'1'11"11~~~1. 

DATE 

MOC,EL AFFECTED: 

SUBJECT: 

HELIC,OPTl: RS A FECTED: 

CO'MPUANCE: 

DESCRIPT~ON: 

ALERT SERVICE BULL TIN 

pterl i £4 i tt•J! I 

!., 

~0 230-00-18, 

O,lin; 05-19..()0 

PAGE 1 of6 

Model2.30 

HYDRA ULJ C ACTIUA TOrR SUPPORT PJ.N 222-040-

125 .. 001, IINS P'E,CTI ON 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 support with the transmission upper a d lower cases. 

The purpose of thrs bulletin is to requ i:re a one-time inspection of the hyd rauiic 

actuators support nstal~tion by accomplishing' a torque check of the support attaching 

nuts. In add it ion. a Revision to the mai ntena.nce manua I will introduce a recurring 

torque check of the support attaching nuts. 

APPROVAL: 

Not required 

MANPOWER: 

Approximately .5 man-hour rs required to compte e this bulletin if rtle support is not 

remove-d from the transmiss·o An addftional 6 man-hours will be required to remove, 

inspect and reinstall lhe support. Man-hours are based on hands-on time. and may 

vary with personnel and facilities avallable . 

... r •1 F E ~ ;: i -:..• ~ Jl Jl 1 r r 

~ 1 r ·'-ill' "lF IJ:jl ;;.,n T 

II 
230-00-18 

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 affected 
REFERENCES: 

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 required, inspect the transmission 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 . 

1 0. Annotate helicopter records to reflect compliance with this bulletin. 
0.343 - 0.350 IN Dia. 

(8. 71 - 8.89 mm) 

Hydraulic Actuator Support Assembly 

P/N 222-040-125-001 

Figure 1 

230-00-18 

Page 5 of 6 

ILL00101 
230-00-18 

Page 6 of 6 

DOWEL PINS 

Transmission Top Case Assembly 

P/N 222-040-061-105 

Figure 2 

.. 

ILL00102