FUEL SYSTEM - Fuel System (73-00-00) - Visual Inspection for Fuel Filter Differential

Pressure Switch Cracks

GE PROPRIETARY INFORMATION

The information contained in this document is GE proprietary information and is disclosed in

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.

July 08, 2011 CT7-8 S/B 73-A0007

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FUEL SYSTEM - Fuel System (73-00-00) - Visual Inspection for Fuel Filter Differential

Pressure Switch Cracks

1. PLANNING INFORMATION

A. Effectivity

This Alert Service Bulletin is applicable to:

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

B. Description

This Alert Service Bulletin recommends a daily visual inspection and provides

criteria for cracks on the fuel filter differential pressure switch (differential pressure

switch) P/N TD028VF0H7Y5.

C. Compliance

Category 2

GE recommends that you do this Alert Service Bulletin on a DAILY interval.

NOTE: This Alert Service Bulletin can be accomplished on-wing.

This Alert Service Bulletin is offered to improve the reliability or performance of your

GE product, or to help prevent the occurrence of the event or condition described

in this Alert Service Bulletin. If the operator elects not to participate in the bulletin,

that decision will be taken into consideration by GE in evaluating future product

performance issues that may arise in the operator’s fleet.

D. Concurrent Requirements

None.

E. Reason

(1) Objective:

To reduce significant events by performing daily fuel filter differential pressure

switch flange inspections per Accomplishment Instructions in paragraph 3.

(2) Condition:

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

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

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

(4) Substantiation:

Substantiation for the inspection requirement and allowable crack criteria is

accomplished by CT7-8A fleet experience (>400,000 flight hours) on P/N

TD028VF0H7Y5 switches with no events.

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 for each engine or component.

H. Weight and Balance

Weight and balance are not changed.

I. References (Use the latest version of this document)

GEK 105159, CT7-8 Maintenance Manual (MM)

J. Publications Affected

Not applicable.

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:

None.

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

(2) Other Spare Parts:

Part Number

Qty/

Eng Part Name

Unit ($)

Price

Pkg

Qty

Lead

Time

Days

TD028VF0H7Y5

or

(1) Switch,

Differential

Pressure

Quote (-) Quote

TD028VF0H7Y4 (1) Switch,

Differential

Pressure

Quote (-) Quote

NOTE: If TD028VF0H7Y5 is not immediately available, then replace

with TD028VF0H7Y4 and decomply with SB 73-0004.

J228P908 (1) Packing,

Preformed

Quote (-) Quote

J228P014 (1) Packing,

Preformed

Quote (-) Quote

(3) Consumables:

None.

B. Industry Support Information

None.

C. Configuration Chart

None.

D. Parts Disposition

Discard old parts.

E. Tooling - Price and Availability

None.

3. ACCOMPLISHMENT INSTRUCTIONS

A. General

NOTE: If TD028VF0H7Y5 is not immediately available, then replace with

TD028VF0H7Y4 and decomply with SB 73-0004.

Check for fuel leak or evidence of fuel leakage around the flange area. A mirror

and white light will help with this visual inspection (Figure 2). Cracks are acceptable

provided that they are not fully through the flange (across the top and continues

down one or both sides). If either flange is completely separated, the differential

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

pressure switch must be replaced with a new differential pressure switch. Refer to

GEK 105159, 73-00-00, REMOVAL 010, and INSTALLATION 010. Then continue

with the recommended daily visual inspections, that follow:

(1) Cracks partially across the top and continuing partially down one side (VIEW

A, Figure 1) - Permitted.

(2) Crack completely down one side (VIEW B, Figure 1) - Not Permitted.

(3) Cracks partially down both sides (VIEW C, DETAIL D, Figure 1) - Not

Permitted.

NOTE: . Cracks on both ears - Permitted if and only if they both meet the

requirements of step 3.A.(1).

. Cracks on differential pressure switches on both engines - Not

Permitted.

. If crack cannot be evaluated, or if switch has any "Not Permitted"

conditions, replace the differential pressure switch.

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

Visual Inspection of the Differential Pressure Switch P/N TD028VF0H7Y5

Figure 1, ( Sheet 1 of 3 )

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

Visual Inspection of the Differential Pressure Switch P/N TD028VF0H7Y5

Figure 1, ( Sheet 2 )

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

Visual Inspection of the Differential Pressure Switch P/N TD028VF0H7Y5

Figure 1, ( Sheet 3 )

July 08, 2011 CT7-8 S/B 73-A0007

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

Pressure Switch Cracks

Example of Visual Inspection Using Mirror and White Light

Figure 2

July 08, 2011 CT7-8 S/B 73-A0007

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