Functional Check of the Pressure Relief Door Latch Tension [CFMI]

TASK 71-13-11-280-802-A
Functional Check of the Pressure Relief Door Latch Tension

1. Reason for the Job
Refer to the MPD TASK: 711000-C5
FUNCTIONAL CHECK OF PRESSURE RELIEF DOOR LATCH TENSION.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)
RSE1234	1	ADAPTER TORQUE TOOL

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-A	Closing of the Fan Cowl Doors
Pressure Relief Door

3. Job Set-up
Subtask 71-13-11-941-074-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 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/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).

Subtask 71-13-11-010-070-A ** ON A/C NOT FOR ALL

B. Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR

4. Procedure
Subtask 71-13-11-280-051-A ** ON A/C NOT FOR ALL

A. Do a functional check of the pressure relief door as follows:
(1) Calculate the torque wrench force required to open the latch with the formula shown below:

0.53P X L/(L + 1.5) where:

P = Latch release load
L = Torque wrench effective length

NOTE: The torque wrench effective length is the distance between the point of application of force (where the hand is placed on the torque wrench handle) and the center line of the torque wrench 0.375 drive.

The latch release loads for the fan cowl pressure relief door are between 98 lbf (43.59 daN) and 118 lbf (52.49 daN).
Example:

Latch release load = 98 lbf. (P = 98)

Torque wrench effective length = 12 in. (L = 12)
Calculated as:

0.53 X 98 X 12 51.94 X 12

-------------- = ---------- = 46.168888

12 + 1.5 13.5

The results (46.168888) can be rounded to 46.2 lbf. The torque shown on the torque wrench when the latch releases, with a 12 in. effective length, should be 46 lbf.in (0.52 m.daN) to 56 lbf.in (0.63 m.daN).

(2) Install the RSE1234 ADAPTER TORQUE TOOL on the torque wrench.
(3) Put the torque wrench in the latch release slot.
(4) Measure the effective length of the torque wrench handle and put the hand at that position. Hold the handle with the thumb and the forefinger.
(5) Slowly apply force to the torque wrench. Make sure that the force is applied at a 90 degree angle to the torque wrench handle.
(6) When the latch starts to move write down the force shown on the torque wrench.
(7) Make sure that the torque wrench force indication is within the range of values calculated in procedural step 4.A.(1).
(8) If the force required to open the latch is above or below the calculated limits, replace the door latch.

5. Close-up
Subtask 71-13-11-410-065-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(3) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(4) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(5) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:22:22 UTC