Allison Engine Company
ENGINE TURBINE ASSEMBLY, GAS PRODUCER--ROTOR ASStMBLY -
REPLACE TIE BOLT BY TIE BOLT OF IMPROVED STRENGTH
1. PLANNING INFORMATION:
A. Effectivitv:
Affected turbine assemblies are as shown below:
All 250.B15G turbines CAT 50001 up to and includirlg 50099 have the
6843388 tie bolt installed. CAT 50100 and subseqLlent turbines have the
6876991 tie bolt installed.
All 250-817 turbines CAT 60003 up to and including 60062 have the 6843388
tie bolt installed. CAT 60063 and subsequent turbines have the 6876991
tie bolt installed.
All 250-B17B turbines CAT 80001 up to and including 80299 have the
6876991 tie bolt installed.
All 250.B17C, B17D, B17E turbines CAT 80300 up to and including 80610,
CAT 80612 up to and including 80614 have the 6876991 tie bolt installed.
All 250-C18, -C18A, -ClSB, and -ClSC turbines CAT 20208 up to and
including 21799, CAT 21900 up to and including 22492, CAT 23500 up to and
including 23639 have the 6843388 tie bolt installed. CAT 23640 BC
(except CAT 23641) and subsequent have the 6876991 tie bolt installed.
CAT 23641 has a 6843388 tie bolt installed.
All 250.C20 turbines CAT 30000 (excluding CAT 31766, 31803, 31944) up to
and including 32059 have the 6843388 tie bolt installed. CAT 31766,
31803 and 31944 have the 6876991 tie bolt installed. CAT 32060 up to and
including 32999, CAT 38001 up to and including 387!57 have the 6876991 tie
bolt installed.
All 250-C20B, C2OJ, C2OF turbines CAT 22550 up to iand including 23499,
CAT 23800 up to and including 23951, CAT 33001 up to and including 38000
have the 6876991 tie bolt installed. CAT 33000 has a 6843388 tie bolt
installed. CAT 40000 up to and including 40699 have the 6876991 tie bolt
installed.
February 15, 1985 250-C18. T63-A-700 CEB 234
Revision No. 3 250X20; C2OB, C2OJ, CZOS, C2OF, CEB 1212
January 15, 1990 T63-A-720
250-B15G TP CEB 104
250-817, B17B, B17C, B17D TP CEB 1173
250-C288, C28C CEB 72-2093
250-C30, C30L, C30M, C3OP, C3OS, C30R CEB 72-3109
Page 1 of 6
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
Allison Engine company
Commercial Engine Bulletin
A. Effectivity: (Continued)
All 250.CZOS turbines up to and including S/N CAT 10011.
All 250.C28B turbines up to and including S/N CAT 70802 and CAT 70804.
All 250.C28C turbines up to and including S/N CAT 28022, 28042 and
28044.
All 250.C30, -C3OP, and -C3OS turbines up to and including S/N CAT 95423
except for the following which presently do conform to this bulletin:
CAT 95243, 95281, 95295, 95297, 95321, 95325, 95336, 95348, 95351,
95354, 95357, 95361, 95363, 95364, 95367, 95370 thru 95375, 95377 thru
95384, 95386 thru 95394, 95396, 95397, 95399, 95400, 95402 thru 95407,
95409, 95411, 95414, 95416 thru 95420, and 95422.
(1) All 250.C2OF turbines S/N CAT 22868, 22894, 22999, 22864, 22869, 23000,
23001, 23002, 23006, 23009, 23011, 23037, 23041, 23042, 23043, 23044,
23045, 23047, 23048, 23051, 23064, 23068, 23069, 23065, 23072, 23073,
23076, 23109, 23110, 23141, 23143, 23320, 23321, 23339, 23337, 23342,
23395, 23414, 23416, 23446, 23475, 23476, 23452, 23474, 23415, 23477,
23835, 23836, 23038, 23841, 23848, 23853, 23854, 23863, 23864, 23887,
23888. 23889, 23891, 23912, 23916. 23917. 40436, 40440, 40612, 40629,
40691; 40687:
NOTE: If any of these turbines have been overhauled
you will need to check your log book for
compliance with CEB 234, 1212, TP 104, TP 1173.
B. Reason:
Superseded part numbered Tie Bolts have experienced fatigue cracks in
the threaded area.
WARNING: FAILURE OF THE TIE BOLT COULD RESULT IN GAS
PRODUCER ROTOR FAILURE WITH COMPLETE LOSS OF
POWER. A FAILURE OF THIS TYPE CAN POSSIBLY
CAUSE WHEEL FRAGMENTS TO EXIT THE ENGINE WITH
POTENTIALLY SEVERE DAMAGE TO THE AIRCRAFT.
C. Description:
The current tie bolts are superseded by tie bolts which feature in-
creased fatigue strength and more secure locking of the tie bolt nut.
D. Approval: Technical aspects are FAA approved.
February 15, 1985 250.C18, T63-A-700 CEB 234
Revision No. 3 250.C20, C20B, C2~OJ, CZOS, C2OF, CEB 1212
January 15, 1990 T63-A-720
250-8156 TP CEB 104
250-B17, B17B, B17C, B17D TP CEB 1173
250.C28B, C28C CEB 72-2093
250-C30, C30L, C30M, C3OP, C3OS, C30R CEB 72-3109
Page 2 of 6
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
Allison Engine Company
Commercial Engine Bulletin
E. Compliance:
(1) Compliance Code 2. Remove P/N 6843386 (Series I and II) tie bolt at
the next turbine repair or overhaul, but in no case later than
February 28, 1990.
(2) Compliance Code 2. Remove P/N 6876991 (Series I and II) and P/N
6889320 (Series III and IV) at the next turbine repair or overhaul,
but in no case later than February 28, 1992.
! (3) Compliance Code 2. All turbines referenced in Effectivity Section A
Cl), remove P/N 6876991 Tie Bolt at the next turbine repair or
overhaul, but in no case later than February 28, 1994.
F. Interchanseability: Not affected.
G. Material Availabilitv:
WY
u New P/N Nomenclature Per Enqine
250.Cl8 23008020 Bolt, Turbine Tie
250.C20, C2OE, C2OJ, C2OS,
C2OF
250.B15G
250.B17, BI7B, B17C, B17D,
B17E
250.C28B, C28C 23008030 Bolt, Turbine Tie
250.C30, C301, C30M, C3OP,
C3OS, C30R
H. Toolino: None.
I. Weiqht and Balance: None.
J. Electrical Load Data: Not affected.
K. References: ATW 223113, ATW 2239
L. Other Publications Affected:
250-Cl8 Illustrated Parts Catalog 5w4
250-C20 Illustrated Parts Catalog lOW4
250-8151; Illustrated Parts Catalog 6W4
250-B17 Illustrated Parts Catalog llW4
250-C30 Illustrated Parts Catalog 14w4
250.C28 Illustrated Parts Catalog 16W4
M. Prerequisites: None.
February 15, 1985 250.C18, T63-A-700 CEB 234
Revision No. 3 250.C20, C20B, C2OJ, C2OS, C2OF, CEB 1212
January 15, 1990 T63-A-720
250.B15G TP CEB 104
250.B17, 8178, B17C, B17D TP CEB 1173
250-C288, C28C CEB 72-2093
250.C30, C3OL, C30M, C3OP, C3OS, C30R CEB 72-3109
Page 3 of 6
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
TP CEB-104
TP CEB-1173
250.B17, B17B, B17C, 6886445 TP CEB-1173
B17D, B17E
250.cI8 6888514 or 6887194 CEB-234
250.C20 6871480 or 6887194 CEB-1212
250.C20, C20B, C2OJ, C2OF 6886445 CEB-1212
250.c288, czac 6898928 or 6899186 CEB 72-2093
or 23008592
250.C30, C30L, C30M, C3OP 6898988 or 23008589 CEB 72-3109
C3OS, C30R
B. Record Compliance as applicable in the Engine Log Book, Turbine Assembly
(pink pages), Modification Record, Part III:
250-B15G TP CEB-104
250-817, 8178, B17C, B17D, B17E TP CEB-1173
250.cia CEB-234
250-C20, C2OB, CZOJ, C2OS, C2OF CEB-1212
250.c2aB, c2ac CEB 72-2093
250.C30, C3OL, C30M, C3OP, CEB 72-3109
C3OS, C30R
February 15, 1985 250.C18, T63-A-700 CEB 234
Revision No. 3 250-C20, C20B, C2OJ, C2OS, C2OF, CEB 1212
January 15, 1990 T63-A-720
250-B15G TP CEB 104
250-817, 617B, B17C, B17D TP CEB 1173
250-C28B. C28C CEB 72-2093
250.C3O,'C3OL, C30M, C3OP, C3OS, C30R CEB 72-3109
Page 4 of 6
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
Allison Engine Company
Commercial Engine Bulletin
3. MATERIAL INFORMATION:
A. Basis for quantities is per turbine assembly.
B. Bill of material:
Instructions/
New P/N !EY Nomenclature Old P/N QQ Disoosition
6888514 1 Rotor Assy, G.P. 6888514 1 1
CES-234 (250-C18)
TP'FEB-104 (250-8156)
6887194 Alt. Rotor Assy, G.P. 6887194 Alt. 1
CEB-234 (250.C18)
TP?EB-104 (250.B15G)
CEK212 (250.C20)
TP'LEB-1173 (250-817)
6871480 Alt. Rotor Assy, G.P. 6871480 Alt. 1
CEB-1212 (250.C20, C2OB, C2OJ,
C2OF)
TP':EB-1173 (250-817)
6886445 1 Rotor Assy, G.P. 6886445 1 1
CEB-1212 (250-C20)
TP':EB-1173 (250-B178, B17C, B17D)
23008020 1 . Tie Bolt 6843388 1 2
23008020 Alt. Tie Bolt 6876991 Alt. 2
February 15, 1985 250.C18, T63-A-700 CEB 234
Revision No. 3 250.C20, C2OB, C2OJ, C2OS, CZOF, CEB 1212
January 15, 1990 T63-A-720
250-B15G TP CEB 104
250.B17, B17B, B17C, B17D TP CEB 1173
250-C28B, C28C CEB 72-2093
250-C30, C3OL, C30M, C3OP, C3OS, C30R CEB 72-3109
Page 5 of 6
Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
Allison Engine Company
Commercial Engine Bulletin
3. MATERIAL INFORMATION: (Continued)
B. Bill of material: (Continued)
Instructions/
New P/N QQ Nomenclature Old P/N !zY Disoosition
6899186 1 Rotor Assy, G.P. 6899186 1 1
CEB 72-2093 (250.C28B, C28C)
6898928 Alt. Rotor Assy, G.P. 6898928 Alt. 1
CEB 72-2093 (250-C288, C28C)
23008592 Alt. Rotor Assy, G.P. 23008592 Alt. 1
CEB 72-2093 (250.C28B, C28C)
6898988 1 Rotor Assy, G.P. 6898988 1 1
CEB 72-3109 (250.C30, C30L, C30M,
C3OP, C3OS, C30R)
23008589 Alt. Rotor Assy, G.P. 23008589 Alt. 1
CEB 72-3109 (250.C30, C30L, C30M,
C3OP, C3OS, C30R)
23008030 1 Tie Bolt 6889320 1 2
INSTRUCTIONS/DISPOSITION NOTES:
1. Modify and reidentify.
2. Scrap removed item.
PRODUCT SUPPORT
Allison Engine Company
February 15, 1985 250-C18, T63-A-700 CEB 234
Revision No. 3 250-C20, C2OB, C2OJ, C2OS, C2OF, CEB 1212
January 15, 1990 T63 ,, 71,-
T63-A-720
250.B15G
25 TP CEB 104
250.B17,
25, -. I ) IB17B,
_ I , IB17C,
_ B17D TP CEB 1173
250.C28B, C28C
r7*1- CEB 72-2093
250-C30, L-L,
C30L, __v..,
C30M, C3OP,
v-w., __
C3OS, C30R CEB 72-3109
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Rolls-Royce Proprietary Data – Uncontrolled Printed Copy
