Date: 202107
Local time of day: 1201-1800
Flight conditions: IMC
Weather elements / visibility: Thunderstorm; Turbulence
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Communication Breakdown
Second reporter function: Pilot Flying; Captain
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action; General Flight Cancelled / Delayed
Contributing factors: Human Factors; Procedure; Weather
Primary problem: Weather

Narrative: On a step climb around FL300; between ZZZ and ZZZZZ; we noticed a weather cell we wanted to deviate around. The Captain had already briefed the FAs (Flight Attendants) about the en route weather; that we would most likely have some bumps; that we were keeping the seat belt sign on; and to use caution. We were in full IMC and our radar return showed that a turn to the left would be best. We requested an initial left turn of 20 degrees but almost immediately we encountered heavy and extreme precipitation and ultimately had to turn 80 degrees. We were given the necessary deviations but then told to go direct ZZZZZ when able as well as climb to FL340. We also encountered moderate and possibly severe turbulence. We experienced both positive and negative G's. The speed tape never went into the red but the trend vector showed both rapid climbing and simultaneous descending trends that took up the entire top to bottom range of the speed tape. The plane was moving quite a bit as we were both in updrafts and then subsequent downdrafts getting bumped around. After about 5 minutes when we could actually get everything sorted out; we called back to check on the status of both the Flight Attendants and Passengers. FA1 answered and she proceeded to tell us there was an accident in the aisle and she would call us back. FA2 was about mid aircraft doing her beverage service when we encountered the worst of the turbulence. She thought she had hit her head and beverages had been thrown from the cart and some passengers tray tables into the ceiling. We consulted our FOM and made the decision we needed to contact Dispatch and make them aware to coordinate with [Maintenance Control]. We continued to keep checking on the FAs for the rest of the flight and as we got closer; FA1 called and said FA2 had requested In-Flight to meet us at the gate. Upon block in; [flight attendant representative] and member of [Company] met the aircraft. CA (Captain) called Dispatch/[Maintenance Control] to explain event and to assess if an aircraft inspection for severe turbulence was required. Based on our reading and interpretation of FOM on the definition of severe turbulence; we determined we encountered severe turbulence. However; [Maintenance Control] said because the autopilot did not disengage; that there was no 'momentary loss of aircraft control' and it was only moderate turbulence which does not require an aircraft inspection. The aircraft was not removed from service; boarding for the next flight started immediately; and [Company] took FA2 for a medical evaluation.Pilot interpretation of FOM differed from [Maintenance Control]. [Maintenance Control] did not accept our interpretation of severe turbulence. It kept them from having to inspect the aircraft and delaying the flight schedule. Any disconnection of autopilot is apparently the determining factor in deciding if aircraft control is lost. There needs to be a more clear definition of what severe versus moderate turbulence is and pilot experience should be held in account. Safety should always be the priority over schedule integrity.


Second narrative: On final climb out from FL300 to FL340 between ZZZ and ZZZZZ intersection; we had to deviate for weather. Seat belt sign was on and FA (Flight Attendant) briefing and PA to passengers included weather/ thunderstorms in the area and to expect a bumpy ride on the climb out. We were in and out of IMC conditions as the weather radar depicted a buildup. We discussed a plan for deviations prior to the radio frequency change that we received at the same time. Originally asked for 20 degree left turn; ATC approved it and said no other traffic in the area do what we need to and cleared back direct ZZZZZ when able.Simultaneously; we encountered heavy to extreme precipitation which FA1 later said she could hear In the galley. FA1 started to clean up galley and observed FA2 in the middle of aircraft conducting beverage service. We continued the left turn to approximately a 270 degree heading due to the intensity of precipitation and increasing turbulence; while still trying to climb to FL340. In the turn and climb; we encountered moderate to potentially severe turbulence: VSI showed +/- 2000 fpm climb; ASI showed a white positive and negative trend vector for the entire range of speed tape; and we experienced zero G and positive G due to the turbulence.Once clear of the weather; we immediately called the FAs to get a status of the cabin. FA1 answered and she said there was an accident in the aisle. A few minutes later; she called back and reported that FA2 believes she hit her head on the ceiling and the surrounding passengers in the area agreed. Beverages had spilled on to passengers and were also dripping from the ceiling. Throughout the rest of the flight; we were in constant communication with the cabin on the status of FA2 and the passengers; as well as Dispatch/[Maintenance Control] via ACARS. FA1 requested that inflight meet us at the gate for FA2.Upon block in; a member from inflight and from [Company] met the aircraft. CA (Captain) called Dispatch/[Maintenance Control] to explain the event and to assess if an aircraft inspection for severe turbulence was required. Based on our reading and interpretation of FOM on the definition of severe turbulence; we determined we encountered severe turbulence. However; [Maintenance Control] said because the autopilot did not disengage; that there was no 'momentary loss of aircraft control' and it was only moderate turbulence which does not require an aircraft inspection. The aircraft was not removed from service; boarding for the next flight started immediately; and inflight took FA2 for a medical assessment.Pilot interpretation of company FOM definition and procedures differed from [Maintenance Control] definition and interpretation of company FOM defined severe turbulence [Maintenance Control] decided NOT to err on the side of safety and do a precautionary severe turbulence inspection of the aircraft due to their interpretation of the FOM severe turbulence definition; solely based on the fact that the autopilot did not disconnect during the event in order to save the integrity of the flight schedule. In the interest of safety; a severe turbulence inspection should have been conducted and a better definition of severe turbulence needs to be updated in company FOM defining what 'momentary loss of aircraft control' means. Safety should always be a priority over schedule integrity.


Synopsis: EMB-175 Flight Crew reported turbulence injured a Flight Attendant. The flight crew reported the event to Maintenance as severe turbulence; but Maintenance overruled them and stated it was moderate turbulence; reportedly to not have to inspect the aircraft and delay the flight.