Dhc-8 flight crew reported turbulence during descent that injured the flight attendant.

Attributes
ACN	1424173
Time
Date	201702
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Flight Deck / Cabin / Aircraft Event Illness Inflight Event / Encounter Weather / Turbulence

Narrative:

Flight was smooth during the cruise portion of the flight. As we started our descent from 17000 feet it was also smooth and no turbulence was noticed. After we finished the before landing checklist and level at 4000 ft approximately 50 miles south of ZZZ we encountered a pocket of heavy turbulent air and the aircraft suddenly dropped 800 ft per minute and lost about 400-500 ft in altitude. Concerned about the passengers and flight attendant; I tried calling the flight attendant in the cabin but she did not answer. So I called again and she answered the phone and right away I knew she was in pain due to her voice. She told me she hurt her leg really bad and she couldn't walk. I [advised ATC] and asked for medical personnel to meet the plane at the gate.

Original NASA ASRS Text

Title: DHC-8 flight crew reported turbulence during descent that injured the Flight Attendant.

Narrative: Flight was smooth during the cruise portion of the flight. As we started our descent from 17000 feet it was also smooth and no turbulence was noticed. After we finished the before landing checklist and level at 4000 ft approximately 50 miles south of ZZZ we encountered a pocket of heavy turbulent air and the aircraft suddenly dropped 800 ft per minute and lost about 400-500 ft in altitude. Concerned about the passengers and FA; I tried calling the FA in the cabin but she did not answer. So I called again and she answered the phone and right away I knew she was in pain due to her voice. She told me she hurt her leg really bad and she couldn't walk. I [advised ATC] and asked for medical personnel to meet the plane at the gate.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.