Reciprocating Helicopter Engine and QECA

in Engine Removal and Replacement

The engine is installed facing aft with the propeller shaft approximately 39° above horizontal. The engine is supported by the engine mount, which is bolted to the fuselage structure. The installation of the engine provides for ease of maintenance by allowing easy access to all accessories and components when the engine access doors are opened. The QECA contains the engine, engine mount, engine accessories, engine controls, fuel system, lubrication system, ignition system, cooling system, and hydromechanical clutch and fan assembly.

Removal of Helicopter QECA


Prior to removing the helicopter QECA, the engine should be preserved if it is possible to do so. Then, shut off the fuel supply to the engine and drain the oil. Make the disconnections necessary to remove the QECA, and then perform the following steps:

  1. Attach the engine lifting sling to a hoist of at least a two-ton capacity.
  2. Raise the hoist to apply a slight lift to the QECA. Loosen both engine mount lower attachment bolt nuts before leaving the upper attachment bolts.
  3. Remove the bolts from the sway braces and remove both engine upper attachment bolts. Then, remove both engine mount lower attachment bolts and remove the QECA from the helicopter. Mount the power package in a suitable workstand and remove the sling.

Installation, Rigging, and Adjustment of Helicopter QECA

The installation of a new or an overhauled engine is in reverse of the removal procedure. The manufacturer’s instructions for the helicopter must be consulted to ascertain the correct interchange of parts from the old engine to the new engine. The applicable maintenance instructions should be followed.

Refer to the Maintenance Instructions Manual and associated technical publications for detailed information concerning rigging the throttle, mixture control, cable tensions, and related data.

Testing the Engine Installation

Normal engine run-in procedures must be followed in accordance with the manufacturer’s instructions. A flight test is usually performed after the engine has been installed and the engine controls have been adjusted.