Textron Bell 412 - Page 287

BHT-412-MM-2
5-00-00
Export Classification C, ECCN EAR99
Refer to TB 412-03-191.
Special inspection required each 3000 hours on helicopters S/N 36020 through 36999 and helicopters
modified by 412-570-001-103 or Post BHT-412-SI-74 (412SP to 412HP Upgrade) (paragraph 5-34).
Incorporation of Increased Maximum Continuous Power Kit (BHT-412-SI-38) P/N 412-706-029-ALL
reduces the Time Between Overhaul (TBO) interval to 3000 hours.
Refer to BHT-412-SI-36 for maintenance information.
Visually inspect (BHT-412-CR&O) tube assembly 412-040-510-103 at mast assembly overhaul.
Special inspection required each 2500 hours on helicopters S/N 36020 through 36999 and helicopters
modified by 412-570-001-103 or Post BHT-412-SI-74 (412SP to 412HP Upgrade) (paragraph 5-31).
Special inspection required each 3000 hours on helicopters prior to S/N 36020 and helicopters not
modified by 412-570-001-103 or BHT-412-SI-74 (412SP to 412HP Upgrade) (paragraph 5-33).
Special inspection required each 3000 hours on helicopters prior to S/N 36020 and helicopters not
modified by 412-570-001-103 or BHT-412-SI-74 (412SP to 412HP Upgrade) (paragraph 5-32).
Refer to Pratt & Whitney Canada PT6T-3D Series Maintenance Manual for instructions on 2500 hour
clutch inspection requirements.
The 10%/100 hour inspection and overhaul tolerance permitted by Bell Helicopter Textron does not
apply to power plant components. Contact Pratt & Whitney Canada for any deviation in maintenance
requirements.
Special inspection required each 3000 hours on helicopters S/N 36020 through 36999 and helicopters
modified by 412-570-001-103 or Post BHT-412-SI-74 (412SP to 412HP Upgrade) and Post TB
412-14-231 (paragraph 5-30).
If the intent of TB 412-14-231 has been accomplished, special inspection (paragraph 5-30) is required
each 3000 hours on helicopters S/N 36020 through 36999, S/N 37002 through 37999, and helicopters
modified by 412-570-001-103 or Post BHT-412-SI-74 (412SP to 412HP Upgrade).
If the intent of TB 412-14-231 has been accomplished, then the overhaul interval is 6000 hours.
Applicable to 412EP S/N 36694 thru 36999 with next higher assembly 412-140-001-101.
Applicable to 412EPI S/N 37002 thru 37999 with next higher assembly 412-140-001-103
Table 5-1. Component Overhaul Schedule (Cont)
NOTES: (CONT)
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