Powhatan, VA, USA
UNK
BOEING 757
The pilots of a Boeing 757 air carrier flight and a regional jet both reported to an air route traffic controller that they had encountered severe turbulence while en route on instrument flight. The controller asked the Boeing 757 pilot to confirm that the turbulence occurred between flight level 370 and 360; the pilot confirmed the information, and no further communications were made regarding the turbulence encounter. After landing, all four flight attendants and several passengers aboard the flight were transported to the hospital (later, no injuries were reported), and a postflight examination of the airplane revealed hail damage, which required the radome to be replaced. Shortly after the 757 pilot reported the severe turbulence, the pilot of the regional jet checked in the with the air route traffic controller, and the controller informed him about the reported severe turbulence and authorized a deviation. About 7 minutes later, the regional jet pilot reported that the flight had encountered severe turbulence and requested a lower altitude. The flight crew reported no damage or injuries. Review of recorded Federal Aviation Administration (FAA) radar weather information showed an area of moderate-to-extreme intensity precipitation along the airplanes' routes of flight. Despite the available weather information and numerous pilot requests for weather deviations (including before the 757 pilot reported the turbulence), the controller did not advise any pilots of flights under his control of the significant areas of radar-observed precipitation along their routes of flight in accordance with FAA Order 7110, "Air Traffic Control." Further, the air route traffic control center's facility support manager for quality control stated that the center had no program to ensure that displayed precipitation information was being provided to flight crews as required; the center has since made several corrective changes, including a remedial training program and performance monitoring, to ensure that weather services are provided to flight crews as required. In addition, if the flight crews had detected the precipitation using the on-board radar and then requested deviations, as necessary, they may have been able to avoid encountering the severe turbulence.
AWE815 was en route from Orlando, Florida, to Philadelphia, Pennsylvania, and contacted ZDC sector 16 at 1930:42, reporting level at FL390. At 1935:04, the R16 controller instructed AWE815 to descend and maintain FL350. The pilot acknowledged. At 1939:02, the controller instructed AWE815 to cross SHONA intersection at FL310. The pilot began to acknowledge, transmitting, "SHONA at 310 Cactus 8 uh 15, we're in…we're in severe turbulence." At 1939:42, the pilot of AWE815 transmitted, "OK – say again for Cactus 815?" The controller reissued the crossing restriction at SHONA, the pilot acknowledged, and the controller then asked the pilot for further information about the reported turbulence. At 1939:56, the pilot responded, "Well, it lasted about, uh, wherever we just were, just about uh, ten south of Flat Rock, and it lasted about 30 seconds." The controller asked the pilot to confirm that the event occurred between FL370 and FL360, and the pilot did so. The controller then asked the pilot if he needed anything else, and the pilot replied, "We just need to catch our breath here." There were no further exchanges about the turbulence encounter with AWE815, and the pilot was instructed to contact the next sector at 1944:05. The crew did not report any damage or injuries before changing frequencies. At 1938:34, JIA4678 checked in with the R16 controller, reporting climbing through FL270 to FL330. At 1941:14, after the severe turbulence report from AWE815, the R16 controller advised the crew of JIA4678 that they could deviate right or left as they deemed necessary, adding that a report of severe turbulence had occurred at their 12:00 position and 45 to 50 miles. The pilot responded, "Appreciate it – deviations approved." The controller continued, "…and uh yeah 50 miles straight ahead and he was out of 37 for 36." At 1944:22, the pilot of JIA4678 asked, "Any chance of direct COYLE?" At 1944:52, after talking to another aircraft, the controller responded, "I can't do direct COYLE – I can do direct AGARD." The crew accepted direct AGARD, and the controller continued, "If you need to deviate to the right that's approved, go direct AGARD when able, that's 15 degrees right about." The pilot accepted the clearance and approval of the deviation. At 1947:07, the controller asked the pilot of JIA4678, "How's the ride through the weather?, and the pilot responded, "Uh, pretty smooth." At 1948:06, JIA4678 called and the controller responded, "Go ahead." The pilot then stated, "Uh we're reporting severe turbulence, and we'd like to level off here at FL320." The controller acknowledged the report and told the crew to do what they needed to do, including deviate right "to get out of it," and to go direct AGARD when able. The pilot responded, "AGARD when able, right turn, and uh, does that look better?" The controller replied, "Yeah," and again told the crew to, "…do what they needed to do to get out of it." At 1948:53, the controller instructed the pilot of AWE778 to fly heading 010 to go around the area where they turbulence reports had occurred. The pilot asked if a lower altitude would be better, and the R16 controller replied that he did not know because there were no other aircraft at lower altitude to provide a report. The pilot then requested FL270, and was assigned FL280. The controller then asked the crew of JIA4678 to advise when they were "out of it." The crew reported that they were out, and were climbing to FL330. They additionally recommended that aircraft stay away from the area 10 miles south of Flat Rock. JIA4678 was transferred to the next sector at 1951:11. The crew did not report any damage or injuries. At 1950:17, the R16 controller coordinated with another sector to accommodate a northerly deviation for AWE778, stating, "I'm going to run north around that weather and then go to Nottingham, I've got severe turbulence in that cloud there." During the approximately 1 3/4 hour session on the R16 position, no compliance with FAA order 7110.65, "Air Traffic Control", paragraph 2-6-4, "Weather and Chaff Services," was noted, although there were clearly areas of precipitation present in the sector as evidenced by review of recorded WARP/NEXRAD data, comments about weather made by the controller to several pilots, and numerous pilot requests for weather deviations. According to information provided by the facility support manager for quality control, ZDC had no program for live monitoring of weather services to ensure that displayed precipitation information was being provided to flight crews as required. Two pilot reports about the severe turbulence encounters were submitted by the R16 controller following the incidents. According to information supplied by American Airlines, all four flight attendants and several passengers aboard AWE815 requested medical examinations following the flight, although none of them reported injuries meeting the standard for an aircraft accident. Two of the flight attendants remained in a non-duty status for at least three weeks after the incident. The aircraft sustained hail damage and required replacement of the radome. For further information, see the air traffic control group chairman's report in the docket for this case.
The air traffic controller’s failure to provide required advisories about significant radar-observed convective precipitation along both airplanes’ flight routes and the air route traffic control center’s lack of a program to ensure that air traffic controllers provide this required information to pilots, which led to both airplanes encountering severe turbulence. Contributing to the airplanes’ encounters with severe turbulence was the flight crews’ failure to detect the precipitation using on-board radar and request deviations, as necessary, to avoid the hazard.
Source: NTSB Aviation Accident Database
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