Britten-Norman 

SERVICE 

BULLETIN 

Britten-Norman Aircraft Limited 

Commodore House, Mountbatten Business Centre, Millbrook Road East, 

Southampton S015 1 HY United Kingdom 

Models Affected 

All Islander BN2, BN2A, BN2B, BN2T, BN2T -4S and BN2T-4S series 

Islander aircraft and BN2A Mkllll series Trislander aircraft. 

Service Bulletin number 

58310 

Issue 4- 25/09/2015 

PilOT/STATIC PRESSURE HEAD - INSPECTION AND TEST 

This is a highly recommended safety related Service Bulletin for aircraft fitted with the DU130-24 

pilot/static pressure head only. 

1 COMPLIANCE STATEMENT 

Do the inspection procedure of this Service Bulletin at the next daily check. 

Do the leak test procedure in this Service Bulletin within the next 50 flying hours. 

2 REASON FOR CHANGE 

This Service Bulletin has been revised to issue 4 to amend the recommended inspection intervals from 

every 500 hours to every 50 hours following a number of reported DU130-24 pitotlstatic pressure head 

failures after significantly less than 500 flight hours service. 

3 INTRODUCTION 

On receipt of this Service Bulletin, disseminate the information to all flight crew, engineers and operators 

as soon as possible. 

Incidents have been reported to Britten-Norman Aircraft Ltd where cracks have been found in the inner 

shell of the DU130-24 pitotlstatic pressure head. 

This Service Bulletin tells operators how to inspect the immediate inner circumferential surface of the 

total pressure hole in the nose of the pitotlstatic pressure head. 

The circumferential area is the soldered joint between the pilot/static pressure head outer shell and the 

inner shell that contains the heater element. 

When the aircraft is on the ground, it is recommended that the use of the pitotlstatic pressure head 

heater be kept to a minimum. Excessive use of the heating element in still air may cause the heating 

element to overheat, which will reduce the life of the heater element. 

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4 APPLICABILITY 

This Service Bulletin is applicable to all Islander BN2, BN2A, BN2B, BN2T, BN2T -4S and BN2A Mklll 

series aircraft fitted with the DU130-24 pitot/static pressure head. 

5 WEIGHT and BALANCE 

None. 

6 EFFECT ON PUBLICATIONS 

Reference to the inspection of the circumferential area immediately inside the total pressure hole in the 

nose of the pitot/static pressure head will be incorporated into the maintenance documentation by 

amendment action at the earliest opportunity. 

7 ACTION 

Table 1 Support Equipment Special Tools 

Nomenclature Identification Qty 

Pitot/Static Test Set (Microleak) 371030104 

Pitot/Static Adapter (Part of Avimo Test Set) 1373 1 

Pitot/Static Adapter (Alternate Tool) NB-88-0725 1 

Pitot System Tool NB-88-0677 

7.1 Inspection 

1. In the flight compartment, on the switch panel, make sure that the PITOT & STALL 

WARNING HEATER switch is set OFF. 

2. Use a strong light source to visually inspect the circumferential area made by the hard 

soldered joint between the pressure head outer shell and the heater element inner shell for 

cracks and/or other separation (refer to Fig.1). 

3. If cracks and or separation are found, replace the pressure head with a serviceable item. 

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Notes: 

If there are no 'visible' cracks, within 50 flying hours, do a Pitot and Static System Leak 

Test (refer to paragraphs 7.2 and 7.3 for these procedures). 

The pitot static adapter (NB-88-0725) can be used as an alternative to the pitot static 

adapter shown in Figs 2 and 3. 

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Fig 1 Pitot-Static System - Inspection Area 

7.2 Pitot Leak Test 

7.2.1 Preparation 

1. In the flight compartment, on the switch panel, make sure that the PITOT & STALL 

WARNING HEATER switch is OFF. 

2. Refer to Fig 2. 

3. Carefully install the pitot system tool (2) in the pressure head (3). 

4. On the pitot system tool (2), car·efully turn the knob (1) to seal the pitot system. 

5. Install the pitot-static adapter (5), on the pressure head (3). Make sure that the adapter does 

not cover the static vents. 

6. Tighten the clamp ring (6). 

7. On the pitot-static test set, connect the pitot output to the pitot-static adapter (5). 

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7.2.2 Leak Test 

1. Slowly increase the pitot pressure until the airspeed indicator shows 120 knots. 

2. After one minute, examine the airspeed indicator display. 

3. The pressure must not decrease by more than three knots. 

Note: 

If the airspeed indicator decreases by more than three knots, find the cause of the leak. 

4. On the pitot-static test set, slowly adjust the pitot pressure to ambient pressure. On the 

airspeed indicator, the speed shows zero knots. 

5. On the pitot-static adapter (5), loosen the clamp ring (6) and remove the pitot-static adapter 

from the pressure head (3). 

6. On the pitot system tool (2), tum the knurled knob (1) to loosen the tool. Remove the tool 

from the pressure head (3). 

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Fig 2 Pitot-Static System- Pilot Leak Test 

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7.3 Static Leak Test 

7.2.1 Preparation 

1. In the flight compartment, on the switch panel, make sure that the PITOT & STALL 

WARNING HEATER switch is OFF. 

2. Refer to Fig 3. 

3. Carefully install the pitot system adapter (1) in the pressure head (4) make sure that it is 

covering the static vents. 

4. Push the rubber adapter (6) in position over the drain hole (5). 

5. Install the attachment ring (3), on the rear of the pressure head (4). Carefully push the 

attachment ring forward to secure. 

6. On the pitot static adapter (1 ) tighten the clamp ring (2). 

7. On the pitot-static test set, connect the static output to the pitot-static adapter (1). 

7.2.2 Leak 

CAUTION 

Do not let the vertical speed indicator show more than 1500 feet per minute when static 

pressure is increased or decreased. Damage to the instrument can occur. 

Note: 

If a microleak test set is used, the rate of change in static pressure is set to 1700 feet per 

minute. 

1. In the flight compartment, on the altimeter, turn the adjusting control and set the barometric 

pressure scale to the airfield barometric pressure. 

2. On the altimeter, make sure that the altitude shows zero ft. plus or minus 50 ft. 

3. Slowly decrease the static pressure until the altimeter shows 2000 ft. 

4. On the altimeter, after one minute, the altitude must not change by more than 100 ft. 

5. On the pitot-static test set, slovlly adjust the static pressure to ambient pressure. On the 

altimeter, the speed shows zero ft. plus or minus 50 ft. 

6. On the pitot-static adapter (1), loosen the clamp ring (2) and remove the pitot-static adapter 

from the pressure head (4). 

7. If necessary, do a Pitot Heater and Stall Warning Heater Operational Test. 

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

clean. 

9. Complete all documentation relating to this procedure. 

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Fig 3 Pitot-Static- Static Leak Test 

8 MANPOWER 

The inspection and test procedure will take approximately 1 hour. 

9 PROVISIONING 

The special tools required are available from Britten-Norman Ltd. Customer Services Department, at 

Britten-Norman Group Ltd. Bembridge Airport, Isle of Wight, P035 5PR, United Kingdom. 

10 FOLLOW ON ACTION 

The following are to be repeated every 50 hours: 

• An inspection of the pressure head for cracks and damage. 

• A check of the drain traps for moisture. If moisture is present purge complete system with warm 

air for five minutes. 

• A leak test of the pitot-static system. 

If any cracks or damage to the pressure head is found, please notify Britten-Norman Aircraft Ltd in 

accordance with Service Letter 58 for further instructions. 

11 APPROVAL 

The technical content of this document is approved under the authority of DOA number EASA.21J.138. 

t tvt/'/ _,~ Signed ........................ :.:~J···· ·· ···· ·· ············ ··· ······ · 

Date ............... 2.5./CJ./(f..~ ........................................................... . 

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