TB 212-11-211
Page 4 of 8
ECCN EAR99
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.
