I don't really want to tell this story....but there may be some lessons in it which may be useful to someone...someday.
A funny thing happened to me on the way to the airport....the propeller stopped. I was at about 2,500 feet AGL and 8 miles from the runways in an idle descent at 70 mph experimenting with engine out profiles. The engine was idling a little rough so I tried adjusting the mixture to full rich. That changed nothing. I then tried to lean the mixture beyond the rough idle. That is when the propeller stopped.
My first instinct was to make the propeller start turning again. I pointed the nose at the ground and got as much airspeed as possible (maybe 120 mph). The propeller did not budge. When the shrubs started looking like trees I pulled the nose up and traded airspeed for altitude. The propeller turned over in the pull but only 180 degrees. It stopped in the vertical position which is probably to be expected for a prop set up for hand starting.
Surveying my situation, I had a rocky pasture underneath me and power lines in front of me. I was already headed into the prevailing winds. To minimize my downrange travel, I made a 90 degree turn away followed by a turn back into the wind. The altitude burned off very quickly. Following the turns there was nothing left to do but set the attitude and meet the ground. My intention in this situation has always been to plant the aircraft as firmly as possible to scrub off energy. With a little help from slightly rising terrain and a good rate of descent, I achieved that goal. The gear spread, the prop broke, and the plane skidded to a stop in about 150 feet.
That was two weeks ago, Saturday. No damage to the pilot (other than a bruised ego). The gear has been straightened, the new prop is on order, the wheel pants are history, new tires and tubes are mounted, and new brake calipers are in the mail. When the prop arrives I will give the engine an opportunity to exonerate itself from all culpability. I guess the problem with being the builder and the pilot is that all fingers point to you...no matter what happens.
Thinking through the mixture issue (probable cause of the incident) I realize some quirks about the slide injector carburetor. The most important is that we don't really have a mixture control. What we have is a second fuel shutoff valve...albeit a valve more finely adjustable than a ball valve. In retrospect, the fuel flow at idle is so small that trying to adjust it with the mixture control is clearly a recipe for disaster (case in point).
Hope you can glean something from my story. Happy to answer any questions. I'll let you know when N136DE is back in the air.
All the best,
Chucker
A funny thing happened to me on the way to the airport....the propeller stopped. I was at about 2,500 feet AGL and 8 miles from the runways in an idle descent at 70 mph experimenting with engine out profiles. The engine was idling a little rough so I tried adjusting the mixture to full rich. That changed nothing. I then tried to lean the mixture beyond the rough idle. That is when the propeller stopped.
My first instinct was to make the propeller start turning again. I pointed the nose at the ground and got as much airspeed as possible (maybe 120 mph). The propeller did not budge. When the shrubs started looking like trees I pulled the nose up and traded airspeed for altitude. The propeller turned over in the pull but only 180 degrees. It stopped in the vertical position which is probably to be expected for a prop set up for hand starting.
Surveying my situation, I had a rocky pasture underneath me and power lines in front of me. I was already headed into the prevailing winds. To minimize my downrange travel, I made a 90 degree turn away followed by a turn back into the wind. The altitude burned off very quickly. Following the turns there was nothing left to do but set the attitude and meet the ground. My intention in this situation has always been to plant the aircraft as firmly as possible to scrub off energy. With a little help from slightly rising terrain and a good rate of descent, I achieved that goal. The gear spread, the prop broke, and the plane skidded to a stop in about 150 feet.
That was two weeks ago, Saturday. No damage to the pilot (other than a bruised ego). The gear has been straightened, the new prop is on order, the wheel pants are history, new tires and tubes are mounted, and new brake calipers are in the mail. When the prop arrives I will give the engine an opportunity to exonerate itself from all culpability. I guess the problem with being the builder and the pilot is that all fingers point to you...no matter what happens.
Thinking through the mixture issue (probable cause of the incident) I realize some quirks about the slide injector carburetor. The most important is that we don't really have a mixture control. What we have is a second fuel shutoff valve...albeit a valve more finely adjustable than a ball valve. In retrospect, the fuel flow at idle is so small that trying to adjust it with the mixture control is clearly a recipe for disaster (case in point).
Hope you can glean something from my story. Happy to answer any questions. I'll let you know when N136DE is back in the air.
All the best,
Chucker
