BELL HELICOPTER 212 Service manual

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ECCN EAR99
TECHNICAL BULLETIN 212-11-211
21 March 2011
MODEL AFFECTED: 212
SUBJECT: NUMBER ONE ENGINE JACKSHAFT SUPPORT
INSPECTION AND MODIFICATION OF.
HELICOPTERS AFFECTED: Model 212 helicopters serial number 30501
through 30999, 31101 through 31311, 32101
through 32142 and 35001 through 35103.
[Model 212 helicopters serial number 31312 and
subsequent, 32143 and subsequent, 35104 and
subsequent will have the intent of this bulletin
accomplished prior to delivery.]
COMPLIANCE: Part 1: Recommended.
Part 2: At customer’s option.
DESCRIPTION:
Bell Helicopter has been made aware of a possible fouling condition that may exist
between the number one jackshaft support and the forward firewall of the intake
cowling. This Technical Bulletin provides an inspection procedure to verify adequate
clearance between the N1 jackshaft support and if a fouling condition exists, the
corrective action to be taken. Applicability of this bulletin to any spare parts shall be
determined prior to its installation on an affected aircraft.
APPROVAL:
The engineering design aspects of this bulletin are FAA/ODA approved.
CONTACT INFO:
For any questions regarding this bulletin, please contact:
Bell Helicopter Product Support Engineering - Medium Helicopters
Tel: [phone] / psem[email protected]

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MANPOWER:
Approximately 3.0 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:
Required Material:
The following material is required for the accomplishment of this bulletin and may be
obtained through your Bell Helicopter Textron Supply Center.
Part Number Nomenclature Qty
412-060-024-101 Snubber Assembly 1
212-060-700-131 Spacer 1
212-060-700-133 Spacer 2
MS27039-1-21 Screw 3
NAS1149C0316R Washer 3
Consumable Material:
The following material is required to accomplish this bulletin, but may not require
ordering, depending on the operator’s consumable material stock levels. This material
may be obtained through your Bell Helicopter Textron Supply Center.
Part Number Nomenclature Qty Reference *
AMS3276 1 pt Sealant 1 C-599
299-947-152, TY III Adhesive 1 C-314
P-P-101 Abrasive 400 grit 1 C-423
MILC81706 CL1AFORM11 Alodine 1200 1 C-100
513X395/910X710 Primer 1 C-204
* C-XXX numbers refer to the consumables list in BHT-ALL-SPM Standard Practices Manual
SPECIAL TOOLS:
None required

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WEIGHT AND BALANCE:
Longitudinal Lateral*
Weight Arm Moment Arm Moment
+0.2 Lbs 153 in. +31 in-Lbs -17.0 in. -3.0 in-Lbs
+0.1 kgs 3886 mm +3.5 kg x mm/100 -432 mm -0.4 kg x mm/100
* In lateral calculations, - is left and + is right.
ELECTRICAL LOAD DATA:
Not affected
REFERENCES:
BHT-212-IPB Illustrated Parts Breakdown
BHT-212-MM Maintenance Manual
BHT-MED-SRM-1 Structural Repair Manual
BHT-ALL-SRM Structural Repair Manual
BHT-ALL-SPM Standard Practices Manual
PUBLICATIONS AFFECTED:
BHT-212-IPB Illustrated Parts Breakdown
ACCOMPLISHMENT INSTRUCTIONS:
Part 1:
1. Prepare helicopter for maintenance.
2. Open forward transmission cowling (1, Figure 1).
3. Remove left hand air inlet cowling (2).
4. Inspect N1 Jackshaft support bearing boss for wear on the forward side of the boss
see Figure 2.
5. If wear is found proceed to Part 2 of this Technical Bulletin.
6. If no wear is found reinstall left hand air inlet cowling (2) and latch in place.
7. Close forward transmission cowling (1).
8. Make an entry in helicopter historical service records indicating compliance with Part
1 of this Technical Bulletin.

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Part 2:
1. Prepare helicopter for maintenance.
2. Open forward transmission cowling (1, Figure 1).
3. Remove left hand air inlet cowling (2).
4. Inspect N1 Jackshaft support bearing boss for wear on the forward side of the boss
see Figure 2.
5. Maximum permissible wear on the 1.22” (31.0 mm) Diameter boss is 0.060”
(1.53mm) after clean up Figure 2 View A.
6. Blend damaged area including any sharp edges smooth with minimum material
removal using 400 grit paper (C- 423).
7. Chemical film treat (C-100).
8. Prime repaired surface (C-204).
9. Remove the forward and aft outboard two support retaining screws and the forward
inboard support retaining screw (3, Figure 3) and washers (4) from the support and
discard.
10.Apply a thin film of sealant (C-599) to the top and bottom of the faying surfaces of
the two spacers (6).
11.Apply a thin film of sealant (C-599) to the top and bottom of the faying surfaces of
spacer (5).
12.Install the two spacers (6), one on the forward and one on the aft outboard holes on
top of the support.
13.Install one spacer (5) on the forward inboard hole on top of the support.
14.Place the Snubber Plate Assembly P/N 412-060-024-101(1) on top of the spacers (5
and 6) as shown in figure 3.
15.Apply sealant (C-599) to the shank only of the three screws (2) and install with
washers (4) through the Snubber Assembly (1), spacers (5 and 6), and support.
Torque the three screws 20-25 in/lbs.
16.Remove the transition duct (2, Figure 4) from the inlet cowling (1) by removing the
two screws (3) and washers (4) securing the transition duct to the intake cowling
assembly.

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17.Reinstall the left hand air inlet cowling (2, Figure 1) without the transition duct
installed and latch in place.
18.With a bright light verify that there is clearance between the N1 jackshaft support
and the forward firewall. If the firewall is still contacting the N1 jackshaft support
please contact Product Support Engineering.
19.Remove left hand air inlet cowling (2).
20.Reinstall the transition duct (2, Figure 4) on the inlet cowling by installing the two
screws (3) and washers (4).
21.Reinstall the left hand air inlet cowling (2, Figure 1) and latch in place.
22.Close and latch transmission cowling (1).
23.Make an entry in helicopter historical service records indicating compliance with Part
2 of this Technical Bulletin.
Figure 1