Hole Through Deicer Outside Of Tube Area; Preparation Of Leading Edges; Preparation Of Deicer; Mounting Deicer On Leading Edge - Piper Cheyenne IIIA Airplane Maintenance Manual

PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. Airfoil - Description and Operation (continued)
(m) Hole Through Deicer Outside of Tube Area
(1.) Repair surface side and patch backside (see paragraph titled Holes or Tears Through
Backside of Tube Area). Cure complete repair for 22 minutes. Restore conductive
surface (see paragraph titled Resurfacing Conductive Cement).
11. Installation
The following procedure for installing deicers requires that airplane have provisions for air
connections, etc.
(a) Preparation of Leading Edges
If leading edges are painted, remove all paint including zinc chromate primer.
(1.) With one inch masking tape, mask off leading edge boot area, following 1/2-inch margin
for non-recessed boots. Ensure tape is masked accurately to eliminate cleaning off
excess cement later.
(2.) Clean metal surfaces at least twice with MEK or acetone. For final cleaning, wipe off
solvent film quickly with clean, dry cloth before it dries.
NOTE: If desired, reapply zinc chromate primer over bare leading edges. When hard,
scuff sand chromate surfaces and clean before applying cement.
Deicers can be installed on alodined or anodized surfaces.
(3.) Fill gaps of skin splices that lead under deicers with sealing compound EC-801.
(4.) Remove sump plugs from air connection grommets. Remove sections of doped fabric
used to cover the air connection holes, if necessary. Draw out ends of non-kink hose
section to protrude through connection holes in leading edge. If hole is cracked or
deteriorated, replace hose.
(b) Preparation of Deicer
Moisten clean cloth with MEK or acetone. Carefully clean rough, back surface of boot at least
twice. Change cloths frequently to avoid recontamination of cleaned areas.
(c) Mounting Deicer on Leading Edge
Thoroughly mix EC-1300L cement before using. Brush on one even coat to cleaned back
surface of boot and to cleaned metal surface. Allow cement to air dry for a minimum 1 hour.
Apply second coat to both surfaces and allow to air dry another hour. Keep ambient installation
temperature between 40
°
and 11 0°F. Longer drying time for cement coats may be required as
humidity approaches 99%. Deicer and leading edge can be cemented a maximum 48 hours
before actual installation if cemented parts are covered and kept clean.
Snap a chalk line along leading edge of airfoil section. Darken chalk line on leading edge and
white reference line on boot with a ball point pen. Most boots are made with excess material at
inboard and outboard edges for final trimming after installation. Some recessed boots trim on
upper and lower edges.
EFFECTIVITY:
040-999
Jan 10/90
Jan 10/90
30-10-00