# De Havilland Canada Service Bulletin 84-54-28

Copy: Revision B ("84-54-28 Rev B"), 24 pages: PDF https://openairdocs.org/files/sha256/98/1d/981de4c2f94134a733d0ce3f7b44d4a6afe7899efa1cfe4e475a073351109350; text https://openairdocs.org/service-documents/bombardier/sb-84-54-28/file/981de4c2f941.md. Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2021-0514; AD 2022-01-02 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.

## Details

- Manufacturer: [Bombardier](https://openairdocs.org/service-documents/bombardier.md) (issued as De Havilland Canada)
- Type: Service bulletin (Service Bulletin)
- Number: 84-54-28
- Latest revision known: 84-54-28, Revision B, dated January 24, 2020 (OpenAirDocs)
- Page: https://openairdocs.org/service-documents/bombardier/sb-84-54-28

## ADs that cite it (1) (OpenAirDocs)

Newest first, with the revision each names, as OpenAirDocs read it from the AD's text.

- [AD 2022-01-02](https://openairdocs.org/ad/2022-01-02.md), effective Mar 3, 2022: Revisions A and B

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/bombardier/sb-84-54-28/proposed.md).

## Text (24 pages)

Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2021-0514; AD 2022-01-02 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

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Revision ‘B’ 24 Jan 2020
BM
D H C --- 8 ( D A S H 8 )
S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 2 8
Nacelle - - - Wing Rear Spar Attachment Pin Corrosion Issues - - - Improvement
to Finish - - - ModSum 4- - - 113948
This page transmits Revision ‘B’ of Service Bulletin 84- - -54- - -28, pages 1 thru 20,
dated 24 Jan 2020
This service bulletin is re- - -issued in its entirety for the reasons that follow:
- - - Bombardier ordering and support information has been changed to current
De Havilland Aircraft of Canada Limited information
--- T h eReferences section is revised to convey the latest revision of the service
bulletin
--- T h eJ o b S e t --- U psection and the Close Out section are revised to add the
AMM TASK reference 07- - -10- - -00- - -582- - -805, in order to include the jacking
procedure for Cargo Combi configuration.
The Compliance in the previous issue(s) of this service bulletin is not affected by
this revision. No additional rework to the aircraft is introduced by this revision.
Remove the previous revision of Service Bulletin 84- - -54- - -28 and replace with
attached.
Previous issue(s) of Service Bulletin 84- - -54- - -28:
Initial issue - - - Pages 1 thru 18 dated 11 Aug 2017
Revision ‘A’ - - - Pages 1 thru 18 dated 10 Apr 2019

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Revision ‘B’ 24 Jan 2020
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This Page Intentionally Blank
1

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BMRevision ‘B’ 24 Jan 2020
SERVICE BULLETIN
ATA SYSTEM: 5400 NUMBER: 84- - -54- - -28
DE HAVILLAND AIRCRAFT OF CANADA LIMITED (DHC) CONSIDERS
URGES OPERATORS TO PROMPTL Y EVALUATE THE CONTENTS
THIS SERVICE BULLETIN TO BE PARTICULARL Y SIGNIFICANT AND
SUBJECT : Nacelle - - - Wing Rear Spar Attachment Pin Corrosion Issues - - -
Improvement to Finish - - - ModSum 4- - - 113948
1. PLANNING INFORMA TION
A. Effectivity
Aircraft Affected:
In- - -Service: DHC- - -8 Aircraft Models 401 and 402 Serial Numbers 4001,
4003 thru 4550.
Production: ModSum 4- - -113948 will be installed before delivery on
applicable DHC- - -8 Aircraft at Serial Numbers 4551 thru 4585,
4587.
Production: ModSum 4- - -170082 will be installed before delivery on
applicable DHC- - -8 Aircraft at Serial Number 4586, 4588 and
subsequent.

### Page 4

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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 DHC Service Bulletin(s). Before you do this bulletin,
examine all STC or equivalent action changes to make sure this
bulletin can be completed.
Spares Affected:
The following is a list of spares affected by this change. Review spares and
procurement systems to determine the existence of any listed parts.
Part Number Description
85414566- - -107 Rear Spar Attachment Pin
85414566- - -109 Rear Spar Attachment Pin
85414566- - -953 Rear Spar Attachment Pin
8Z10124- - -101 Rear Spar Attachment Pin
8Z10124- - -104 Rear Spar Attachment Pin
8Z10124- - -105 Rear Spar Attachment Pin
8Z10124- - -107 Rear Spar Attachment Pin
8Z10124- - -109 Rear Spar Attachment Pin
8Z10124- - -111 Rear Spar Attachment Pin
NOTE: Pins that are pre MS 4- - -113948 must be reworked per this service
bulletin before they can be installed on aircraft that are post MS
4- - -113948.
B. Reason
Problem: De Havilland Aircraft has conducted a design review and discovered
insufficient corrosion protection within the bore of the nacelle attachment
pins. A lack of primer can lead to premature corrosion and structural
degradation of the part. A structural failure of the part can lead to
asymmetrical landing gear configurations.
Solution: Do a detailed visual inspection of the inner bore surface of the nacelle
attachment pins for signs of corrosion.

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If corrosion is not found, the affected pin is removed and primer is applied
to the inner bore surface of the pin.
If corrosion is found, the affected pin is removed, the corrosion is removed,
and a fluorescent magnetic particle inspection is done for cracks. If the part
is within acceptable limits, primer is applied to the inner bore surface of the
affected pin. If the the part is beyond acceptable limits, it is replaced.
If crack indications are found, the affected pin is replaced before next flight.
C. Description
The procedures in this service bulletin give the instructions to do the tasks that follow:
- - - Aircraft electrical power is removed
- - - The nose landing gear lock is engaged
- - - The main landing gear lock pins are installed thru each main gear and main gear door
mechanism
- - - The aircraft is placed on jacks and access is gained to the nacelle attachment pins
located in the left and right hand nacelle
- - - The nacelle attachment pins are removed and a detailed visual inspection of the inner
bore of the attachment pins is done for signs of corrosion
- - - If corrosion is not found, chromated primer is applied to the inner surface of the pins
- - - If corrosion is found, the corrosion is removed. The inner surface of the affected pins
are cleaned and inspected by a fluorescent magnetic particle inspection (MPI)
process for cracking. If crack indications are not found (AND THE REWORKED PART
IS WITHIN ACCEPTABLE LIMITS), chromated primer is applied to the inner bore
surface. If crack indications are found (OR THE REWORKED PART IS NOT WITHIN
ACCEPTABLE LIMITS), the affected pins are replaced before next flight
- - - The reworked pins are re- - -part marked and installed
- - - Close out.

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D. Compliance
De Havilland Aircraft of Canada Limited highly recommend that ModSum 4- - -113948
be incorporated at the earliest opportunity unless otherwise directed by the operator’s
airworthiness authority.
A Transport Canada Airworthiness Directive is Pending.
E. Approval
The technical content of this service bulletin has been approved under the authority of
the Transport Canada Civil Aviation (TCCA) Design Approval Organization No: DAO
# 9 3 --- Q --- 0 2 .
This Service Bulletin affects Airworthiness Limitations (AWLs) and/or Damage
T olerance Inspections (DTIs). Reference applicable Post/Pre ModSum 4- - -113948 and
Service Bulletin 84- - -54- - -28 in the Maintenance Requirements Manual.
F. M a n p o w e r
It will take an estimated 7.00 man- - -hours to complete this service bulletin. The
breakdown of the man- - -hours is shown in the table that follows:
TASK M A N --- H O U R S
J o b S e t --- U p 0.50
Procedure 6.00
T e s t/R T S 0.00
Close- - -Out 0.50
This estimate is for direct labour done by an experienced crew and it does not
include, planning, familiarization, cure tim e, part fabrication, tool acquisition or lost
time.
G. Material - - - Price and Availability
Kit Number Description
8DK4317- - -001 Drawing Kit- - -Pin, Wing Rear Spar Attachment, Nacelle

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Drawing Kit(s) (DKs) listed in the table above are drawings only. No parts will be
supplied.
The part(s) and material(s) required are listed in Paragraph 2.A. The parts required
may be either furnished or fabricated from the operator’s existing stock, purchased as
single items from DHC or purchased directly from industry sources. DK parts are to
be manufactured and approved locally (refer to disclaimer in the related text or
illustration). In some cases, an equivalen t to the DK part may be available from DHC
under the production part number shown as reference in Parts Required Per Aircraft.
See the contact information below.
DE HAVILLAND AIRCRAFT OF CANADA LIMITED
Material Services
123 Garratt Blvd.
To r o n t o
Ontario
Canada M3K- - -1Y5
DHC Phone Numbers :
North America:T oll Free: 1 (844)- - -CRC- - -CRC0 (1 (844) 272- - -2720) or
Direct: 1 (514) 855- - -8500
DHC Emails:
Parts: Europe, Middle East, Africa, and Russia: emear.parts@dehavilland.com
Americas and Rest of World: parts@dehavilland.com
If required the related 8DK drawings listed in the T able above can be requested by
writing to the email address that follows:
dwg.request@dehavilland.com
H. T ooling - - - Price and Availability
None
I. Weight and Balance
Not affected

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J. Electrical Load Data
Not affected
K. Publications Affected
Aircraft Maintenance Manual PSM 1- - -84- - -2.........................
Structural Repair Manual PSM 1- - -84- - -3............................
Aircraft Illustrated Parts Catalog PSM 1- - -84- - -4......................
Maintenance Requirement Manual PSM 1- - -84- - -7....................
ModSums Manual PSM 1- - -84- - -12..................................
L. References
The Revision ‘B’ of this service bulletin was prepared to the engineering drawings and
related data that follows:
DRAWING SHEET REV
8DK4317 1 A
8Z10124 1 E
ModSum 4Q113948 Rev. ‘K’
ModSum 4- - -113948 Rev. ‘K’
ModSum 4- - -170082 Rev. ‘D’
ModSum 4D170082 Rev. ‘D’
PCA 45581 Revision 1 (for internal reference only)
Transport Canada Airworthiness Directive is Pending.
2. MATERIAL INFORMA TION
A. Parts Required Per Aircraft
(1) Drawing Kit 8DK4317- - -001

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(2) Detailed Kit Content:
Quantity Per Kit
--- 0 0 1
Part Number Description Remarks
1 8DK4317 Kit Drawing drawing
1 8Z10124 Pin, Retrofit Drawing drawing
Listed drawings that are required to complete the kits above can be requested by
writing to the following e- - -mail address:
dwg.request@dehavilland.com
(3) In addition to the above part(s), the following material(s) are required for the
completion of this service bulletin and may be procured as single items from
De Havilland Aircraft of Canada Limited or purchased directly from industry
sources.
Each consumable product listed in the table below is given its own unique
Product ID Number. The number is used to identify a particular recommended
product, the specifications and the trade names any of which can be used
unless specified otherwise (refer to PSM 1- - -84- - -18 Consumable Products
Manual).
Consumable
Product ID
Number
Qty. Per
Aircraft
Description Remarks
07- - -02A 20 oz. F19 T ype 2 Chromated Primer DHMS C4.01
07- - -08 10 oz. Coating, Enamel, Polyurethane, for
Aircraft Exterior Paint System
DHMS C4.04
08- - -12 10 oz. Solvent, Degreaser
(4) The parts listed in the table that follows are not shown in the Consumable
Products Manual and must be procured by the operator as single items from
De Havilland Aircraft of Canada Limited or purchased directly from industry
sources.

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Qty. Per Aircraft Parts Description Remarks
4 MS24665- - -306 Cotter Pin
4 AS15001- - -3P Lubricated Fitting
B. Parts Required to Modify Spares
None
C. Special T ools 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 for non- - -indented parts and the quantity per next
higher assembly for indented parts.
Existing
Part Number Description Qty. IC DC
New Part
Number PNC
8Z10124- - -101 R
85414566- - -107 Rear Spar Attachment Pin 4 B RWK or
8Z10124- - -105 R
85414566- - -109 Rear Spar Attachment Pin 4 B RWK 8Z10124- - -104 R
or
8Z10124- - -107 R
8Z10124- - -109 R
85414566- - -953 Rear Spar Attachment Pin 4 B RWK or
8Z10124- - -111 R
8Z10124- - -101 Rear Spar Attachment Pin 4 B RWK 8Z10124- - -105 R
8Z10124- - -104 Rear Spar Attachment Pin 4 B RWK 8Z10124- - -107 R
8Z10124- - -109 Rear Spar Attachment Pin 4 B RWK 8Z10124- - -111 R

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IC Interchangeability Code
A Not interchangeable.
B Removed Part. (before rework) No direct replacement.
C Conditionally Interchangeable. Inst allation of superseded part negates the
intent of this service bulletin.
DC Disposition
DIS Discard Part.
MUI Multiple Usage Item: Return to stock if serviceable.
RWK Rework existing part in accordance with this service bulletin.
RWI Rework existing part per .....
SAL Salvage. Return to operator’s stores for salvage consideration.
PNC Part Number Code
N No equivalent De Havilland Aircraft of Canada Limited part number for
reworked part. Indicate on part that this service bulletin has been
accomplished.
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.
3. ACCOMPLISHMENT INSTRUCTIONS
If it is not possible to complete all the instructions of this service bulletin because of the
configuration of the aircraft, speak with a representative of DHC in the CRC at 1 (844)
272- - -2720 (1 (844) CRC- - -CRC0) or email at thd@dehavilland.comfor analysis and to get an
approved disposition to complete this service bulletin.
NOTE: If accomplishing this service bulletin for spares parts, then only
complete the following steps:
3.B.2 through 3.B.5.

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NOTE: Refer to Part B Procedure of Accomplishment Instructions if initial issue
of this service bulletin has been accomplished.
A . J o b S e t --- U p
WARNING: MAKE SURE YOU INSTALL THE LOCKPINS ON THE MAIN LANDING
GEAR. MAKE SURE YOU ENGAGE THE NOSE GEAR LOCK. IF YOU
DO NOT DO THIS, THE LANDING GEAR CAN ACCIDENTALL Y
RETRACT . THIS CAN CAUSE INJURIES TO PERSONS AND
DAMAGE TO THE EQUIPMENT .
WARNING: MAKE SURE YOU INSTALL THE LOCKPINS IN THE DOOR
MECHANISMS OF THE MLG AND NLG. THE DOOR MECHANISMS
CAN ACCIDENTALL Y CLOSE THE LANDING GEAR DOORS. THIS
CAN CAUSE INJURIES TO PERSONS AND DAMAGE TO THE
EQUIPMENT .
(1) Placard and select all aircraft electrical power to OFF . Obey all relevant
W A R N I N G S a n d C A U T I O N S ( r e f e r t o A M M T A S K ’ S 2 4 --- 0 0 --- 0 0 --- 8 6 1 --- 8 0 2 a n d
24- - -00- - -00- - -910- - -801).
(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) Set wheel chocks in front and behind the landing gear tires.
( 5 ) R e f e r t o A M M T A S K 0 7 --- 1 0 --- 0 0 --- 5 8 2 --- 8 0 1 o r A M M T A S K 0 7 --- 1 0 --- 0 0 --- 5 8 2 --- 8 0 5
and put the aircraft on jacks.
(6) Refer to Figure 1 and set up the work platforms or ladders as required to gain
access to the nacelle attachment pins located in the left and right hand nacelle.
Make sure the work platforms or ladders are electrically grounded.
B. Procedure
NOTE: For aircraft that have done the initial issue of this service bulletin,
complete Part B only. Otherwise complete Part A only.

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Part A
(1) Refer to AMM TASK 54- - -20- - -07- - -000- - -801 and remove rear spar attachment pins
85414566- - -107/- - -109/- - -953 located in the left and right hand nacelle. Keep all
nuts and washers, discard all cotter pins.
(2) Solvent clean nacelle attachment pins 85414566- - -107/- - -109/- - -953 per SRM
TASK 51- - -26- - -00- - -02- - -01 using solvent 08- - -12.
(3) Do a detailed visual inspection of the inner surface of nacelle attachment pins
85414566- - -107/- - -109/- - -953 for signs of corrosion.
(4) If corrosion is not found, refer to the steps that follow and apply epoxy primer to
the bore surface of the affected pin(s).
( a ) R e f e r t o S R M T A S K 5 1 --- 2 5 --- 1 0 --- 0 2 --- 0 1 a n d a p p l y t w o c o a t s o f F 1 9 Ty p e 2
Chromated Primer (07- - -02A) to the bore surface of the affected pin(s) using the
fill and drain method. Make sure grease holes are temporarily plugged during
application of epoxy primer.
(b) After the application of epoxy primer, refer to NOTE 2 of drawing 8Z10124 and
part mark the reworked pin(s) accordingly.
(5) If corrosion is found, refer to the steps that follow and do the rework of the pin(s).
(a) Refer to AMM TASK 51- - -27- - -00- - -910- - -801 and clean the inner surface of the
affected pin(s) with solvent 08- - -12.
( b ) R e f e r t o S R M 5 1 --- 2 1 --- 0 0 --- 0 0 --- 0 2 a n d t h e a p p l i c a b l e s t e p s i n t h e G E N E R A L
NOTES: of drawing 8Z10124 and remove the corrosion to a maximum depth of
0.005 inches.
(c) After corrosion removal, refer to the pages that follow and do the SPECIAL
DETAILED INSPECTION OF THE NACELLE PIN, LH & RH on any affected
nacelle attachment pin(s). If any crack indications are found, the pin must be
replaced before next flight.
(d) If crack indications are not found, refer to SRM TASK 51- - -25- - -10- - -02- - -01 and
apply two coats of F19 T ype 2 Chromated Primer (07- - -02A) to the bore surface
of the affected pin(s) using the fill and drain method. Make sure grease holes
are temporarily plugged during application of epoxy primer.

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(e) After the application of epoxy primer, refer to NOTE 4 of drawing 8Z10124 and
part mark the reworked pin(s) accordingly.
(6) Refer to AMM TASK 54- - -20- - -07- - -400- - -801 and drawing 8Z10124 and install the
reworked pin(s) with cotter pins MS24665- - -306. After pin installation, if grease
fitting MS15001- - -1 is installed, replac e the fitting with lubricated fitting
AS15001- - -3P .
(7) Go to Close Out.
P a r t B ---This section is only applicable to aircraft that have done the Initial Issue of this
service bulletin.
(1) Refer to AMM TASK 54- - -20- - -07- - -000- - -801 and remove rear spar attachment pins
8Z10124- - -101/- - -104/- - -105/- - -107/- - -109/- - -111 located in the left and right hand
nacelle. Keep all nuts and washers, discard all cotter pins.
(2) Solvent clean nacelle attachment pins 8Z10124- - -101/- - -104/- - -105/- - -107/- - -109/- - -111
per SRM T ask 51- - -26- - -00- - -02- - -01 using solvent 08- - -12.
(3) Do a detailed visual inspection of the bore of pins
8Z10124- - -101/- - -104/- - -105/- - -107/- - -109/- - -111 for signs of corrosion.
(a) If no corrosion is found on pins 8Z10124- - -101/- - -104/- - -105/- - -107/- - -109/- - -111,
apply two coats of the primer (F19 T ype 2 Chromated primer, CPM07- - -02A) to
the bore surface of the pin per SRM TASK 51- - -25- - -10- - -02- - -01. The part
number of these pins remains unchanged.
(b) If corrosion is found on pins 8Z10124- - -105/- - -107/- - -111, discard the pin and
replace it with a serviceable pin P/N 85414566- - -111 or
8Z10124- - -101/- - -104/- - -105/- - -107/- - -109/- - -111.
NOTE: If P/N 85414566- - -111 is not available, it is acceptable to order pin P/N
85414566- - -109 and rework it using this SB.
(c) If corrosion is found on pins 8Z10124- - -101/- - -104/- - -109, rework the pins, inspect
for cracks, apply primer and part mark in accordance with Part A (5) and (6).
(4) Refer to AMM TASK 54- - -20- - -07- - -400- - -801 and drawing 8Z10124 and install the
reworked pin(s) with cotter pins MS24665- - -306. After pin installation, if grease
fitting MS15001- - -1 is installed, replac e the fitting with lubricated fitting
AS15001- - -3P .

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(5) Go to Close Out.
C. Close Out
( 1 ) R e f e r t o A M M T A S K 0 7 --- 1 0 --- 0 0 --- 5 8 2 --- 8 0 1 o r A M M T A S K 0 7 --- 1 0 --- 0 0 --- 5 8 2 --- 8 0 5
and lower the aircraft from the jacks.
(2) Remove all tools and equipment from the work area.
(3) 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.
NOTE: The pins in this service bulletin are Life Limited (reference PSM 1- - -84- - -7). If
the pins are re- - -assigned to a different aircraft than the original installation,
the life of the pins must continue to be tracked separately from the aircraft.

### Page 16 (OCR)

SERVICE BULLETIN 84-54-28
SPECIAL DETAILED INSPECTION OF THE NACELLE PINS, LH & RH
1. EFFECTIVITY:
De Havilland Dash 8-400
2. MRM TASK:
Not Applicable
3. AREA DESCRIPTION:
Refer to Figure 1.
Pins: 85414566-107/-109/-953 & 8Z10124-101/-104/-105/-107/-109/-111.
4. PURPOSE:
To detect surface cracks in the internal diameter of the pins as shown in Figure 2
5. ZONE:
Refer to Figure 1.
6. ACCESS:
The following pins have to be removed for inspection:
85414566-107/-109/-953 & 8Z10124-101/-104/-105/-107/-109/-111
7. INSPECTION METHOD:
Fluorescent Magnetic Particle Inspection (MPI).
8. EQUIPMENT REQUIRED:
Use the items identified as follows or their equivalent (Refer to PSM 1-84-7A NDT
Manual Task 51-00-07-910-801).
NOTE: Equivalent equipment can be used if it satisfies the requirements of this inspection
procedure and can get the required sensitivity.
(1) High intensity UV-A LED Inspection flashlight OPX-365 (SPECTROLINE Company) or
high intensity MidBeam hand held UV LED Light (LABINO Company) that can produce a
minimum black light intensity of 4500 microwatts per square centimeter at 15.0 in (381
mm).
Note: High intensity focused UV Light source must be used to detect cracks in the inner
diameter of the pins.
(2) Cellulose sponge or nylon brush, commercially available.
(3)  Lint-free cloth, commercially available.
(4) Horizontal wet bench type machine; three phase full wave rectified AC.
11 Aug 2017  S.B. 84-54-28
Revision 'B' 24 Jan 2020  Page 14 of 20

### Page 17 (OCR)

SERVICE BULLETIN 84-54-28
Manufacturer "Ardrox", Model: 3505A-6
Fluorescent magnetic particles - "Magnaflux" Magnaglo 14A.
(6) Oil Vehicle - "Magnaflux" Carrier II.
(7) Quantitative Quality Indicator (QQI's), commercially available
Open AC Demagnetizer- "Magnaflux", Model SB-2824.
(9) Residual field strength meter - "Ardrox" MD-220
(10) Noncorrosive, nonabrasive and easily removable marker to mark the location of the
inspection area. The marker must not contain chlorine, lead or graphite (refer to the AMM,
PSM 1-84-2, Chapter 20).
9. PREPARATION:
Prepare the inspection area as follows:
1) Identify pins, 85414566-107/-109/-953 & 8Z10124-101/-104/-105/-107/-109/-111 to be
Clean the inspection surfaces (Refer to SRM, PSM 1-84-3, SRM 51-26-00).
Warning: Make sure that there is a good flow of clean air and sufficient fire protection.
Use approved body protection when you use solvents. All solvents are poisonous and
some are flammable
Visually examine pins for cracks, corrosion, damage and other unserviceable conditions.
10. INSPECTION (REFER TO FIGURE 2):
Equipment performance test and materials verification (Refer to NDTM Part 1, Task 51-00-07):
Before the inspection, do the system performance checks for the magnetic particle
bench, lighting, and facilities.
B. Demagnetization:
1)  The parts to be examined must be demagnetized before the inspection. The field strength
meter must not detect residual field that exceeds 3 Gauss anywhere on the part.
C. Set-Up, Magnetic Particle and Magnetization application.
NOTE: Proper sequencing and timing of part magnetization and application of the particle
suspension is required to get optimum indication formation and retention. Apply the
suspension on the part simultaneously with or slightly before energizing the magnetic circuit.
NOTE: The use of shims that contain artificial flaws (QQI) is required to make sure the correct
level of magnetism is applied before inspection. Refer to Figure 2
NOTE: Do not use MPI Equipment that does not detect the flaw indications on the QQI shims.
1. Insert 0.4 in (10.2 mm) diameter central conductor in pins 85414566-107/-109/-953 &
8Z10124-101/-104/-105/-107/-109/-111 and put it between the headstocks firmly with
2. Magnetize the pins and use wet continuous method with the current specified in Table 1
NOTE: Apply the magnetization for a minimum of 0.5 second for each application, with
a minimum two applications of magnetizing current.
11 Aug 2017  S.B. 84-54-28
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### Page 18 (OCR)

SERVICE BULLETIN 84-54-28
3. Remove the pin and central conductor from between the head stocks and examine the
entire internal diameter of the pin for cracks.
Note: Typical cracks will be in a longitudinal direction plus or minus 45 degrees.
4. Reinsert 0.4 in (10.2 mm) diameter central conductor in pins 85414566-107/-109/-953 &
8Z10124-101/-104/-105/-107/-109/-111 and put it between the headstocks firmly with
5. Magnetize the pin and use wet continuous method with the current specified in Table 1
NOTE: Apply the magnetization for a minimum of 0.5 second for each application, with
a minimum two applications of magnetizing current.
6. Remove the pin and central conductor from between the head stocks and examine the
entire internal diameter of the pin for cracks.
Note: Typical cracks will be in a longitudinal direction plus or minus 45 degrees.
7. Place pins 85414566-107/-109/-953 & 8Z10124-101/-104/-105/-107/-109/-111 as
applicable against the coil inside diameter with the Pin length parallel to the coil center
line.
8. Magnetize the pin and use wet continuous method with the current shown in Table 1
Magnetization 3
NOTE: Apply the magnetization for a minimum of 0.5 second for each application, with
a minimum two applications of magnetizing current.
9. Examine the entire internal diameter of the pin
NOTE: Typical cracks will be in circumferential direction plus or minus 45 degrees.
Table 1
Inspection data for Pins
85414566-107/-109/-953 & 8Z10124-101/-104/-105/-107/-109/-111
Magnetization  Circular Magnetization-  Longitudinal Magnetization-
No.  DC  DC
Conductor  Contact  Coil - 5 Turns
1  700 A
2  2500A
4500A
11. INDICATION EVALUATION:
A. Non-relevant indications caused by magnetic leakage fields do not represent discontinuities.
B. Design factors such as keyways, drilled holes, abrupt changes in section, metallurgical
changes, permeability variation, damaged coating or dissimilar materials can produce non-
C. False indications are not caused by leakage field, they are caused mechanically. These
indications do not reappear after the parts are cleaned and reprocessed.
D. Relevant indications are caused by magnetic leakage fields and represent the presence of a
discontinuity and will reappear after the part is cleaned and reprocessed.
E. Surface indications are sharp and distinct.
F. Slightly subsurface indications are broad and fuzzy.
11 Aug 2017  S.B. 84-54-28
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BM

### Page 19 (OCR)

SERVICE BULLETIN 84-54-28
12. ACCEPTANCE / REJECTION CRITERIA:
A. Any crack indication is cause for rejection.
13. REPORTING:
A. Report all defect and reject indications to DeHavilland Aircraft of Canadaon the "Dash 8-400
Aircraft Structural Defect Report" (Refer to the Nondestructive Testing Manual (NDTM), PSM
1-84-7A, Appendix A).
14. POST INSPECTION REQUIREMENTS:
A. Pins must be demagnetized after the final inspection. The field strength meter must not detect
residual fields exceeding 3 Gauss anywhere on the part (Refer to NDTM Part 1, Task 51-00-
B. Pins must be cleaned to remove all traces of magnetic particle residue (Refer to SRM, (PSM 1-
84-3), SRM 51-26-00).
C. After removal of the magnetic residues, examine the Pin surface with a white and black light.
Make sure that no traces of magnetic residue are visible. If there is residue, clean the Pin until
all traces are removed.
15. CLOSE-UP:
A. If the finish in the inspection area was removed, apply the finish again (Refer to SRM, (PSM 1-
84-3), SRM 51-20-10-00-01).
B. Remove all tools, equipment and unwanted materials from inspection area.
11 Aug 2017  S.B. 84-54-28
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### Page 20 (OCR)

SERVICE BULLETIN 84-54-28
LEGEND
1. Spar attachment pin.
2. Cotter pin.
3. Nut.
4. Washer.
5. Special washer.
6. Bolt.
7. Anti-rotation plate.
8. Cotter pin.
9. Nut  REAR SPAR
SUPPORT FITTING
(REF)
5  00
WASHER
(REF)
Location of Rear Spar Attachment Pin 85414566-107 / -109 / -953 &
8Z10124-101/-104/-105/-107/-109/-111
Figure 1
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### Page 21

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 2 8
S . B . 8 4 --- 5 4 --- 2 8
Page 19 of 20
11 Aug 2017
BMRevision ‘B’ 24 Jan 2020
Rear Spar Attachment Pin 85414566- - - 107 / - - - 109 / - - - 953 &
8Z10124 - - - 101/ - - - 104/ - - - 105/ - - - 107/ - - - 109/ - - - 111
Special Detailed Inspection
Figure 2
- - - QQI Placement
LEGEND
Central Conductor 0.4  dia.
1

### Page 22

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 2 8
S . B . 8 4 --- 5 4 --- 2 8
Page 20 of 20
11 Aug 2017
BMRevision ‘B’ 24 Jan 2020
This Page Intentionally Blank
1

### Page 23

Oct 2019
SERVICE BULLETIN (SB) - - - RECORD OF INCORPORATION
DASH 8 AIRCRAFT
To : CMDB Focal
Email: cmdb.request@dehavilland.com
From:
Company:
Phone: Extn:
Facsimile: Date:
Email:
The data that you provide below will help us record the incorporation of this Service
Bulletin and the aircraft effectivity in the maintenance manual.
Operator: Service Bulletin: __________________ Revision: _________
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Email PDF to:
cmdb.request@dehavilland.com

### Page 24

Oct 2019
SERVICE BULLETIN (SB) - - - COMMENT SHEET - - - DASH 8 AIRCRAFT
To : SB Focal, DE HAVILLAND AIRCRAFT OF CANADA LIMITED
Phone: 1 (416) 373 - - -5098
Email: george.moffatt@dehavilland.com
From:
Company:
Phone: Extn:
Facsimile: Date:
Email:
Select appropriate box(es) and add comments or suggestions you would like us to know
that may enhance the quality of our service bulletins.
Service Bulletin: Revision: ModSum:
1. PLANNING INFORMATION
V Effectivity V Reason V Description V Compliance
V Approval V Manpower V Material V Weight and Balance
V Electrical Load V T ooling V References V Publications Affected
2. MATERIAL INFORMATION
V Kit Content V Special T ools/Equipment V Parts to Modify Spares
V Consumables V Disposition of Existing Parts V Other
3. ACCOMPLISHMENT INSTRUCTIONS
V J o b S e t --- U p V Procedure V Close- - -Out V Te s t
V Illustration(s) V Other
4. COMMENTS, REMARKS, SUGGESTIONS
Email PDF to:
george.moffatt@dehavilland.com

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