ERA22FA318

The low-wing airplane pilot’s failure to ensure that the airplane was aligned with the correct runway, which resulted in a collision with the high-wing airplane on final approach. Contributing to the accident was the controller’s failure to provide timely and adequate traffic information to either airplane and his failure to recognize the developing conflict and to act in a timely manner. Also contributing was the Federal Aviation Administration’s insufficient staffing of the facility, which required excessive overtime that did not allow for proper controller training or adequate recovery time between shifts.

The commercial pilot and private-rated copilot on board the low-wing airplane were performing a visual approach to their home airport at the end of an instrument-flight-rules flight. They were instructed by the approach controller to cross the destination airport over midfield and enter the left downwind leg of the traffic pattern for landing on runway 30L. Meanwhile, the flight instructor and student pilot on board the high-wing airplane were conducting takeoffs and landings in the right traffic pattern for runway 30R and were cleared to conduct a short approach for landing on runway 30R. Upon contacting the airport tower controller, the crew of the low-wing airplane was instructed to proceed to runway 30L, and the copilot acknowledged. The controller subsequently confirmed the landing approach to runway 30L, and the copilot again acknowledged with a correct readback of the landing clearance. Automatic Dependent Surveillance-Broadcast (ADS-B) flight track data indicated that, after crossing over the runway, the low-wing airplane performed a continuous, descending turn through the final approach path for runway 30L and rolled out aligned with the final approach path for runway 30R. The airplanes collided about ¼ nautical mile from the approach end of the runway. Although day visual meteorological conditions prevailed at the airport at the time of the accident, a visibility study determined that it would have been difficult for the pilots of the two airplanes to see and avoid one another given the size of each airplane in the other’s windscreen and the complex backgrounds against which they would have appeared. The pilot of the low-wing airplane would likely have had to move his head position in the cockpit (e.g., by leaning forward) in order to see the approach ends of the runways during most of the turn. If looking in the direction of the runways, he would have been looking away from the direction of the oncoming high-wing airplane, which was also obscured from view by aircraft structure during a portion of the turn, likely including the final seconds before the collision. The visibility study indicated that sun glare was not likely a factor. The high-wing airplane was not equipped with a cockpit display of traffic information (CDTI). The low-wing airplane was equipped with a CDTI, which may have generated a visual and aural traffic alert concerning the high-wing airplane before the collision; however, this may not have provoked concern from the flight crew, since other aircraft are to be expected while operating in the airport traffic pattern environment. The circumstances of this accident underscored the difficulty in seeing airborne traffic (the foundation of the “see and avoid” concept in visual meteorological conditions), even when pilots might be alerted to traffic in the vicinity by equipment such as CDTI. Given the low-wing airplane pilots’ familiarity with the airport, it is unlikely that they misidentified the intended landing runway; however, it is possible that they were unfamiliar with their issued instructions to overfly the airport and join the traffic pattern, as this was a fairly new air traffic control procedure for routing inbound traffic to the airport that had been implemented on a test basis, for a period of about one week, about two months before the accident. Their lack of familiarity with the maneuver may have resulted in a miscalculation that resulted in the airplane rolling out of turn farther to the right of runway 30L than expected. A performance study indicated that, during the turn to final approach, the airplane was between 38 knots (kts) and 21 kts faster than its nominal landing approach speed of 85 kts. This excess speed may have contributed to the pilots’ alignment with runway 30R instead of runway 30L. Analysis of the turn radius required to align the airplane with runway 30L indicated a required roll angle of between 32° and 37° at the speeds flown; at 85 kts. While the wrong runway line up by the low-wing airplane may have been the crew’s misidentification of the runway to which they were cleared to land, it may also have been a miscalculation in performing a maneuver that was relatively new and that they may have never conducted before. Thus, resulting in a fast, short, and tight continuous descending turn to final that rolled them out farther right than expected. The high-wing configuration of the Cessna in a right turn to final, and the low-wing configuration of the Piper in a left turn to final, only exacerbated the conflict by reducing the ability of the pilots to see the other aircraft. The pilot of the low-wing airplane had cardiovascular disease that increased his risk of experiencing an impairing or incapacitating medical event, such as arrhythmia or stroke. Although such an event does not leave reliable autopsy evidence if it occurs just before death, given that the airplane was in controlled flight until the collision, and had two pilots on board, one of whom was communicating with air traffic control, it is unlikely that an incapacitating medical event occurred. The pilot also had advanced hearing impairment, which may have made it more difficult for him to discern speech; however, the circumstances of the accident are not consistent with a pilot comprehension problem; the crew correctly read back the instruction to land on runway 30L. Whether the pilot’s hearing loss impacted his ability to detect cues such as the high-wing airplane’s landing clearance to the parallel runway or a possible CDTI aural alert could not be determined based on the available information. Although both the pilot and copilot’s ages and medical conditions were risk factors for cognitive impairment, there was no specific evidence available to suggest that either of the pilots on board the low-wing airplane had cognitive impairment that contributed to the accident. Autopsy of the flight instructor on board the high-wing airplane identified some dilation of his heart ventricles; while this may have been associated with increased risk of an impairing or incapacitating cardiovascular event, given the circumstances of the accident, it is unlikely that such an event occurred. The instructor also had hydronephrosis of the left kidney, with stones in the left renal pelvis. This may have been asymptomatic (kidney stone pain typically is associated with passage of a stone through the ureter, not with stones in the renal pelvis). The instructor’s vitreous creatinine and potassium elevation cannot be clearly attributed to hydronephrosis of a single kidney. Additionally, the instructor was producing urine and had no elevation of vitreous urea nitrogen. The vitreous chemistry results should be interpreted cautiously given the extent of thermal injury. The instructor’s heart and kidney issues are unlikely to have affected his ability to see and avoid the other airplane. The student pilot on board the high-wing airplane also had heart disease identified at autopsy, including moderate coronary artery disease and an enlarged heart with dilated ventricles. While his heart disease was associated with increased risk of an impairing or incapacitating cardiovascular event, given the circumstances of the accident, it is unlikely that such an event occurred. The student pilot’s vitreous chemistry test indicated hyponatremic dehydration; however, it is unlikely that dehydration contributed to the accident. The controller did not issue traffic advisory information to either of the airplanes involved in the collision at any time during their respective approaches for landing, even though the low-wing airplane crossed about 500 ft over the high-wing airplane as it descended over the airport toward the downwind leg of the traffic pattern. His reasoning for not providing advisories to the airplanes as they entered opposing base legs was that he expected the high-wing airplane to be over the runway numbers before th

The recorded weather at VGT at 1153, about 10 minutes before the accident, included wind from 320° at 4 knots, 10 miles visibility, clear skies, temperature 38°C, dew point 12°C, and an altimeter setting of 29.91 inches of mercury. Low-Wing Airplane The 82-year-old male pilot’s medical history included hypertension, hyperlipidemia, aortic valve replacement with a bioprosthetic valve in 2014, ministroke around 2014, chronic right carotid artery occlusion, atrial flutter controlled without the need for anticoagulation following cardiac ablation and pacemaker placement in December 2017, chronic left mastoiditis treated with mastoidectomy, marked hearing loss affecting both ears, cataracts, and recurrent urinary tract infections. His medical records documented the use of multiple medications that are not generally considered impairing. His most recent aviation medical examination was October 17, 2017. At that time, he reported his remote history of mastoidectomy and tympanic membrane reconstruction procedures on the left side. He answered “no” to a question about whether he had ever had heart or vascular trouble. The aviation medical examiner (AME) noted a right-sided hearing aid and a systolic heart murmur on physical examination. The AME documented that the pilot passed a conversational voice hearing test at 6 feet, and that the heart murmur was asymptomatic. The AME issued the pilot a third-class medical certificate limited by a requirement to wear lenses for distant vision and have glasses for near vision. That medical certificate expired in 2019. The pilot completed the requirements for operation under BasicMed on May 16, 2022. On the Comprehensive Medical Examination Checklist (CMEC) form, the pilot answered “yes” to a question about whether he had ever had heart or vascular trouble. His cardiologist signed the CMEC form and did not identify any condition that, in the cardiologist’s opinion, could interfere with the pilot’s ability to safely operate an aircraft. The pilot had not obtained an Authorization for Special Issuance for his heart valve replacement, and therefore was not eligible to fly as pilot-in-command or as a required flight crewmember under the provisions of BasicMed. According to the pilot’s autopsy report, his cause of death was blunt trauma, and his manner of death was accident. The pilot’s heart weight was elevated, with dilation of both cardiac ventricles. A prosthetic aortic valve was present, as was an implantable medical device with wiring extending to the heart. Mild coronary artery disease was also present, as was moderate aortic atherosclerosis. The remainder of the autopsy, including the heart, did not identify other significant natural disease. Postmortem toxicological testing of specimens from the pilot did not detect any tested-for substances that are generally considered impairing, and a postmortem vitreous chemistry test was generally unremarkable. The 76-year-old female copilot’s last aviation medical examination was June 10, 2020. At that time, she reported a history of 2016 bilateral cataract surgery, as well as a history of Graves’ disease treated with thyroid ablation, resulting in low thyroid hormone, for which she reported using thyroid hormone replacement medication. She had been granted an FAA Authorization for Special Issuance of medical certification for low thyroid hormone and use of medication in 2010 and subsequently received an FAA Letter of Eligibility in 2014 for low thyroid hormone, Graves’ disease, and bilateral exophthalmos. At her last aviation medical examination, the copilot reported using the medications rosuvastatin, celecoxib, glucosamine, and a multivitamin. No significant issues were identified, and the copilot was issued a third-class medical certificate limited by a requirement to wear corrective lenses. That medical certificate expired at the end of June 2022. The copilot completed a BasicMed education course in June 2022 and reported completing a BasicMed CMEC most recently in June 2020. According to the copilot’s autopsy report, her cause of death was blunt trauma, and her manner of death was accident. Her autopsy did not identify evidence of significant natural disease. Postmortem toxicological testing of specimens from the copilot did not detect any tested-for substances that are generally considered impairing, and a postmortem vitreous chemistry test was generally unremarkable. High-Wing Airplane The 40-year-old male flight instructor’s last aviation medical examination was August 6, 2021. At that time, he reported no medication use or active medical conditions. No significant issues were identified, and he was issued a first-class medical certificate limited by a requirement to wear corrective lenses. According to the flight instructor’s autopsy report, his cause of death was blunt trauma, and his manner of death was accident. Diffuse thermal injury was present. Both ventricles of the heart were described as dilated. The remainder of the heart examination, including the coronary arteries, did not identify other evidence of natural disease. Hydronephrosis of the left kidney was present, with stones in the renal pelvis of the left kidney; the right kidney and bladder were unremarkable, and the bladder contained abundant urine. The remainder of the autopsy did not identify other significant natural disease. Postmortem toxicological testing of specimens from the flight instructor did not detect any tested-for substances that are generally considered impairing. A vitreous chemistry test showed an elevated vitreous creatinine and vitreous potassium, with normal vitreous urea nitrogen. The 47-year-old male student pilot’s only aviation medical examination was October 16, 2020. At that time, he reported using a testosterone replacement injection. He reported a history of a 2011 driving under the influence (DUI) arrest without a conviction. No significant issues were identified, and he was issued a third-class medical certificate without limitation. In June 2021, the FAA issued him a Letter of Eligibility for his 2011 DUI arrest. According to the student pilot’s autopsy report, his cause of death was blunt trauma, and his manner of death was accident. Diffuse thermal injury was present and structural evaluation of the brain was limited. The left anterior descending coronary artery was 50% narrowed by plaque. The heart weight was elevated, and the ventricles of the heart were described as dilated. The remainder of the autopsy, including visual examination of the heart, was without other evidence of significant natural disease. Postmortem toxicological testing of specimens from the student pilot did not detect any tested-for substances that are generally considered impairing. A vitreous chemistry test was interpreted by the medical examiner to indicate hyponatremic dehydration. The low-wing airplane was a Piper JetProp DLX, which was an aftermarket turbine engine conversion by Rocket Engineering of Spokane, Washington, of a single-engine, pressurized, Piper PA-46-350P, also called a Malibu Mirage. The high-wing airplane was a Cessna 172N. Low-Wing Airplane According to Federal Aviation Administration (FAA) and pilot records, the pilot held a commercial pilot certificate with ratings for airplane single-engine land, airplane multi-engine land, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single- and multi-engine, and instrument airplane. His FAA BasicMed course and Comprehensive Medical Examination Checklist (CMEC) were completed on May 16, 2022. He had accrued about 6,643 total flight hours. The copilot held a private pilot certificate with ratings for airplane single-engine land and sea, airplane multi-engine land, and instrument airplane. Her FAA BasicMed course was completed on June 1, 2022, and her BasicMed CMEC was completed on June 3, 2020. She had accrued about 1,536 total f