Propeller Deicer Boots; Resistance Check Of Deicer Boots; Removal Of Boots/Installation Of Boots; Blade Preparation - Piper PA-44-180 SEMINOLE Maintenance Manual

PROPELLER DEICER BOOTS.

RESISTANCE CHECK OF DEICER BOOTS.

To determine incorrect resistance, short or open at the brush-to-slip ring contact, disconnect harness at the
brush block and use low range ohmmeter to read resistance from each deicer circuit lead (Pins B and C of brush
block) to ground; it should read .52 to .56. If this reading is not obtained, disconnect the deicer lead harness to
measure heater resistances individually. Individual heater should be 1.04 to 1.12. If first check is off limits but
second check is satisfactory, trouble is probably in the brush-to-slip ring area; if the second check is off limits, the
deicer is damaged and must be replaced.
REPLACEMENT.
If tests show the blade deicer to have an open circuit, to be the wrong resistance or to be visibly damaged
beyond repair as outlined in this section, replace the deicer as directed in the following paragraphs.
REMOVAL OF BOOTS.
1. Disconnect terminals of propeller deicer from studs on the spinner bulkhead.
2. Use MEK or Toluol to soften the adhesion line between the deicer and the propeller blade.
DO NOT ALLOW SOLVENTS TO LEAK INTO PROPELLER HUBS AND
CAUSE DAMAGE TO SEALS.
3. Starting at one corner of the deicer, loosen enough of the deicer to grasp in the jaws of vise grip pliers or
similar tool.
4. Apply a steady pull on the deicer to pull it off the propeller surface. Continue using MEK or Toluol to
soften the adhesion lines. Unless the deicer being removed is damaged and is to be scrapped, cushion the
jaws of any pulling tool used to prevent damage to the deicer surface. Remove very slowly and carefully. If
deicer has failed and is to be returned under request for warranty, extreme care should be exercised so that
no additional damage is incurred to the deicer during and after removal.
5. Remove residual cement from blade. Use Turco No. 3 or equivalent to help with dried cements.
INSTALLATION OF BOOTS.

BLADE PREPARATION.

1. Mark and cut from masking tape a pattern the size of the propeller deicer. (Refer to Figure 30-10.)
2. Place a mark at the hub end of the blade in line with the blade leading edge. The location for this mark can
be determined by sighting along the leading edge. Starting at the hub (see Note below), center the pattern
on this mark and stick the pattern to the leading edge. Mark the position of the deicer harness.
All deicers on a single propeller must be located at same distance from the hub for
rotational balance.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— CAUTION —
— Note —
2E18
3 0 - 6 8 - 0 5
Page 30-38
Revised: May 15, 1989