FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

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confidence. It is the property of GE and shall not be used, disclosed to others or reproduced

without the express written consent of GE, including, but without limitation, it is not to be used

in the creation, manufacture, development, or derivation of any repairs, modifications, spare

parts, designs, or configuration changes or to obtain FAA or any other government or regulatory approvalto do so. If consent is givenfor reproduction inwhole or in part,this notice andthe

notice set forth on each page of this document shall appear in any such reproduction in whole

or in part.

This technical data is considered EAR controlled pursuant to 15 CFR Parts 730-774 respectively. Transfer of this data by any means to a Non-US Person, whether in the United States

orabroad,withoutthe properU.S.Governmentauthorization (e.g., License, exemption,NLR,

etc.), is strictly prohibited.

Copyright (2011)GeneralElectric Company, U.S.A.

August 17, 2011 CT7-8 S/B 73-A0008

PAGE 1 of 8
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

1. PLANNING INFORMATION

A. Effectivity

CT7-8/-8A/-8A1/-8A5/-8B/-8B5/-8E/-8E5/-8F/-8F5

This Alert Service Bulletin is applicable to the following engines that have a fuel

differential pressure switch P/N TD028VF0H7Y5:

CT7-8A engines, serial numbers 947583 and below

CT7-8A1 engines, serial numbers 530019 and below

CT7-8E engines, serial numbers 953076 and below

CT7-8F5 engines, serial numbers 731012 and below, 817021, and 817022.

This Alert Service Bulletin has been introduced in production to these CT7-8

turboshaft engines:

CT7-8A engines, serial numbers 947584 and up

CT7-8A1 engines, serial numbers 530020 and up

CT7-8E engines, serial numbers 953077 and up

CT7-8F5 engines, serial numbers 731013 and up.

B. Description

This Alert Service Bulletin introduces a new collar to the differential pressure switch.

The new fuel filter differential pressure switch collar kit, P/N 59TC02800K1T includes

the collar, P/N 88TC02800000, and two (2) longer screws, P/N NAS1352C08LE12.

The collar will retain the differential pressure switch, P/N TD028VF0H7Y5, from

separating from the filter head of the fuel filter assembly, P/N 4110T53P06, due to

cracks on flanges.

C. Compliance

Category 2

GE recommends that you comply with this Alert Service Bulletin within 500 Hours

EOT of the issuance of this bulletin, OR before December 31, 2011, whichever

comes first.

NOTE: This Alert Service Bulletin can be accomplished on-wing and/or in shop.

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

D. Concurrent Requirements

CT7-8 S/B 73-A0007

Once this Alert Service Bulletin is complied with, discontinue requirement of CT7-8

S/B 73-A0007, Visual Inspection for Fuel Filter Differential Pressure Switch Cracks.

E. Reason

(1) Objective:

To improve reliability and reduce significant events.

(2) Condition:

CT7-8 engines may display cracking across the two bolt hole flanges of the

differential pressure switch, P/N TD028VF0H7Y5. The differential pressure

switch is part of the fuel filter assembly (P/N 4110T53P06), located on the

accessory gearbox.

(3) Cause:

High stresses causing anodized coating to crack and associated buildup of

corrosion.

(4) Improvement and Inspection:

If fuel filter differential pressure switch collar kit P/N 59TC02800K1T is

not available, continue daily inspections per CT7-8 S/B 73-A0007, Visual

Inspection for Fuel Filter Differential Pressure Switch Cracks.

The collar assembly may be fitted over the differential pressure switch, P/N

TD028VF0H7Y5, to allow continued use without daily inspections. The collar

provides support to the differential pressure switch flanges so that retention of

the differential pressure switch to the fuel filter assembly is maintained.

(5) Substantiation:

Substantiation is by analysis and test.

F. Approval

This Service Bulletin has been reviewed by the FAA and the repair(s) and

modification(s) herein comply with the applicable Federal Aviation Regulations and

are FAA APPROVED for installation in the model(s) listed in this Service Bulletin.

G. Manpower

After you get access to the fuel filter assembly, you will need approximately 10

minutes to install the fuel filter differential pressure switch collar kit for each engine

or component.

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

H. Weight and Balance

The complete compliance with this Alert Service Bulletin increases weight by

0.1 lb (0.05 kg).

I. References (Use the latest version of these documents)

CT7-8 S/B 73-A0007, Visual Inspection for Fuel Filter Differential Pressure Switch

Cracks

GEK 105159, CT7-8 Maintenance Manual (MM)

J. Publications Affected

CT7-8 Turboshaft Engine Service Record

GEK 105158, CT7-8 Illustrated Parts Catalog (IPC)

GEK 105159, CT7-8 Maintenance Manual (MM)

K. Interchangeability

Not applicable.

L. Software Accomplishment Summary

Not applicable.

2. MATERIAL INFORMATION

A. Material - Price and Availability

(1) Parts necessary to do this Alert Service Bulletin:

Part Number

Qty/

Eng Part Name

Unit ($)

Price

Pkg

Qty

Lead

Time

Days

59TC02800K1T (1) Kit, Fuel Filter

Differential Pressure

Switch Collar

Quote (-) Quote

.88TC02800000 (1) Collar Quote (-) Quote

.NAS1352C08LE12 (2) Capscrew, Socket

Head

Quote (-) Quote

(2) Other Spare Parts:

None.

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

(3) Consumables:

None.

B. Industry Support Information

None.

C. Configuration Chart

New

Part Number

Qty/

Eng Part Name

Old

Part Number/

IPC Location

Qty/

Eng

Op

Code

Chg/

Sprt

Code

3062T85G01 (X) Accessory

Section Module

(SIN 29900)

3062T85G01

72-00-00-01-140

(X) RM -/-

.4110T53P06 (X) Fuel Filter

Assembly

(SIN 31300)

.4110T53P06

73-00-00-01-440

(X) RM -/-

..TD028VF0H7Y5 (X) Switch,

Differential

Pressure

..TD028VF0H7Y5

73-00-00-01-485

(X) RM -/C

-- (-) Capscrew,

Socket Head

..NAS1352C08LE8

73-00-00-01-480

(2) SU 3/-

..59TC02800K1T (X) Kit, Fuel Filter

Differential

Pressure Switch

Collar

-- (X) AD 3/-

...88TC02800000 (1) Collar -- (-) AD 3/-

...NAS1352C08LE12 (2) Capscrew,

Socket Head

-- (-) AD 3/-

Operation Codes

AD = Add

RM = Remains

SU = Superseded

Change Codes

3 = Not interchangeable

Support Codes

C = Old parts will be supplied until redesigned differential pressure switch is available.

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

D. Parts Disposition

None.

E. Tooling - Price and Availability

None.

3. ACCOMPLISHMENT INSTRUCTIONS

A. Installation of Collar

NOTE: . A collar may be installed on a differential pressure switch that

exceeds the crack limits of CT7-8 S/B 73-A0007.

. It is not necessary to unseat the differential pressure switch from

the filter head of the fuel filter assembly or disconnect the electrical

harness. If the differential pressure switch is removed from the filter,

the packings must be replaced and a normal leak check must be

performed. Refer to GEK 105159, 73-00-00, INSTALLATION 010.

. There is normally a small gap between the bottom of the bolt flanges

of the differential pressure switch and the surface of the filter head.

This is normal.

. There will be a small gap between the bottom of the collar bolt

flanges and the top of the differential pressure switch bolt flanges.

This is normal.

. Do not attempt to close gaps during torquing of the screws.

(1) While holding differential pressure switch (1, figure 1) flush against the filter

head of the fuel filter assembly, remove two socket head capscrews (4), P/N

NAS1352C08LE8. Discard the capscrews.

(2) Place collar (2) against the forward face of differential pressure switch (1) and

secure collar with two capscrews (3) (P/N NAS1352C08LE12).

(3) Alternately tighten the capscrew by hand. Be sure the collar remains evenly

seated while tightening. Torque capscrews (3) to 13-15 lb in. (1.5-1.8 N.m).

(4) After the collar (2) has been installed on a differential pressure switch (1),

cease daily crack inspections required by CT7-8 S/B 73-A0007.

B. Reidentification

Not applicable.

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

C. Post Maintenance Test

(1) If the differential pressure switch (1) was removed, perform an IDLE leak

check. Refer to GEK 105159, 72-00-00, TESTING 004.

(2) If the electrical harness was disconnected, check for fault codes at next start.

D. Service Record Entry

Record compliance with this Service Bulletin in the appropriate CT7-8 Turboshaft

Engine Service Record.

Report compliance to your GE Field Service Representative.

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.
FUEL SYSTEM - Fuel System (73-00-00) - Introduction of Fuel Filter Differential Pressure

Switch Collar

Differential Pressure Switch P/N TD028VF0H7Y5, Installation of Collar P/N 88TC02800000

Figure 1

August 17, 2011 CT7-8 S/B 73-A0008

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GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.