Sevierville, TN, USA
N4478F
PIPER PA-32R-300
Before departure, the pilot had contacted the air traffic control (ATC) facility and received his instrument flight rules (IFR) clearance, which entailed flying direct to a navigational facility about 22 miles west of the departure airport. Shortly after departure, the pilot contacted ATC, and was given radar vectors toward that navigational facility and toward rising terrain. Because the airplane was in instrument conditions, the pilot was unable to see the surrounding terrain. When the airplane’s global position system's terrain feature alerted the pilot of a possible terrain issue, the pilot queried the air traffic controller. However, before the controller responded, the airplane impacted a pole and trees; a postimpact fire ensued and consumed the airplane. The Federal Aviation Administration (FAA) defines minimum vectoring altitude (MVA) as the lowest altitude at which an IFR aircraft will be vectored by a radar controller to ensure obstacle clearance. The FAA further states that air traffic controllers are to give first priority to separating aircraft, issuing safety alerts, and providing safety alerts regarding terrain or obstructions. Despite FAA requirements, a review of accident-related ATC radar and voice data revealed that ATC personnel issued a radar vector without first identifying the accident airplane on radar, provided radar vectors when the airplane was below the MVA, and did not provide safety alerts to the accident airplane or another airplane that had departed just before the accident flight. Interviews with the accident ATC personnel indicated that a facility-wide culture of providing vectors to aircraft below minimum altitudes existed, air traffic controllers supervised other controllers while performing operational duties, and the facility was non-compliant with safety alert requirements. The accident air traffic controller failed to adhere to the required procedures for vectoring and providing appropriate safety alerts, which negated the safety margins afforded by those procedures. This culture of disregard for standard operating procedures among the controller workforce at the ATC facility was indicative of a continuous failure of management at the facility.
HISTORY OF FLIGHT On October 28, 2012, about 1434 eastern daylight time, a Piper PA-32R-300, N4478F, impacted a pole and trees after departure from Gatlinburg-Pigeon Forge Airport (GKT), Sevierville, Tennessee. The private pilot and one passenger were not injured, and three passengers received minor injuries. The airplane, forward of the empennage, was consumed by postimpact fire. The airplane was registered to Space Coast Aviation Sales LLC and operated by a private individual under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions were present at the departure airport; however, instrument meteorological conditions prevailed in the area and an instrument flight rules (IFR) flight plan had been filed for the flight destined for the Space Coast Regional Airport (TIX), Titusville, Florida. The pilot filed an IFR flight plan at 1328, utilizing the Direct User Access Terminal System (DUATS). The flight plan filed anticipated departing from GKT to TIX via the Volunteer (VXV) very high frequency omni-directional radio range tactical air navigation aid (VORTAC), direct to the DUBBS intersection, direct to the NELLO intersection, direct to the Craig (CRG) VORTAC, Ormond (OMN) VORTAC, and then direct to the destination airport with a cruise altitude of 6,000 feet msl. The flight was provided radar vectors by an air traffic controller at a nearby approach control facility. The pilot had received a terrain warning on his global positioning system (GPS) and queried the controller; however, he received no reply. Subsequently the GPS provided an obstacle warning, and the pilot observed a rooftop and trees through the clouds. He pitched up and banked the airplane in order to clear the obstacles, however, the underside of the airplane impacted several trees, and the airplane came to rest inverted in a tree, about 15 feet above ground level. A postimpact fire began and the occupants exited the airplane. PERSONNEL INFORMATION The pilot, age 48, held a private pilot certificate with ratings for airplane single-engine land and instrument airplane, and a Federal Aviation Administration (FAA) third-class medical issued June 23, 2011. The pilot reported 502 total flight hours, with 242 hours in the accident airplane make and model. The pilot estimated that he had approximately 80 hours of instrument flight experience; however, since his pilot logbook was consumed by the post impact fire, his exact instrument flight experience could not be accurately determined. AIRCRAFT INFORMATION The seven-seat, low-wing, retractable-gear airplane was manufactured in 1976. It was powered by a Lycoming IO-540-K1GSD 300 horsepower engine, and equipped with a Hartzell model HC-C2YK-1BF controllable pitch propeller. The airplane was equipped with a Garmin GNS430 GPS navigation system with an integrated terrain database. According to the pilot, the airplane’s most recent annual inspection was completed on July 31, 2012, at a recorded airframe total time of 3,051 hours, and the engine time since overhaul was 1,271 hours. Thermal damage precluded determination of the current values from the instruments. According to the pilot, the gross weight at the time of the accident was 3,461 pounds. METEOROLOGICAL INFORMATION A review of recorded data from the GKT automated weather observation station revealed the 1420 conditions included wind 330 at 7 knots, visibility 3 miles, scattered clouds at 1,000 feet above ground level (agl), overcast at 1,700 feet agl, temperature 8 degrees C, dew point 7 degrees C, and a barometric altimeter setting of 29.89 inches of mercury. COMMUNICATION According to voice and radar data provided by the FAA air traffic control facility in Knoxville, Tennessee (TYS), located about 22 nautical miles west of the departure airport, the pilot first contacted TYS at 1419. He requested and received his IFR clearance as filed, and was assigned an initial altitude of 5,000 feet msl. At 1428:01, the pilot reported that he was number one for departure from runway 28 and, was subsequently released for departure by the controller. The pilot was told to contact the same controller when the flight was airborne. At 1430:28, the pilot reported climbing through 1,500 feet. About one minute later he was asked to "ident" and subsequently received clearance to continue the climb to 6,000 feet. At 1430:36, the first recorded radar data target indicated that the airplane was at 1,400 feet msl. At 1431:52, the controller stated "seven eight foxtrot did you want to go all the way to volunteer or do you want some vectors for departure and then direct dubbs in about fifty miles or so". The pilot acknowledged with "vectors will be fine." At 1432:02, the controller instructed the pilot to "fly heading two six zero climb and maintain six thousand." Radar data indicated that about the same time, the airplane's ground track indicated a left turn towards the assigned heading. The last recorded transmission from the accident pilot occurred at 1434:05, in which he stated "and uh knoxville seven eight fox uh we getting a uh terrain advisory are we still in the clear." The associated radar data indicated that the airplane altitude was 2,400 feet msl. At 1435:19, the controller stated "say uh traffic I mean not traffic uh a obstruction thirty four hundred feet fly heading uh two niner zero for now" On November 5, 2012, the NTSB convened an Air Traffic Control (ATC) Group at TYS to review radar and voice data, as well as interview facility managers and controllers. On November 7, 2012, the accident flight's controller was interviewed. After review of the radar playback, the controller acknowledged that he had not radar identified the accident airplane, and that he issued a radar vector without the required radar identification. He further acknowledged that he had not issued the pilot a safety alert, even though the airplane was maneuvering below the FAA charted minimum vectoring altitude (MVA). The controller also reported that just prior to the accident, he was obtaining flight strips from the unmanned flight data position. Several other controllers and managers were interviewed by the ATC Group, and the consensus among those interviewed was that deviation from the approved departure procedure occurred on a "regular basis," and the controllers would normally query the pilot to confirm that the terrain was in sight and also give a suggested heading. It was noted that prior to the accident flight, another airplane had departed from GKT, and was given the same turn below MVA and was not issued a safety alert. Refer to the accident docket for detailed information about the ATC Group's investigation. AIRPORT INFORMATION GKT was a publically-owned airport and at the time of the accident, did not have an operating control tower. The airport was equipped with a single runway designated as runway 10/28. The runway was 5,506 feet long by 75 feet wide. The airport elevation was 1,014 feet above mean sea level. The local topography consisted of rising mountain terrain primarily to the west, south, and east of the airport. The airport was situated about 6 nautical miles to the northeast of the accident site. A receipt provided by the fixed base operator at GKT indicated that on the day of the accident, the accident airplane was fueled with 44 gallons of 100LL Avgas. In a review of the FAA MVA chart for the surrounding areas, the minimum altitudes varied from 3,200 feet msl to 8,000 feet msl, with the highest MVA elevations located south and southeast of the airport. In the area of the accident site, the MVA was charted as 4,400 feet msl. WRECKAGE AND IMPACT INFORMATION Examination of the airplane by a FAA inspector revealed that the airplane initially impacted a pole and some trees located on a mountain about 2,600 feet above mean sea level. The airplane was consumed by post-impact fire, except for approximately 6 feet of the empennage. Control cable continuity was confirmed throughout the airplane. Several tree limbs exhibited marks consistent with being cut by the airplane's propeller during the impact sequence. One of the two propeller blades exhibited curling on its tip, and the other exhibited slight bowing in the forward direction. According to the pilot, there were no mechanical malfunctions or anomalies that would have precluded normal operation of the airplane According to a topographical chart provided by the Sheriff's Department, the area around the flight track, leading to the accident site, consisted of tightly-spaced contour lines, indicative of rapidly rising terrain. The accident location was located near a contour line of 2,520 feet, with the highest contour line indicating 2,600 feet. ADDITIONAL INFORMATION FAA Publication JO7110-65U "Air Traffic Organization Policy" Minimum Vectoring Altitude (MVA) is defined as "The lowest MSL altitude at which an IFR aircraft will be vectored by a radar controller, except as otherwise authorized for radar approaches, departures, and missed approaches. The altitude meets IFR obstacle clearance criteria…It may be utilized for radar vectoring only upon the controller's determination that an adequate radar return is being received from the aircraft being controlled…" Section 2-1-2 "Duty Priority" states in part "give first priority to separating aircraft and issuing safety alerts as required…good judgment must be used in prioritizing all other provision…" Section 2-1-29 "Terrain Awareness Warning System (TAWS) Alerts" states in part "…provide safety alerts regarding terrain or obstructions…" According to Section 5-6-3 "Vectors Below Minimum Altitude" an aircraft may be vectored below minimum altitude "if the flight path is 3 miles or more from the obstacle." GKT Departure Procedure According to the Terminal Procedures Publication current at the time of the accident, the obstacle departure procedure for runway 28 was to climb direct to VXV VORTAC to 5,000 feet before turning on course. Air Traffic Controller Duties At the time of the accident, the radar room was manned by two controllers, the accident controller and one other controller. Each controller had the assigned operational responsibility of the radar for specific airspace sectors. The other controller was also the controller in charge (CIC) and was tasked with oversight and supervision of the radar room and facility. His duties included overseeing the accident controller at the time of the accident while performing required operational duties. A frontline manager was also present in the facility; however, at the time of the accident he was in an office, which was not located in the radar room, performing administrative duties. Neither the CIC nor the Frontline Manager observed the controller's interaction with the accident airplane. FAA Advisory Circular 61-134 FAA Advisory Circular 61-134 Section 9 "GA [General Aviation] IFR Operations in IMC Conditions on an IFR Flight" states in part "Techniques or suggestions for avoiding some of these IFR risk factors include:… d. Knowing the planned procedure well enough to know if air traffic is issuing an unsafe clearance… k. knowledge of minimum safe or sector altitude and of the highest terrain in the area…" NTSB Recommendations The NTSB issued a safety recommendation A-11-17 to the FAA on March 21, 2011, recommending that the FAA prohibit air traffic controllers from providing supervisory oversight while performing operational air traffic duties. At the time of this writing, this recommendation remains open with a status of "open – unacceptable response."
The air traffic controller’s failure to comply with the required vectoring and safety alert procedures, which resulted in the airplane’s flight into rising terrain. Contributing to the accident was the Federal Aviation Administration’s continued practice of using air traffic controllers who were performing required radar operational duties to supervise other controllers and the air traffic control facility’s culture of non-compliance with required procedures.
Source: NTSB Aviation Accident Database
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