## '1'11"11~~~1.

DATE



### MOC,EL AFFECTED: SUBJECT:



### HEL IC, OPTl: RS A 

### FECTED: CO'MPUANCE:**DESCRIPT~ON:** 

### ALERT SERVICE BULL TIN 

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# £4 i

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### 230-00-18, O,li n; 05-19..()0 P

AGE 1 of6

Model2. 30 

### HYDRA ULJ C ACTIUATOr R SUPPORT 

### PJ.N 222-040- 125..001, 

### II NS P'E, CTION 

### 0 F Model 230 helicopters**sel'lia~** number 23001 through 23038 Within 25 houii'S foUowing receipt of this bulletin.

A Modei222U helicopter was in fll9hl when 

### it experienced a control loss. The cause of control loss was attributed to the main rotor hydraulic actua or support separating from the transmission . All**eta ning**  studs were found sheared or pulled out at the junction of the s upport with the transm ission upper a d lower cases . The purpose 

### of thrs bu lletin is to r equ 

### i:re a 

### one-time inspection of the hydrauiic actuators s upport**nstal~tion** by accomplishing' a 

### torque check of 

### the support 

### attaching nuts. In add ition. a Revis ion 

### to the mai ntena.nce manua I wi l l introduce a recur ri ng torq ue check of the support attach ing nuts . APPROVAL: Not required MANPOWER: Approximately 

### .5 man-hour r s required to compte e this bulletin 

### if rtle 

### support is not remove-d from the transmiss·o An addftional 6 man-hours wi ll be required to remove, inspect and reinstal l lhe support. Man-hours are based on hands-on time. and 

### may vary 

### with person nel and facilities avallable.

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## II230-00-18 Page 2 of 6 MATERIAL: Required Material: The following material is required for the accomplishment of this bulletin and may be obtained through your Bell Helicopter Textron Supply Center. Part Number Nomenclature Quantity * MS21042L4 Nut 4 * MS21042L5 Nut 4 * 222-040-268-001 Washer 4 * 222-040-268-003 Washer 4 * Nuts and washers are required only if actuator support is removed for inspection . Consumable Material: The following material is required to accomplish this bulletin , but may not require ordering , depending on the operator's consumable material stock levels . This material may be obtained through your Bell Helicopter Textron Supply Center. Part Number Nomenclature Quantity Reference * MILS8784CLB2 Sealant 

### 3.50Z C-328 * Sealant is required only if actuator support is removed for inspection. SPECIAL TOOLS: None required WEIGHT AND BALANCE: Not affected ELECTRICAL LOAD DATA: Not affectedREFERENCES: BHT-230-MM-6 , Chapter 63 BHT-230-MM-9 , Chapter 71 BHT-230-CR&0-2 , Chapter 63 BHT-ALL SPM PUBLICATIONS AFFECTED: BHT-230-MM-2 , Chapter 5 BHT-230-CR&0-2, Chapter 63 ACCOMPLISHMENT INSTRUCTIONS: 

### 230-00-18 Page 

### 3 of 6

1 . Remove fairings and cowlings as required to gain access to the hydraulic actuators support . Refer to BHT-230-MM-9, Chapter 71 . 2. Verify that the dowel pins installed in the transmission upper case are not missing and that evidence of sealant is present at the joint between the actuator support and the transmission . Refer to figure 2. If any of the pins are missing and/or if no sealant is visible , remove the actuator support and proceed to step 5. 3 . Verify torque of actuators support P/N 222-040-125-001 attaching nuts. Apply the torque in the tightening direction . For the upper row of nuts , if 40 in . lb . is reached without nut movement, increase the torque to 50-70 in .lb plus tare . For the lower row of nuts, if 90 in. lb . is reached without nut movement, increase the torque to 100-140 in.lb plus tare . -NOTEAnti fretting washers installed between the actuator support and the transmission lower case may be reinstalled provided the coating is not worn through or damaged . 4 . If two or more of the nuts within the upper row of the support attaching nuts move below 40 in.lb torque or two or more of the nuts within the lower row of the support attaching nuts move below 90 in.lb torque , remove the hydraulic actuators support from the transmission for further inspection and repair. Refer to BHT-230-MM-6 , Chapter 63 and BHT-230-CR&0-2 , Chapter 63 for removal instructions . Discard nuts and washers . 5 . If required , inspect the support P/N 222-040-125-001 in accordance with instructions in BHT-230-CR&0-2 , Chapter 63. The holes at the lower and upper end of the support were manufactured to the dimensions shown in Figure 1.230-00-18 Page 4 of 6 6 . If requ ired, inspect the transmi ssio n lower case assembly as follows : a) Inspect surface of transmission case in contact with the actuator support for damage , fretting and corrosion. Refer to BHT-230-CR&0-2 , Chapter 63 for damage/wear limits . b) Inspect the studs , retaining the actuators support, for condition of threads and for looseness . Replace damaged studs in accordance with BHT-230-CR&0-2 , Chapter 63 and BHT-ALL-SPM. 7. If required , inspect the transmission upper case assembly as follows: a) Inspect surface of transmission case in contact with the actuator support for damage , fretting and corrosion. Maximum depth and/or size of corrosion , wear, scratches , nicks and marks shall not exceed 0.005 inch depth , 40% of any one square inch or more than 20% of the total surface . Pitting/corrosion around studs and dowel pins shall not exceed 0.005 depth or 50% of the circumference of the stud/dowel pin . b) Inspect the studs , retaining the actuators support, for condition of threads and for looseness . Replace damaged studs in accordance with BHT-230-CR&0-2 , Chapter 63 and BHT-ALL-SPM . c) Inspect the dowel pins in transmission case for damage , fretting , corrosion and looseness . The large outboard pins should measure 0.500 inch minimum and protrude 0.55 inch from the surface of the case . The small inboard pins should measure 0.375 inch minimum and protrude 0.45 inch from the surface of the case . Refer to Figure 2 8 . If removed for inspection , reinstall actuators support on the transmission with new nuts and washers in accordance with instructions in BHT-230-CR&0-2 , Chapter 63 . Reinstall all parts previously removed in accordance with BHT-230-MM-6, Chapter 63 . 9 . Reinstall fairings and cowlings previously removed. Refer to BHT-230-MM-9 , Chapter 71 . 10. Annotate helicopter records to reflect compliance with this bulletin.0.343 - 0.350 IN Dia . (8. 7 1 - 8 .89 mm) Hydraulic Actuator Support Assembly P/N 222-040-125-001 Figure 1 230-00-18 Page 5 of 6

ILL00101230-00-18 Page 6 of 6

DOWEL PINS Transmission Top Case Assembly P/N 222-040-061-105 Figure 2 

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ILL00102