# Bell Alert Service Bulletin 412CF-24-77: No revision named

- Rights: © Bell Textron Inc. Filed by the FAA in regulations.gov docket FAA-2024-2010; AD 2024-16-01 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Bell Alert Service Bulletin 412CF-24-77](https://openairdocs.org/service-documents/bell/412cf-24-77.md)
- Title as filed: Bell ASB 412CF-24-77
- Pages: 4
- PDF: https://openairdocs.org/files/sha256/df/5f/df5f084c7b77f6a85d5a5c3425b6b9887d16ab1b13b9e0f01793c7e8e2e92e2a
- Page: https://openairdocs.org/service-documents/bell/412cf-24-77/file/df5f084c7b77

## Text

Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

ASB 412CF-24-77 
Page 1 of 4 
Approved for public release. 
 
 
  ALERT SERVICE BULLETIN 412CF-24-77 
22 April 2024 
 
 
MODEL AFFECTED:  412CF 
 
SUBJECT: CAP ANGLE, P/N 212 -030-191-001, INSPECTION 
INTERVAL, REDUCTION OF. 
 
HELICOPTERS AFFECTED: Serial numbers 46400 through 46999. 
 
 
COMPLIANCE: For helicopters that require the next 100 Hour 
tailboom attachment inspection to be accomplished in 
less than 25 flight hours after the release date of this 
bulletin, accomplish the inspection as scheduled, and 
every 25 flight hours thereafter.  
 
For helicopters that had the last 100 Hour t ailboom 
attachment inspection accomplished within the last 25 
flight hours after the release date of this bulletin, 
accomplish the next tailboom attachment inspection 
no later than 25  flight hours after the release date of 
this bulletin and every 25 flight hours thereafter.  
 
DESCRIPTION: 
 
Bell has investigated reports of fractured 212- 030-191-001 cap angles. Some were 
found during routine inspection and some during the scheduled 100 Hour Tailboom 
Attachment Inspection. The investigation indicates that the 100 flight  hour inspection 
interval established in 2000, introduced by the ASB 412CF-00-11 and the FAA AD 2000-
18-09, is not adequate to detect all cracks before complete fracture of the cap angle. 
This ASB reduces the 100 Hours tailboom attachment inspection interval from 100 flight 
hours to 25 flight hours and supersedes ASB 412CF -00-11. The Maintenance Manual 
Chapter 5 will be revised to incorporate this change.

### Page 2

ASB 412CF-24-77 
Page 2 of 4 
Approved for public release. 
APPROVAL: 
 
The engineering design aspects of this bulletin are FAA approved. 
 
CONTACT INFO: 
 
For any questions regarding this bulletin, please contact: 
 
Bell Product Support Engineering 
Tel: 1-450-437-2862 / 1-800-363-8023 / productsupport@bellflight.com 
 
MANPOWER: 
 
Approximately 0.5 man- hours are required to complete this bulletin.  This estimate is 
based on hands-on time and may vary with personnel and facilities available. 
 
WARRANTY: 
 
There is no warranty credit applicable for parts or labor associated with this bulletin. 
 
MATERIAL: 
 
None required. 
 
Consumable Material: 
 
None required. 
 
SPECIAL TOOLS: 
 
10x Magnifying glass. 
 
WEIGHT AND BALANCE: 
 
Not affected. 
 
ELECTRICAL LOAD DATA: 
 
Not affected. 
 
REFERENCES: 
 
Alert Service Bulletin, ASB 412CF-00-11. 
C-12-146-000/MY-001 Illustrated Parts Breakdown, Chapter 53. 
BHT-412CF-IPB Illustrated Parts Breakdown, Chapter 53. 
C-12-146-000/MF-001 Maintenance Manual, Chapter 5.

### Page 3

ASB 412CF-24-77 
Page 3 of 4 
Approved for public release. 
PUBLICATIONS AFFECTED: 
 
Alert Service Bulletin, ASB 412CF-00-11. 
C-12-146-000/MF-001 Maintenance Manual, Chapter 5. 
 
ACCOMPLISHMENT INSTRUCTIONS: 
 
1. Prepare the helicopter for maintenance and gain access to the cap angle in the tail 
rotor servo compartment through the R/H aft fuselage door. 
CAUTION 
 
Do not damage aluminum cap angle or fitting during sealant 
removal. 
 
2. If sealant is present, remove sealant from edge of fitting (Figure 1).  
3. Inspect the cap angle area shown with a 10x magnifying glass and bright light. 
4. If a crack is found, replace the cap angle before further flight. If the helicopter is at a 
location where the cap angle cannot be replaced, contact Product Support 
Engineering. 
5. Touch up primer if damaged during sealant removal. Paint touch up is optional. Do 
not reapply sealant. 
6. If no cracks are found, the helicopter can be returned to service. 
7. Make an entry in the helicopter logbook and historical service records indicating 
findings and compliance with this Alert Service Bulletin.

### Page 4

ASB 412CF-24-77 
Page 4 of 4 
Approved for public release. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure1. Fuselage Tailboom Attachment Inspection.

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