(2) Remove engine fuel and pneumatic lines. Inspect fittings and lines for cracks, chafing,
scratches/dents and improper seating on sealing surfaces. Inspect for contamination. Clean all lines in
accordance with applicable technical manuals. Reinstall pneumatic lines and filter. Leak check pneumatic
system in accordance with TM 55-2840-231-28.
(3) Remove all hoses, fittings and valves including shut-off valve from the fuel boost pump to the en-
gine. Clean and inspect for damage and restrictions in accordance with TM 55-1520-228-23. Reinstall or
replace as applicable. Bleed the fuel system in accordance with the appropriate technical manual. With the
aircraft fuel shutoff valve open, start the fuel boost pump and check all accessible fuel line connections and fit-
tings outside the fuel cell for leakage, inspect and lubricate starter generator splines. Check calibration of
dual tachometer (N2 and rotor RPM).
(4) Check main and tail rotor systems for proper rigging and pitch angle, and re-rig as necessary.
If the reason/reasons for power degradation cannot be established using the procedures specified in para-
graphs a. and b. above, replace the fuel control governor and double check valve (unless replaced in para a.
above). Perform deceleration check, if satisfactory, perform test flight in accordance with established proce-
Aircraft are restricted from NOE contour, low level, and night flight for 10 hours after completion of the
preceding procedures and must be flown at an altitude to allow safe autorotation as defined in TM 55-1520-
228-10 or TM 55-1520-235-10 charts. After completion of the 10-hour restriction, repeat deceleration check. If
satisfactory, perform test flight in accordance with established procedures. No further flight restrictions are