Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Altitude Overshoot; Inflight Event / Encounter Weather / Turbulence
Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; General Maintenance Action
Weather; Procedure; Airspace Structure
Severe turbulence was encountered during arrival / descent phase of flight due to convective weather. This document is being submitted to give account of severe turbulence encountered during the arrival phase of flight. The First Officer was pilot flying and I was pilot monitoring. The initial visual condition was VFR and the towering cumulonimbus cloud formations were north of our position. I made a PA announcement to our passengers advising them of our potential turbulent flight conditions; weather at the airport; and estimated arrival time to the airport. During the beginning of the descent into the airport on the arrival; Approach Control advised all flights of weather conditions associated with moderate; heavy; and extreme precipitation. We were advised to expect course deviations; and thence to resume the arrival. Also advised all flights that course deviations to the west were not available at that time. ATC assigned us to fly heading 040; descend from FL210 to FL190; and maintain 250 knots. We could the see weather in the distance. As we leveled off; I contacted the Flight Attendant and advised her to return to her station due impending weather ahead. I consulted with my First Officer to cross reference and assess we were seeing visually with the radar return. We considered turning left because it seemed clear of weather but sure of traffic. ATC frequency was inundated with multiple transmissions. Collectively; we decided to elect to continue straight ahead on course; disengaged the autopilot to fly manually; and reduce airspeed toward 200 KIAS to ride out possible up and down drafts. I turned igniters switches to on. We entered the cloud formation and experienced moderated to severe turbulence associated with heavy to extreme precipitation. I considered the turbulence to be severe because it was difficult to maintain the assigned altitude. I observed a 2;000 feet per minute descent trend on the VSI and we lost approximately 300 - 500 feet from assigned altitude. The First Officer did a great job to maintain aircraft upright attitude and airspeed. Once clear of the weather; the First Officer returned to the assigned altitude and airspeed. I gave a PIREP to the ATC controller to advise not to direct traffic towards that vicinity because we encountered severe turbulence with heavy to extreme precipitation. I contacted the Flight Attendant to get an updated status on her condition and to get a status on the passengers for possible injuries incurred. The aircraft condition appeared normal and verified with the First Officer the flight characteristics of the aircraft. He confirmed that aircraft was flying normal with no abnormalities. The Flight Attendant followed up and reported the cabin was secure and no passengers sustained any injuries. I notified ATC that the passengers; and crew were well with no injuries sustained. The aircraft did not appear to have any abnormalities or damage. We were ready to resume the arrival into the airport.Once things settled down; I informed with company dispatch via ACARS of the severe turbulence encounter. I also contacted Operations for the in-range call to give status update on passengers and requested to have a Customer Service Representative or supervisor meet us once we arrived at the gate. The flight continued to the airport without further incident. The First Officer completed his post flight walk-around report no damaged to aircraft being discovered. Once the flight was completed; I initiated a maintenance write up to have the aircraft inspected for the severe turbulence encounter and called it in to Dispatch and Maintenance Control. I debriefed with the flight duty manager and subsequently the Chief Pilot.
I was the Pilot Flying. The Captain was the Pilot Monitoring. As part of our descent planning; we noted strong storm build-up on the flight path for our assigned arrival into the airport. Our radar was identifying the build-up and we heard preceding aircrews discussing it with ATC. The preceding aircrews were requesting vectors around the build-up; but most were being told the request could not be accommodated. The Captain requested a left (west) deviation around the build-up; and ATC replied they were unable to approve the request. We were concerned about flying through the build-up. Preceding aircrews also seemed frustrated based on their conversations with ATC. As we approached the build-up on the arrival; we were assigned a descent down to FL 190. The Captain notified the Flight Attendant to ensure passengers were seated and buckled in; and for her to be seated and buckled in. The autopilot was engaged; and I commanded a 1;000 FPM descent rate. I also slowed the aircraft to approximately 250 knots. I did not want the aircraft too fast to avoid structural damage; nor too slow to avoid a stall situation. As we descended into the build-up; the aircraft began shaking more than normal when flying through turbulence. The autopilot was still flying; but I had my hands on the yoke and feet on the rudder pedals; just in case it disconnected; and the aircraft was placed into an unusual attitude. The descent rate varied; although I cannot recall the maximum rate of descent. The Captain stated the descent rate reached 2;000 FPM; even though I had commanded a 1;000 FPM rate. We began experiencing the most severe hail and rain that I've experienced as a pilot. That was a bit more concerning to me than the turbulence. I had been in severe turbulence in the past; but never hail that heavy. It was quite loud. The Captain notified ATC with a PIREP that we were experiencing severe turbulence and heavy hail. As we approached FL 190; the autopilot appeared to be leveling; but it passed below FL 190. I immediately disconnected the autopilot; ensured my airspeed was approximately 250 knots; the wings were level; and I began leveling out the altitude. We passed approximately 300 to 500 feet below our assigned altitude. Once the aircraft was stable and we were out of the build-up; I immediately added power and climbed back to FL190. The aircraft seemed to be handling/operating normally; all engine indications were normal; and we did not have any EICAS messages. The Captain contacted the Flight Attendant to determine if she was okay and to ensure none of the passengers were injured. The Captain informed ATC that the aircraft appeared to be operating properly and there were no known injuries onboard. The rest of the flight was uneventful. Following aircraft shutdown; I completed a thorough aircraft inspection and did not see any damage to the aircraft. I found it unusual that ATC could not approve deviations around weather that multiple aircrews were concerned about and having to fly through. I do not want to place blame on ATC; as I do not have the bigger picture. The incident was the first time for me where ATC had not been able to accommodate a deviation around strong build-up. I hope ATC and aircrews can work better in the future to avoid flying through that type of weather.
Air carrier flight crew reported severe turbulence on descent.