Hesperia, CA, USA
N410MA
Bell 412SP
The emergency medical services (EMS) helicopter was performing a cross-country repositioning flight from a hospital back to its base during dark night conditions back over a routing that the pilot had flown 5 times that day and also earlier in the evening when they had transported a patient to the hospital. Visual meteorological conditions predominantly prevailed along the route of flight; however, analysis of the weather reports disclosed conditions consistent with broken to overcast clouds having bases at 4,000 feet msl in the vicinity of the accident site. An AIRMET had been issued for the area for IFR conditions, with mountain obscuration, precipitation, mist, and fog. The helicopter was equipped with a satellite-based tracking system that reports the helicopter's GPS location to the operator's ground base while the system is in operation, and the data for the accident flight was reviewed. The route of flight proceeded toward the apex of a mountain pass, which is the main transition route from one side of a mountain range to the other, where the helicopter's base is located. The tracking data indicated that the helicopter appeared to follow a major highway in the lower portion of the pass. The highway makes a large "S" shaped path as it gains in elevation toward the top of the pass, which is about 4,200 feet mean sea level (msl). The route along the highway is away from a well-lit major city area that has a well-defined light horizon, toward rising and dark terrain with no ground reference lights other than vehicles on the highway. Once at the top of the pass as the highway turns toward the northeast, the upper desert communities on the other side of the mountain range once again provide a well-lit and clearly defined horizon. Near the upper end of the pass, the helicopter's satellite derived flight track showed that it inexplicably diverged toward the east, away from the highway, instead of continuing to follow the highway into the upper desert valley. The helicopter collided with terrain about 0.7 nautical miles east of the highway at 4,026 feet msl. The accident site was located in a small ravine, near the base of a 100-foot tall electrical transmission tower that was located along the ravine's east ridge. During subsequent examination of the airframe structures, flight control components, and engines, no pre-impact anomalies were found that would have precluded normal operation prior to impact. While the operator was in the process of equipping its helicopter fleet with night vision goggles, the accident helicopter had not as yet been equipped with any enhanced night vision devices. The helicopter was equipped for instrument flight, including a 3-axis autopilot. The first fire department responders to the accident site reported that the area was covered by what they described as "intermittent waves" of fog that would suddenly form and then dissipate, which made it difficult to locate the wreckage.
"THIS CASE WAS MODIFIED JULY 29, 2008." HISTORY OF FLIGHT On December 10, 2006, about 1755 Pacific standard time, a Bell 412SP helicopter, N410MA, call sign "Mercy Air 2," impacted mountainous terrain near Hesperia, California. LifeNet, Inc., d.b.a. Mercy Air Services, Inc., was operating the helicopter under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot and two medical crew members were killed; the helicopter was destroyed as a result of the post impact fire. The cross-country repositioning flight departed Loma Linda University Medical Center (94CL), Loma Linda, California, at 1742, with a planned destination of Southern California Logistics Airport (VCV), Victorville, California. Visual meteorological conditions predominately prevailed along the route of flight, and a company visual flight rules (VFR) flight plan had been filed. Mercy Air 2 had transported an injured patient from Phelan, California, to Loma Linda, and was returning to their assigned base at the time of the accident. Mercy Air 2 had traversed through the Cajon Pass in the area of the accident site five times previously on the date of the accident. The accident flight was the first flight of the day that was conducted during night conditions. After departing the Loma Linda University Medical Center Heliport, the flight proceeded toward the Cajon Pass. The Cajon pass is one of the main avenues of transition between the San Bernardino/Riverside basin and the helicopter's base in Victorville. Satellite tracking data from the operator indicated that the helicopter appeared to follow the Interstate 15 (I-15) highway in the lower portion of the Cajon Pass. The highway makes a large "S" shaped route as it gains in elevation toward the top of the pass, which is about 4,200 feet mean sea level (msl). The route along the highway is away from a well-lit residential/industrial area having a well-defined light horizon, toward rising and dark terrain. Once at the top of the pass as the highway turns toward the northeast, the upper desert communities are once again well-lit. Near the upper end of the pass, the helicopter flight track indicated that it proceeded toward the east, away from the highway. The Safety Board investigator-in-charge (IIC) reviewed the data from the Outerlink system. The satellite data indicated that the helicopter departed from 94CL and flew towards the Cajon Pass in a northwest direction. The flight path then followed the northbound I-15 until it had almost reached the summit of the Cajon Pass. The Satellite tracking system tracked the helicopter as it continued toward the northeast while the Interstate turned toward the north. At the time of the accident, position data from the helicopter was downloaded to the company's flight tracking/dispatch center every 30 seconds, but the time reference was only recorded in whole minutes, for each whole minute there would be two position reports. Altitude data was not reported. Airspeed and heading information were derived from the position reports. At the second of two position reports from 1753, the helicopter was over or adjacent to the I-15. At the first position report of 1754, it was slightly southeast of the highway. At the second position report of 1754, the helicopter proceeded on a magnetic heading of 060 degrees, and had traveled about .3 nm from the first 1754 position report, diverging away from the highway to the east-northeast. At the first position report of 1755 (the last received report), the helicopter had traveled about .7 nm, on a magnetic heading of 064 degrees from the previous report, and was about .4 nm east of the Interstate. The accident occurred before the company's tracking software received a second position report from 1755. The accident location was on a bearing of 110 degrees from the last position report at 1755, having traveled about .4 nm to the crash scene. The helicopter collided with terrain about 4,026 feet msl, about .7 nm east of the Interstate. The accident site was located in a small ravine, near the base of about a 100 foot tall electrical transmission tower. The electrical transmission tower was located along the east ridge of the ravine. The tower was part of a section of electrical support towers oriented north-northeast to south-southwest, east of the Cajon Pass. The power lines supported by the towers were depicted on the Los Angeles area aeronautical navigational charts. A witness reported that he was in the area of Highway 138, and a side road that crossed the lower Cajon Pass railroad tracks. About 45 minutes after dark, he was looking north and initially saw what appeared to be the glow of a small grass fire, about three-quarters of a mile north of his location. About 5 seconds later he observed a large fireball. The glow of the fire was obscured by waves of fog that would drift over the area in patches. He described the fog as not very thick, but it would "swoop down" and dissipate at an estimated elevation of about 3,500 feet. The witness said that earlier in the day, he had been using a wind gauge to check the local wind conditions near Highway 138. He recalled that the winds averaged about 13 miles per hour (mph), with gusts to 29 mph. At the time of the accident, the wind was blowing toward the northwest. The post-crash fire was visible from I-15, and 911 call centers began receiving reports of the accident starting at 1800. Callers reported some fog in the area of the accident, obscuring the tops of the power transmission towers and mountain ridges near the top of the pass. The first fire department responders to the accident site reported that the area was covered by intermittent waves of fog, which made it difficult to locate the wreckage. First Responders reported that upon their arrival the wreckage site was fully engulfed in fire. The post impact fire consumed approximately 2 acres of mountainside. Weather conditions at the bottom of the pass were VFR, with the upper desert at the destination airport was clear. PERSONNEL INFORMATION PILOT Prior to being hired by the operator, the 46 year old pilot had 21 years of previous military service, 12 years of which were as a military helicopter pilot, and he accrued about 3,094 hours of military rotorcraft experience. He held a Federal Aviation Administration (FAA) issued commercial rotorcraft helicopter certificate, and a rotorcraft helicopter instrument certificate. The pilot was hired by the operator in December 2005, for the Twentynine Palms, California, base, which at that time, utilized Bell 222U helicopters. The pilot completed the initial hire training syllabus and a check ride with a company check airman. He then had 3 to 4 ride-alongs on Aeromedical flights, and then he began flying medical flights as the pilot-in-command. He moved to the Victorville base in August 2006, and completed the company's transition training for the Bell 412SP helicopters. His most recent Part 135 check ride was August 29, 2006, at the Victorville base, which was conducted by a company check airman. The check ride was 1.5 hours, of which .3 was under an instrument training device (hood). The check ride form noted that the pilot was not authorized the use of an autopilot under instrument flight rules (IFR) flights The pilot was not IFR current, and not authorized by his company to conduct medical flights under IFR conditions, or the use of night vision goggles under any flight conditions. Between his date of hire and the accident, he accrued about 220 flight hours, for a total of about 3,371 hours, which included about 57 hours in airplanes. The Victorville pilots work a 7-day on, 7-day off rotation, and work either a 0800 to 2000 or a 2000 to 0800 shift during their 7-day rotation. The pilot began a 7-day rotation on December 8, 2006, and worked 0800 to 2130. On December 9, he worked 0800 to 2030. On December 10, the day of the accident, he began work at 0800. At the beginning of the day of the accident, the Victorville base received a mission request for a hospital transfer from Apple Valley, California. After checking the weather at 0753, the pilot declined the flight due to poor weather conditions in the Cajon Pass. The pilot then conducted three medical flights during the afternoon. The accident occurred during the positioning flight back to Victorville, at the conclusion of the third mission. A company check airman, who gave the pilot his initial training at the Twentynine Palms base, reported that he taught the pilot, and those who flew in the area, a VFR route up the Cajon Pass from Loma Linda to Victorville. The route, generally used for night operations, consisted of the following: Fly from Loma Linda to the I-15/I-215 interchange "the split"; if the weather/visibility was good, fly along I-15 to "windy point," which is a prominent bend in the highway to the right; if the weather/visibility was good, proceed to the I-15/Hwy 138 interchange, which is well-lit at night; if the weather/visibility was good, proceed along I-15 until the lights of Oak Hill, California, (at the top of the pass) were visible, and proceed to the top on about a 340 to 350 degree heading. AIRCRAFT INFORMATION The helicopter was a Bell 412SP, serial number 33125. The operator reported that the helicopter had a total airframe time of 9,978 hours at the last inspection. The left engine was a Pratt & Whitney Canada; model PT6T-3B, serial number CPPS-60169. Total time recorded on the engine at the last inspection was 17,799 hours, and time since major overhaul was 4,528 hours. The right engine was a Pratt & Whitney Canada; model PT6T-3B, serial number CPPS-63543. Total time recorded on the engine at the inspection was 5,521 hours, and time since major overhaul was 5,521 hours. The helicopter was configured for air ambulance operations. Among other equipment, it contained communications equipment, seating for the medical crew, stretchers for patients, medical monitors, medical equipment, and on-board oxygen. The helicopter was certified for day/night VFR flight by one pilot. It had standard instrumentation for instrument flight, and was certified for single-pilot instrument operations. The FAA approved company operations specifications indicated that the Bell 412SP helicopter was authorized to conduct IFR/VFR flights during day/night operations, but as it was assigned to a VFR base, it was only utilized for VFR flights. The helicopter had an Argus 5000 moving map, which did not contain any enhanced terrain contour information, a panel mounted global positioning system (GPS) receiver, 3 axis autopilot with a stability augmentation system (SAS), force trim, radar altimeter, a Spectrolab SX-5 search light, directional/controllable landing light, and full flight controls and anti-torque pedals installed at the left cockpit seat position. The helicopter was maintained on a Bell factory approved aircraft inspection program (AAIP). The most recent maintenance was on December 7, 2006, when the number 1 engine oil was changed, along with a change of the left hydraulic servo due to a leak. The most recent airframe inspection was a 25 hour inspection performed on December 8, 2006, at 9,978.0 hours. The inspection intervals are 25-, 100-, 300- and 600-hour or 12 month inspections The most recent 600 hour/annual was on September 27, 2006, at 9,738.6 hours. The engines have an inspection cycle of 25-, 50-, 100-, 150 hours or 12 months, 300-, 600-, and 1,200 hour inspections. An annual inspection on the engines is required every 600 hours or 12 months which ever occurs first. The helicopter was equipped with the OuterLink Automatic Flight Following System, a satellite-based tracking system that reports the helicopter's location to the ground base while it is in operation. The unit installed in the accident helicopter reported the following parameters every 30 seconds: date, time, latitude, and longitude. The installed system was capable of recording the altitude and airspeed, but Mercy Air had not yet installed the software upgrade required to make those parameters functional. METEOROLOGICAL INFORMATION Reported weather conditions from Victorville (VCV), 15 nautical miles (nm) northeast of the accident site, were visibility 10 statute miles; a broken cloud layer at 3,800 feet, and an overcast cloud layer at 4,900 feet; temperature 11 degrees Celsius; dew point 03 degrees Celsius; altimeter 30.17 inHg. Weather conditions at Ontario International Airport, Ontario, California, 19 nm southwest of the accident site, were visibility 10 statute miles; a broken cloud layer at 3,800 feet, and an overcast cloud layer at 5,500 feet; temperature 13 degrees Celsius; dew point 06 degrees Celsius; altimeter 30.19 inHg. Following notification that an accident had likely occurred in the Cajon Pass, the Victorville base safety officer began to check the weather conditions at the San Bernardino, Riverside, and Ontario airports. He learned that the weather conditions in the area were generally about 4,000 feet broken to overcast. An NTSB senior meteorologist prepared a factual report that included an amended area forecast for southern California, issued December 10, 2006, at 1324, which stated, in part: Clouds and weather, valid until 0100 on December 11: Coastline, south of Los Angeles International Airport: 4,000 feet scattered. From 1800, sky clear. From 2100, 2,000 feet broken, tops at 3,000 feet. Inland sections: 4,000 to 5,000 feet scattered to broken, tops at 8,000 feet. Between 1900 and 2100, 4,000 to 5,000 feet scattered. Interior mountains: 800 to 10,000 feet broken, tops at 13,000 feet with isolated light rain showers. Between 1900 and 2100, 10,000 feet scattered to broken. Deserts: Sky clear, occasionally, 10,000 feet scattered. Westerly winds at 20 knots, gusts to 30 knots. Between 1900 to 2100, sky clear. Northwest winds at 15 knots, gusts to 25 knots. Additionally, the area forecast included an airmen's meteorological information notice (AIRMET). AIRMET Sierra, update Three, was issued at 1245 for IFR and mountain obscuration, which was valid until 1900. It noted mountains obscured by clouds, precipitation, mist and fog. AIRMET Tango, update Four, also issued at 1245 and valid until 1900, noted moderate turbulence. See the meteorological factual report for complete details. COMMUNICATIONS No communications were received from the helicopter after departure from Loma Linda University Medical Center. WRECKAGE AND IMPACT INFORMATION The wreckage site was located on mountainous terrain in a ravine on a 45-degree slope at an elevation between 4,000 to 4,300 feet above mean sea level (msl). The first identified point of impact was near the base of the ravine with the debris path emanating upslope. The first identified impact point (FIPC) was a ground scar located next to the separated tail boom and the left skid. The debris path consisted of the tail boom, both skids, both engines, the main rotor assembly, and various other fuselage panels. The energy path was measured on a 155-degree magnetic bearing from the first identified impact point. The debris field was about 170 feet from the FIPC. MEDICAL AND PATHOLOGICAL INFORMATION The San Bernardino County Sheriff's Coroners Office completed an autopsy on the pilot and the two crew members. The cause of death for the pilot and the two crew members was listed as "blunt injuries causing immediate death." The FAA Bioaeronautical Sciences Research Laboratory Forensic Toxicology Research Team, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilot. Analysis of the specimens for the pilot contained no findings for volatiles or tested drugs. They did not perform tests for carbon monoxide or cyanide. TESTS AND RESEARCH The wreckage had been subjected to post impact thermal damage. Examination of the airframe structures, flight control components, and engines that were not destroyed by fire displayed no pre-impact anomalies. The representative for the airframe manufacturer identified the damage as being consistent with an accident involving a high energy impa
The pilot's inadvertent encounter with instrument meteorological conditions and subsequent failure to maintain terrain clearance. Contributing to the accident were the dark night conditions, fog, and mountainous terrain.
Source: NTSB Aviation Accident Database
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