Documents / Warranty Safety
Alert Service Bulletin for Bell 204B Planetary Spider Replacement
This guide outlines the mandatory replacement of the planetary spider (part 204-040-785-003) with the upgraded version (412-040-785-103) for Bell 204B helicopters, including compliance timelines and replacement instructions.
Quick answers from the manual
Quick answer
- This bulletin mandates the replacement of the planetary spider (204-040-785-003) with an upgraded version (412-040-785-103) on specific Bell 204B helicopters. p. 1
Key actions
- Replace planetary spider 204-040-785-003 with 412-040-785-103. p. 3
Technical specifications
| Parameter | Value | Meaning | Pages |
|---|---|---|---|
| Part Number | 412-040-785-103 | Replacement planetary spider | p. 2 |
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Where to find it in the PDF
- Bulletin Details p. 1
- Material and Contact p. 2
- Instructions p. 3
Table of contents
Important Information
This Alert Service Bulletin (ASB 204B-26-79) mandates the replacement of the lower planetary spider (part 204-040-785-003) with an upgraded version (412-040-785-103) on specific Bell 204B helicopters. This action is required due to reports of cracked lower planetary spiders.
Compliance
The replacement must be completed no later than the next 3100 flight hours or 6 years from the bulletin date of 16 April 2026, whichever comes first.
Affected Helicopters
This bulletin applies to Bell 204B helicopters with the following serial numbers:
- 2001 through 2070
- 2196 through 2199
No action is required if the lower planetary spider 204-040-785-003 was previously replaced by the upgraded planetary spider 412-040-785-103.
Replacement Procedure
The disassembly and assembly instructions, inspection criteria, and damage limits are contained in the BHT-204B-M&O (Maintenance & Overhaul Manual). Follow these steps:
- Replace planetary spider 204-040-785-003 with the upgraded planetary spider 412-040-785-103.
- Make an entry in the helicopter logbook and historical service records indicating compliance with this Alert Service Bulletin.
Required Material
The following part is required for the accomplishment of this bulletin:
- Planetary Spider: Part Number 412-040-785-103 (Quantity: 1)
Refer to the 204B Maintenance & Overhaul Manual (BHT-204B-M&O) for any additional consumable materials required.
Contact Information
For any questions regarding this bulletin, please contact Bell Product Support Engineering:
Tel: 1-450-437-2862 / 1-800-363-8023Email: [email protected]
Practical help
Common problems
Cracked lower planetary spider (204-040-785-003)
Replace with upgraded planetary spider (412-040-785-103)
Before use
- Verify helicopter serial number is within 2001-2070 or 2196-2199
- Check if part 204-040-785-003 is currently installed
- Obtain replacement part 412-040-785-103
- Consult BHT-204B-M&O manual for specific disassembly/assembly steps
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Specs in practice
- Compliance Deadline
- Must be completed within 3100 flight hours or 6 years from 16 April 2026
Model compatibility
- Only applies to serial numbers 2001-2070 and 2196-2199
- No action required if already replaced with 412-040-785-103
Manual page author
Emily Carter
User documentation editor