ASB No. AS355-28.00.20 

Revision 0 2013-06-06 Page 1/12 

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 Civil version(s): E, F, F1, F2 

 

ALERT SERVICE BULLETIN 

SUBJECT: FUEL 

 Removal of the FUELTRON flowmeter 

 Corresponds to modification 355A085801 

Revision No. Date of issue 

Revision 0 2013-06-06 

Summary: 

Removing and disabling the optional FUELTRON flowmeter installation. 

Compliance: 

Compliance with this ALERT SERVICE BULLETIN is mandatory. 

For the attention of 
 

 ASB No. AS355-28.00.20 

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1. PLANNING INFORMATION 

1.A. EFFECTIVITY 

1.A.1. Helicopters/installed equipment 

Helicopters embodying modification 350A070791 (installation of the FUELTRON flowmeter) and not 

embodying modification 355A085801. 

NOTE 

Modification 350A070791 (installation of the FUELTRON 

flowmeter on each of the fuel systems) was embodied on new 

helicopters or through Service Bulletin 28.00.02. 

1.A.2. Non-installed equipment 

FUELTRON flowmeter P/N 704A37-670-001. 

1.B. ASSOCIATED REQUIREMENTS 

Not applicable. 

1.C. REASON 

After landing an AS355 helicopter, the pilot remarked the uncontrolled flame-out of engine 1. 

The analysis carried out concerning this event has shown that particle contamination obstructed the 

FUELTRON flowmeter, which provoked the uncontrolled flame-out of engine 1. 

This obstruction which led to engine flame-out is due to the cross-section of the passage area of the 

flowmeter being smaller than the meshes in the upstream fuel pump strainer. For this reason, the particles 

can pass through the strainer and then get blocked inside the FUELTRON flowmeter. 

The FUELTRON flowmeter installation is identical on the two engines. The simultaneous obstruction of both 

flowmeters can lead to the flame-out of both engines in flight. 

Consequently, pending a modification to this installation, EUROCOPTER makes it mandatory to remove and 

disable the FUELTRON flowmeter installation. 

ATTENTION 

EUROCOPTER REMINDS OPERATORS THAT THIS 

CONTAMINATION CAN BE GENERATED WHEN 

REFUELING AND THAT THE PRÉCAUTIONS TO BE 

TAKEN ARE GIVEN IN INFORMATION NOTICE 

NO. 2145-I-28 AND WORK CARD 20.07.02.208. 
 

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1.D. DESCRIPTION 

This ALERT SERVICE BULLETIN comprises: 

- Removal of the flowmeter and modification of the fuel system. 

- Disabling of the electrical system and the flowmeter installation. 

1.E. COMPLIANCE 

1.E.1. Compliance at the works 

Helicopters/installed equipment: 

Not applicable. 

 Non-installed equipment: 

Not applicable. 

1.E.2. Compliance in service 

Helicopters/installed equipment: 

 Comply with paragraph 3. of this ALERT SERVICE BULLETIN within 750 flying hours or within 6 months 

whichever occurs first from receipt of this ALERT SERVICE BULLETIN, issued on the date indicated at the 

foot of the page. 

 Non-installed equipment: 

 Upon receipt of this ALERT SERVICE BULLETIN and pending a modification to the installation, FUELTRON 

flowmeters P/N 704A37-670-001 are prohibited from being installed on AS355 helicopters. 

1.F. APPROVAL 

 Approval of modifications: 

 The information or instructions relate to modification 355A085801 which were approved 

on May 28, 2013 under the EASA Design Organization Approval No. 21J.056 for helicopters of civil versions 

subject to an Airworthiness Certificate. 

The information or instructions relate to modification 355A085801 which were approved 

on May 28, 2013 under the prerogatives of the recognition of design capability FRA21J-002-DGA for French 

Government helicopters. 

Approval of this document: 

The technical information contained in this ALERT SERVICE BULLETIN Revision 0 was approved 

on June 06, 2013 under the authority of EASA Design Organization Approval No. 21J.056 for helicopters of 

civil versions subject to an Airworthiness Certificate. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 0 was approved 

on June 06, 2013 under the prerogatives of the recognition of design capability FRA21J-002-DGA for French 

Government helicopters. 
 

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1.G. MANPOWER 

Qualification: 

For compliance with this ALERT SERVICE BULLETIN: 

1 Mechanical Engineering Technician. 

1 Avionics Technician. 

Time for the operations: 

4 hours. 

Estimated helicopter grounding time: 

4 hours. 

1.H. WEIGHT AND BALANCE 

Not applicable. 

1.I. EFFECT ON ELECTRICAL LOADS 

Negligible. 

1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD 

Not applicable. 

1.K. REFERENCES 

The following documents are required for compliance with this ALERT SERVICE BULLETIN: 

Maintenance Manual (MET): 

24.00.00.301 General instructions 

28.00.00.301 General instructions 

28.41.10.401 Flowmeter installation: Installation - Removal 

 

Standard Practices Manual (MTC): 

20.02.01.103 Installation of pipes 

20.02.06.402 Safetying with lockwire 

20.07.02.208 Refueling an aircraft from a barrel or any other container 

20-09-01-902 Storage and service life limits - Pipes - Hoses and flexible pipes 

1.L. DOCUMENTS AFFECTED 

Not applicable. 

1.M. INTERCHANGEABILITY OR MIXABILITY OF PARTS 

Not applicable. 
 

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2. MATERIAL INFORMATION 

2.A. MATERIAL: PRICE - AVAILABILITY - PROCUREMENT 

For any information concerning the price of kits and/or components, contact the EUROCOPTER Network 

Sales & Customer Relations Department. 

EUROCOPTER 

Etablissement de Marignane 

Direction Ventes et Relations Client (ECR) 

13725 MARIGNANE CEDEX 

FRANCE 

NOTE 1 

On the purchase order, please specify the mode of transport, 

the destination, and the numbers of the aircraft to be modified. 

NOTE 2 

For ALERT SERVICE BULLETINS, order by: 

Telex: HELICOP 410 969F 

Fax: +33 (0)4 42 85 99 96 

2.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable. 

2.C. MATERIAL REQUIRED FOR EACH HELICOPTER/COMPONENT 

Kits or components to be ordered for one helicopter or one assembly: 

 Kit P/N 355A08-5801-0071 Removal of the FUELTRON flowmeter comprising: 

Key Word Qty New P/N Item Former 

P/N → Instruction 

 

 Hose 1 704A34-416-029 1 

 Hose 1 704A34-416-030 2 

 Blank 1 355A08-4587-20 3 

 Cap 22 E0737R1332 4 

 Screw 4 A0164TK040S010X 5 

 Snap nut 4 NU504 6 

 

 Material to be ordered separately: 

Key Word Qty New P/N Item Former 

P/N → Instruction 

 

 Lockwire A/R EN3628-0,8 20 

 Snap wire A/R 21 

 

2.D. MATERIAL TO BE RETURNED 

 Not applicable.
 

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3. ACCOMPLISHMENT INSTRUCTIONS 

3.A. GENERAL 

Comply with the General Instructions as per MET Work Cards 24.00.00.301 and 28.00.00.301. 

NOTE 1 

The procedure is identical for the LH and RH sides of the 

helicopter. 

Only the procedure for the LH side is given. 

3.B. OPERATIONAL PROCEDURE 

3.B.1. Preliminary steps 

- Open the engine cowlings. 

- Close the fuel shut-off valves. 

- Remove the lower cowlings. 

- Open the LH and RH MGB cowlings. 

- Remove the rear instrument panel cowling. 

- Remove the instrument panel covering. 

3.B.2. Procedure 

WARNING 

DURING INTERVENTIONS ON THE FUEL SYSTEM, 

TAKE EVERY CARE NECESSARY TO PREVENT 

CONTACT WITH THE FUEL. 

3.B.2.a. Removal of the flowmeter and modification of the fuel system 

 Figure 1 - DETAIL A 

- Remove and store the FUELTRON flowmeter (a) as per MET Work Card 28.41.10.401. 

- Remove the union nut (b) from the union (c). 

 Figure 1 - DETAIL B 

- Mark the routing of the hose (d). 

- Cut and remove the lockwires (e). 

- Disconnect the hose (d). 

- Remove and store the hose (d) as per MTC Work Card 20-09-01-902. 

 Figure 2 - DETAILS C and D 

- Connect the LH hose (1) in the previously marked position as per MTC Work Card 20.02.01.103. 

- Lock the hose assembly (1) and unions using lockwire (20) as per MTC Work Card 20.02.06.402. 

NOTE 2 

Connect and lock the hose (2) for the RH side. 
 

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3.B.2.b. Disabling the electrical system and disabling the installation 

NOTE 3 

There are two possibilities for the position of the flowmeter 

indicator. It may be installed on the console (paragraph 

3.B.2.b.2.) or on the instrument panel (paragraph 3.B.2.b.3.). 

3.B.2.b.1. Disabling the flowmeter wiring (Figures 3, 4 and 5) 

- Remove and store the flowmeter indicator (j) (Figure 3: console) and (k) (Figure 4: instrument panel). 

- Disconnect then blank all the wires using the caps (4) as indicated in Figure 5 (battery, LH overhead 

panel and fuel system, indicators). 

- Store or coil the wires to prevent any interference. 

- Remove and store the 2.5A fuse (f) (Figure 5 - Detail G). 

3.B.2.b.2. Disabling the flowmeter installation on the console (Figure 3) 

- Mark and drill 4 holes (r) with a diameter of 6mm on the console covering (m) and according to the 

dimensions indicated in Figure 3 - DETAIL E. Use the existing diameter (q) of 75mm on the console 

covering in order to correctly position the drilling. 

- Deburr and round off sharp edges. 

- Position the four snap nuts (6). 

- Position the blank (3) and attach it using the 4 screws (5) as per Figure 3 - Cross-Section A-A. 

3.B.2.b.3. Disabling the flowmeter installation on the instrument panel (Figure 4) 

- Mark and drill 4 holes (t) with a diameter of 6mm on the instrument panel covering (u) and according 

to the dimensions indicated in Figure 4 - DETAIL F. Use the existing diameter (s) of 75mm on the 

instrument panel covering in order to correctly position the drilling. 

- Deburr and round off sharp edges. 

- Position the four snap nuts (6). 

- Position the blank (3) and attach it using the 4 screws (5) as per Figure 4 - Cross-Section B-B. 

3.B.3. Final steps 

- Install the instrument panel covering. 

- Install the rear instrument panel cowling. 

- Close the LH and RH MGB cowlings. 

- Install the lower cowlings. 

- Open the fuel shut-off valves and safety with snap wire (21) as per Work Card 20.02.06.402. 

- Close the engine cowlings. 

3.C. IDENTIFICATION 

Identification of this document: 

Record compliance with this document, with the revision number, in the helicopter documents. 

3.D. OPERATING AND MAINTENANCE INSTRUCTIONS 

Not applicable. 
 

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Figure 1 

DETAIL A 

c b a 

Cloison pare-feu 

Firewall

e d 

DETAIL B 

B 

d 

PRE MOD 355A085801 
 

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Figure 2 

2 

1 

1 

2 

20 

DETAIL C 

DETAIL D 

C 

D 

20 

1 

2 

POST MOD 355A085801 
 

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Figure 3

FWD 

FWD 

CROSS-SECTION A-A 

POST MOD 355A085801 

FWD 

PRE MOD 355A085801 

j 

5 3 

3 

6 

m

6 

5

m

DETAIL E 

q r 
 

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Figure 4 

CROSS-SECTION B-B 

POST MOD 355A085801 

PRE MOD 355A085801 

k 

5 3 

3 

6 

6 

5

u 

s 

u 

DETAIL F 

t 
 

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Figure 5 

4 4

4

4 

POST MOD 

355A085801 

PRE MOD 

355A085801 

4

f

DETAIL G