the accident airplane about 3,000 feet in the air spinning to the right. The witness stated that the airplane “tried to make a loop” and started to descend again in a spinning downward motion. The witness further stated that prior to losing sight of the airplane; it was pulling up to level the nose.

Another witness, who was a rated pilot, reported that while driving east bound on German Gulch Road, about one-half mile south of the accident site, he observed the airplane in a tight left spin, left wing low, from an altitude of about 300 feet agl. The witness stated that prior to losing site of the airplane behind a bluff, it appeared considerably less steep than when they first saw it. The witness further stated that he felt the airplane was in the process of a spin recovery when he lost site of the airplane.

There were no reported witnesses that observed the impact sequence.

A representative from JJ Aviation reported that prior to the accident flight, the CFI informed them that his intentions for the local training flight were to conduct 4 or 5 touch and go landings at BTM before proceeding to the west training area, where he was intending on having the student pilot practice steep turns, turns around a point, and holding a level altitude. The company representative observed the accident airplane conduct 5 touch and go landings prior to departing the area to the west. The company representative further stated that during training, the CFI typically used altitudes between 7,500 feet and 8,500 feet mean sea level for instruction.

The certified flight instructor, age 61, held an airline transport pilot certificate with an airplane multi-engine land rating, a commercial pilot certificate with airplane single-engine land rating. A second-class airman medical certificate was issued on June 3, 2011, with the limitation stated “must hold glasses for near and intermediate vision.” The CFI reported on his most recent medical certificate application; he had accumulated 10,440 total flight hours. As of his most recent logbook entry dated August 9, 2011, the pilot had recorded a total of 10,331.6 hours of flight time, and 34.4 hours within the previous 30 days. His most recent CFR Part 135 checkride was conducted on May 6, 2011. The pilot reported his weight to be 180 pounds on his medical application.

The student pilot, age 19, held a student pilot certificate. A third-class airman medical certificate was issued on January 5, 2011, with no limitations stated. Review of the student pilot’s logbook revealed that as of the most recent entry, dated July 24, 2011, he had accumulated 19.6 hours of flight time. The student pilot reported his weight to be 174 pounds on his most recent medical application.

The two-seat, low-wing, fixed-gear airplane, serial number (S/N) 38-79A-031, was manufactured in 1979. It was powered by a Lycoming O-235-L2C engine, serial number L-19357-15, rated at 112 horse power. The aircraft engine was modified under Supplemental Type Certificate SE792NW, which increased the engine horsepower rating from 112 horsepower at 2,700 rpm to 125 horsepower at 2,800 rpm. The airplane was also equipped with a Sensenitch 71CK-0-56 fixed pitch propeller. Review of the aircraft maintenance logbooks revealed that the most recent annual inspection was completed on April 29, 2011, at a total airframe time of 1,874.2 hours, engine total time of 1,874.2 hours, and a tachometer time of 1,874.2 hours

According to representatives from JJ Aviation, the airplane had been previously refueled about a week prior. Both fuel tanks were refueled to the tab, or collar level, totaling 20 gallons.

The most current aircraft weight and balance indicated the empty weight of the airplane as 1,216 pounds with a useful load of 454 pounds. The maximum gross weight of the airplane was 1,670 pounds. Using the reported weights of both occupants of the airplane and 20 gallons of fuel, the center of gravity (CG) was calculated to be 76.62 inches. The airplane’s total weight at the time of departure was 1,690 pounds. The CG envelope for the airplane was +73.5 (forward) to +78.5 (rear) inches for normal and utility category.

According to the PA-38-112 performance charts within the pilot operating handbook, fuel burn at 75 percent power is about 6.5 gallons per hour.

A review of recorded data from the Dillon Airport, Dillon, Montana, automated surface observing system, located 44 miles south of the accident site, revealed at 1153 conditions were wind variable at 3 knots, visibility 10 statute miles, clear sky, temperature 26 degrees Celsius, dew point 7 degrees Celsius, and an altimeter setting of 29.90 inches of Mercury. Using the reported weather conditions and accident site elevation, the calculated density altitude was about 7,938 feet and a pressure altitude of 5,375 feet.

Examination of the accident site revealed that the airplane impacted terrain about 7 nautical miles west of BTM, at an elevation of about 5,355 feet mean sea level (msl). The handheld global positioning system (GPS) coordinates for the accident site were recorded to be N46 00.102’, W 112 39.340’. The airplane came to rest upright on a magnetic heading of about 299 degrees. The approximate 342-foot long wreckage debris path was oriented on a magnetic heading of about 082 degrees.

The first identified point of contact (FPIC) with terrain was a ground scar about 10 inches in width and 24 feet in length. The first portion of the ground scar contained fragments of green lens material, consistent with the right wing navigational light. The ground scar contained a four foot by four foot area of disturbed dirt, which contained the propeller and various plexi glass debris. The starter ring gear and portions of engine cowling were located about 11 feet beyond the propeller. The main wreckage came to rest about 52 feet beyond the FPIC. Two navigational instruments were located about 140 feet beyond the FPIC and the left main wheel assembly was located about 342 feet beyond the FPIC.

Examination of the airframe revealed that the engine, engine firewall, instrument panel, and fuselage structure were separated just forward of the leading edges of both wings. The instrument panel was fragmented into multiple sections with numerous instrument and radio separation.

All major structural components of the airplane were observed within the wreckage debris path. Flight control continuity from the cockpit controls to all primary flight control surfaces was obtained.

The stall warning lift detector was found separated from the wing structure and attached by one electrical wire. The lift detector unit exhibited impact damage to the front housing area. The vane was bent, however, remained intact. Switch continuity was verified throughout the lift detector unit using an ohm meter. The stall warning horn was found separated from the airframe and recovered. Electrical power was applied to the warning horn and an audible sound was heard.

Examination of the recovered engine, a Lycoming O-235-L2C, serial number L-19357-15, exhibited impact damage. All four cylinders remained attached to the engine crankcase. The oil filter, propeller, right magneto, and carburetor were separated from the engine. The left magneto was partially separated. The intake and exhaust exhibited impact damage. The exhaust stacks were flattened. The intake and exhaust pushrod tubes for all cylinders exhibited impact damage. The engine crankshaft was manually rotated by hand at the crankshaft propeller flange. Rotational continuity was established throughout the engine and valve train. Thumb compression and suction was obtained on all four cylinders.

The propeller was separated from the crankshaft propeller flange. One propeller blade exhibited “S” bending and was twisted opposite direction of rotation. Chordwise scratching was observed on the forward face of the propeller blade along with blade face polishing. The other propeller blade exhibited a slight bend opposite direction of rotation with light chordwise scratching.

No mechanical anomalies were observed with the airframe or engine that would have precluded normal operation. For further information regarding examination of the accident site, airframe, and engine, refer to the Accident Site, Airframe, and Engine Examination Summary within the public docket for this accident.

The State Medical Examiner conducted an autopsy on the CFI on August 16, 2011. The medical examiner determined that the cause of death was “...Blunt force injuries.”

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the flight instructor. According to CAMI's report, volatiles, and drugs were tested, and had positive results for unspecified amounts of Atenolol in the liver and kidney, unspecified amounts of Chlorpheniramine in the liver and kidney, and unspecified amounts of Diphenhydramine in the liver and kidney.

An autopsy was not conducted on the student pilot.

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the student pilot. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested, and had negative results.

A Garmin GPSMap 295 GPS was removed from the aircraft wreckage and shipped to the NTSB Vehicle Recorders Laboratory, Washington, DC., for data extraction. No recorded data was extracted from the GPS unit.