Aviation Accident Summaries

Aviation Accident Summary FTW04FA097

Pyote, TX, USA

Aircraft #1

N502MT

Bell 407

Analysis

While maneuvering during dark night conditions, an emergency medical services helicopter impacted the terrain near Pyote, Texas, after encountering a gust front that produced localized blowing dust and moderate to severe turbulence. The pilot did not obtain any formal preflight weather briefing before departure or en route. No flight dispatch services were used for the flight. No evidence was found to indicate that the pilot obtained any preflight weather briefing before departure or en route. Radar data depicted the helicopter traveling in a north-northeasterly direct route toward the destination after departing from a hospital. Approximately 34 minutes after departure, the helicopter executed a right turn to the east. About that time, the pilot contacted the company dispatch and began a position report, stating, "...hold on a [minute] dispatch, [approximately 14 seconds later] look at, gimme something to look at." There were no further communications from the helicopter. Radar data indicated that the helicopter continued in a right turn back to the north. Examination of the accident site revealed the helicopter impacted the terrain on a southerly heading in the opposite direction of the destination, consistent with the helicopter turning around again. Examination of the helicopter revealed no evidence of an in-flight control or system malfunction before the initial impact. According to documents provided by the operator, the pilot had accumulated a total of 86 flight hours as pilot-in-command of the accident helicopter make and model and a total of 4,209 rotorcraft flight hours. Reported weather conditions at the time of the accident and near the accident site included strong winds, moderate to severe turbulence, and unstable atmosphere that supported thunderstorm activity.

Factual Information

HISTORY OF FLIGHT On March 21, 2004, approximately 0216 central standard time, a Bell 407 air ambulance helicopter, N502MT, was destroyed when it impacted terrain while maneuvering in reduced visibility conditions near Pyote, Texas. The instrument-rated commercial pilot, a flight paramedic, an infant patient, and a passenger sustained fatal injuries, and a flight nurse sustained serious injuries. The single-engine helicopter was owned and operated by Med-Trans Corporation (MTC), of Bismarck, North Dakota, and doing business as CareStar, Odessa, Texas. Night instrument meteorological conditions (IMC) prevailed throughout the area for the Title 14 Code of Regulations Part 135 on-demand air ambulance flight for which a company visual flight rules (VFR) flight plan was filed. The flight originated from the Big Bend Regional Medical Center, near Alpine, Texas, approximately 0139 to transfer the patient to the University Medical Center (UMC), near Lubbock, Texas. According to MTC personnel, the pilot reported for duty approximately 2000, March 20, 2004, at the base hangar at the Odessa-Schlemeyer Field (ODO), near Odessa, Texas, and was relieving the base chief pilot. Approximately 2200, the base chief pilot informed the accident pilot via a telephone call that there was weather in the area and to be careful on any possible flights. He advised the accident pilot to move the helicopter into the hangar due to weather, and that there was a pending pediatric flight. At 2330, the medical staff requested, through dispatch personnel that an infant patient be transfered from Alpine to Lubbock. At 2342, the MTC pilot departed the base hangar and arrived at the Medical Center Hospital (MCH) in Odessa to pick up the flight nurse and paramedic for the flight to Alpine. A review of the MCH dispatch log revealed that at 2346, the following transmission from dispatch was recorded, "[CareStar], Adv yellow weather status, pilot checked weather, will take run." At 2352, the flight departed MCH en route to the Big Bend Regional Medical Center, and arrived at 0044 (March 21, 2005). Approximately 0135, the patient and passenger boarded the helicopter. At 0139, the flight departed Big Bend Regional Medical Center en route to Lubbock (Lubbock is approximately 220 miles north-northeast of Alpine). A review of the radar data depicted the helicopter heading in a north-northeasterly direction after departure from Alpine. At 0155, the pilot contacted the MCH dispatch and gave the following position report, "[N] 30.51.50, [W] 103.23.56, ETA 1 hr. 28 min, 740 [pounds of] fuel." At 0213, approximately 1 mile south of the accident site, the helicopter executed a turn to the north, and then a turn back to the northeast. At 0215, the radar data depicted the helicopter turned to the east and then turned 270 degrees back to the north. Approximately the same time the helicopter executed the turn to the east, the pilot contacted the MCH dispatch and began a position report, when he stated, "...hold on a [minute] dispatch, [approximately 14 seconds later] look at, gimmie something to look at." There were no further communications from the helicopter. The last radar position of the helicopter was recorded at 0216:13, at 31 degrees 24 minutes 08 seconds north latitude and 103 degrees 07 minutes 31 seconds west longitude, at an altitude of 5,900 feet msl, approximately 1,200 feet north of the accident site. At 0323, the MCH dispatch facility notified the Texas Department of Public Safety (DPS) of a possible missing helicopter. Due to weather in the Odessa area, the DPS helicopter could not initiate a search until approximately 0600. At 0619, DPS helicopter rescue personnel located the helicopter wreckage approximately 6 miles south of Pyote. The geographical coordinates of the helicopter wreckage were north latitude 31 degrees 23.944 minutes by west longitude 103 degrees 07.554 minutes at an elevation of approximately 2,480 feet msl. (It should be noted that the communications transcripts and radar data times are off by up to 4 minutes at some points, and the time noted in this report is from the radar data.) Several attempts to obtain a statement from the flight nurse were unsuccessful. PERSONNEL INFORMATION The pilot held a commercial helicopter certificate issued on February 18, 1999, with an instrument helicopter rating, which was issued October 4, 1999. The pilot held a certified flight instructor certificate with rotorcraft and instrument rotorcraft ratings. In addition, the pilot held an airline transport pilot certificate with a rating for multi-engine land airplanes. The pilot was issued a second-class medical certificate on March 3, 2004, with the limitation, "Holder shall possess glasses that correct for the near vision." According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the operator reported the pilot accumulated 17,307 total flight hours, and 4,209 hours total rotorcraft flight time. The pilot accumulated 1,747 hours of night flight time, 130 hours of actual instrument flight time, and 87 hours of simulated instrument time; however, it was unknown how many night and instrument hours were in rotorcraft operations. According to the pilot's resume, as of October 1, 2003, the pilot had accumulated 13,032 total hours in aerial application flight operations, of which 1,200 hours were in rotorcraft. The pilot's logbook was not provided to investigators during the investigation. The operator provided the pilot's duty time records to the National Transportation Safety Board Investigator-In-Charge (NTSB IIC). As of March 19, 2004, the pilot accumulated 86 flight hours as pilot-in-command in the Bell 407. The pilot accumulated 60.6, 39.2, and 25.4 flight hours in the last 90, 60, and 30 days, respectively. According to the operator's "Record of Flight Training," the pilot accumulated 4.4 flight hours of new hire training, which covered, "Normal and Emergency Procedure Training, Night Flight [and] Approaches." The 4.4 hours of new hire training consisted of 3 hours of day flight, 0.2 hours of simulated instrument conditions (under a view limiting hood), and 1.2 hours of night flight. On November 11, 2003, the pilot satisfactorily completed his Federal Aviation Regulations Part 135 Airman Competency/Proficiency Check in the Bell 407 helicopter. According to the remarks, the pilot successfully completed the "Initial new hire" check ride. According to the company's "Pilot Interview" form, question 14 asked, "How many times have you been Inadvertent IMC? How did you react? How do you avoid Inadvertent IMC?" The pilot answered the first question, "No" and did not answer the last two questions. COMPANY INFORMATION Med-Trans Corporation was issued an operating certificate by the Federal Aviation Administration (FAA) in 1995, to conduct on-demand air taxi operations under the provisions of Title 14 CFR Part 135. At the time of the accident, MTC had air ambulance operations in the states of Tennessee, Kentucky, South Carolina, Texas, Arizona, California, South Dakota, North Dakota, and Nebraska. The corporate headquarters was located in Bismarck, the Director of Maintenance was located in Bismarck, the Director of Operations was located in Tucson, Arizona, and the Chief Pilot was located in Johnson City, Tennessee. The Part 135 operating certificate was managed by the FAA Flight Standards District Office in Scottsdale, Arizona. The FAA approved company operation specifications did not allow flights to be conducted in IMC. AIRCRAFT INFORMATION The red and white accident helicopter (serial number 53549) was configured for the transport of medical patients with two seats in the cockpit, one rear-facing seat aft of the pilot's seat, two forward-facing seats, and one medical bed. The helicopter was powered by one 650-horsepower Rolls Royce Corporation turbo-shaft engine (serial number CAE 847594) and equipped with a four bladed main rotor system, and a two bladed tail rotor. The helicopter was equipped for Instrument Flight Rules operations. The helicopter was maintained in accordance with an Approved Airworthiness Inspection Program on a continuous basis. At the time of the accident, the airframe and engine accumulated a total of 500.8 flight hours. The 100-hour airframe inspection and 150-hour engine inspection was completed on February 28, 2004, at a total time of 452.4 hours. The last inspection conducted on the accident helicopter was a 50-hour inspection, which was completed on March 18, 2004, at a total time of 497.2 hours. METEOROLOGICAL INFORMATION The National Weather Service (NWS) Storm Prediction Center (SPC) issued a Convective Outlook at 1900 on March 20, 2004, for expected thunderstorm activity across the country. A slight risk of severe thunderstorms was expected from southwest Texas to northern Mississippi, which included the accident site area. Surrounding the slight risk area was a larger area of general thunderstorm activity, which also encompassed the accident site. The SPC outlook indicated that several multi-cellular to marginal super cell type thunderstorm clusters had formed over west central Arkansas, and in the area of Abilene, Texas, westward to near Midland, Texas, in the vicinity of pre-frontal wind shifts. The advisory warned that many short-lived thunderstorms would be the rule along the frontal system during the evening with the potential for large hail and gusty winds. The advisory also warned that the most intense thunderstorms that developed near the frontal boundaries had the potential to briefly become a super cell. The NWS Aviation Weather Center issued a Convective SIGMET (Significant Meteorological Information) 25C at 0154, which was valid until 0355, for portions of western Texas. The advisory was issued for an area of thunderstorms moving from 040 degrees at 30 knots, with cloud tops to 41,000 feet. The accident site was located approximately 15 miles southwest of the boundary area for the advisory. The convective outlook, valid from 0355 to 0755, warned that the area could expect continued thunderstorm development that met convective SIGMET criteria. The accident site was within this outlook region. The Geostationary Operations Environmental Satellite number 12 image for 0132 displayed two large convective systems on either side of the direct route between Alpine and Lubbock (which ran south to north). The accident site was located on the southwestern side of the eastern system. The image for 0215 also displayed the accident site between two large convective systems. A comparison between the 0132 and 0215 images revealed the cloud system to the west had moved to the west-southwest with the cloud tops lowering, and the system to the east had pushed southward and had developed a defined leading edge band of cumulonimbus clouds. The NWS Radar Summary Chart for 0217 depicted an area of echoes associated with thunderstorms and rain showers stretching across southwest to eastern Texas and Louisiana. The area of echoes began in the vicinity of the accident site and turned into a solid line of thunderstorms associated with intense to extreme intensity echoes to the east of the accident site, with another area of very light intensity echoes to the west. The NWS Surface Analysis Chart for 0300 depicted the primary surface features within the hour of the accident. The chart depicted a stationary front extending east-to-west central Texas into northern Mexico in the immediate vicinity of the accident site. A squall line or instability band was depicted south of the stationary front across Texas, east of the accident site. The station models in the vicinity of the accident site indicated temperatures ranging from the low 70's (degrees Fahrenheit) south of the front to the upper 50's north of the front, and west of the accident site. Dew point temperatures were in the mid to upper 60's south of the front and decreased rapidly to the west of the accident site to the mid 50's. Cloud cover varied from overcast skies along the front to clear west of the accident site. The closest upper air or rawinsonde observation was from the NWS Midland Regional Forecast Office, Midland, Texas, located approximately 62 miles northeast of the accident site and was issued at 1800, on March 20th. The sounding provided a maximum probable gust from thunderstorms of 57 knots, and a microburst maximum gust potential of 67 knots. The area forecast for southwestern Texas, which was issued at 1234 on March 20, 2004, and was valid until 0200, was for clear skies or scattered cirrus clouds. From 1800, on March 20, 2004, the forecast called for scattered-to-broken clouds at 5,000 feet agl with widely scattered thunderstorms and light rain, with cumulonimbus cloud tops to 35,000 feet. The outlook, from 0200 to 0800 on March 21, 2004, was for VFR conditions with thunderstorms and moderate rain. The closest terminal aerodrome forecast (TAF) to the accident site was for Winkler County Airport, Wink, Texas, located approximately 29 miles north of the accident site at an elevation of 2,820 feet. The TAFs are valid for a 5-mile radius of the airport center point. Temporarily from 2300 to 0200, the forecast called for a visibility of 1/2 mile in thunderstorms and heavy rain, and an overcast ceiling at 1,000 feet in cumulonimbus clouds. At 0027, the ODO (original departure point) automated surface observing system (ASOS), located approximately 50 miles north-northeast of the accident site, reported the wind from 050 degrees at 16 knots, visibility 10 statute miles, broken cloud layers at 2,000, 2,400, and 11,000 feet agl, temperature 17 degrees Celsius, dew point 13 degrees Celsius, and an altimeter setting of 30.40 inches of mercury. The closest weather reporting location to the accident site was from Pecos Municipal Airport (KPEQ), Pecos, Texas, located approximately 19 miles west of the accident site at an elevation of 2,613 feet msl. The airport had an Automated Weather Observing System (AWOS), which reported the weather conditions every 20 minutes. At 0125, PEQ AWOS reported the wind from 120 degrees at 6 knots, visibility 10 statute miles, sky clear below 12,000 feet, temperature 20 degrees Celsius, dew point 15 degrees Celsius, and an altimeter setting of 30.32 inches of mercury. At 0225, PEQ AWOS reported the wind from 010 degrees at 3 knots, visibility 10 statute miles, sky clear below 12,000 feet, temperature 19 degrees Celsius, dew point 15 degrees Celsius, and an altimeter setting of 30.30 inches of mercury. There was no report of the pilot obtaining any formal preflight weather briefing (from a flight service station, DUATS or WSI weather program) prior to departure or en route. According to the U.S. Naval Observatory astronomical data for Pyote, Texas, the moonset was at 1903 on March 20, 2004. The phase of the moon was a waxing crescent with 1 percent of the moon's visible disk illuminated. A family traveling in a recreational vehicle from El Paso, Texas, northeastward on Interstate 20 reported the weather conditions they encountered while en route in the vicinity of the accident. They reported they could see a defined thunderstorm in the distance from the time they left El Paso. Approximately 0030, when they were approximately 15 miles west of Pecos, they encountered what they called a "strong storm front" that almost blew them off the road. They indicated that there was no precipitation, only extremely high winds and dust. They continued in the storm at a slower speed to approximately Monahans, Texas, which was located approximately 15 miles northeast of the accident site. They described the storm as being "vicious" and almost took them off the road, and they could barely control their vehicle through the storm. The local authorities also reported strong thunderstorms throughout the area around the time of the accident. The FAA Advisory Circular 00-24B "Thunderstorms" identifies the hazards associated with thunderstorms. Section C of that advisory deals with turbulence associated with thunderstorms and identifies a gust front. The advisory states that potentially hazardous turbul

Probable Cause and Findings

The pilot's inadvertent encounter with adverse weather, which resulted in the pilot failing to maintain terrain clearance. Contributing factors were the dark night conditions, the pilot's inadequate preflight preparation and planning, and the pressure to complete the mission induced by the pilot as a result of the nature of the EMS mission.

 

Source: NTSB Aviation Accident Database

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