Narrative:

En route from denver to hayden, co, we encountered some mountain wave turbulence due to some very strong winds aloft (moderate to severe turbulence had been forecast for the denver area). The altitude deviation was noticed almost immediately by both myself and the captain. I brought the power back to well below cruise power settings, and pushed over as we approached 300 ft above our assigned altitude but was unable to prevent the aircraft from climbing through our 300 ft limit (the entire event, from first encountering the wave to breaking 300 plus ft above our assigned altitude took no longer than 6-10 seconds we estimated).

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Original NASA ASRS Text

Title: MOUNTAIN WAVE TURB CAUSES ALTDEV EXCURSION FROM ASSIGNED.

Narrative: ENRTE FROM DENVER TO HAYDEN, CO, WE ENCOUNTERED SOME MOUNTAIN WAVE TURB DUE TO SOME VERY STRONG WINDS ALOFT (MODERATE TO SEVERE TURB HAD BEEN FORECAST FOR THE DENVER AREA). THE ALTDEV WAS NOTICED ALMOST IMMEDIATELY BY BOTH MYSELF AND THE CAPT. I BROUGHT THE PWR BACK TO WELL BELOW CRUISE PWR SETTINGS, AND PUSHED OVER AS WE APCHED 300 FT ABOVE OUR ASSIGNED ALT BUT WAS UNABLE TO PREVENT THE ACFT FROM CLBING THROUGH OUR 300 FT LIMIT (THE ENTIRE EVENT, FROM FIRST ENCOUNTERING THE WAVE TO BREAKING 300 PLUS FT ABOVE OUR ASSIGNED ALT TOOK NO LONGER THAN 6-10 SECONDS WE ESTIMATED).

Data retrieved from NASA's ASRS site as of July 2007 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.