BELL 412CF Helicopters Instructions

: June 1, 2024
: Bell

Table of Contents

ALERT SERVICE BULLETIN
References
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ALERT SERVICE BULLETIN

412CF-00-11
26 May 2000
Revision A, 22 April 2024

MODEL AFFECTED: 412CF
SUBJECT: CAP ANGLE, P/N 212-030-191-001, INITIAL INSPECTION
HELICOPTERS AFFECTED: Model 412CF helicopters serial number 46400 through 46499.
COMPLIANCE: L/H Upper Cap Angle, P/N 212-030-191-001, must be initially inspected within 25 flight hours after receipt of this bulletin.

-NOTE-

Additionally, the L/H upper Cap Angle of all Model 412 Helicopters must be inspected each 100 hours thereafter. Revise C-12-146-000/MF-001 CH146 Maintenance Manual Scheduled 100 hour Inspection to include the inspection instructions accomplished in step 4 of the instructions.

DESCRIPTION:

This Alert Service Bulletin (ASB) has been superseded and replaced by ASB 412CF-24-77. Bell Helicopter has recently completed an investigation of a fractured Upper Left Fuselage Tailboom Attachment Cap Angle, P/N 212-030-191-001. The fracture was the result of a fatigue crack, which originated from metal chips left between the bottom side of the cap and the upper side of the fittings, or between the cap angle and the adjacent structure. This has been determined to be the result of improper de-burring and cleaning during manufacture.

As a result of the above investigation, the following maintenance procedures are initiated to assure continued structural integrity of the cap:

The L/H upper cap angle, P/N 212-030-191-001, must be inspected within 25 flight hours after receipt of this bulletin.
A recurring inspection at each fourth 25 hour and 100 hour interval thereafter is added to the Maintenance Manual.

APPROVAL:
Not required

MANPOWER:
Approximately 0.5 man-hours are required to complete this bulletin. Man-hours are based on hands-on time and may vary with personnel and facilities available.

MATERIAL:
None Required

SPECIAL TOOLS:
10x magnifying glass.

WEIGHT AND BALANCE:
Not effected

ELECTRICAL LOAD DATA:

REFERENCES:
C-12-146-000/MY-001 CH146 Illustrated Parts List
C-12-146-000/MY-001 CH146 Maintenance Manual

PUBLICATIONS AFFECTED:
C-12-146-000/MY-001 CH146 Maintenance Manual

ACCOMPLISHMENT INSTRUCTIONS:

Gain access to the cap angle in the tail rotor servo compartment through the R/H aft fuselage door.
Inspect area noted on figure 1 of cap angle, P/N 212-030-191-001, with 10x magnifying glass.
If no cracks are found, return the aircraft to service.
Revise C-12-146-000/MY-001 CH146 Maintenance Manual Scheduled 100 hour Inspection to include the following statement and copy of the figure 1: “Inspect fuselage Tailboom attachment components and hardware for cracks with a 10X magnifying glass, pay particular attention to the interface between the end of the Tailboom attachment fitting and cap angle. Refer to figure 1.”
If a crack is found, contact Product Support Engineering before further flight:
Phone (USA) 800-363-8028
Phone (Canada) 800-363-8224
International 450-437-6201
Fax 450-433-0272
e-mail psemedium@bellhelicopter.textron.com
Annotate helicopter historical service records to reflect compliance with this bulletin.