Strictly confined to LNC2s - 235, 320, 360:

 

Let's see, if there is a failure that causes the engine to stop turning, you will have a stopped prop (if it is still attached).

 

If you are flying with a fixed pitch prop, it is probably best to stop it.

 

If you are flying with a controllable pitch prop and it is still controllable, consider the coarse pitch setting.

 

Data:

 

On a nice fall day in my Lancair 320 @ 1700 pounds and a 70.25 inch Hartzell CS prop.  At best glide (about 107 Kts, AOA indication), cruise pitch, zero thrust, the sink rate was 1500-1600 fpm.  When the prop was pulled to coarse pitch and 107 KIAS was maintained, the sink rate decreased to 400-500 fpm.

 

I have no data on operation with a stopped prop although it is estimated that the drag is somewhere between the flat pitch and the coarse pitch condition.

 

Consider this:  The LNC2s are slicker than snot - a very, very low coefficient of drag (unlike many SEL commercially available spam cans).  Because of this, the drag of the dead engine's propeller is a significant performance factor, more significant than airframe drag.

 

All things being equal, upon a non-seized engine failure with a controllable pitch prop (especially on takeoff):

 

1. Begin to establish best glide speed with one hand.

 

2. Pull the prop to coarse pitch with the other hand (use your teeth if there is a dual hand deficiency).

 

3. Do all the other things on your emergency checklist, if you can find it.