A captain reported a 900 ft altitude loss after encountering severe turbulence a FL210 along with he...

Attributes
ACN	937163
Time
Date	201102
Local Time Of Day	1801-2400
Place
Locale Reference	ZAU.ARTCC
State Reference	IL
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Make Model Name	Medium Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence

Narrative:

[We were] enroute several aircraft reporting occasional severe turbulence. We were assigned headings from chicago center to avoid known areas. We seated all passengers and the flight attendant as a precautionary measure. Just south of cgt VOR at FL210 we experienced severe turbulence and a loss of approximately 800-1;000 ft of altitude. We reported to ATC and were re-assigned an altitude of FL200. No traffic conflicts were observed or reported by us or ATC. Aircraft continued to mke without incident.

Original NASA ASRS Text

Title: A Captain reported a 900 FT altitude loss after encountering severe turbulence a FL210 along with heavy rain. ATC assigned a lower altitude and the flight continued to its destination.

Narrative: [We were] enroute several aircraft reporting occasional severe turbulence. We were assigned headings from Chicago Center to avoid known areas. We seated all passengers and the Flight Attendant as a precautionary measure. Just south of CGT VOR at FL210 we experienced severe turbulence and a loss of approximately 800-1;000 FT of altitude. We reported to ATC and were re-assigned an altitude of FL200. No traffic conflicts were observed or reported by us or ATC. Aircraft continued to MKE without incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

A captain reported a 900 ft altitude loss after encountering severe turbulence a FL210 along with heavy rain. ATC assigned a lower altitude and the flight continued to its destination.