Incident Overview

Date: Monday 16 December 2019
Aircraft Type: Embraer ERJ-140LR
Owner/operator: Envoy Air, opf American Eagle
Registration Number: N805AE
Location: Alexandria, Louisiana – ÿ United States of America
Phase of Flight: En route
Casualties: Fatalities: 0 / Occupants: 39
Component Affected: Aircraft Flight Controls (Autopilot, Thrust, Speed Brakes, Canopy)Aircraft Flight Controls (Autopilot, Thrust, Speed Brakes, Canopy)
Investigating Agency: NTSBNTSB
Category: Accident
On December 16, 2019, an Envoy flight 3960, an EMB140, experienced severe turbulence during cruise flight to Gainesville Regional Airport (KGNV) due to convective activity. The flight crew reported seeing ‘nothing worse than moderate chop’ from a CRJ aircraft an hour prior, and then experienced rapid, intense turbulence. The flight was operating under 14 Code of Federal Regulations Part 121, a regularly scheduled domestic flight from Dallas-Fort Worth International Airport (KDFW) to KGNV. The pilot initiated maneuvers to visually avoid the convective activity, resulting in the aircraft entering a state of reduced visibility and rapid turbulence. The flight attendant secured the seatbelts, and the captain announced potential turbulence. Approximately 50 miles from GNV, the captain commanded the flight to reduce thrust and deploy speed brakes, leading to significant vertical speed fluctuations. The autopilot was disengaged, and the aircraft transitioned to a normal flight path. The injured passenger sustained injuries, including neck fractures, and was subsequently transported to a local hospital. The incident was attributed to a convergence of factors, including convective activity, the pilot’s maneuvering around the turbulence, and the aircraft’s response to the rapidly changing weather conditions. The NWS issued a moderate risk of severe thunderstorms and a Convective SIGMET current in the area.On December 16, 2019, an Envoy flight 3960, an EMB140, experienced severe turbulence during cruise flight to Gainesville Regional Airport (KGNV) due to convective activity. The flight crew reported seeing ‘nothing worse than moderate chop’ from a CRJ aircraft an hour prior, and then experienced rapid, intense turbulence. The flight was operating under 14 Code of Federal Regulations Part 121, a regularly scheduled domestic flight from Dallas-Fort Worth International Airport (KDFW) to KGNV. The pilot initiated maneuvers to visually avoid the convective activity, resulting in the aircraft entering a state of reduced visibility and rapid turbulence. The flight attendant secured the seatbelts, and the captain announced potential turbulence. Approximately 50 miles from GNV, the captain commanded the flight to reduce thrust and deploy speed brakes, leading to significant vertical speed fluctuations. The autopilot was disengaged, and the aircraft transitioned to a normal flight path. The injured passenger sustained injuries, including neck fractures, and was subsequently transported to a local hospital. The incident was attributed to a convergence of factors, including convective activity, the pilot’s maneuvering around the turbulence, and the aircraft’s response to the rapidly changing weather conditions. The NWS issued a moderate risk of severe thunderstorms and a Convective SIGMET current in the area.

Description

On December 16, 2019 at about 13:23 CST, Envoy flight 3960, an EMB140, N805AE, encountered severe turbulence during cruise flight while enroute to Gainesville Regional Airport (KGNV), Gainesville, Florida.ÿ Of the 39 passengers and crew onboard, one passenger sustained serious injuries. The airplane was not damaged. The flight was operating under14 Code of Federal Regulations Part 121 as a regularly scheduled domestic passenger flight from Dallas-Ft Worth International Airport (KDFW), Dallas, Texas, to KGNV. According to the flight crew, as the flight was cruising at flight level (FL) 370 in visual meteorological conditions, they could see convective activity ahead. Air traffic control informed them that pilot reports along their route of flight had reported “nothing worse than moderate chop”ÿwith one report of “severe turbulence” from a CRJ that was an hour old.ÿ About 50 miles from GNV, the captain made an announcementÿto the passengers about impeding weather and possible turbulence and requested that the flight attendant (FA) take her seat.ÿÿÿThe seat belt sign was illuminated. As the flight approached the weather, the first officer (FO), who was the pilot flying, began to maneuver around several cells visually. The airplane radar did not show any returns. Upon entering visible moisture, moderate rain and turbulence began immediately but increased rapidly in intensity. Airspeed and altitude began fluctuating rapidly and upon receiving an over speed warning, the FO retarded the thrust levers to idle and deployed the speed brakes. Large fluctuations in vertical speed continued to occur and the autopilot automatically disengaged simultaneously with stick shaker activation. EICAS displayed AUTOPILOT FAIL and YAW DAMPER FAIL. Shortly after, the FO returned the airplane to a normal flight condition and returned to FL 370. The captain informed ATC that the flight had encountered severe turbulence and then contacted the FA to check on if there were any injuries. At that time, the FA reported no injuries; however, approximately 5 minutes later the captain was informed that a passenger had been injured. According to the FA and deadheading crewmembers, all passengers and the FA were seated with their seatbelts fastened when the turbulence was encountered. After the turbulence stopped, drinks covered the walls and ceiling, and magazines and electronic devices were located multiple rows from their original location. The injured passenger indicated that her seatbelt, with extender, was fastened, however, she had hit her head ‘pretty hardƒ? and had back and neck pain. The captain notified dispatch and ATC of the injury and requested that paramedics meet the airplane at the gate.ÿ After landing the injured passenger was transported to a local hospital and diagnosed with two small neckÿfractures.ÿ Post accident examination of the weather data determined that the flight encountered convectively induced turbulence after penetrating cumulonimbus clouds, with tops near FL400, while attempting to overfly a large area of known convection. In the area of the encounter, Weather Surveillance Radar depicted extreme echoes at lower altitudes with lighter echoes at the airplane’s altitude, with lightning in the vicinity. The National Weather Service (NWS) Convective Outlook had warned of a moderate risk of severe thunderstorms over the area. In addition, there was a NWS tornado watch and a Convective SIGMET current for severe embedded thunderstorms in the area.ÿ Probable Cause: an encounter with convectively induced turbulence while overflying an area of known convective activity.

Primary Cause

Convective turbulence during overflight of known convective activity.Convective turbulence during overflight of known convective activity.

Share on:

Leave a Reply

Your email address will not be published. Required fields are marked *