# MAINTENANCE MANUAL

FILING INSTRUCTIONS:

REASON FOR ISSUE: 

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# 503-60 Sherpa TEMPORARY REVISION
TEMPORARY REVISION TRSD360S-AMM-36
This Temporary Revision incorporates TRSD360S-AMM-15. Remove TRSD360S-AMM-15 and insert this TR before Chapter 5-50-00, page 1. Microfiche holders ofthe 8D3-60 Sherpa Aircraft Maintenance Manual should insert this Temporary Revision atthe front oftheir microfiche folder.
1.Acritical design configuration control limitation 

### (COCel) definition is introduced. 2. Additional 

### GOCel's have been identified associated with preservation offuel tank system ignition prevention design features when assessed against the EASAlFAA harmonised 

### criteria. 3. Notes related to application of

### COCel's are introduced. 4.All other information inTRSD360S-AMM-15 (section introduced as aconsequence of completing the system safety review required by EASA fNT/POU25/12 (and hence SFAR 88)) is re-issued.

NOTE: Record the incorporation ofthis Temporary Revision on the yellow RECORD OF TEMPORARY REVISIONS sheet atthe front ofthe Manual.
The technical content ofthis document isapproved under the authority of DOA No. EASA21J.068.

Signed

. Date



# 5-20-02 TRSD360S-AMM-36 Page 1 of3 Jun 27/06

# MAINTENANCE MANUAL
TEMPORARY REVISION FUEL SYSTEM CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION 

### 1. General COCeL's (Critical Design Control Configuration Limitations) are Fuel System Ahworthiness Limitations that are a means of identifying certain design configuration features intended to preclude afuel lank ignition source for the operational life ofthe airplane. COGeL's are mandatory and cannot be changed ordeleted without the approval ofthe European Aviation Safety Agency (EASA), orthe national regulatory authority office that is responsible forthe SD3 Type Certificate. A critical fuel tank ignition source prevention feature may exist inthe fuel system and its related installation, or insystems that, ifafailure condition were to develop, could interact with the fuel system in such away that an unsafe condiUon would develop without this limitation. Strict adherence to configuration, methods, techniques and practices as prescribed below is required to ensure the 

### CDCCl iscomplied with. Any use of parts, methods, techniques or practices not contained inthe applicable 

### GOGGl requires approval bythe European Aviation Safety Agency (EASA), orthe national regulatory authority office that is responsible for the SD3 Type Certificate. The purpose ofthe

### GOCel, isto provide instructions to retain acritical ignition source prevention feature during configuration change, that may be caused by modifications, repairs, or maintenance actions.

ITEM NOTE A Float switch assemblies Field maintenance ofthe float switches is not permissible. There are internal design features which are critical tofuel tank safety. The unit must be maintained inaccordance with the original equipment manufacturer (OEM) overhaul manual (section 28-41-65), byappropriately approved maintenance organisations. B Fuel contents gauging Routing ofany additional electrical power/signal cables is not permitted within six inches ofthe fuel contents gauging system (FCGS) co-axial cables, external tothe fuel tanks (refer to 28-42-02, Figure 201). Itis not permissible to route any additional electrical power/ signal cables within the fuel tank. Itis not permissible to clip/attach any additional electrical power/signal cables tothe outside surfaces ofthe fuel tank, or tofuel pipes.



# 5-20-02 TRSD360S-AMM-36 

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# MAINTENANCE MANUAL

ITEM C FCGS co-axial cable assemblies



# o Fuel tank external bonding leads

E Fuel tank internal bonding leads and cables TEMPORARY REVISION NOTE Itis important to assure the physical condition ofthe harness cables, which the FCGS co-axial cable assemblies are routed within. When performing maintenance or incorporating design change, all cables must be adequately protected against accidental damage, including swarf penetration. Cables must be inspected following completion ofwork, to ensure that no damage has occurred and no swarf material has contaminated the harness (refer to 28-42-02, pb201 and 28-42-03, pb201). Repair of FCGS co-axial cable assemblies is not permitted; they must be replaced (refer to 20~09-13, pb201). Ifdisturbed and/or disassembled, the bonding leads onthe fuel vent pipes atthe external forward and afttank interfaces must undergo adetailed visual inspection (DVI), after re-assembly (refer to 20-09-05, pb201). After all internal-to-tank maintenance, itis important to make sure that both fuel vent system bonding leads in cell 2ofthe forward fuel tank have not been disturbed. These bonding leads must not foul adjacent pipes/structure and the security of their attachment must be confirmed. Additionally make sure that the sensor cables for the FCGS and the float switches, which go into orthrough the tank have not been disturbed. These cables must not contact adjacent structure and any loose or broken clips must be replaced (refer 

### to 20·09- 

### t2, pb201).
2. Notes (1) Any alterations or modifications impacting aCDCel are considered major design changes and require approval bythe European Aviation Safety Agency (EASA) or bythe responsible local regulatory authority under whose jurisdiction the National Type Certificate is issued. (2) Incases where the critical ignition source prevention features ofacomponent are designated, any test equipment ortooling utilized to repair oroverhaul the component must be inaccordance with the CMM.



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