Narrative:

I was on an IFR training flight with one of my students. We were unable to maintain the assigned altitude only because the small AA5 was underpwred for that particular day and altitude because of downdrafts. There was mountain wave sometimes pushing us down and sometimes giving a lot of lift. We knew the ceilings were plenty high so as not to be a danger of hitting mountain tops -- actually seeing down to the ground through small breaks in the cloud. When we told ATC about it; they had us squawk 7700. I never felt there was a real emergency; knowing it was temporary and knowing we had plenty of room below us. I used the experience to point out to the student that you can never underestimate the power of mother nature; even in the benign WX we were flying in. The plane (belonging to the student) needs to be considered if ever flown in more serious WX conditions.

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Original NASA ASRS Text

Title: AN AA5 INSTRUCTOR AND STUDENT PILOT WERE UNABLE TO MAINTAIN THEIR ASSIGNED ALT BECAUSE OF LACK OF POWER AND DOWNDRAFTS.

Narrative: I WAS ON AN IFR TRAINING FLT WITH ONE OF MY STUDENTS. WE WERE UNABLE TO MAINTAIN THE ASSIGNED ALT ONLY BECAUSE THE SMALL AA5 WAS UNDERPWRED FOR THAT PARTICULAR DAY AND ALT BECAUSE OF DOWNDRAFTS. THERE WAS MOUNTAIN WAVE SOMETIMES PUSHING US DOWN AND SOMETIMES GIVING A LOT OF LIFT. WE KNEW THE CEILINGS WERE PLENTY HIGH SO AS NOT TO BE A DANGER OF HITTING MOUNTAIN TOPS -- ACTUALLY SEEING DOWN TO THE GND THROUGH SMALL BREAKS IN THE CLOUD. WHEN WE TOLD ATC ABOUT IT; THEY HAD US SQUAWK 7700. I NEVER FELT THERE WAS A REAL EMER; KNOWING IT WAS TEMPORARY AND KNOWING WE HAD PLENTY OF ROOM BELOW US. I USED THE EXPERIENCE TO POINT OUT TO THE STUDENT THAT YOU CAN NEVER UNDERESTIMATE THE PWR OF MOTHER NATURE; EVEN IN THE BENIGN WX WE WERE FLYING IN. THE PLANE (BELONGING TO THE STUDENT) NEEDS TO BE CONSIDERED IF EVER FLOWN IN MORE SERIOUS WX CONDITIONS.

Data retrieved from NASA's ASRS site as of May 2009 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.