Adjustment/Test of the Thrust Reverser Stow Tube Clearance [IAE]

TASK 78-32-48-820-801-A
Adjustment/Test of the Thrust Reverser Stow Tube Clearance

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

NOTE: This task is applicable to PRE SBN 70-970 upper actuators. POST SBN 70-970 units do not need to be check for clearance.

1. Reason for the Job
Stow tube is causing damage inside the fan cowl door.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V01-438)	solvent
(Material No.V02-099)	lint free cloth

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
2	LAMINATED PEELABLE SHIM	AIPC 78-32-42-81-030
2	LAMINATED PEELABLE SHIM	AIPC 78-32-72-81-030

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-10-00-220-010-A	Aerodynamic Smoothness
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-800-010-A	Functional Check of Fan Cowl Latch Tension
TASK 71-13-00-800-011-A	Adjustment of the Fan Cowl Spigots and Bumpers
Stow Tube Clearance and Shim Location

3. Job Set-up
Subtask 78-32-48-941-055-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than five minutes before you do this procedure.
(3) On the ENG section of the maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR 1(2) pushbutton switch is OFF.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

4. Procedure
Subtask 78-32-48-820-052-A ** ON A/C NOT FOR ALL

A. Shim the Fan Cowl

NOTE: If the fan cowl doors are not already open, open fan cowl doors (Ref. AMM TASK 71-13-00-010-010).

NOTE: Pay special attention to the step between the trailing edge of the fan cowl door and the leading edge of the thrust reverser.

(1) Determine the shims (2,3) thickness required to achieve the 0.04 in. (1.02 mm) minimum gap requirement. Make sure that the fan cowl trailing edge is no more than 0.10 in. (2.54 mm) higher than the thrust reverser leading edge.
(a) The exact amount of the shims (2,3) required is determined by adding shim and checking the results.

NOTE: As a guide, the gap is increased by roughly 2/3 of the shim thickness added.

(2) Before cutting the AIPC 78-32-42-81-030 LAMINATED PEELABLE SHIM (2) for the left side or AIPC 78-32-72-81-030 LAMINATED PEELABLE SHIM (2) for the right side , make sure that each shim(s) end is located approximately in the middle of a rivet pitch.

NOTE: Laminated shim may be used for minor additional thickness adjustments

(3) Fabricate repair shim (2) by cutting a long piece 14 in. (0.36 m). Make sure that each shim(s) end is located approximately in the middle of a rivet pitch.

NOTE: Shim (2) may be installed end to end to achieve longer shim. Shim (3) may be used for additional thickness.

(4) If the thickness of one shim (2) is not sufficient to achieve the required gap, a second and a third shim may be used.
(a) The second shim length has to measure around 27 in. (0.69 m). Place symmetrically under the first shim.
(b) The third shim length has to measure around 45 in. (1.14 m). Place symmetrically under the second shim.
(c) Add peel shim , if necessary. Make sure that each shims end is located approximately in the middle of a rivet pitch.
(5) The shims need to have a 50:1 taper ratio with a minimum thickness of 0.01 in. (0.25 mm) at each shim edge to avoid multiple steps 4.(a) to 4.(c).
(6) File the shims.

CAUTION: HIGH OR LOW AREAS ARE PROHIBITED. MECHANICAL SANDING IS NOT PERMITTED BEYOND TOUCH TEMPERATURE OF THE SHIM.

(a) File tapered shims to produce uniform surfaces using a metal file or equivalent shop tool.
(7) Clean shims using lint free cloth (Material No.V02-099) made moist with solvent (Material No.V01-438) . Rub the surface dry before the solvent dries.

Subtask 78-32-48-820-053-A ** ON A/C NOT FOR ALL

B. Install Shim(s)

CAUTION: DO NOT DAMAGE PAINT ON THE INTERFACE STRUCTURE.

(1) Remove and discard rivets (4) along the length of the prepared shim(s) and an additional 4X fasteners on each side of the shim(s) end.
(2) Install prepared shim (2,3) under rub strip (1). Center on the 43° and/or 317° radials. Make sure that each shims end is located approximately in the middle of a rivet pitch. See the view C of the figure.

Stow Tube Clearance and Shim Location ** ON A/C NOT FOR ALL

(3) Drill holes on mating structure.

CAUTION: DO NOT DAMAGE OR ENLARGE EXISTING HOLES IN THE MATING STRUCTURE.

(a) Match drill a second hole and clamp in place using cleco or equivalent device.
(b) Match drill remaining holes.
(c) Remove clecos and shim(s).
(d) Remove all burrs from the shim(s) and/or mating structure.
(4) Apply 10P20-13 primer to all exposed surfaces of the shim(s) or mating structure.
(5) Wet install rivets using primer 10P20-13 in the drilled holes through shim(s), rub strip and torque box fairing.
(6) Close fan cowl door(s) (Ref. AMM TASK 71-13-00-410-010).
(7) Verify the fan cowl latch, spigot, and bumper rigging (Ref. AMM TASK 71-13-00-800-010). Adjust the spigots and bumpers, if the tests are out of the given limits (Ref. AMM TASK 71-13-00-800-011).
(8) Verify aerodynamic smoothness at the fan cowl interfaces to the thrust reverser and to the inlet cowl. Verify interface between the fan cowl door (Ref. AMM TASK 71-10-00-220-010). Check if the gap measured between the fan cowl door and the actuator stow tube is larger than or equal to 0.04 in. (1.02 mm).

NOTE: If any of these checks fail, add or remove shims as necessary and/or re adjust the spigots and bumpers (Ref. AMM TASK 71-13-00-800-011).

[Rev.10 from 2021] 2026.04.01 03:28:49 UTC