Narrative:

In VMC at 4;500 MSL we encountered sustained moderate turbulence. During this time; we encountered an isolated incidence of severe turbulence; resulting in momentary loss of control; an altitude loss of approximately 200 feet; and the pilot and copilot striking their heads on the ceiling. There were no passengers on board. We were approximately 75 miles northeast of bil.

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Original NASA ASRS Text

Title: C402 Captain experiences moderate to severe turbulence at 4;500 feet resulting in a 200 foot altitude loss.

Narrative: In VMC at 4;500 MSL we encountered sustained moderate turbulence. During this time; we encountered an isolated incidence of severe turbulence; resulting in momentary loss of control; an altitude loss of approximately 200 feet; and the pilot and copilot striking their heads on the ceiling. There were no passengers on board. We were approximately 75 miles northeast of BIL.

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.