Confusion
No Specific Anomaly Occurred All Types
Human Factors; Procedure
[Engineering Order] should break down task to allow less or no partial signing which creates confusion and possibly missing procedural steps.[Engineering Order] REV N OP 5 HSTA (Horizontal Stabilizer Trim Actuator) JACKSCREW REPLACEMENT Op 5 Step 6 instructs to replace the HSTA per the AMM (Aircraft Maintenance Manual) 27-XX-XX; including Stab Clutch Friction System Test per the AMM 27-XX-XX-XXX-XXX; and lubricate it per Op 4 Step 14. There are too many tasks in Step 6 which results in numerous short signs or [unfinished write ups]. The stab clutch friction test and the lubrication per Op 4 should not be listed in Step 6. The lubrication per Op 4 is covered in the AMM Step H. (15) and in Step 14 of the [Engineering Order] Op 5. Lubrication in the [Engineering Order] needs to be relocated after Step 6. But before Functional Tests. It would be helpful if Step 6 only listed the installation of the HSTA per AMM. Step 6 also instructs to do the Stab Clutch Friction Test per the AMM. This test should be first under the Functional Tests of the [Engineering Order] Op 5 with all the other Functional Tests; starting after Step 6 of the [Engineering Order]. Also; is it possible to leave the stab trim motor out until the Stab Clutch Friction Test is performed? If so; the AMM will need to explain this. This would be Step H. (13) Stab Trim Motor Installation and Step H. (19) Stab Clutch Friction Test of the AMM 27-XX-XX. When following Trim Motor Installation before Friction Test; it is required to remove trim motor again which means removing motor not once but twice. Explain why? Keep in mind; Stab Trim Motor Installation requires an Installation Test. Op 5 Step 9 instructs to perform the HSTA Brake Servicing per AMM 12-XX-XX-XXX-XXX. Step 9 should be relocated after Step 6 of the [Engineering Order] but before Steps of Functional Tests. This brake servicing is also covered in the AMM not once but twice and listed in the [Engineering Order] Step 6. Does that mean HSTA brake requires to be serviced twice or is it a mistake in the AMM? If required twice per AMM; then have [Engineering Order] match AMM in the same sequence for brake servicing to be done twice.
Maintenance Technician reports confusion in work card instructions regarding the Horizontal Stabilizer Trim Actuator.