PIPER PA-28-181

Full Narrative

HISTORY OF FLIGHTOn May 31, 2013, at 1003 mountain standard time, a Piper PA-28-181, N327PA, and a Cessna 172S, N2459K, collided in-flight about 3 miles west of Anthem, Arizona. Both certified flight instructors (CFI's) occupying the Piper were fatally injured; the CFI and student pilot occupying the Cessna were also fatally injured. Both airplanes impacted desert terrain in the vicinity of the collision; the Piper was substantially damaged and the Cessna was destroyed. The Piper was registered to Bird Acquisition LLC and operated by TransPac Academy; the Cessna was registered to Westwind Leasing LLC and operated as a rental airplane. Both airplanes were operated as instructional flights under the provisions of Title 14 Code of Federal Regulations, Part 91. Visual meteorological conditions prevailed, and both airplanes had company flight plans. The Cessna departed Phoenix Deer Valley Airport, Phoenix, Arizona, at 0930, and the Piper departed the same airport at 0917.

Radar data shows two tracks operating VFR (visual flight rules) about 1 mile apart. The western track was operating at 2,500 msl and 106 knots ground speed, as recorded by the radar playback. The eastern track was operating at 2,600 feet msl and 92 knots ground speed as recorded by the radar playback. The western track was on a northerly heading and made a 180-degree right turn to a southerly heading. The eastern track was also on a northerly heading and made a left turn to a southwesterly heading. Both airplanes executed their turn simultaneously. Shortly after each target completed its turn the paths of both targets intersected.

The wreckages of both airplanes were in the immediate vicinity of the radar depicted target intersection. The Piper had impacted the flat desert terrain in a flat and upright attitude. All essential components of the airplane were at the accident site. The Cessna wreckage was located 468 feet southwest of the Piper wreckage. The Cessna impacted the desert terrain vertically, imbedding the engine and propeller in to the ground and the wings were crushed accordion style from the leading edges aft. The entire Cessna wreckage was consumed by a post impact fire. The vertical stabilizer and left elevator of the Cessna was located 1,152 feet north of the wreckage.

According to CFI's from TransPac the area of the accident is commonly used to practice ground reference maneuvers because of the prominence and relatively linear aspect of New River Road. Ground reference maneuvers are normally performed at 1,000 feet above ground level (approximately 2,700 feet msl). PERSONNEL INFORMATIONThe two CFI's flying in the Piper were on a training flight. The CFI in the left seat was TransPac's CFI Standardization Instructor, who was responsible for the ensuring that TransPac's flight instructors teach the training flight maneuvers following standard guidelines. The CFI in the right seat was a newly hired CFI who was undergoing TansPac's standardization training before beginning to instruct students. The Standardization training is normally 3 weeks long, and the new CFI had completed about 2 weeks of the 3-week instructional period.

The TransPac Standardization Instructor, age 37, held a commercial certificate with ratings for single-engine land, multi-engine land, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single and multiengine, and instrument airplane, which was issued on February 22, 2012. He held a first-class medical certificate issued May 8, 2012, with the limitation that he wear corrective lenses. Examination of the pilot's logbook revealed that he had 2,924.4 total flight hours, 2,229.2 single engine hours, 695.2 multiengine hours, and 2,694.2 instructor pilot hours. His most recent proficiency check was a recurrent instructor flight proficiency check on November 29, 2012, conducted under the guidance of FAR 141.79(d)(2); all maneuvers were graded as "satisfactory" (S).

The newly hired TransPac Instructor Pilot, age 26, held a commercial pilot certificate with ratings for airplane single engine land, multiengine land, and instrument airplane. He also held a certified flight instructor certificate with a rating for single and multiengine airplane. He held a first-class medical certificate dated May 15, 2012, with the limitation that he wear corrective lenses. He had been a student pilot at TransPac where he received the majority of his flight training. TransPac training and flight records showed that he had 289.9 hours of total flight time, 237.1 hours of airplane single engine time, and zero hours of instruction given. His most recent flight check was on May 17, 2013, when he received his CFI airplane single-engine land (ASL) rating. AIRCRAFT INFORMATIONThe four-seat, low-wing, fixed-gear airplane, serial number 2843511, was manufactured in 2002. It was powered by a Lycoming O-360-A4M, 180-hp engine, and equipped with a Sensenich model 76EM8S14-0-62 fixed pitch propeller. Review of the maintenance logbook records showed that the airframe had 12,616.4 total flight hours (TT) at the time of the accident, and the most recent inspection was a Phase 4 inspection completed on May 28, 2013, at TT 12,595.0 hours. The most recent engine inspection was the Phase 4 inspection on May 28, 2013, at 659 hours since major overhaul (TSMO), 6,529.0 hours time since new (TSN). The engine TSMO at the time of the accident was 680 hours.

WRECKAGE & IMPACT INFORMATION

The wreckage was located on flat desert terrain populated by barrel cactus, saguaro cactus, and scrub brush. The wreckage was upright on flat ground in a near level attitude. There were no ground scars leading up to the wreckage, however, paint transfer on to nearby rocks and fuel blight on a nearby cactus showed evidence that the wreckage recoiled aft approximately 10 feet from the point of initial ground contact. The wreckage was orientated on a 215-degree magnetic bearing measured from tail to nose. The wreckage of the Cessna 172 was 468 feet away on a bearing of 100 degrees magnetic.

Both left and right wings remained attached to the fuselage, both wings exhibited leading edge damage, and fuel tank hydraulic deformation. Both main landing gear mounts protruded up through the upper wing skin. Both ailerons were attached to the wings; control and balance cables were attached to both aileron bell crank assemblies. The tail section remained attached to the empennage, and all control surfaces remained attached. Control cables to the stabilator and rudder were attached to the rudder horn and stabilator arm assembly, respectively. Stabilator trim drum had two exposed threads indicating slight nose down trim. The cabin area remained mostly intact. The cabin floor deck had been displaced upwards into the rudder pedals of both pilots. On the right side of fuselage aft of the firewall a hole was present, which exhibited aircraft skin and plastic interior panel portions pushed in towards the cabin. Within this hole were pieces of Cessna 172 rudder skin, navigation light, and VOR antenna fragments. The Cessna 172's rudder balance weight and portions of the VOR antenna were located in the right cockpit interior floor near the rudder pedals. Examination of the Cessna 172 balance weight showed a divot that corresponds in length and shape to a witness mark on a propeller blade. The engine oil sump was cracked with oil observed draining from the sump. The propeller remained attached to the engine and was pulled through by hand. Compression was verified on all four cylinders and power train continuity. Both propeller blades were nearly straight, one blade exhibited forward bending of the last 6 inches of blade, and a semicircular 1.5-inch divot observed near the blade tip. No leading edge polishing or chordwise scratches were observed.

The Garmin 430 was removed from the airplane and sent to the NTSB Vehicle Recorders Laboratory for examination. The laboratory was able to apply power to the unit and determine the radio frequency that was active at the time of the accident was 122.750 Mhz. This frequency is the locally published training coordination frequency used between training aircraft operating north of Phoenix.

A collision angle and closure rate was calculated utilizing the radar ground speeds of each airplane, 106 knots and 92 knots, and the midpoints of the propeller slashes on the upper left wing of the Cessna 172 created an equivalent scratch mark of 60 degrees from the longitudinal axis. The two airplanes collided at a 72-degree angle with a closure rate of 116 knots. Propeller slashes on the left wing of the Cessna and the fact that the Cessna's rudder balance weight was located in the wreckage of the Piper would indicate that the Piper was above the Cessna at the moment of collision.

MEDICAL & PATHOLOGICAL INFORMATION

An autopsy was performed on the CFI Standardization Instructor on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed forensic toxicology on the specimens from the CFI with negative results for carbon monoxide, cyanide, ethanol, and listed drugs.

An autopsy was performed on the CFI who was receiving instruction on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed forensic toxicology on the specimens from the CFI receiving instruction with negative results for carbon monoxide, cyanide, ethanol, and listed drugs. AIRPORT INFORMATIONThe four-seat, low-wing, fixed-gear airplane, serial number 2843511, was manufactured in 2002. It was powered by a Lycoming O-360-A4M, 180-hp engine, and equipped with a Sensenich model 76EM8S14-0-62 fixed pitch propeller. Review of the maintenance logbook records showed that the airframe had 12,616.4 total flight hours (TT) at the time of the accident, and the most recent inspection was a Phase 4 inspection completed on May 28, 2013, at TT 12,595.0 hours. The most recent engine inspection was the Phase 4 inspection on May 28, 2013, at 659 hours since major overhaul (TSMO), 6,529.0 hours time since new (TSN). The engine TSMO at the time of the accident was 680 hours.

WRECKAGE & IMPACT INFORMATION

The wreckage was located on flat desert terrain populated by barrel cactus, saguaro cactus, and scrub brush. The wreckage was upright on flat ground in a near level attitude. There were no ground scars leading up to the wreckage, however, paint transfer on to nearby rocks and fuel blight on a nearby cactus showed evidence that the wreckage recoiled aft approximately 10 feet from the point of initial ground contact. The wreckage was orientated on a 215-degree magnetic bearing measured from tail to nose. The wreckage of the Cessna 172 was 468 feet away on a bearing of 100 degrees magnetic.

Both left and right wings remained attached to the fuselage, both wings exhibited leading edge damage, and fuel tank hydraulic deformation. Both main landing gear mounts protruded up through the upper wing skin. Both ailerons were attached to the wings; control and balance cables were attached to both aileron bell crank assemblies. The tail section remained attached to the empennage, and all control surfaces remained attached. Control cables to the stabilator and rudder were attached to the rudder horn and stabilator arm assembly, respectively. Stabilator trim drum had two exposed threads indicating slight nose down trim. The cabin area remained mostly intact. The cabin floor deck had been displaced upwards into the rudder pedals of both pilots. On the right side of fuselage aft of the firewall a hole was present, which exhibited aircraft skin and plastic interior panel portions pushed in towards the cabin. Within this hole were pieces of Cessna 172 rudder skin, navigation light, and VOR antenna fragments. The Cessna 172's rudder balance weight and portions of the VOR antenna were located in the right cockpit interior floor near the rudder pedals. Examination of the Cessna 172 balance weight showed a divot that corresponds in length and shape to a witness mark on a propeller blade. The engine oil sump was cracked with oil observed draining from the sump. The propeller remained attached to the engine and was pulled through by hand. Compression was verified on all four cylinders and power train continuity. Both propeller blades were nearly straight, one blade exhibited forward bending of the last 6 inches of blade, and a semicircular 1.5-inch divot observed near the blade tip. No leading edge polishing or chordwise scratches were observed.

The Garmin 430 was removed from the airplane and sent to the NTSB Vehicle Recorders Laboratory for examination. The laboratory was able to apply power to the unit and determine the radio frequency that was active at the time of the accident was 122.750 Mhz. This frequency is the locally published training coordination frequency used between training aircraft operating north of Phoenix.

A collision angle and closure rate was calculated utilizing the radar ground speeds of each airplane, 106 knots and 92 knots, and the midpoints of the propeller slashes on the upper left wing of the Cessna 172 created an equivalent scratch mark of 60 degrees from the longitudinal axis. The two airplanes collided at a 72-degree angle with a closure rate of 116 knots. Propeller slashes on the left wing of the Cessna and the fact that the Cessna's rudder balance weight was located in the wreckage of the Piper would indicate that the Piper was above the Cessna at the moment of collision.

MEDICAL & PATHOLOGICAL INFORMATION

An autopsy was performed on the CFI Standardization Instructor on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed forensic toxicology on the specimens from the CFI with negative results for carbon monoxide, cyanide, ethanol, and listed drugs.

An autopsy was performed on the CFI who was receiving instruction on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed forensic toxicology on the specimens from the CFI receiving instruction with negative results for carbon monoxide, cyanide, ethanol, and listed drugs. ADDITIONAL INFORMATIONThe Arizona Flight Training Workgroup (AFTW) is an organization of pilots and certified flight instructors who are dedicated to improving pilot judgment and decision-making to reduce accidents, incidents, and pilot deviations in Arizona. The AFTW in coordination with the FAA has established a Phoenix Terminal Area chart overlay that depicts common flight training airspace areas, standardized nomenclature, and training coordination frequencies. A copy of the AFTW Phoenix Terminal Area Chart overlay is included in the docket of this investigation. According to the AFTW chart the area that both airplanes were operating in was referred to as the "prison," and the associated frequency to coordinate training activities between aircraft was 122.75 Mhz.

Witness statements from the pilots who were airborne in the area were inconsistent regarding the amount of radio communication traffic that was occurring during the period prior to the accident. Some pilots reported heavy radio traffic requiring them to wait for a break in the transmissions in order to make their transmission, and other pilots reported light radio traffic. However, one pilot did recall hearing the student of the Cessna 172 make position reports, and another pilot did hear the pilots of the PA-28 make a radio announcement asking if anyone was working GRM? (ground reference maneuvers).
HISTORY OF FLIGHTOn May 31, 2013, at 1003 mountain standard time, a Piper PA-28-181, N327PA and a Cessna 172S, N2459K collided in-flight about 3 miles west of Anthem, Arizona. Both certified flight instructors (CFI's) occupying the Piper were fatally injured; the CFI and student pilot occupying the Cessna were also fatally injured. Both airplanes impacted desert terrain in the vicinity of the collision; the Piper was substantially damaged and the Cessna was destroyed. The Piper was registered to Bird Acquisition LLC and operated by TransPac Academy; the Cessna was registered to Westwind Leasing LLC and operated as a rental airplane. Both airplanes were operated as instructional flights under the provisions of Title 14 Code of Federal Regulations, Part 91. Visual meteorological conditions prevailed and both airplanes had company flight plans. The Cessna departed Phoenix Deer Valley Airport, Phoenix, Arizona, at 0930, and the Piper departed the same airport at 0917.

Radar data shows two tracks operating VFR (visual flight rules) about 1 mile apart. The western track was operating at 2,500 msl and 106 knots ground speed, as recorded by the radar playback. The eastern track was operating at 2,600 feet msl and 92 knots ground speed as recorded by the radar playback. The western track was on a northerly heading and made a 180-degree right turn to a southerly heading. The eastern track was also on a northerly heading and made a left turn to a southwesterly heading. Both airplanes executed their turn simultaneously. Shortly after each target completed its turn the paths of both targets intersected.

The wreckages of both airplanes were in the immediate vicinity of the radar depicted track intersection. The Piper had impacted the flat desert terrain in a flat and upright attitude. All essential components of the airplane were at the accident site. The Cessna wreckage was located 468 feet southwest of the Piper wreckage. The Cessna impacted the desert terrain vertically, imbedding the engine and propeller in to the ground and the wings were crushed accordion style from the leading edges aft. The entire Cessna wreckage was consumed by a post impact fire. The vertical stabilizer and left elevator of the Cessna was located 1,152 feet north of the wreckage.

According to CFI's from TransPac the area of the accident is commonly used to practice ground reference maneuvers because of the prominence and relatively linear aspect of New River Road. Ground reference maneuvers are normally performed at 1,000 feet above ground level (approximately 2,700 feet msl). PERSONNEL INFORMATIONThe pilot of the Cessna, age 42, held a commercial pilot certificate with ratings for airplane single engine and multi-engine land, instrument airplane, and lighter-than-air balloon. He also held a flight instructor certificate with ratings for airplane single engine land initially issued on March 20, 2007. He held a first-class medical certificate issued on March 8, 2012, with the limitation that he must wear corrective lenses for distant vision. The pilot's flight logbook was never located by investigators, however, on his most recent FAA Airman Certificate and/or Rating Application for his commercial balloon rating on December 21, 2012, he reported having 1,678 total flight hours in airplanes, and 1,570 hours as pilot-in-command. The Westwind School of Aeronautics chief flight instructor stated that the CFI was an Affiliate Instructor who rented airplanes from Westwind as an independent CFI. Westwind provided billing records showing that the CFI had started flying with them on August 24, 2012, and had accumulated 54 hours of billed airplane rental time up to the day of the accident.

The student pilot of the Cessna, age 58, held a student pilot certificate and third-class medical certificate issued on October 31, 2012. Examination of her pilot logbook revealed that she had been flying since August 24, 2012, that she had flown only with the accident flight instructor, and she had accumulated 49.3 of dual instruction in that time. All of her flights had been flown out of Phoenix Deer Valley Airport (KDVT). AIRCRAFT INFORMATIONThe four seat, high wing, fixed-gear airplane, serial number 172S10034, was manufactured in 2005. It was powered by a Lycoming IO-360-L2A, 160-hp engine, and equipped with a McCauley fixed pitch propeller. A review of the airplane's maintenance records showed that an annual inspection of the airplane and engine was performed on April 19, 2013, at 3,920.0 hours total time, and an 100-hour inspection was performed on May 16, 2013, at total time of 4,027.2 hours. A 50-hour inspection was performed on May 28, 2013, at a total time of 4,077.7 hours. The engine's total time since new (TTSN) was 6,962.5 hours, time since overhaul (TSO) was 2,173.2 hours.

WRECKAGE & IMPACT INFORMATION

The wreckage was located on flat desert terrain populated by barrel cactus, saguaro cactus, and scrub brush. The wreckage was inverted with the engine and propeller imbedded into the ground. The cabin and fuselage has been consumed by a post impact fire. The wings were discolored grey, black, and covered with soot from exposure to the fire. The wreckage was oriented on a bearing of 216 degrees magnetic measured from tail to nose. The wreckage of the Piper PA-28 was 468 feet away on a magnetic bearing of 280 degrees.

Both wings were observed in their appropriate position between the cabin, inverted, and exhibited extreme leading edge crushing accordion style along the entire wing span. Both left and right lift struts were present and attached to the wings. Both left and right aileron and flaps were present and attached to their respective hinge points. Control continuity was established from both ailerons to the cockpit. Three propeller slashes were observed on the left wing from wing station 100 along the aileron progressing inboard to outboard. The slashes were angled 30 degrees from the longitudinal axis, the longest slash was outboard and the shortest slash was inboard. Distance between the slashes was 17 inches. The metal edges of each slash was deformed upward in relation to the wing's normal orientation. The majority of the fuselage was consumed by the fire. The rudder and rudder horn had remained attached to the hinge that had been separated from the vertical stabilizer, and remained attached to the rudder control cables. Also identified with the rudder and rudder horn was the tail tie down ring. The majority of the rudder had been consumed by fire, and what did remain showed damage to the left side. Control continuity was established by tracing the rudder and elevator cables to the cockpit.

The vertical stabilizer and left elevator were located 1,156 feet from the wreckage on a magnetic bearing of 349 degrees, and exhibited no fire damage. The vertical stabilizer exhibited black witness marks on its left side consistent with tire material and blue paint transfer marks. The rudder hinge was not present on the vertical stabilizer. The left elevator leading edge exhibited a 22-inch-long semicircular leading edge crush.

The engine remained attached to the airplane and exhibited extreme fire damage. The induction system was fragmented and fire damaged. The exhaust headers had been separated from the cylinders. The fuel servo had separated from its mounting pad. Magneto ignition leads were fire damaged. All 8 sparkplugs were observed in place on their respective cylinders. The bottom sparkplugs from cylinder numbers 1 and 3 were removed and observed to have normal wear according to the Champion Check-A-Plug chart. The engine could not be rotated by hand and power train continuity was not established. The propeller flange had separated from the crankshaft. The propeller remained attached to the crankshaft propeller flange, and it exhibited an s-bend from tip to tip. One blade exhibited coarse chordwise scratches at the shank and hub area, minimal leading edge damage along the blade, and the outboard 6 inches measured from the blade tip were bent forward approximately 15 degrees. The other blade was bent aft at the shank, exhibited chordwise scratches, leading edge polishing, and torsional twisting along its length.

The thermally damaged comnav, King KX155, was removed from the wreckage and sent to the NTSB Vehicle Recorders Laboratory for further examination. Due to the extreme thermal damage to the KX155 unit, laboratory technicians were not able to determine what active frequency was programmed into the radio prior to the accident.

A collision angle and closure rate was calculated utilizing the radar ground speeds of each airplane, 106 knots and 92 knots, and the midpoints of the propeller slashes on the upper left wing of the Cessna 172 created an equivalent scratch mark of 60 degrees form the longitudinal axis. The two airplanes collided at a 72-degree angle with a closure rate of 116 knots. Propeller slashes on the left wing of the Cessna and the fact that the Cessna's rudder balance weight was located in the wreckage of the Piper would indicate that the Piper was above the Cessna at the moment of collision.

MEDICAL & PATHOLOGICAL INFORMATION

An autopsy was performed on the flight instructor on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed forensic toxicology on the specimens from the flight instructor showed negative results for carbon monoxide, positive results for ethanol in muscle and various organs, no ethanol detected in the brain, and negative results for other screen drugs. Testing for cyanide was not performed.

An autopsy was performed on the student pilot on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed forensic toxicology on the specimens from the student pilot showed negative results for carbon monoxide, positive results for ethanol in various organs, no ethanol detected in the brain, positive results for N-Propanol in gastric, heart, lung, and cavity blood. Negative results for other screen drugs. Testing for cyanide was not performed. AIRPORT INFORMATIONThe four seat, high wing, fixed-gear airplane, serial number 172S10034, was manufactured in 2005. It was powered by a Lycoming IO-360-L2A, 160-hp engine, and equipped with a McCauley fixed pitch propeller. A review of the airplane's maintenance records showed that an annual inspection of the airplane and engine was performed on April 19, 2013, at 3,920.0 hours total time, and an 100-hour inspection was performed on May 16, 2013, at total time of 4,027.2 hours. A 50-hour inspection was performed on May 28, 2013, at a total time of 4,077.7 hours. The engine's total time since new (TTSN) was 6,962.5 hours, time since overhaul (TSO) was 2,173.2 hours.

WRECKAGE & IMPACT INFORMATION

The wreckage was located on flat desert terrain populated by barrel cactus, saguaro cactus, and scrub brush. The wreckage was inverted with the engine and propeller imbedded into the ground. The cabin and fuselage has been consumed by a post impact fire. The wings were discolored grey, black, and covered with soot from exposure to the fire. The wreckage was oriented on a bearing of 216 degrees magnetic measured from tail to nose. The wreckage of the Piper PA-28 was 468 feet away on a magnetic bearing of 280 degrees.

Both wings were observed in their appropriate position between the cabin, inverted, and exhibited extreme leading edge crushing accordion style along the entire wing span. Both left and right lift struts were present and attached to the wings. Both left and right aileron and flaps were present and attached to their respective hinge points. Control continuity was established from both ailerons to the cockpit. Three propeller slashes were observed on the left wing from wing station 100 along the aileron progressing inboard to outboard. The slashes were angled 30 degrees from the longitudinal axis, the longest slash was outboard and the shortest slash was inboard. Distance between the slashes was 17 inches. The metal edges of each slash was deformed upward in relation to the wing's normal orientation. The majority of the fuselage was consumed by the fire. The rudder and rudder horn had remained attached to the hinge that had been separated from the vertical stabilizer, and remained attached to the rudder control cables. Also identified with the rudder and rudder horn was the tail tie down ring. The majority of the rudder had been consumed by fire, and what did remain showed damage to the left side. Control continuity was established by tracing the rudder and elevator cables to the cockpit.

The vertical stabilizer and left elevator were located 1,156 feet from the wreckage on a magnetic bearing of 349 degrees, and exhibited no fire damage. The vertical stabilizer exhibited black witness marks on its left side consistent with tire material and blue paint transfer marks. The rudder hinge was not present on the vertical stabilizer. The left elevator leading edge exhibited a 22-inch-long semicircular leading edge crush.

The engine remained attached to the airplane and exhibited extreme fire damage. The induction system was fragmented and fire damaged. The exhaust headers had been separated from the cylinders. The fuel servo had separated from its mounting pad. Magneto ignition leads were fire damaged. All 8 sparkplugs were observed in place on their respective cylinders. The bottom sparkplugs from cylinder numbers 1 and 3 were removed and observed to have normal wear according to the Champion Check-A-Plug chart. The engine could not be rotated by hand and power train continuity was not established. The propeller flange had separated from the crankshaft. The propeller remained attached to the crankshaft propeller flange, and it exhibited an s-bend from tip to tip. One blade exhibited coarse chordwise scratches at the shank and hub area, minimal leading edge damage along the blade, and the outboard 6 inches measured from the blade tip were bent forward approximately 15 degrees. The other blade was bent aft at the shank, exhibited chordwise scratches, leading edge polishing, and torsional twisting along its length.

The thermally damaged comnav, King KX155, was removed from the wreckage and sent to the NTSB Vehicle Recorders Laboratory for further examination. Due to the extreme thermal damage to the KX155 unit, laboratory technicians were not able to determine what active frequency was programmed into the radio prior to the accident.

A collision angle and closure rate was calculated utilizing the radar ground speeds of each airplane, 106 knots and 92 knots, and the midpoints of the propeller slashes on the upper left wing of the Cessna 172 created an equivalent scratch mark of 60 degrees form the longitudinal axis. The two airplanes collided at a 72-degree angle with a closure rate of 116 knots. Propeller slashes on the left wing of the Cessna and the fact that the Cessna's rudder balance weight was located in the wreckage of the Piper would indicate that the Piper was above the Cessna at the moment of collision.

MEDICAL & PATHOLOGICAL INFORMATION

An autopsy was performed on the flight instructor on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed forensic toxicology on the specimens from the flight instructor showed negative results for carbon monoxide, positive results for ethanol in muscle and various organs, no ethanol detected in the brain, and negative results for other screen drugs. Testing for cyanide was not performed.

An autopsy was performed on the student pilot on June 4, 2013, by the Maricopa County Medical Examiner, Phoenix. The stated cause of death was multiple blunt force injuries. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed forensic toxicology on the specimens from the student pilot showed negative results for carbon monoxide, positive results for ethanol in various organs, no ethanol detected in the brain, positive results for N-Propanol in gastric, heart, lung, and cavity blood. Negative results for other screen drugs. Testing for cyanide was not performed. ADDITIONAL INFORMATIONThe Arizona Flight Training Workgroup (AFTW) is an organization of pilots and certified flight instructors who are dedicated to improving pilot judgment and decision-making to reduce accidents, incidents, and pilot deviations in Arizona. The AFTW in coordination with the FAA has established a Phoenix Terminal Area chart overlay that depicts common flight training airspace areas, standardized nomenclature, and training coordination frequencies. A copy of the AFTW Phoenix Terminal Area Chart overlay is included in the docket of this investigation. According to the AFTW chart the area that both airplanes were operating was referred to as the "prison," and the associated frequency to coordinate training activities between aircraft was 122.75 Mhz.

Witness statements from the pilots who were airborne in the area are inconsistent regarding the amount of radio communication traffic that was occurring during the period prior to the accident. Some pilots reported heavy radio traffic requiring them to wait for a break in the transmissions in order to make their transmission, and other pilots report light radio traffic. However, one pilot did recall hearing the student of the Cessna 172 make position reports, and another pilot did hear the pilots of the PA-28 make a radio announcement asking if anyone was working GRM? (ground reference maneuvers).