AMERICAN EUROCOPTER CORP AS350B2

Full Narrative

HISTORY OF FLIGHTOn December 19, 2023, about 2004 eastern standard time, an American Eurocopter AS350B2 helicopter, N606HD, was destroyed when it was involved in an accident near Hammonton, New Jersey. The pilot and videographer were fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 ENG flight.
According to the helicopter operator’s chief pilot, about 1923, the helicopter departed Northeast Philadelphia Airport (PNE), Philadelphia, Pennsylvania, after being dispatched by the news station assignment desk to a scene 44 nautical miles to the south/southeast, in the Smithville, New Jersey area. This was the third flight of the day for the helicopter and crew, and a fixed-base operator at PNE had refueled the helicopter before the accident flight.
The helicopter arrived on scene about 20 minutes later and began orbiting while collecting video footage for the news station. After about 10 minutes on scene, the news station assignment desk cleared the crew to return to PNE via radio.
About 2200, the news station assignment desk notified the helicopter operator that they had tried to reach the crew for another assignment but were unable to contact them by telephone. After the operator confirmed the helicopter had not returned to PNE, the operator took actions to obtain the time and location information of the last contact.
The operator contacted state and local authorities with the last contact information, flight route information, and a possible location obtained from internet-based ADSB tracking platforms. They also contacted the FAA New York Air Route Traffic Control Center to initiate an overdue/missing aircraft report. The ADS-B tracking platforms showed the helicopter's last location about 4 nautical miles east/northeast of Hammonton Municipal Airport (N81), Hammonton, New Jersey.
According to FAA air traffic control (ATC) data, about 1945, after orbiting the scene, the helicopter climbed to about 1,000 ft msl while heading direct to PNE, approximately paralleling its outbound course from PNE to the scene. About 1952, the pilot advised that they were done and heading back to PNE. When ATC asked if the pilot would like flight following, he declined. About 1959, ATC terminated radar service.
About 2001, the helicopter drifted right of course and passed through its outbound course from PNE. Then, at 2001:54, the helicopter began to descend and passed through an altitude of 775 ft. At 2002:16, the helicopter continued to descend through 700 ft, and its ground speed increased through 93 kts. At 2003:08, the helicopter descended through 400 ft and accelerated through 103 kts. At 2003:25, the helicopter descended through 250 ft at 107 kts. The last recorded data for the helicopter, at 2003:37, showed it was traveling at a ground speed of 115 kts.
Around this time, a witness observed a solid light traveling quickly at a steep descent angle. He did not see a fire or explosion. Another witness observed a "giant orange ball" in the forest. PERSONNEL INFORMATIONThe pilot was the lead pilot for the helicopter operator and had been employed by them for about 19 years. During the accident flight, he was seated in the front right seat of the helicopter.
The videographer was the lead photographer for the helicopter operator and had also been employed by them for about 19 years. During the accident flight, he was seated in the rear left seat and did not have access to the flight controls. His primary duty onboard was to operate the ENG equipment. METEOROLOGICAL INFORMATIONA High-Resolution Rapid Refresh (HRRR) model sounding analyzed by the RAwinsonde OBservation (RAOB) program estimated the atmosphere below 15,000 ft was cloud-free except for a shallow layer of few clouds near 4,200 ft. The model estimated the freezing level was about 900 ft, the wind near the surface was from the northwest about 5 kts, and the wind veered and increased in magnitude to a north wind of about 30 kts near 5,000 ft. From 5,000 through 10,000 ft, the model estimated the wind remained northerly to north-northwesterly at 25 to 30 kts.
A review of weather surveillance radar imagery from around the accident time did not reveal any pertinent meteorological echoes in the accident region, and no longline-disseminated PIREPs were submitted between 1800 and 2200 within 50 miles of the accident location.
No non-convective or convective SIGMETs were active for the accident region at the accident time, and the Center Weather Service Units at the Washington and New York Air Route Traffic Control Centers had not issued any Center Weather Advisories or Meteorological Impact Statements that were active for the accident region. About 1600, graphical AIRMETs were issued for moderate icing between the freezing level and 8,000 ft that were valid at both 1900 and 2200 for regions that included the accident location.
According to mooncalc.org, on the day of the accident at a point about two miles from the accident location, moonrise occurred at 1209. At the time of the accident, the moon was at an azimuth of 219° and an altitude of 41°, with 53% of its disk illuminated. Moonset occurred about 2359. WRECKAGE AND IMPACT INFORMATIONOn December 20, 2023, about 0005, the wreckage of the helicopter was located in a densely wooded area of the Wharton State Forest near Hammonton, New Jersey. Examination of the accident site revealed a wreckage path that extended about 600 ft on a 320° heading from the first tree strike to the main wreckage.
Most of the helicopter was consumed by a postcrash fire, except for parts of the tailboom, doors, and small pieces that had departed the helicopter near the initial impact. The airframe was destroyed and heavily fragmented, with separation damage from the postcrash fire and signatures of blunt force impact.
The instrument panel was separated from the airframe and heavily damaged. The rest of the cockpit and cabin was unrecognizable other than the floor structure and some of the steel components from the flight controls.
All three main rotor blades were found at the main wreckage site, remained attached to the rotor head, and exhibited damage consistent with high rotational energy of the rotor system. They remained attached at the root ends at their respective main rotor blade sleeves, which were damaged from fire but remained attached to the Starflex bearingless main rotor hub. All three Starflex arms were fractured, with diagonal fracture signatures across the star arms.
All three main rotor blades exhibited impact and thermal damage. Two appeared more heavily impact damaged at the outboard ends, with broom straw signatures. Main rotor blade debris (including rotor blade skin and core foam) was observed near the beginning of the wreckage path and throughout the woods up to the main wreckage. Several trees were observed with smooth cuts consistent with main rotor blade strikes in a long shallow descending path through the woods to the main ground impact area.
The main rotor transmission was separated from the helicopter but generally intact, with the rotor system attached. The chip detector was clean and free of debris. All three main rotor hydraulic servos remained attached and displayed blunt impact damage, and the hydraulic lines were separated. The hydraulic pump was impact damaged and remained attached by its bracket.
Functional continuity of the flight control system and main rotor drive system could not be established due to the postimpact fire damage. However, the flight control path was traced from the cockpit input devices to their aerodynamic component connections through the thermal or blunt impact damage areas. No preimpact anomalies were noted.
Dual flight controls were installed. The collective control arms were found about mid-position. The fuel flow control lever setting was near the forward position. The pilot’s cyclic grip was separated and found about 20 ft forward of the main wreckage. The pilot’s anti-torque pedals were present; however, the pilot’s right pedal was bent in a downward direction. The pilot’s left-side inboard pedal was separated and found on the ground about 20 ft forward of the main wreckage.
Several electronic components, related to ENG, were found separated, lying along the wreckage path. All four cockpit/cabin doors were separated from the airframe and found on the ground near the broken tree limbs at the beginning of the wreckage path. The right front door exhibited a tree impact with a forward/side impact signature.
None of the plastic fuel tank material was observed. Pieces of the windshield and window material were observed throughout the wreckage path.
The tail rotor gear box was separated from the tailboom, both blades were separated from the root, and both weights were separated from the blades. Impact signatures and markings on the tail rotor and driveshaft were consistent with tail rotor driveshaft rotation at impact. The tail rotor gearbox chip detector plug had broken off the gearbox and was not recovered. The ventral fin on the tail section was separated from the tailboom and exhibited impact and postcrash fire thermal damage. The forward section of the tailboom was also broken off and thermally decomposed aft of the rear cargo hold. The section of tailboom with the horizontal control surfaces was also separated, and both horizontal surfaces exhibited leading edge damage and aft bending of the surfaces.
The helicopter was equipped with a high-skid landing gear system. The forward section of each skid and the remainder of the right skid were found toward the beginning of the wreckage path. The rest of the gear system came to rest with the main wreckage. A cargo hook assembly was found underneath the wreckage.
Examination of the Plexiglas windows using black light did not reveal any evidence of a bird strike.
Examination of the engine revealed that it had separated from the airframe during the accident sequence. It remained attached to the main transmission via the liaison tube and was facing opposite the direction the main cabin came to rest. The engine showed thermal damage from the postcrash fire.
All fuel, oil, and air connections remained connected on the engine side but were separated from the airframe side. The main transmission shaft remained connected on the engine side but disconnected on the transmission side. The flector group on the transmission side was destroyed in the accident sequence.
The gas generator could be turned by hand. The axial compressor exhibited foreign object damage on several blades, and the nose cone exhibited rotational and thermal damage. The free turbine could be turned by hand and proper freewheel operation was established. No blades were shed.
The main and rear bearing electric chip detectors were clean. The module 1 and module 5 magnetic plugs were clean. The oil and fuel filters were not removed.
The engine electrical harness was still connected to its respective bases but was separated from the engine deck.
The castellated nut on the front of the freewheel shaft exhibited impact damage with the inside of the transmission shaft.
The throttle and anticipator arms remained connected to the fuel control unit; however, the cables had separated.
The module 5 reduction gear box was removed to examine the input pinion scribe marks. The mark was misaligned in the tightening direction by about 3mm, consistent with power delivery at the point of main rotor impact.
No anomalies of with the engine were discovered that would have precluded normal operation. ADDITIONAL INFORMATIONA witness observed a solid light traveling quickly at a steep descent angle. He did not see a fire or explosion. A second witness observed a "giant orange ball" in the forest. A third witness reported an unusual grinding noise from a helicopter that flew overhead, and a fourth witness reported a 3-ship formation of C130 airplanes in the area of the accident. The investigation determined that the C-130s were part of the 166th Airlift Wing, had visually identified the helicopter, and had reported to ATC that they had “traffic in sight.” Reviews of radar data and ATC audio recordings also indicated that no loss of separation occurred and the C-130s were about 1,000 ft higher in altitude than the helicopter at the time of their encounter. FLIGHT RECORDERSThe helicopter was equipped with an Appareo Vision 1000 self-contained image, audio, and data recorder. This device is typically mounted in the overhead panel of an aircraft’s cockpit and records an image four times per second with its internal camera.
The device sustained severe heat damage. An SD card was recovered from the wreckage; however, no card was installed in the device’s SD card slot. The internal non-volatile memory (NVM) chips were removed from the Appareo Vision, and the NVM chips and SD card were sent to the NTSB Vehicle Recorder Laboratory for examination.
The NVM chips contained 532 images, the equivalent of 2 minutes and 13 seconds of data at a 4-frames-per-second rate. The images showed a laboratory bench. No tabular parametric data were present. The contents indicated that the device was not powered on during the accident flight; thus, no accident-related data were recovered.
The SD card contained 3 video files from an image recorder mounted on the exterior of the helicopter. The data file format was inconsistent with data files typically generated by an Appareo Vision; therefore, it was determined that the SD card was not installed in the device. The image files were time-stamped April 6, 2022, and were not relevant to the accident.
The NTSB Vehicle Recorder Laboratory reviewed mobile phone records containing the pilot’s mobile phone activity history from 1900 on December 19 to 0100 on December 20, 2023. The records showed no phone call or text message activities from 1923 to 2004 on December 19, 2023. The records showed internet connection activity during the accident flight, but it was not possible to distinguish between user-initiated data activity and automatic background data activity by the device’s operating system or installed applications. MEDICAL AND PATHOLOGICAL INFORMATIONThe Burlington County Medical Examiner’s Office performed an autopsy of the pilot. According to the autopsy report, the cause of death was multiple injuries, and the manner of death was accident. Due to the extent of the pilot’s injuries, his autopsy was severely limited for evaluation of natural disease. Structural evaluation of his heart and lungs was not possible, and structural evaluation of his brain was markedly limited.
The 68-year-old male pilot’s last aviation medical examination was July 18, 2023. At that time, he was 73 inches tall and weighed 208 lbs. His reported medical history included prediabetes and high blood pressure. His high blood pressure was noted to be qualified under Conditions Aviation Medical Examiners Can Issue (CACI) criteria. He reported using the medications metformin (a prescription oral medication commonly used for blood sugar control in diabetes and prediabetes), valsartan (a prescription medication that can be used to treat high blood pressure and heart failure), nifedipine (a prescription medication that can be used to treat high blood pressure, angina, and certain other conditions), carvedilol (a prescription beta blocker medication that can be used to treat high blood pressure and heart failure), simvastatin (a prescription medication commonly used to control cholesterol and reduce cardiovascular risk), and alfuzosin (a prescription alpha blocker medication commonly used to treat symptoms of an enlarged prostate). He was issued a second-class medical certificate limited by a requirement to use corrective lenses to meet vision standards at all required distances. According to the FAA medical certification file, the pilot had a diagnosis of new onset diabetes not on medication in 2000 and had a 2015 FAA Letter of Eligibility for second-class medical certification with prediabetes and high blood pressure.
NMS Labs (at the request of the Medical Examiner’s Office) and the FAA Forensic Sciences Laboratory performed toxicological testing of postmortem specimens from the pilot. NMS Labs identified a presumptive positive result for caffeine in chest cavity blood. This unverified positive screening test was performed without a confirmation test.
Of the medications the pilot reported using at his last aviation medical examination, the FAA detected metformin and alfuzosin in cavity blood and urine; carvedilol was detected in cavity blood and was not detected in urine. Additionally, the FAA detected chlorpheniramine at 18 ng/mL in cavity blood and at 15 ng/mL in urine. Telmisartan, HCTZ, tadalafil, and salicylic acid were detected in cavity blood and urine. Chlorothiazide was detected in urine; cavity blood testing for chlorothiazide was inconclusive. Trimethoprim was detected in urine and was not detected in cavity blood. Glucose was not detected in urine or vitreous (a normal result).
Metformin use has low potential to result in symptomatic low blood sugar and is not typically impairing. A pilot on metformin may be granted FAA medical certification depending on the status of the pilot’s underlying condition and response to treatment.
Chlorpheniramine is a sedating antihistamine medication that is available over the counter (OTC) in a variety of cold and allergy products, and that sometimes also may be used for motion sickness or as a sleep aid. Chlorpheniramine use can result in psychomotor slowing and drowsiness. It often carries warnings that drowsiness may occur, and that users should use caution when driving a motor vehicle or operating heavy machinery. The FAA lists chlorpheniramine as “No Go” OTC medication and a “Do Not Fly” medication, and states that pilots should not fly within 5 days of using chlorpheniramine, to allow time for it to be cleared from circulation. In living individuals, the typical elimination half-life of chlorpheniramine is about 12-43 hours and the therapeutic range of chlorpheniramine in plasma is about 3-20 ng/mL, with chlorpheniramine levels in blood being about 1.2-1.3 times those in plasma. Chlorpheniramine may undergo postmortem redistribution, affecting measured drug levels. Furthermore, comparing drug levels in postmortem cavity blood to reference ranges in living individuals generally is unreliable.
Telmisartan is a prescription angiotensin receptor blocker (ARB) medication commonly used to treat high blood pressure; it may also be used in the treatment of heart failure.
HCTZ is a prescription thiazide diuretic medication used very commonly to treat high blood pressure. Using a thiazide diuretic together with an ARB also is common, and combination medication containing both HCTZ and telmisartan is available. Chlorothiazide may be present as an impurity in HCTZ, and also may occasionally be prescribed as a thiazide diuretic medication, primarily to treat edema.
Tadalafil is a prescription medication commonly used to treat erectile dysfunction, as a sexual enhancement aid, and to treat symptoms of an enlarged prostate. It also is sometimes used to treat other conditions, including pulmonary hypertension. Tadalafil is not typically impairing, although the FAA states that pilots who use it on an as-needed basis should wait 24 hours after use before flying, and that otherwise-qualified pilots who use it daily should undergo a 7-day ground trial before flying, to monitor for side effects. Additionally, tadalafil typically carries a warning that use in combination with alpha blocker medication (like alfuzosin) may result in symptomatic low blood pressure or fainting in some individuals. The FAA states that if a pilot uses tadalafil with an alpha blocker, the pilot should not fly until verification that no low blood pressure episodes or other side effects occur.
Salicylic acid is the primary active metabolite of aspirin, a widely available over-the-counter medication that can be used to control pain and fever and to reduce cardiovascular risk. Salicylic acid also is a metabolite of some other drugs and is used as a topical skin exfoliant in a variety of retail products. Salicylic acid is not typically impairing.
Trimethoprim is a prescription antibiotic medication. Trimethoprim is not typically impairing.
Telmisartan, HCTZ (and chlorothiazide), carvedilol, and alfuzosin are not generally considered impairing. The combination of telmisartan, HCTZ, and carvedilol can be acceptable under CACI criteria for high blood pressure if all criteria are met. The FAA states that daily use of telmisartan, HCTZ, carvedilol, or alfuzosin requires pilots to first pass a 7-day ground trial when beginning the medication, to monitor for side effects.