Piper PA-32R-301T SARATOGA S, Maintenance Manual

Page: 441 / 956

PROPELLER DEICING SYTEM (Cont.)
E INSPECTION (Cont.)
(2) 100 HOUR INSPECTION (Cont.)
(a)Remove cowling.
(b) Conduct 50 hour inspection.
(c) Check for radio noise or radio compass interference by operating engine at near takeoff
power with radio gear ON while turning deicer switch ON and OFF. If noise or interference
occurs with deicer switch ON, and disappears when switch is OFF, see troubleshooting chart.
(d) Ascertain that all clamps, clips, mountings and electrical connections are tight. Check for
loose, broken or missing safety wire.
(e) Deicers: Closely check deicers for wrinkled, loose or torn areas, particularly around outboard
end and especially where strap passes under strap retainer. Look for abrasion or cuts, espe-
cially along leading edge and flat or thrust face. If heater wires are exposed in damaged areas
or if rubber is found to be tacky, swollen or deteriorated (as from oil or solvent contact),
replace damaged deicer in accordance with Installation of Deicer.
– NOTE –
Check that strap restrainers are correctly located and secure.
Look for cracks or other damage. Operate propeller from full
pitch to low pitch and check that deicer lead straps do not
come under tension, or are pinched by propeller blade.
(f) Slip Rings: Check slip rings for gouges, roughened surface, cracks, burned or discolored
areas and for deposits of oil, grease or dirt.
1 Clean greasy or contaminated slip rings with CRC2-26 solvent.
2 If uneven wear is found or if wobble is noticed, set up dial indicator as shown in figure
30-9 to check alignment of slip rings to propeller shaft.
(g) Brush Block - Brushes: Examine mounting brackets and housing for cracks, deformation or
other physical damage.
1 Test that each brush rides fully on its slip ring over 360. Figure 10 shows wear pattern if
this condition is not corrected. If alignment is off, shim where brush block bracket
attaches to engine back bone or pivot at support arm which is attached to generator idler
pulley bracket.
2 Check for proper clearance of brush block to slip rings as shown in Figure 12. If not cor-
rect, loosen mounting screws and move in elongated holes to correct block position
before tightening securely.
3 Visually check brush block for approximately 2 angle of attack. (Refer to Figure 12.) If
not, loosen mounting screws and twist block, but be sure to hold clearance limits shown
when tightening.
(h) System Wiring: With deicer system operating, have assistant observe ammeter while visually
inspecting and physically flexing wiring from brush blocks through firewall, to timer, to
ammeter, to switch and to aircraft power supply. The ammeter will flicker as the timer
switches approxi- mately every 90 seconds in cycle. Jumps or flickers at other times indi-
cates loose or broken wiring in area under examination at that moment. In such case, check
continuity through affected harness, while flexing and prodding each wire in area that gave
inital indication of trouble. Use wiring diagram in Chapter 91 to trace circuitry.
PIPER AIRCRAFT
PA-32R-301/301T
MAINTENANCE MANUAL
30-60-00
Page 30-35
Reissued: July 1, 1993
2I5