Prop Feather vs. Idle Times in the PT6A

Should the prop be feathered prior to shut-down or should I feather the propeller as I shut the engine down? Should I start the engine with the prop lever in fine pitch (forward) or in course pitch?

The airframe operator’s instructions or Pilot Operating Handbook takes precedence in such procedures, when they are available. One aircraft Owners Manual  (serves as POH) reads thus:

“The Propeller lever may be placed in the full forward position during the start sequence for more convenient movement of the Start lever providing the temperatures are warm. For cold weather starts the Prop lever should be aft, as called out in the starting instructions (refers to engine maintenance manual), as initial oil pressure will go to engine bearings instead of the propeller dome.”

prop feather vs. idle times

This particular instruction leaves it to the pilot’s judgment as to what defines “warm” or “cold” weather. The Pratt & Whitney Canada PT6A-34AG Maintenance Manual starting instructions place the prop condition lever in FEATHER position at start-up.

The Covington Mobile Response Team helping a #Thrush get back in the air! #PT6A

A photo posted by Covington Aircraft (@covingtonaircraft) on

The logic behind this is that oil flow, minimal at start-up, is best utilized for engine bearing lubrication. The Maintenance Manual instructions for shutdown instruct the operator, in check-list fashion , to:

1. Place the power control lever in the Ground-Idle position with a note to allow the engine to stabilize for a minimum of one minute at the minimum obtainable ITT (Inter Turbine Temperature or T-5).

2. Place the propeller control lever in Feather position.

3. Start Control or fuel condition lever in Cut-Off. Then- the fuel boost pump switch, fuel system shutoff switch and, master switch are placed in off positions.

Ya’ll Fly Safe!
Ron Hollis

Related posts:

Share and Enjoy

  • Facebook
  • Twitter
  • Delicious
  • LinkedIn
  • StumbleUpon
  • Add to favorites
  • Email
  • RSS

One thought on “Prop Feather vs. Idle Times in the PT6A

  1. For all Hartzell and McCaully props, always remember it is “Pressure to Fine”. Which means you need oil pressure to get the props to fine pitch. The PT6A manual should be followed, for shut down of an engine. Most Turboprops have auto feather, if not, follow as below:

    1. Place the power control lever in the Ground-Idle position with a note to allow the engine to stabilize for a minimum of one minute at the minimum obtainable ITT (Inter Turbine Temperature or T-5).

    2. Place the propeller control lever in Feather position.

    3. Start Control or fuel condition lever in Cut-Off. Then- the fuel boost pump switch, fuel system shutoff switch and, master switch are placed in off positions.

    On twin engine aircraft, do not forget to counteract the asymmetric forces, during single engine operations.

Leave a Reply

Your email address will not be published. Required fields are marked *