TM 55-2840-231-23
First-Stage Turbine Nozzle and Shield Inspection
Item
condition
Serviceable Limits
First Stage Nozzle
1
Axial cracks in vane airfoil.
2
3
4
Nicked or dented leading
and trailing edge. Warped or
burned trailing edge only.
Fillet cracks-inner and outer
band.
Outer band cracks-leading
and trailing edges.
5
Inner band cracks-leading
and trailing edges.
First Stage Nozzle Shield
6
Cracks around spotwelds on
heat shield.
Combustion Section Components
Leading edge 1/4 in. (6.4 mm) maximum; trailing edge
5/16 in. (7.9 mm) maximum.
a. No two cracks in same plane.
b. Adjacent cracks 1/4 in. (6.4 mm) apart.
c. Adjacent cracks not progressing toward each other.
Leading edge 1/16 in. (1.6 mm) maximum; trailing edge
1/8 in. (3.2 mm) maximum.
Leading edge 1/4 in. (6.4 mm) maximum; trailing edge 1/8
in. (3.2 mm) maximum.
Leading edge-visible portion of crack extends 3/8 in. (9.5
mm) maximum axially into the band.
Trailing edge-crack extends 1/2 in. maximum axially into
the band.
Cracks on leading edge must not be in line with cracks on
trailing edge.
Leading edge-visible portions of crack extends 1/16 in.
(1.6 mm) maximum axially into the band. Trailing edge-
none permitted.
Cracks are acceptable provided the length of the crack is
not greater than 50 percent of the distance around the weld.
7
(Refer to paragraphs 3-2,
3-4, 3-8 and 3-10.)
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