ateamer
Pattern Altitude
Wanted to start a separate thread to avoid pulling the other icing thread off track.
A friend has a 150 with an O-200 with fairly high time. A couple times he had a significant uncommanded power reduction and roughness right after takeoff, when climbing through 200-300 AGL/MSL (sea level field); summer mornings, mid to upper 80s with humidity around 90%. Start, runup and mag check were normal both times. He was able to turn back and land safely, and could not recreate the condition on the ground. By the time he was rolling out, the engine was normal.
My theory was carb ice. Taxi at low power, runup and mag check at maybe 50% power at the most, all in perfect conditions for ice. Takeoff seems normal, if somewhat sluggish, and everything gets hot enough to melt and break up the ice shortly after takeoff. By the time he’s landing the ice is gone, and he can’t recreate it because the engine has hardly cooled after landing with the next runup being done upon runway exit.
His A&P inspected the engine and found a sticking valve lifter, to which he attributed the power loss. He found enough worn parts that it’s out for an overhaul.
Is a single malfunctioning lifter going to cause a power loss/roughness after a 15 seconds or so of smooth full-throttle operation, and then not reproduce its behavior until the next flight days later?
Am I tracking anywhere close to course with the ice idea?
Just wanting to learn more here and have knowledge for future use.
A friend has a 150 with an O-200 with fairly high time. A couple times he had a significant uncommanded power reduction and roughness right after takeoff, when climbing through 200-300 AGL/MSL (sea level field); summer mornings, mid to upper 80s with humidity around 90%. Start, runup and mag check were normal both times. He was able to turn back and land safely, and could not recreate the condition on the ground. By the time he was rolling out, the engine was normal.
My theory was carb ice. Taxi at low power, runup and mag check at maybe 50% power at the most, all in perfect conditions for ice. Takeoff seems normal, if somewhat sluggish, and everything gets hot enough to melt and break up the ice shortly after takeoff. By the time he’s landing the ice is gone, and he can’t recreate it because the engine has hardly cooled after landing with the next runup being done upon runway exit.
His A&P inspected the engine and found a sticking valve lifter, to which he attributed the power loss. He found enough worn parts that it’s out for an overhaul.
Is a single malfunctioning lifter going to cause a power loss/roughness after a 15 seconds or so of smooth full-throttle operation, and then not reproduce its behavior until the next flight days later?
Am I tracking anywhere close to course with the ice idea?
Just wanting to learn more here and have knowledge for future use.
