seethru
Works for a Living
- Joined
- Apr 15, 2004
- Posts
- 144
Howdy, I have been having a problem lately with a propeller on our 414A. This is like one of those Puzzlers you might hear on Car Talk on NPR. 
Ours is a 1978 414A with the Ram VII upgrade that was completed in 2003. It has the Continental TSIO-520 335HP engines and Hartzell Scimitar 3-Blade Props.
The problem is that occasionally, after we shut down both engines after our flight, the right propeller will feather all on its own, which clearly it should not do this.
Oil pressures and temperatures are all within normal operating limits. The Prop levers are moved to full forward after landing. The throttles are reduced to Idle power before engine shutdown with the mixtures.
We have never had an issue during the Before Takeoff check or flight that caused us to be concerned about either propeller. They both attain equal RPM on takeoff and adjust appropriately in cruise.
History of troubleshooting:
Our shop, which BTW we have enjoyed their quality and attention to our concerns, had the right propeller looked at by the local Hartzell people. They did not find anything to be out of adjustment.
We continued to fly and found a few flights later that the problem occurred again. This time RAM was involved because they found that the right engine was damaged by this. There was something about where the prop and engine connection was made that grooves had been worn into the engine, necessitating a new overhauled engine (at RAM's expense).
At the same time the right prop was removed and sent to the Hartzell shop for a complete overhaul (at RAM's expense). As before, nothing was found on the prop to be wrong.
It was decided to swap propellers. So the right prop went on the left engine, and the left prop got mounted on the right engine. We flew this way without problems for over six months, at which time the props were swapped back to their original positions (right prop, right engine; left prop, left engine).
This last week I got the airplane back from annual inspection, and low and behold the right prop is feathering again! It is back for inspection at Hartzell, but I am not confident that they will find any problems. Again, RAM has agreed to pay for the overhaul.
Has anybody experienced anything like this, or maybe could offer some suggestions? I know my shop is working hard on it, but I think they are stumped as well. I am sure that there is a lot of other checks/inspections they have performed, such as oil pressure and prop governor issues.
Thanks,
Greg
BTW, as good as RAM has been in backing up their products, Hartzell won't even talk to us. Nice to see some corporate responsiblity...
Ours is a 1978 414A with the Ram VII upgrade that was completed in 2003. It has the Continental TSIO-520 335HP engines and Hartzell Scimitar 3-Blade Props.
The problem is that occasionally, after we shut down both engines after our flight, the right propeller will feather all on its own, which clearly it should not do this.
Oil pressures and temperatures are all within normal operating limits. The Prop levers are moved to full forward after landing. The throttles are reduced to Idle power before engine shutdown with the mixtures.
We have never had an issue during the Before Takeoff check or flight that caused us to be concerned about either propeller. They both attain equal RPM on takeoff and adjust appropriately in cruise.
History of troubleshooting:
Our shop, which BTW we have enjoyed their quality and attention to our concerns, had the right propeller looked at by the local Hartzell people. They did not find anything to be out of adjustment.
We continued to fly and found a few flights later that the problem occurred again. This time RAM was involved because they found that the right engine was damaged by this. There was something about where the prop and engine connection was made that grooves had been worn into the engine, necessitating a new overhauled engine (at RAM's expense).
At the same time the right prop was removed and sent to the Hartzell shop for a complete overhaul (at RAM's expense). As before, nothing was found on the prop to be wrong.
It was decided to swap propellers. So the right prop went on the left engine, and the left prop got mounted on the right engine. We flew this way without problems for over six months, at which time the props were swapped back to their original positions (right prop, right engine; left prop, left engine).
This last week I got the airplane back from annual inspection, and low and behold the right prop is feathering again! It is back for inspection at Hartzell, but I am not confident that they will find any problems. Again, RAM has agreed to pay for the overhaul.
Has anybody experienced anything like this, or maybe could offer some suggestions? I know my shop is working hard on it, but I think they are stumped as well. I am sure that there is a lot of other checks/inspections they have performed, such as oil pressure and prop governor issues.
Thanks,
Greg
BTW, as good as RAM has been in backing up their products, Hartzell won't even talk to us. Nice to see some corporate responsiblity...