# Bombardier Service Bulletin 84-27-63

Copy: No revision named ("SB 84-27-63"), 8 pages: PDF https://openairdocs.org/files/sha256/1f/4f/1f4f3e8c142e4256902c051cab24cfbdb9aaa1d39d3b9edb1d502aad22ea729d; text https://openairdocs.org/service-documents/bombardier/sb-84-27-63/file/1f4f3e8c142e.md. Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2015-0494; AD 2015-19-13 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.

## Details

- Manufacturer: [Bombardier](https://openairdocs.org/service-documents/bombardier.md)
- Type: Service bulletin (Service Bulletin)
- Number: 84-27-63
- Page: https://openairdocs.org/service-documents/bombardier/sb-84-27-63

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

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

- [AD 2015-19-13](https://openairdocs.org/ad/2015-19-13.md), effective Nov 3, 2015: No revision named

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/bombardier/sb-84-27-63/proposed.md).

## Text (8 pages)

Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2015-0494; AD 2015-19-13 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. Each page's text from the PDF; open the PDF at a page with #page=N.

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SERVICE BULLETIN
Customer
Support
ATA SYSTEM: 2700 NUMBER: 84- - -27- - -63
SUBJECT : Flight Controls - - - Outer Wing - - - Spoiler PCU - - - Design Change to
Eliminate Inadvertent Deployment - - - ModSum 4- - - 113783
1. PLANNING INFORMA TION
A. Effectivity
Aircraft Affected:
In- - -Service: DHC- - -8 Aircraft Models 401 and 402 Serial Numbers 4001,
4003 thru 4453.
Production: ModSum 4- - -113783 will be installed before delivery on
applicable DHC- - -8 Aircraft at Serial Number 4454 and
subsequent.
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 this bulletin
can be completed.
Spares Affected:
None
B. Reason
Problem: Operators have reported numerous cases of inadvertent deployment of a
single outboard spoiler in- - -flight. In all cases the inadvertent deployment
occurred when airspeed decreased below 165 kts and outboard spoilers
became enabled.
The lift dump valve upgrade thru Bombardier Service Bulletin 84- - -27- - -43
(mandated by TC AD CF- - -2009- - -26) has not reduced the rate of
occurrence in the fleet. The controllability of the aircraft could be
significantly affected if an inadvertent deployment of a spoiler occurred in
combination with an engine failure or jam in the aileron system.
Bombardier PDF Merged Document SB 84-27-63_17Oct2013 & Parker VSB 390700-27-001_Oct28, 2013
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Cause: Investigation has identified the root cause as seal blow- - -by at the spoiler
PCU main control valve, causing a leak path from the supply pressure to
the PCU extend chamber.
Solution: Remove and replace the existing outboard spoiler PCU’s with revised
PCU’s designed with seal blow- - -by protection.
C. Description
The procedures in this service bulletin give the instructions to do the tasks that
follow:
- - - aircraft is put into standard configuration for maintenance
- - - 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
- - - access is gained to the outboard spoiler PCU’s- - -left and right hand side
- - - the PCU’s are removed and replaced with revised PCU’s reworked by Parker per
Parker VSB 390700- - -27- - -001
- - - an operational test of the roll spoiler system is done
- - - close out.
NOTE: This service bulletin is applicable to the outboard spoiler PCU’s only. It
does not authorize upgrade of the inboard spoiler PCU’s, as it will be
addressed per Bombardier Service Bulletin 84- - -27- - -62.
D. Compliance
Bombardier Inc. recommends incorpora tion of ModSum 4- - -113783 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
O r g a n i z a t i o n N o : D A O # 9 3 --- Q --- 0 2 .
This service bulletin does not affect Airworthiness Limitations (AWLs) or Damage
T olerance Inspections (DTIs).
Bombardier PDF Merged Document SB 84-27-63_17Oct2013 & Parker VSB 390700-27-001_Oct28, 2013
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F. M a n p o w e r
It will take an estimated 4.50 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 (left and right hand side) 2.00
T e s t/R T S 1.50
Close- - -Out 0.50
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 T echnical Help
Desk by telephone at 416- - -375- - -4000 or email at: thd.qseries@aero.bombardier.com
G. Material - - - Price and Availability
The parts detailed in Paragraph 2.A. may be either purchased as single items from
Bombardier Aerospace Regional Aircraft or purchased directly from industry
sources.
H. T ooling - - - Price and Availability
None
I. Weight and Balance
None
J. Electrical Load Data
Not affected
K. Publications Affected
Dash 8 Illustrated Parts Catalogue PSM 1- - -84- - -4....................
ModSums Manual PSM 1- - -84- - -12..................................
L. References
The initial issue of this service bulletin was prepared to the engineering drawings
and related data that follows:
Bombardier PDF Merged Document SB 84-27-63_17Oct2013 & Parker VSB 390700-27-001_Oct28, 2013
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DRAWING SHEET REV
8DK4220 1 ---
ModSum 4Q113783 Rev. ‘C’
ModSum 4- - -113783 Rev. ‘D’
PCA 43563 Revision 1 (for internal reference only)
2. MATERIAL INFORMA TION
A. Parts Required Per Aircraft
(1) Drawing Kit 8DK4220- - -001, Retrofit - - - Flight Spoiler PCU/Actuator, RH/LH
Outboard
(2) Detailed Parts List:
Quantity
Per Aircraft
Part Number Description Remarks
2 390700- - -1009 Actuator
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
p e rn e x th i g h e ra s s e m b l yf o ri n d e n t e dp a r t s .
Existing
Part Number Description Qty. IC DC
New Part
Number PNC
390700- - -1007 Actuator 2 C RWK 390700- - -1009 R
IC Interchangeability Code
A Discarded part.
B Reworked Part. No direct replacement.
C Conditionally Interchangeable. Installation of superseded part negates the
intent of this service bulletin.
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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 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.
3. ACCOMPLISHMENT INSTRUCTIONS
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.
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(4) Set up the work platforms or ladders as required to gain access to the PCU’s for
the outboard flight spoilers- - -left and right hand side. Make sure the work
platforms or ladders are electrically grounded (refer to Figure 1).
(5) Open and tag the circuit breakers that follow:
CB PANEL AND CB NO NAME
LEFT DC (ESSENTIAL), F8 H Y DP R E S SI N D1
LEFT DC (ESSENTIAL), H7 HYD SYS CONT
RIGHT DC (ESSENTIAL), F6 R O L L S P L R S --- A R M --- O U T B D
RIGHT DC (ESSENTIAL), H6 R O L L S P L R S --- A R M --- I N D
RIGHT DC (ESSENTIAL), L8 HYD PWR XFER
RIGHT DC (ESSENTIAL), M8 H Y DP R E S SI N D2
RIGHT DC (ESSENTIAL), M7 HYD SYS 3 CONT
(6) Remove the access panels that follow:
REFERENCE DESIGNATION
532ST Panel
542AL Panel
642AL Panel
632EB Closure Panel
B. Procedure
( 1 ) R e f e r t o A M M T A S K 2 7 --- 6 1 --- 1 6 --- 0 0 0 --- 8 0 1 a n d r e m o v e t w o e x i s t i n g P C U ’ s
390700- - -1007 used for the outboard flight spoilers- - -left and right hand side.
Removed PCU’s may be returned to Parker for upgrade to 390700- - -1009
(reference Parker VSB 390700- - -27- - -001).
(2) Refer to AMM TASK 27- - -61- - -16- - -400- - -801 and install two PCU’s 390700- - -1009
for the outboard flight spoilers- - -left and right hand side.
C. Close Out
(1) Remove the tags and close the circuit breakers that follow:
Bombardier PDF Merged Document SB 84-27-63_17Oct2013 & Parker VSB 390700-27-001_Oct28, 2013
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CB PANEL AND CB NO NAME
LEFT DC (ESSENTIAL), F8 H Y DP R E S SI N D1
LEFT DC (ESSENTIAL), H7 HYD SYS CONT
RIGHT DC (ESSENTIAL), F6 R O L L S P L R S --- A R M --- O U T B D
RIGHT DC (ESSENTIAL), H6 R O L L S P L R S --- A R M --- I N D
RIGHT DC (ESSENTIAL), L8 HYD PWR XFER
RIGHT DC (ESSENTIAL), M8 H Y DP R E S SI N D2
RIGHT DC (ESSENTIAL), M7 HYD SYS 3 CONT
( 2 ) R e f e r t o A M M T A S K 2 7 --- 6 1 --- 0 0 --- 7 1 0 --- 8 0 1 a n d d o a n o p e r a t i o n a l t e s t o f t h e r o l l
spoiler system. During the operational test, make sure that there is clearance
between the spoiler components and the aircraft structure or other components.
(3) Install the access panels that follow:
REFERENCE DESIGNATION
532ST Panel
542AL Panel
642AL Panel
632EB Closure Panel
(4) Remove all tools and equipment from the work area.
(5) 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.
Bombardier PDF Merged Document SB 84-27-63_17Oct2013 & Parker VSB 390700-27-001_Oct28, 2013
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Flight Spoiler PCU / Actuator - - - Left Hand and Right Hand Side - - - Outboard
Figure 1
LOCATION OF RETROFIT
1
Bombardier PDF Merged Document SB 84-27-63_17Oct2013 & Parker VSB 390700-27-001_Oct28, 2013
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