aircraft flight. The simulations demonstrated that when such factors are present and actual hands on
flying is not being observed, the aircraft may perform uncommanded movements with a slow degradation
in flight capabilities. The computer simulation is not sophisticated enough at this time to produce the
exact maneuvers of the `ncident aircraft, therefore we have not been able to establish a rigorous cause
and effect relationship between any single factor or combination of factors for which the specific flight
control anomalies have occurred. To resolve corrosion hazards with the integrated lower control valve
actuator (ILCA) control valve, the CH-47 PMO will fund and request an engineering change to
manufacture the control valve from corrosive resistant material.
c. The purpose of this TB is to eliminate those known deficiencies which have been identified as
suspect causes of uncommanded maneuvers or flight control lock up.
End Items to be Inspected. All CH-47D, MH-47D, and MH-47E Helicopters.
6. Assembly to be Inspected. The following components with a 1,200 hour TBO will be inspected. and
reported to the Logistical Point of Contact (POC).
Parts to be Inspected. N/A.
8. Inspection Procedures.
a. Perform a visual inspection of the forward and aft pivoting and swiveling servocylinders (4
servocylinders per aircraft) to determine part number.
b. If a servocylinder listed in paragraph 6 is Installed, the historical records will be reviewed to
determine the hours accrued.
c. Each unit will notify the Logistical POC with the number of servocylinders that are affected. The
serial number of the aircraft on which the components are installed along with the component serial
number, part number, time remaining until TBO and an estimated date that components will reach TBO
will be repotted to the Logistical POC.