What led up to the crash?    When the Engine Quit!    What caused the engine to quit?

  What could have been done to keep this from happening?     How much damage?

 

 

When the Engine Quit!
Shock! After a short moment of shock, my first instink was to restart the engine. Before I could move my hand to the starter I thought about the area I was in. I had flown over this area alot and knew that the area in front of me had trees and possibly fences and powerlines, directly behind me was a corn field without any other obstructions. There was even a dirt road back a little ways, at first I thought I could make it to that road. I started a left hand turn. Things were happening too fast. I did not get time to look at my instruments. I got the plane turned around, but in the process I loss alot of airspeed and altitude. I knew I loss alot of airspeed because when I pulled the stick to the right to level the wings nothing happened, I was in a stall. I moved the stick back to the left and then back to the right and held it there. I had done spins and wing overs before and knew that I had to push right rudder, but before I could make my foot move, I heard the corn stalks and I hit the ground in a nose down attitude. It was quit a jolt, but I had a shoulder strap and a seat belt on. I didn't get hurt, but I believe that if I had a passenger they would have. It seems that the plane did finally turn toward the right just before impact. I realized that I was ok. I looked at the crumpled passenger side and then out at the pilot side wing tip on the ground. I was even with the ground and knew that the gear were folded up. I heard my brother-in-laws wife yelling for me and I yelled back that I was ok. We drained the fuel out of the tanks. My brother-in-law showed up and had some guys with him, they were getting ready to cut his tobacco. We all grabbed hold of the airplane and carried it out of the corn. I know I was coming down at a steep angle because I did not knock down much more corn than what you see in the picture.

What caused the engine to quit? -
In short: Cold Seizure - Cylinder cooled too fast for piston.
At first I thought it was either fuel starvation or somthing electrical that shorted out. I checked everything I could think of, I took the carbs apart, I checked all the fuel lines, I checked all the wiring, no luck. I then took off the muffler to looked inside the engine cylinders at the pistons, there it was the rear piston was scarded. The Rotex 582 is a liquid cooled engine and ships without a theromstat. Rotex does make a thermostat for this engine but it is not installed on a new engine. While decending with the engine at idle it appears that the engines rear cylinder cooled faster than the piston and caused it to seize.

 

What could have been done to keep this from happening? -
In short: A thermostat and idleing back to 3000 rpm rather than 2000 except for final approch.
I called two differant Rotex engine repairman and explained the what led up to the engine quiting. The first question both of them asked me was if the engine had a thermostat installed on it. At the time I was not sure because the pictures I had seen in the California Power Systems Catalog showed a thermostat. When I told them that the engine was new, they told me that if I had not installed a thermostat, then the engine did not have one. They said that if the engine had a thermostat install, it would have kept the hot water around the cylinder during the decent and then the cylinder would not have cooled off too fast, therfore the piston would not have seized. They also said not to leave the engine at idle for a long period, periodicly rev the engine during long idle times while flying, as in long decents. I asked about warrenty coverage and was told that Rotex will not pay for any type of seizures unless it was caused by something in the engine that malfunctioned. They said that Rotex claims that seizures are caused by somthing that the operator did wrong.

How much damage? -
About $350 for the engine repair (one new piston, cylinder wall cleaned, and a thermostatinstalled). All the parts to repair the aircraft $3500. New paint and clear coat about $500. The total should be between $4000 - $5000.

Final thoughts -
The main thing that I cannot understand is why does Rotex not install a theremostat on their liquid cooled engines? Why would you not want a thermostat? If anyone out there has had this same type of problem, please send me e-mail. You might be able to let me know somthing else to lookout for. I hope that what I have done will keep this from happening again. One other thing that I noticed was the amount of carbon on the pistons after only 28 hours. I was using Texeco Halvoline 2 stroke oil but will be switching to Pennzoil 2 stroke for air cooled engines. I have read and been told that this is the best oil for Rotex engines air or liquid cooled. I am in the process of rebuilding now (March 21,1998) and hope to be flying again by May. I hope to get alot more than 28 hours of flying in this year!

May 9,1998 All work is done and I'm flying again. I now have a thermostat and I run the engine up before every flight untill the water temp has started to come up. I can feel the radiator hoses and when they get warm I'm good to go!

May 24,1998 Over 44 hours and all is well!

I had piston scaring during a 100 hr inspection and switched to Valoline outboard oil. I have been checking the pistons every 25 hr. I have found that on a Rans S12xl with a 582 that the bottom rings will stick after 75 hrs.. I have discussed this with one other pilot with the same setup and we both have the same conditions and in the same area. There is not alot of carbon but the bottom ring will stick after 75 hrs and needs to be removed and the groove cleaned good.