Britten-Norman 

SERVICE 

BULLETIN 

8-N Group Limited. BEMBRIDGE, Isle of Wight, United Kingdom P035 5PR 

Models Affected Service Bulletin number 

All Islander BN2, BN2A and Trislander BN2A Ill BN2A 111-1 58 332 

aircraft. 

Issue 1 - 06/12/2012 

Fuel Filler Cap Sealing 

1 Compliance Statement 

Implement this highly recommended Service Bulletin at the earliest opportunity but within five (5) 

days of receipt of this Service Bulletin. 

2 Introduction 

Preliminary investigations into a recent engine failure have attributed it to water contaminated fuel. 

The contamination is suspected to have occurred due to inadequate sealing between a post-mod 

NB-M-477 fuel filler cap and a pre-mod NB-M-477 fuel filler receptacle. 

This Service Bulletin requires the operator to perform an inspection of the aircraft fuel 

replenishment points on the upper surface of the wings to ensure that both the quick release fuel 

filler cap and the fuel filler receptacle are at the same modification state. 

3 Applicability 

This Service Bulletin is applicable to all Islander BN2/BN2A and Trislander BN2A III/BN2A 111-1 

aircraft. 

4 Weight and Balance 

None. 

5 Effect on Publications 

The Islander Aircraft Maintenance Manual (MM/1) will be amended to include an advisory Warning 

and an inspection procedure by normal revision action. 

The Trislander Aircraft Maintenance Manual (MM/2) will be amended to include an advisory 

Warning and an inspection procedure by normal revision action. 

Other publications including flight manuals are not affected by this bulletin. 

06/12/2012 

Issue 1 

SB 332 

Page 1 of 5 
Service Bulletin 

6 Action 

CAUTION 

Make the aircraft safe for maintenance. 

Place warning signs DO NOT CONNECT POWER SUPPLY and DO NOT START THE 

ENGINES. 

2 Put a maintenance platform adjacent to the aircraft wings. 

3 Examine the aircraft fuel replenishment points on the top surface of the wings, 

4 Remove and examine each of the quick release fuel filler caps, ensure that the cap and the 

fuel filler receptacle are at the same modification state, Pre-mod NB-M-477 receptacle (Fig. 

1) has a mainly circular flange attached to the wing skin. Post-mod NB-M-477 (Fig. 2) has a 

flange with a number of flat edges attached to the wing skin. 

5 If the fuel filler caps and the receptacles are at the same modification state, no further action 

is required. To aid identification of fuel filler cap modification status, it should be noted that 

Post-Mod NB-M-477 fuel filler caps are fitted with a quick-release key (see Fig. 2) whereas 

the Pre-Mod NB-M-477 fuel filler cap does not (see Fig. 1). 

6 If a mismatch of fuel filler cap and fuel filler receptacle is found, the correct quick release fuel . 

filler cap must be fitted as soon as possible. To mitigate the risk of water contamination 

prior to fitting the correct fuel filler cap, pre-flight water contamination checks of the 

gascolators and fuel tank sump drains (including wing tip tanks, if fitted) must be 

performed in addition to the normal dally checks specified by the Maintenance 

Schedule MS/1 (Section 2: Check 'A' Inspection). 

7 Refer to Section 8 of this Service Bulletin for the Part Numbers of both the pre- mod NB-M477 quick release fuel filler cap and the post-mod NB-M-477 quick release fuel filler cap and 

receptacle assembly. 

8 On completion of the inspection, refit the correct quick release fuel filler caps. 

9 Remove the maintenance platform and the warning signs. 

10 Remove all tools, equipment and materials from the work area. Make sure the work area is 

clean. 

11 Complete all documentation related to these actions. 

SB 332 06/12/2012 

Page 2 of 5 Issue 1 
06/1212012 

Issue 1 

Service Bulletin 

No Quick Release 

Key 

... . 

··" 

Fig 1. Fuel Filler Cap Assembly Pre-Mod NB-M-477 

$6332 

Page 3 of 5 
56332 

Page 4 of 5 

Quick Release 

Key 

Service Bulletin 

Fuel Filler Cap 

Fuel Filler 

Receptacle 

' ' 

··[)..... 

) 

Fig. 2 Fuel Filler Cap Assembly Post-Mod NB-M-477 

Bonding 

Peg 

06/1 2/2012 

Issue 1 
Service Bulletin 

Terminating Action 

This Service Bulletin is completed only after the fuel filler caps and receptacles have been 

confirmed to be at the same modification state, Britten-Norman Aircraft Limited expect that both 

port and starboard fuel filler caps and receptacles will be at the same modification standard which 

is recorded in the aircraft log book. 

7 Manpower 

This Service Bulletin can be done by one person in less than 1 hour. 

8 Provisioning 

Fuel Filler Cap Part Numbers: 

Pre-Mod NB-M-477 

King Aircraft Filler cap and receptacle assembly C.18563 

Post-Mod NB-M-477 

Shaw Aero Devices Fuel Filler Cap 416-1299 

The necessary parts to install modification NB-M-477 can be obtained from Customer Services 

Department, B-N Group Ltd, Bembridge, Isle of Wight, P035 5PR, United Kingdom. 

9 Follow-on Action 

None. 

10 Approval 

06/12/2012 

Issue 1 

S~gned 

.· .......~;;? ...................... -... " .................... . 

Date ... ~.: .. ~~~ .... 49..!~ ...... .. 

EASA Approval Number EASA.21J.138 

SB 332 

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