Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 1338 / 1956

PAGE 4
Feb 28/07
7C12
61-10-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
(2) Inspection.
Inspect entire blade for nicks, gouges, looseness of material, erosion, cracks and debonds,
and lightning strikes. Each 500 hours coin tap the erosion shield. Each 1000 hours coin tap the
entire blade surface. Defects or damage discovered during inspection must be evaluated in
accordance with the following criteria to determine: if repairs are required prior to further flight;
and, if so, whether or not repairs may be conducted locally or must be performed by a qualified
propeller shop.
Coin-Tap Test:
(a) Composite blades can be inspected for delaminations and debonds by tapping the blade,
or cuff (if applicable), with a “metal washer.”
(b) Use a washer-shaped metal tapper, approximately 2.5 inches O.D. x 1.25 inches I.D. x
0.25 inch thick, and weighing no less than 3 oz. Tap the surface. If an audible change is
apparent, sounding hollow or dead, a debond or delamination is likely.
NOTE: Blades which incorporate a “cuff” will have a different tone when coin-tapped in
the cuff area. To avoid confusing sounds, the cuff area and the transition area
between cuff and blade should be coin-tapped separately from the blade area.
(c) Mapping of the area being inspected is recommended. Coin-tap within an imaginary grid
or matrix consisting of 2 inch squares during scheduled aircraft inspections. During blade
overhaul, a more thorough inspection is required by using a smaller, 0.5 inch, grid.
(d) The metal erosion shield is more likely to have problems than the blade, therefore a more
thorough coin-tapping of the erosion shield is desirable. Also, slight deformations in the
erosion shield may be noticed by careful visual and manual (touch) inspection. Such
deformations may be the result of a debond and should be given a careful coin-tap
inspection.
(e) If a suspected delamination or debond is discovered, a localized, thorough coin-tap
inspection is required to define the precise area of delamination or debond.
(f) Outline any suspect areas with a grease pencil to determine approximate size of damage.
If repairable, proceed per Hartzell Manual No. 135, latest revision.
(3) Definitions.
Airworthy Damage Damage that does not affect the safety or flight characteristics of the
propeller blade. Although a blade may continue in service with
airworthy damage, this type of damage should be repaired at the
earliest practical time to prevent further damage to the blade.
Unairworthy Damage Damage that exceeds the maximum limits of airworthy damage.
Unairworthy damage can affect the safety or flight characteristics of
the propeller blade. This type of damage must be repaired at prior to
the next flight. Exceptions may be possible, but require written
authorization from Hartzell.
Minor Repair Correction of damage that may be safely performed in the field by a
certified aircraft mechanic (preferably one who has completed Hartzell
composite blade training).
Major Repair Correction of damage that cannot be performed by elementary
operations. Major repairs must be performed by a Hartzell Propeller
Inc. approved repair station. Exceptions may be possible, but require
written authorization from Hartzell.