A B737-300 encountered severe turbulence. Unable to maintain altitude; the aircraft descended 600 ft...

Attributes
ACN	1173057
Time
Date	201405
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 128
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence

Narrative:

At FL320 we encountered severe turbulence that caused loss of aircraft control. There no reports of turbulence in the area at the time. This resulted in an altitude deviation of approximately 600 ft. We informed ATC that we were descending to FL280. ATC asked if we were declaring an emergency and we informed them that we were not. ATC told us to maintain FL320 due to oncoming traffic. We regained control of the aircraft at approximately FL314 and climbed back to FL320. The turbulence was reported to ATC.

Original NASA ASRS Text

Title: A B737-300 encountered severe turbulence. Unable to maintain altitude; the aircraft descended 600 FT before the pilots regained control and returned to FL320 for on coming traffic.

Narrative: At FL320 we encountered severe turbulence that caused loss of aircraft control. There no reports of turbulence in the area at the time. This resulted in an altitude deviation of approximately 600 FT. We informed ATC that we were descending to FL280. ATC asked if we were declaring an emergency and we informed them that we were not. ATC told us to maintain FL320 due to oncoming traffic. We regained control of the aircraft at approximately FL314 and climbed back to FL320. The turbulence was reported to ATC.

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.

A B737-300 encountered severe turbulence. Unable to maintain altitude; the aircraft descended 600 ft before the pilots regained control and returned to FL320 for on coming traffic.