BELL 412EPI/EPX Public Safety Energy Helicopter Owner’s Manual
- June 14, 2024
- Bell
Table of Contents
INFORMATION LETTER
412-23-95
20 September 2023
TO: All owners and operators of Model 412EPI/EPX helicopters
SUBJECT: ACA COURSE HEADING SELECT PANEL (CHSP) KNOB INSERT REPLACEMENT
INSTRUCTIONS
The purpose of this Information Letter is to achieve complete distribution of
the attached supplier Service Bulletin (SB) to the current affected model
Technical Publications distribution list on record by Bell.
The Astronautics Corporation of America (ACA) SB No. 277190-34-SB-001 provides
the instructions to replace the CHSP knob inserts for those knobs that are
affected by decal wear and chipping. The SB applies to Bell model 412EPI/EPX
helicopters with ACA
CHSP (412-374-012) installed.
For any questions regarding this letter, please contact:
Contact information:
Astronautics Corporation of America
135 West Forest Hill Ave.
Oak Creek, WI 53154 U.S.A
Telephone: 414-449-4824
Email:
customerservice@astronautics.com
Website: http://www.astronautics.com/
SERVICE BULLETIN
SUBJECT: CHSP Knob Insert Replacement Instructions
Planning Information
A. Effectivity
This Service Bulletin applies to replacing the CHSP Knob Inserts
(277548/277549).
B. Reason
This Service Bulletin is issued to provide instructions for replacing the
Course and Heading Knob Inserts (277548/277549) for CHSP Knobs that are
affected by decal wear and chipping.
This Service Bulletin will allow the technician to replace the Course/Heading
Insert with pprovided instructions.
C. Compliance
This Service Bulletin is optional.
D. Approval
Approval is the responsibility of the aircraft maintainer / installer.
E. Manpower
Replacing the CHSP Knob Inserts will take approximately 0.5 man-hours.
F. Weight and Balance
N/A.
G. Electrical Load Data
N/A.
H. Software Accomplishment Summary
NA.
I References
NA.
J. Other Publications Affected
N/A.
K. Interchangeability or Intermixability of Parts
NA.
Materials Needed
| Part | Part Number |
|---|---|
| Replacement Course/Heading Insert | 277548/277549 |
| 0.060-inch 6-fiute Spline and Driver | Not Provided |
| Set Screws (2) | ANS65DCAL2 (Not Provided) |
| O-Ring retainer | M8791/1-013 |
| Loctite (Grade E) or Equivalent | Not Provided |
Heading and Course Inserts for replacement available upon request.
Contact information:
Astronautics Corporation of America
135 West Forest Hill Ave.
Oak Creek, WI 53154 US A
414-449-4824
customerservice@astronautics.com
http://www.astronautics.com/
Knob Insert Replacement Instructions
A. Knob Insert Removal
a. Using the Spiine and Driver, remove the 2 Set Screws (AN565DC4L2) on the
CHSP Knob.
i. Note: The old Set Screws should be discarded, new set screws must be
used for Section 3.B Knob Insert Installation.
b. Lightly pull the Knob off the CHSP.
c. Remove the Insert by tuming the Knob over such that the Insert is released.
Ensure that the foam washer (278198) does not fall out.
d. Repeat steps a-c for all Knob Inserts that are to be replaced.
Knob Insert Installation
a. Place the included O-Ring retainer (M8791/1-013) onto the replacement
insert.
b. Insert the replacement Course/Heading Insert into the Heading Knob.
c. Tum the Heading Insert until it falls into place and ensure that the
clearance holes on the knob are aligned with the holes in the insert.
i. Note: The O-Ring retainer may need to be lightly pinched in order to
fit into the bore of the Knob.
d. Attach the combined Knob with Insert onto the CHSP Optical Encoder. Ensure
the flat sides of the knob shaft are aligned with the flat side of the encoder
knob. Space the knob approximately 0.010 inches off of the switch panel.
e. Apply a small amount of Loctite Grade E (or equivalent) to the threads of
each of the new Set Screws (AN565DCA4L2). Use the Spline and Driver to secure
the screws and altemate between each Set Screw until screw stops. The Set
Screws should be torqued
102.87 in-bs.
f. Verify that the Knob is attached correctly by confirming the Insert can be
pressed as a button.
g. Repeat steps a-f for all Knob Inserts that are to be replaced.
Astronautics
Corporation of America
Original Issue: 2023-08-01
SB No. 277190-34-SB-001
IL 412-23-95
Approved for public release.