CEN10FA113

The pilot's loss of situational awareness resulting in controlled flight into terrain. Contributing to the accident was the pilot's unfamiliarity with the hazards of a low-contrast area while using night vision goggles.

The commercial pilot and two paramedics were dispatched to a remote desert area for a simulated patient pick up. This was the pilot's second company flight and first uninstructed night vision goggle (NVG) flight since his recent company training. While maneuvering for the landing zone, ground personnel observed the helicopter orbit one or two times and the pilot was using the non-NVG spotlight to illuminate the ground. Ground personnel then observed the helicopter make a wide orbit before it banked about 45 degrees, entered a steep nose-down attitude, and impacted the ground. None of the witnesses reported an attempt by the helicopter to avoid an impact with the ground. A postcrash fire ensued. An examination of the airframe and engine did not reveal any preimpact anomalies that would have precluded the safe operation of the helicopter. On the night of the accident there was zero percent moon illumination and very little cultural lighting in the remote area where the accident occurred, resulting in low visual contrast when using NVG’s. The pilot’s recent NVG training had all been conducted on nights with high moon illumination and in populated areas with high amounts of cultural lighting and did not prepare the pilot for flight in the conditions encountered on the night of the accident. The low visual contrast conditions, combined with the narrow field of view of the NVG’s, reduced the pilot’s ability to maintain situational awareness. The lack of attempted recovery prior to ground impact suggests that the pilot did not recognize the helicopter’s descent rate and bank angle.

HISTORY OF FLIGHT On February 5, 2010, approximately 1920 mountain standard time, an Aerospatiale AS350/B2 helicopter, N157BC, was substantially damaged upon impact with terrain while maneuvering in the McGregor Military Range, 23 miles northeast of El Paso, Texas. A postaccident fire ensued. The commercial pilot and two paramedics received fatal injuries. The helicopter was owned and operated by Enchantment Aviation Inc., D.B.A. Southwest Med Evac under the provisions of 14 Code of Federal Regulations Part 135 as a practice emergency medical services (EMS) flight. Night visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight departed the El Paso International Airport (KELP), El Paso, Texas, approximately 1825. The flight was conducted under a contract with the United States Army and was attempting to pick up a soldier to simulate transporting injured Army personnel. The flight was to use night vision goggles (NVGs) and standard company practice was for the pilot and the paramedic seated in the left aft seat to be on NVGs. Several Army personnel utilizing various night vision devices were in the vicinity of the accident. The Army personnel stated that the helicopter arrived to the south of the accident site and made two right turn orbits. The helicopter was seen turning on and panning the white spot light during these orbits. Personnel on the ground attempted to make radio contact with the helicopter but were not successful, so they began waving chemical light sticks in an attempt to signal the helicopter. The helicopter was then observed to make a third orbit which was wider than the first two. During the third orbit, the helicopter banked approximately 45 degrees and entered a steep nose down attitude before impacting the ground. None of the witnesses reported an attempt by the helicopter to avoid an impact with the ground. PERSONNEL INFORMATION The pilot, age 63, held a commercial pilot certificates for airplane single-engine land, helicopter, and instrument helicopter. In addition, the pilot held an airline transport pilot certificate for airplane, multi-engine land with Boeing 707, 720, 737, 757, 767, and Lockheed L-1011 type ratings. A review of his logbook revealed that he had logged over 17,610 hours total flight time with over 5,142 hours of rotorcraft time and over 3,351 hours of night time. On July 10, 2009, he was issued a first class medical certificate with restrictions for "holder shall wear lenses that correct for distant vision and possess glasses that correct for near vision." In addition, the pilot had authorizations for special issuance of a medical certification for a history of vitreous exchange, retinal detachment, sclera buckle, cataract surgery, hyperopia, and glaucoma. Review of the pilot's FAA medical records identified a history of cataract surgery with intraocular lens implants in both eyes (left eye 1998, right eye 2005); a bilateral vitreous exchange in 2004 for vitreal detachment with vitreous debris; a right retinal detachment in 2005 treated with a scleral buckle and cryotherapy; glaucoma, treated with eye drops; a "minor arcuate field loss right eye"; and an episode of cystoid macular edema with decreased visual acuity and "distortion" in his right eye in 2005 after his cataract surgery, persisting for several weeks. On September 18, 2008, the pilot was granted a 6-year Authorization for Special Issuance of a Medical Certification for his history of glaucoma, noting, in part, "... you must promptly report any adverse changes in your medical condition ... Because of your history of glaucoma, operation of aircraft is prohibited at any time new symptoms or adverse changes occur or if you experience side effects from, or require a change in medication ...." The pilot's most recent application for (first class) airman medical certificate, dated July 10, 2009, noted the pilot's corrected visual acuity to be 20/15 (distance), 20/20 (near) and 20/25 (intermediate) for each eye separately and for both eyes together. Visual field testing to 30 degrees performed on July 14, 2008 and June 26, 2009 demonstrated a small fixed peripheral right upper quadrant visual field deficit about 25 to 30 degrees out from the center. On November 13, 2009, the FAA indicated that the pilot was "eligible for continued Authorization for Special Issuance of a first class airman medical certificate" and noted that "operation of aircraft is prohibited at any time new symptoms or adverse changes occur or if you experience side effects or require a change in medication." Review of records from the office of the pilot's optometrist and ophthalmologist identified two additional episodes of cystoid macular edema, not noted in the FAA records, involving distortion of vision in the right eye beginning in May of 2008 and in August of 2009, with complete resolution of symptoms after topical treatment for each event. Those records also documented laser surgery on November 6, 2009, to the left eye to help control the pilot's glaucoma, with a follow up evaluation on December 31, 2009, indicating that the pilot's "vision has been stable" with corrected distant visual acuity documented as 20/20 in the right eye and 20/20-2 in the left eye. No subsequent visits were noted. The pilot completed an Airman Competency/Proficiency Check Part 135.293 (initial and recurrent pilot testing requirements), and 135.299 (pilot in command line check) checks on December 22, 2009. The pilot was graded satisfactory for all graded maneuvers. In addition, on January 29, 2010, the pilot completed an Airman Competency/Proficiency Check for night vision training in accordance with FAR 61.31 The commercial pilot had recently been hired by Enchantment Aviation Inc. having previously flown helicopters for the United States Army and was an auxiliary pilot for the Maricopa County Sheriff's Office. Attempts to locate the pilot's flight records through the auxiliary branch of the Sheriff's Air Support Unit were not successful. The pilot began training with Enchantment Aviation near the end of November 2009, and on December 22, 2009, the pilot completed the company's initial pilot-in-command training. On January 29, 2010, the pilot had completed the company's NVG training program. At the time of the accident, the pilot had accumulated 22.3 hours in AS350 B3s, 1.4 hours in AS350 B2s, and 7.5 hours utilizing NVGs. The accident flight was the pilot's second non-training flight and was his first non-training NVG flight. The pilot had not operated in the McGregor Military Range prior to the accident. According to the pilot's spouse, the pilot felt comfortable flying helicopters, did not make any negative comments about the training he received, and felt prepared to be a pilot for the operator. Nor, did he express any concerns about flying with NVGs. AIRCRAFT INFORMATION The single-engine helicopter, N157BC, serial number 2418, was manufactured in 1991. It was powered by a 732-shaft horsepower Turbomeca Arriel 1D1 engine, serial number 9098. Review of the maintenance documents revealed that the last inspection was a continuous airworthiness inspection that occurred on October 29, 2009 at a total airframe time of 8,583.9 hours and an engine total time of 8,512.5 hours. According to company maintenance records, on the morning of the accident, the helicopter had accrued 8,594.7 airframe hours and 8,523.3 engine hours. On January 5, 2009, the helicopter was modified via Supplemental Type Certificate for the installation of night vision goggle compatible interior lighting. METEOROLOGICAL INFORMATION At 1951, an automated weather reporting station at KELP, located 23 nautical miles southwest of the accident site reported wind calm, visibility 10 miles, skies clear, temperature 46 degrees Fahrenheit (F), dew point 28 F, and a barometric pressure of 30.13 inches of Mercury. A review of astronomic