# de HAVILLAND BOMBARDIER 

# DASHB SERVICE BULLETIN

____Customer ___________________ _ Support ATA SYSTEM: 7610 NUMBER: 8-76-33 

### BOMBARDIER AEROSPACE REGIONAL AIRCRAFT CONSIDER THIS SERVICE BULLETIN TO BE PARTICULARLY SIGNIFICANT AND URGES OPERATORS TO PROMPTLY EVALUATE THE CONTENTS
SUBJECT: Engine Controls- Center Console- Beta Warning Horn Microswitch Bracket Improvement - ModSum 80113014 1. PLANNING INFORMATION A. Effectivity Aircraft Affected: In-Service:

13 Dec 2012 DHC-8 Aircraft Models 102, 103, 106, 201 , 202, 301, 311, 314 and 315 Serial Numbers 003 thru 672 with Beta Warning Horn {Mod 8/2852}. Excluding aircraft with option CR873CH00003 , CR873CH00005 , CR873S008112 or MS80902206.

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### SERVICE BULLETIN 8-76-33 NOTE : The instructions in this service bulletin are only applicable to the systems and parts installed at the time of delivery on the aircraft or as changed by Bombardier Aerospace Service Bulletin(s). Before you do this bulletin, examine all STC or equivalent action changes to make sure th is bulletin can be completed . Spares Affected: None 

### B. Reason Problem : The beta warning horn microswitch function was found to be sensitive to center console cover deformation . Th is cou ld affect correct operation of the beta warning horn system . Solution: This service bulletin introduces ModSum 80113014. The ModSum reworks the center console FWD cover p/n 87610098 by replacing the current beta warning horn microswitch bracket p/n 87610428 with new bracket assy 87610164-003 . The new bracket is more robust and will be installed lower on the cover to avoid sensitivity to cover deflection (see Figure 1 view B) . 

### C. Description The procedu res in th is service bulletin give the instructions to do the tasks that follow:

- all aircraft electrical power is d isconnected

- the nose landing gear lock is engaged

- the main landing gear lock pins are installed thru each main gear and main gear 1 3 Dec 20 1 2 S . B. 8-76-33 Page 2 of 1 6 L

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### SERVICE BULLETIN 8-76-33 door mechanism

- certain cover assemblies are removed from the center console

- rework to the center console includes removal of plate p/n 87610427-101 from angle assy 87610428 and removal of angle assy p/n 87610428 from the forward cover p/n 87610098

- open rivet holes in cover p/n 87610098 are plugged

- new bracket assy p/n 87610164 - 003 is installed to cover p/n 87610098

- cover assy 87610098 is re-identified as 8Z9662-053 then installed

- plate p/n 87610427-101 is attached to bracket assy 87610164-003

- the beta warning horn limit switch is rigged to agree with existing AMM instructions

- the center console covers previously removed are installed to original positions

- an operational test of the beta warning horn system is done

- all tools and equipment are removed from the work area

- log book entries are made. 

### D. Compliance Bombardier Inc. recommends incorporation of ModSum 80113014 at the earliest opportunity unless otherwise directed by the operator's airworthiness authority. 

### E. Approval The technical content of this service bulletin has been approved under the authority of the Transport Canada Civil Aviation (TCCA) Design Approval Organ ization No: DAO #93-0-02 .

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### SERVICE BULLETIN 8-76-33 F. Manpower It will take an estimated 6 man-hours to complete this service bulletin. The breakdown of the man- hours is shown in the table that follows : TASK MAN-HOURS Job Set-Up 1.00 Procedure 3.00 Test 

### I RTS 1.00 Close-Out 1.00 For any on-site labor assistance, please speak with a Fleet Services representative for a quote . The Fleet Services group can be contacted via the Q Series Technical Help Desk by telephone at 416-375-4000 or email at: thd.qseries@aero.bombardier .com G. Material - Price and Availability The ModKit listed in the table below is available through the Customer Accounts Service Team at Bombardier Aerospace Regional Aircraft division . Operators should submit a purchase order specifying aircraft serial number(s) to: Bombardier Aerospace Customer Accounts Services Team (Mail Stop N11-32) 123 Garratt Blvd . Toronto Ontario Canada M3K-1Y5 Facsimile: (416) 375-3060 Telephone : (416) 375 - 3920 Kit Number 8MK4616-003 13 Dec 2012 Description Center Console - Beta Warning Horn Microswitch Bracket - Retrofit Kit S.B . 8-76-33 Page 4 of 16LSH. 

### I. J. 

### K. SERVICE BULLETIN 8-76-33 Tooling - Price and Availability None Weight and Balance None Electrical Load Data Not affected Publications Affected Maintenance Manual ................................ PSM 1-8-2, PSM 1- 82-2 and PSM 1-83-2 Dash 8 Parts .................. ...... .... ....... .... PSM 1-8-4, PSM 1-82-4 and PSM 1-83-4 Modifications Manual ............................... PSM 1-813 -1 2 

### L. References The initial issue of this service bulletin was prepared to the engineering drawings and related data that follows: DRAWING SHEET 8MK4616 1

8Z9662 1 ModSum 80113014 Rev. 'C' PCA 07020 Rev 0 (for internal reference only) Transport Canada Ai rworthiness Directive CF - 2012-01 13 Dec 2012 REV -A 

### -8

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### SERVICE BULLETIN 8-76-33 2. MATERIAL INFORMATION A. Parts Required Per Aircraft (1) Modification Kit 8MK4616-003 (2) Detailed Kit Content

Quantity Per Kit Part Number Description Remarks -003 1 8761 0164-003 BRACKET ASSY 1 NAS1351 - 3-8P SCREW See NOTE 1 Below 2 so2oso 17 ADs

# - as RIVET See NOTE 1 Below 

### 2 B0205016AD4 

### -4S RIVET See NOTE 1 Below NOTE 1 : These items are required to install the kit. These items are not included in the kit and must be supplied by the ope rator. 

### B. Parts Required to Modify Spares None 

### C. Special Tools and Equipment Required None 

### D. Existing Parts Accountability The following parts may be affected by this service bulletin . Indented parts are components of the next higher assembly. The quantity (Qty.) column lists the quantity that may be affected per aircraft fo r non - indented parts and th e quantity per next higher assembly fo r indented parts . 13 Dec 20 1 2 S .B. 8-76-33 Page 6 of 16 LS

### SERVICE BULLETIN 8-76-33 Existing New Part Part Number Description Qty. JC DC Number PNC 

### 87610428 Angle Assy 

### 1 A DIS 

### 87610164-003 N JC Interchangeability Code A Not interchangeable. 8 Removed Part. No d irect replacement. C Conditionally Interchangeable . Installation of superseded part negates the intent of this service bulletin. DC Disposition DIS Discard Part. MUI Multiple Usage Item : Return to stock 

### if seNiceable. RWK Rework existing part in accordance with this seNice bulletin . AWl Rework existing part per ..... SAL Salvage . Return to operator's stores for salvage consideration. PNC Part Number Code N New part number R Part number after rework . 

### S Superseding or equivalent part number . 

### X Reworked part and superseding part are functionally and physically equivalent but not identical.



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### SERVICE BULLETIN 8-76-33 3. ACCOMPLISHMENT INSTRUCTIONS A. Job Set-Up (1) Placard and select all aircraft electrical power to OFF. Obey all relevant WARNINGS and CAUTIONS (refer to Chapters 12 and 24 in applicable AMM). (2) Make sure that lock pins are installed through each main gear and main gear door mechanism. (3) Make sure the nose gear ground lock is engaged. (4) Gain access to the center console in the flight deck 

### B. Procedure {1) Remove and retain the screws and washers that attach the center console covers that follow. Keep all hardware (refer to Figure 1 view A) :

- elevator trim wheel cover

- power lever cover

- condition lever cover

- flap lever cover (2) Disconnect plate 87610427 from angle assy 87610428 (refer to Figure 2). Do not remove stop shaft p/n 87610088 from plate (p/n 87610427) and from center console frames. (3) Remove and retain the forward center cover 8761 0098 from the center conso le (refer to flagnote .£.on Figure 2. Retain all hardware for later installation.

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### SERVICE BULLETIN 8-76-33 (4) Remove the rivets that attach angle assy p/n 87610428 to cover assy p/n 87610098 . Discard angle assy p/n 87610428 (refer to flag note 

# ffi on Figure 2) . Deburr open rivet holes . Treat bared metal using alodine 1200, 1200S or 1201 and prime using epoxy chromate primer: (5) Plug open rivet holes leftover in cover p/n 8761 0098 with 2 rivets p/n B0205016AD4 - 4S . Install rivets per SRM Chapters 51-42-05 (refer to flagnote 

# .ffi. on Figure 3.) NOTE : It is acceptable to use alterative rivets p/n MS20470AD4-4. (6) Install bracket assy p/n 8761 0164 - 003 on cover p/n 87610098 using 2 rivets p/n 80205017AD5-8S (refer to Figure 3 flagnote 

# £) . Establ ish bracket assy location on the cover based on the location of plate p/n 87610427. Install rivets per SRM Chapter 51-42-05 . (7) Re-identify reworked cover assy 87610098 as 8Z9662-053 using appl icable instructions in AMM Chapter 20-15-04. (8) Install reworked cover assy 829662-053 using previously removed fasteners . (refer to flagnote

# ffi on Figure 4). (9) Attach plate p/n 87610427 to the bracket assy 87610164-003 using screw NAS1351 - 3- 8P and previously removed washer (refer to flagnote 

# & on Figure 4) . (1

0) Adj ust the li mit switch to agree with appl icab le instructions in AMM Chapter 76-10-13-02 (100/300 series aircraft} or AMM TASK 76-10-13-830-801 (200 series aircraft} and details shown on Figu re 5. (11) Move the power levers between the FLT IDLE and MAX REV positions . Make sure that 0. 100 inch . MIN. clearance exists between detent arm and flange of b racket 87610 164 - 003 (refer to flagnote 

# & on Figure 4) .. 13 Dec 2012 S.B. 8-76-33 Page 9 of 16LS

### SERVICE BULLETIN 8-76-33 (12) Install the center console covers that follow to original position using saved hardware (refer to Figure 1):

- elevator trim wheel cover

- power lever cover

- condition lever cover

- flap lever cover (13) Do an operational test of the beta warning horn system to agree with applicable instructions given in AMM Chapter 31 -51 -02 (1 00 

### I 300 series) or TASK

**31-51-02-710-802~00serie~.** C. Close Out (1) Remove all tools and equipment from the work area. (2) On incorporation of this ModSum, make an entry that conforms to local regulatory requirements in the applicable logbook(s). Enter component serial numbers if applicable. Enter this ModSum number only after complete and functional incorporation of all work defined in this service bulletin.

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### SERVICE BULLETIN 8-76-33

ELEVATOR TRIM WHEEL COVER \ POWER LEVER COVER CONDITION LEVER FLAP LEVER / COVER

**--~L** COVER

' 

### . p _..

**~~ :~**  **\ ·~**  **~** ........ -- .•;;' OLD BRACKET ,;; , • ' .] ; . · ,'

NEW B RACKE T 

# % 

# ® Beta Warning - Installation Figure 1 

# 0

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### SERVICE BULLETIN 8-76-33



## & (CENTER a::tal..E COVERS I REt1JVE & RETAIN 

# & <PLATE 876104271 

# & COVER 87610098 REF RE11JVE & REWCA<



# SECTION THROUGH CENTRE CONSOLE WITH PILOT WARNING HORN ACTUATOR INSTALLED (VIEW PRIOR TO REWORI<l Power Lever in Center Console - Pre Mod Section View Figure 2 

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RIVET 

### SERVICE BULLETIN 8-76-33

0.599 INCH

2. t 3
RIVET 

# £ I B0205016AD4-4S 1'**_y~** 

## ! 

# ;J /j 

# //**r-----~**

## ~;**~...-..~** Q

80205017AD5 -8S 

# 2 .24 COVERASSY 

### (87610098) 2 PLCS 

### ill (INSTALL FLUSH WITH COUNTERSINK HEAD INSIDE)

13 Dec 2012 BRACKET 87610164-003 

### -053 Cover Assembly- Rework Figure 3 S.B. 8-76-33 Page 13 of 16 LS

# M PLATE 87610427 SCREW NAS1351-3-8P 

### CAN960010L WASHER)

WAS 

# ffi COVER ASSY 

### p/n 8761 0098 NOW 

### p/n 8Z9662-053

PATH OF DETENT 

### ARM 

### SERVICE BULLETIN 8-76-33


# A <CENTER C0>6QE COVERS l



### -003 (SECTI**~** Tt-R:LQ-l CENTRE CCNSCl..E J Power Lever in Center Console- Post Mod Section View Figure 4 13 Dec 20 12 S.B. 8-76-33 Page 14 of 16 LS

### 13 Dec 2012 

### SERVICE BULLETIN 8-76-33

SWITCH SCREW I



## (e) Micro Switch Rigging Figure 5 ACTUATOR .ARM 

## /

MINIMUM CLEARANCE

0.030 m. (0.762 mm) WITH PO\"JER LEVERS I N FORWARD POWER RANGE



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### SERVICE BULLETIN 8-76-33

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