NTSB CAROL · Event
Event WPR13FA254
Aircraft involved
Probable cause & findings
The failure of the pilots in both aircraft to maintain adequate visual lookout in a known training area where multiple aircraft frequently operated, which resulted in a midair collision.
Factual 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). A Cessna 172 and a Piper PA-28 collided in midair; both airplanes were operating as instructional flights. Radar data showed the airplanes operating about 1 mile apart. The Cessna was operating to the west of the Piper at 2,500 ft mean sea level (msl) and 106 knots ground speed. The Piper was operating to the east of the Cessna at 2,600 ft msl and 92 knots. The Cessna was on a northerly heading and made a right turn to a southerly heading. The Piper was also on a northerly heading and made a left turn to a southwesterly heading. Both airplanes executed the turns simultaneously. Shortly after each airplane completed its turn, the track of both airplanes intersected. Calculations determined that the two airplanes collided at a 72-degree angle with a 116-knot closure rate. Propeller slashes on the Cessna's left wing indicated that the Piper was slightly above the Cessna at the moment of collision. During the collision sequence, the right side of the Piper's nose contacted the Cessna's rudder and continued forward into its left wing, which allowed the propeller to slash the trailing edge. The wreckages of both airplanes were found in the immediate vicinity of the radar-depicted track intersection. It is likely that the pilots had an opportunity to see each other during the turns. However, as the flights converged and rolled out of their simultaneous turns, structure from both airplanes would have blocked the pilots' visibility and prevented them from seeing the other airplane and avoiding the collision. The area where the accident occurred is commonly used by local flight schools to practice ground reference maneuvers, which are normally performed at 1,000 ft above ground level (about 2,700 ft msl); therefore, the pilots should have been aware that other aircraft were operating in the area and should have been monitoring the environment. Further, the training area had an associated radio frequency to coordinate training activities between aircraft, and the pilots of both airplanes were making position reports and other radio transmissions on the established frequency and should have been listening for other traffic. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).
- C Personnel issues-Psychological-Attention/monitoring-Monitoring other aircraft-Flight crew - C
- C Personnel issues-Psychological-Attention/monitoring-Monitoring other aircraft-Flight crew - C
Verbatim from NTSB's published report. Source file
NTSB_2013_WPR13FA254.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (midair collision, maintenance). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
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