# De Havilland Canada Service Bulletin 84-32-162

Copy: Revision B ("84-32-162 RevB"), 32 pages: PDF https://openairdocs.org/files/sha256/5c/05/5c0535a4f6eab47ed15e67aafd8d453550047f6990000370235cc95c91050cea; text https://openairdocs.org/service-documents/bombardier/sb-84-32-162/file/5c0535a4f6ea.md. Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2021-0018; AD 2021-10-13 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: 84-32-162
- Latest revision known: 84-32-162, Revision B, dated November 13, 2019 (OpenAirDocs)
- Page: https://openairdocs.org/service-documents/bombardier/sb-84-32-162

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

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

- [AD 2021-10-13](https://openairdocs.org/ad/2021-10-13.md), effective Jul 1, 2021: Revisions A and B

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/bombardier/sb-84-32-162/proposed.md).

## Text (32 pages)

Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2021-0018; AD 2021-10-13 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.

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SERVICE BULLETIN
ATA SYSTEM: 3251 NUMBER: 84- - -32- - -162
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 : Landing Gear - - - Nose Wheel Steering - - - Introduction of Dual Channel
PHC and Modified SCU and Removal of Interim Resistor Cable
Assemblies - - - ModSum 4- - - 126579
1. PLANNING INFORMA TION
A. Effectivity
Aircraft Affected:
In- - -Service: DHC- - -8 Aircraft Models 401 and 402 Serial Numbers 4001,
4003 thru 4608.
Pre - - - Requisite
ModSum
Title
4- - -126600 Landing Gear - - - Nose Wheel Steering - - - Wiring
Provisioning for Dual Channel PHC and Modified
SCU - - - Retrofit (Service Bulletin 84- - -32- - -128, See
NOTE)
NOTE: The pre- - -requisite ModSum is only effective for the range of aircraft that
follow: Serial Numbers 4001, 4003 thru 4469, 4471 thru 4474 and 4477.
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Related ModSum Title
4- - -124024 Landing Gear - - - Nose Wheel Steering - - - Wiring
Provisions for Dual Channel PHC and Modified
SCU - - - Production Rework
4- - -123998 Landing Gear - - - Nose Wheel Steering - - - Wiring
Provisions for Dual Channel PHC and Modified
SCU - - - Production Rework
4- - -124501 Landing Gear Nose Wheel Steering Wiring Provi-
sions for Dual Channel PHC and Modified SCU - - -
Rework
4- - -124473 Landing Gear Nose Wheel Steering Wiring Provi-
sions for Dual Channel PHC and Modified SCU - - -
Rework
4N126579 Landing Gear - - - Nose Wheel Steering - - - Introduc-
tion of Dual Channel PHC and Modified SCU
Production: ModSum 4- - -126579 will be installed before delivery on
applicable DHC- - -8 Aircraft at Serial Number 4609 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 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:
None
B. Reason
Problem: The nose wheel steering is designed as hybrid system with dual channel
SCU and single command line input. The design review revealed possible
failure modes that might compromise system safety.
Solution: The nose wheel steering system is redesigned to introduce reference input
command and revised SCU architecture ensuring system safety standards are
met.
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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
- - - Access panels are opened
- - - If required to access pressure bulkhead connector 9811- - -J2, crew oxygen bottle is
removed
- - - Some wires are removed and discarded
- - - Existing taped and stowed wires are reterminated
- - - A new steering control unit is installed
- - - A new nosewheel steering hand control unit is installed
- - - A new label is installed
- - - Some trimming on the nosewheel steering console might have to be done
- - - Close out.
D. Compliance
DE HAVILLAND AIRCRAFT OF CANADA LIMITED highly recommends that ModSum
4- - -126579 be incorporated at the earliest opportunity unless otherwise directed by
the operator’s airworthiness authority.
A Transport Canada Airworthiness Directive 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
# 1 9 --- Q --- 0 1 .
This service bulletin does not affect Airworthiness Limitations (AWLs) or Damage
T olerance Inspections (DTIs).
F. M a n p o w e r
It will take an estimated 13 man- - -hours to complete this service bulletin. The
breakdown of the man- - -hours is shown in the table that follows:
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TASK M A N --- H O U R S
J o b S e t --- U p 2.00
Procedure 7.00
T e s t/R T S 2.00
Close- - -Out 2.00
NOTE: It is possible to complete this service bulletin with three personnel. One
person works on the steering tiller, one person works on the steering
control unit and the third person works on the pressure bulkhead
connector 9811- - -J2.
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
T h eM o d K i tr e q u i r e dt od ot h i ss e r v i c eb u l l e t i ni sl i s t e di nt h et a b l eb e l o w .
Kit Number Description
8MK4724- - -001, - - -003, - - -005 Retrofit - - - Nose Wheel Steering
Removal of Resistor Cable Assembly,
T ermination of Dual Channel Signal
Wiring Installation of PHC and SCU
ModKits necessary to do this service bulletin are available through the Service Bulletin
Kit Group. For any terms and conditions, operators should contact this group at:
DHC Email address:
kits@dehavilland.com
DHC Phone Numbers :
North America:T oll Free: 1- - -844- - -272- - -2720 or
Direct: 1- - -514- - -855- - -8500
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H. T ooling - - - Price and Availability
None
I. Weight and Balance
A/C T ype and
Model
Weight (Lb) Arm (Inches)
Moment
(Inches x Lb)
x 0.001
D H C --- 8 M o d e l 4 0 1 +0.30 - - -79.50 - - -0.02
D H C --- 8 M o d e l 4 0 2 +0.30 - - -79.50 - - -0.02
J. Electrical Load Data
Not affected
K. Publications Affected
Wiring Diagrams Manual PSM 1- - -84- - -2W.............................
ModSums Manual PSM 1- - -84- - -12..................................
L. References
Revision ‘B’ of this service bulletin was prepared to the engineering drawings and
related data that follows:
DRAWING SHEET REV
8MK4724 1 C
8Z9596 1 D
8Z9992 1 --- ---
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ModSum 4- - -126579 Rev. ‘K’
ModSum 4Q126579 Rev. ‘F’
ModSum 4N126579 Rev. ‘C’
ModSum 4- - -126600 Rev. ‘F’
ModSum 4Q126600 Rev. ‘F’
UTC Aerospace Systems Service Bulletin 406300- - -32- - -142
UTC Aerospace Systems Service Bulletin 406330- - -32- - -143
PCA 43189 Revision 4 (for internal reference only)
IS4Q5300048 Rev. ’A’
Transport Canada Airworthiness Directive Pending.
2. MATERIAL INFORMA TION
A. Parts Required Per Aircraft
(1) Modification Kit 8MK4724- - -001, - - -003, - - -005
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(2) Detailed Kit Content:
Quantity Per Kit
--- 0 0 1 --- 0 0 3 --- 0 0 5
Part Number Description Remarks
11 81171023- - -107 Label, Nose Wheel
Steering
Issue PO to
DeHavilland
1 8Z9992- - -101 Reworked Frame Part number after
rework
222 S 0 6 3 --- 3 --- 0 1 Solder Sleeve Operator to source
(See NOTES 1 and
2)
666 M39029/56- - -348 Contact Socket Operator to source
(See NOTE 1)
111 406330- - -05- - -01 Steering Hand
wheel Assy
Issue PO to UTC
(See NOTE 3)
444 NAS7703- - -3 Bolt Operator to source
111 406300- - -10- - -01 Elect Control Unit Issue PO to UTC
(See NOTE 4)
444 NAS6203- - -18 Bolt Operator to source
888 NAS1149D0316J Washer Operator to source
111 8Z9596 Drawing See NOTE 7
111 8Z9992 Drawing See NOTE 7
NOTE 1: BOM quantity contain spares to allow for losses. Damage and
un- - -terminated wire ends.
NOTE 2: The P/N S063- - -3- - -01 is equivalent to the P/N B0816063- - -003.
NOTE 3: Refer to enclosed UTC Aerospace service bulletin 406330- - -32- - -143 to
purchase this part.
NOTE 4: Refer to enclosed UTC Aerospace service bulletin 406300- - -32- - -142 to
purchase this part.
NOTE 5: For S/Ns 4001, 4003 - - - 4226 the - - -003 kit is required.
NOTE 6: For S/Ns 4227 - - - 4417 the - - -005 kit is required.
NOTE 7: Listed drawings that are required to complete the kits above can be
requested by writing to the following email address:
dwg.request@dehavilland.com
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Quantity Per Kit
--- 0 5 1 --- 0 5 3
Part Number Description Remarks
11 81171023- - -107 Label, Nose Wheel
Steering
1 8Z9992- - -101 Reworked Frame Part number after
rework
NOTE: Delta Kit 8MK4724- - -051 or - - -053 is required to incorporate the intent of
ModSum 4- - -126579 for those operators that are in possession of
unconsumed ModKit 8MK4724- - -001.
B. Parts Required to Modify Spares
None
C. Special T ools and Equipment Required
None
D. Existing Parts Accountability
Refer to attached UTC Aerospace Systems VSBs.
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
81171023- - -105 Label, nose
Wheel Steering
1 A DIS 81171023- - -107 S
85311498- - -131 Side Console
Frame
1 C RWK 8Z9992- - -101 R
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IC Interchangeability Code
A Not interchangeable.
B Removed Part. No direct 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 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 DHC 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.
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 .
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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 .
NOTE: Make sure to put a protective cover on any disconnected electrical
connector or any tube, hose, duct and/or line.
(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) If necessary, remove crew oxygen bottle (refer to AMM TASK’S
35- - -11- - -01- - -000- - -801 or 35- - -11- - -01- - -000- - -802).
B. Procedure
Part A - - - T erminate Wires at Bulkhead Connector 9811- - - J2
WARNING: OBEY ALL THE SAFETY PRECAUTIONS WHEN YOU DO
MAINTENANCE ON OR NEAR ELECTRICAL/ELECTRONIC
EQUIPMENT . IF YOU DO NOT DO THIS, YOU CAN CAUSE INJURIES
TO PERSONS AND DAMAGE TO THE EQUIPMENT .
NOTE: Rework to the LH side console frame can be done at this time as well.
(refer to Part B for instructions)
NOTE: For ease of removing heat shrink from the taped & stowed wires, heat up
heat shrink using a heat gun and remove tape using a cloth.
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NOTE: If completing Part A and Part B together the Return T o Service (RTS) only
h a st ob ed o n eo n c e ,a f t e rP a r tBi sc o m p l e t e d .
(1) Open nose fuselage door 112AR (refer to AMM TASK 06- - -41- - -00- - -992- - -801 for
location).
(2) Remove panels 112BR and 122AR (refer to AMM TASK 06- - -41- - -00- - -992- - -801 for
location).
(3) If necessary, strip and crimp wires on wiring bundle 8Z3023- - -019 (refer to WDM
20- - -17- - -10- - -201).
(4) If necessary, terminate and install the shields (refer to WDM 20- - -15- - -00- - -401).
(5) On aircraft with ModSum 4Q126600 incorporated (for PSNs 4001, 4003- - -4469,
4471- - -4474, 4477), terminate the provisioned wires 8Z3023- - -019 on connector
9811- - -J2 (pins D, E, F). (refer to Figure 4)
(6) If not proceeding directly to Part B, do the return to service as follows:
(a) Do the operational test of the main battery system (refer to AMM TASK
24- - -32- - -00- - -710- - -801)
(b) Do the operational test of the right DC generator control unit (refer to AMM TASK
24- - -31- - -06- - -710- - -801).
(c) Do the operational test of the nosewheel steering system (refer to AMM TASK
32- - -51- - -00- - -710- - -801).
(d) Do the operational test of the windshield wiper system (refer to AMM TASK
30- - -42- - -00- - -710- - -801).
(e) Do the operational test of the external AC power system (refer to AMM TASK
24- - -41- - -00- - -710- - -801)
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NOTE: Only for aircraft with AC external power receptacle in nose per
824CH00114 or 824SO90105.
(f) If option 812CH00003- - -AC ground power heated water service
CR824CH00114 installed, do as follows:
(1) Fill the water tank with potable water using a water fill cart, 20GPM, 40PSIG
maximum (water coming out of the overflow drain must indicates that the
system is full).
(2) Close the CBs as follows:
- - - Right DC C/B panel RIGHT SEC LAV SYSTEM D3
- - - Right DC C/B panel RIGHT ESS EXT PWR LOGIC F8
- - - VAR FREQ C/B panel Phase B LAV HTRS
- - - RCBP BATT PWR BUS AC GND SERVICE BUS L1 (Option
812CH00003)
(3) T urn off the DC and AC external power.
(4) Select all batteries off.
(5) T urn on the AC ground cart and make sure that, AC EXT switch in off
position in the cockpit.
( 6 ) T u r no nt h eA CG N Ds e r v i c eP W Rs w i t c h( w a i ta p p r o x .2 0m i n ) .
(7) Set the DC external power to the aircraft.
(8) Press the faucet switch to check that a warm water is coming out.
( 9 ) T u r no f ft h eA CG N Ds e r v i c eP W Rs w i t c h .
(10) T urn off AC ground cart.
(11) T urn off DC external power.
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Part B - - - Remaining Rework
NOTE: For ease of removing tape from the taped & stowed wires, heat up tape
using a heat gun and remove tape using a cloth.
(1) Remove existing Nosewheel Steering Control Unit (refer to AMM TASK
32- - -51- - -01- - -000- - -801).
(2) Rework the the LH side console frame using the instructions theat follow: (refer to
drw 8Z9992)
CAUTION: PROTECT WIRING FROM DAMAGE AND FOREIGN OBJECTS DURING
REWORK
NOTE: If ModSum IS4Q5300048 has been incorporated steps (a) thru (e) below
shall be omitted.
(a) Remove existing Nosewheel Steering Hand Control (refer to AMM TASK
32- - -51- - -06- - -000- - -801).
(b) Remove and discard existing label P/N 81171023- - -105.
(c) T est fit hand control steering handle P/N 406330- - -05- - -01 through frame
P/N 85311498- - -131 and check for fouling.
(d) If required open existing 1.75” dia. hole on frame up to 2.00”.
(1) T ouch up bare edges with C1 and F19. (refer to SRM TASKs
5 1 --- 2 1 --- 1 0 --- 0 2 --- 0 1 a n d 5 1 --- 2 5 --- 1 0 --- 0 2 --- 0 1 )
(e) Part mark reworked frame as P/N 8Z9992- - -101. (refer to AMM TASK
20- - -00- - -01- - -910- - -802)
(f) Apply label P/N 81171023- - -107. (refer to AMM TASK
20- - -00- - -16- - -400- - -801)
(3) If necessary, strip and crimp wires on wiring bundle 8Z3023- - -011 (refer to WDM
20- - -17- - -10- - -201).
(4) T erminate and install the shields (refer to WDM 20- - -15- - -00- - -401).
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NOTE: For connector 3251- - -P1 for ease of backshell removal and to prevent
damage to shields, wrap tape around harness to keep harness
compressed.
(5) Remove and discard or tape and stow the applicable cable assembly
8Z9652- - -011 or 8Z9422- - -011 or 8Z6499- - -011 between connector 3251- - -P1 (pins
35, 34, 36) and connector 9811- - -P2 (pins A- - -, B- - -, C- - -).
(6) Locate and reterminate taped & stowed wires 3251- - -W20A- - -22- - -6/BLK,
3251- - -W20A- - -22- - -6/WHT and 3251- - -W20A- - -22- - -6/RED between connector
3251- - -P1 (pins 35, 34, 36) and connector 9811- - -P2 (pins A- - -, B- - -, C- - -)
respectively (Refer to Figure 2, Sheet 1).
NOTE: For ease of removing tape from the taped & stowed wires, heat up tape
using a heat gun and remove tape using a cloth.
(7) If necessary, strip and crimp wires (refer to WDM 20- - -17- - -10- - -201).
(8) T erminate and install the shields (refer to WDM 20- - -15- - -00- - -401).
(9) Remove and discard or tape and stow the applicable cable assembly
8Z9652- - -013 or 8Z9422- - -013 or 8Z6499- - -013 between the connector 3251- - -P1
(pins 27, 29, 28) and connector 9811- - -P2 (pins D- - -, E- - -, F- - -).
(10) Locate and reterminate taped & stowed wires 3251- - -W21A- - -22- - -6/BLK,
3251- - -W21A- - -22- - -6/WHT and 3251- - -W21A- - -22- - -6/RED between the connector
3251- - -P1 (pins 27, 29, 28) and connector 9811- - -P2 (pins D- - -, E- - -, F- - -)
respectively (Refer to Figure 2, Sheet 1).
NOTE: On connector 9811- - -P2, check to see if the pins are installed in D- - -, E- - -
a n d F --- .
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SERVICE BULLETIN 84-32-162
(11) On aircraft with ModSum 4Q126600 incorporated (for PSNs 4001, 4003-4469,
4471-4474, 4477), terminate the provisioned wires 8Z3023-011 between the
connector 3251-P1 (pins 43, 13, 44) and connector 9811-P2 (pins D, E, F)
(Refer to Figure 2, Sheet 1).
FROM  PIN WIRE CODE  END FITTING  _TO  PIN END FITTING
3251-P1  43  W22A-22-6/BLK  M39029/56-348  9811-P2  D  M39029/58-363
3251-P1  13  W22A-22-6/WHT  M39029/56-348  9811-P2  E  M39029/58-363
3251-P1  44  W22A-22-6/RED  M39029/56-348  9811-P2  F  M39029/58-363
3251-P1  SHD  B0816063-003  9811-P2  SHD  B0816063-003
(12) Terminate and install the shields (refer to WDM 20-15-00-401).
(13) On aircraft with ModSum 4Q126600 incorporated (for PSNs 4001, 4003-4469,
4471-4474, 4477), terminate the provisioned wires 823023-019 between the
connector 9811-J2 (pins (pins D, E, F) and connector -P3 (pins 6, 7, 8) (Refer to
Figure 2, Sheet 1 and Sheet 2).
FROM  PIN WIRE CODE  LEND FITTING  TO  [PIN END FITTING
9811-J2  _D  W22B-22-6/BLK  M39029/56-351  3251-P3  6  M39029/56-348
9811-J2  W22B-22-5/WHT  M39029/56-351  3251-P3  M39029/56-348
9811-J2  W22B-22-6/RED  M39029/56-351  3251-P3  8  M39029/56-348
9811-J2  SHD  B0816063-003  3251-P3  ISHD  B0816063-003
(14) Terminate and install the shields (refer to WDM 20-15-00-401).
S.B. 84-32-162
26 Aug 2019  Page 15 of 28
Revision 'B' 13 Nov 2019  FQ

### Page 16

S E R V I C E B U L L E T I N 8 4 --- 3 2 --- 1 6 2
S.B. 84- - -32- - -162
Page 16 of 2826 Aug 2019
FQRevision ‘B’ 13 Nov 2019
(15) On aircraft with ModSums 4Y123998, 4Y124024, 4Y124501 and 4Y124473
incorporated (for PSNs 4470, 4475, 4476, 4478- - -4608), locate and reterminate
the provisioned wires 3251- - -W22A- - -22- - -6/BLK, 3251- - -W22A- - -22- - -6/WHT and
3251- - -W22A- - -22- - -6/RED at connector 3251- - -P1 (pins 43, 13, 44) respectively
(Refer to Figure 3, Sheet 1).
(16) T erminate and install the shields (refer to WDM 20- - -15- - -00- - -401).
(17) On aircraft with ModSums 4Y123998, 4Y124024, 4Y124501 and 4Y124473
incorporated (for PSNs 4470, 4475, 4476, 4478- - -4608), locate and reterminate
the provisioned wires 3251- - -W22D- - -22- - -6/BLK, 3251- - -W22D- - -22- - -6/WHT and
3251- - -W22D- - -22- - -6/RED at connector 3251- - -P3 (pins 6, 7, 8) respectively (Refer
to Figure 3, Sheet 2).
NOTE: On these aircraft wiring at connector 3251- - -P3, is already terminated.
(18) T erminate and install the shields (refer to WDM 20- - -15- - -00- - -401).
(19) Install Nosewheel Steering Electronic Control Unit P/N 406300- - -10- - -01 (refer to
AMM TASK 32- - -51- - -01- - -400- - -801).
NOTE: Do the bonding measurement on the new SCU in accordance with
AMM 51- - -80- - -00- - -760- - -801. Make sure that, the measured value shall
be less than 5.0 milliohms.
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
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S E R V I C E B U L L E T I N 8 4 --- 3 2 --- 1 6 2
S.B. 84- - -32- - -162
Page 17 of 2826 Aug 2019
FQRevision ‘B’ 13 Nov 2019
(20) Install Nosewheel Steering Hand Control P/N 406330- - -05- - -01 (refer to AMM
TASK 32- - -51- - -06- - -400- - -801).
(21) Do the return to service as follows:
(a) Do the operational test of the main battery system (refer to AMM TASK
24- - -32- - -00- - -710- - -801)
(b) Do the operational test of the right DC generator control unit (refer to AMM TASK
24- - -31- - -06- - -710- - -801).
(c) Do the operational test of the nosewheel steering system (refer to AMM TASK
32- - -51- - -00- - -710- - -801).
(d) Do the operational test of the windshield wiper system (refer to AMM TASK
30- - -42- - -00- - -710- - -801).
(e) Do the operational test of the external AC power system (refer to AMM TASK
24- - -41- - -00- - -710- - -801)
NOTE: Only for aircraft with AC external power receptacle in nose per
824CH00114 or 824SO90105.
(f) If option 812CH00003- - -AC ground power heated water service
CR824CH00114 installed, do as follows:
(1) Fill the water tank with potable water using a water fill cart, 20GPM, 40PSIG
maximum (water coming out of the overflow drain must indicates that the
system is full).
(2) Close the CBs as follows:
- - - Right DC C/B panel RIGHT SEC LAV SYSTEM D3
- - - Right DC C/B panel RIGHT ESS EXT PWR LOGIC F8
- - - VAR FREQ C/B panel Phase B LAV HTRS
- - - RCBP BATT PWR BUS AC GND SERVICE BUS L1 (Option
812CH00003)
(3) T urn off the DC and AC external power.
(4) Select all batteries off.
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S E R V I C E B U L L E T I N 8 4 --- 3 2 --- 1 6 2
S.B. 84- - -32- - -162
Page 18 of 2826 Aug 2019
FQRevision ‘B’ 13 Nov 2019
(5) T urn on the AC ground cart and make sure that, AC EXT switch in off
position in the cockpit.
( 6 ) T u r no nt h eA CG N Ds e r v i c eP W Rs w i t c h( w a i ta p p r o x .2 0m i n ) .
(7) Set the DC external power to the aircraft.
(8) Press the faucet switch to check that a warm water is coming out.
( 9 ) T u r no f ft h eA CG N Ds e r v i c eP W Rs w i t c h .
(10) T urn off AC ground cart.
(11) T urn off DC external power.
C. Close Out
(1) Remove all tools and equipment from the work area.
(1) Install nose fuselage door 112AR.
(2) Install panels 112BR and 122AR.
(3) If removed, install crew oxygen bottle (refer to AMM TASK’S
35- - -11- - -01- - -400- - -801 or 35- - -11- - -01- - -400- - - 802).
(4) Re- - -install all panels removed for access.
(5) On incorporation of this ModSum make an entry that conforms to local regulatory
requirements in the applicable logbook(s). If only part of this ModSum is
completed, use only this service bulleti n number as reference and detail exact
limit of work completed. Enter component serial numbers if applicable. Enter this
ModSum number only after complete and functional incorporation of all work
defined in this service bulletin.
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
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### Page 19 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 19 of 32
SERVICE BULLETIN 84-32-162
10  AC PWR
DC PWR
RF SOURCE
DISCRETES
DIGITAL
ANALOG
COMMUNICATIONS
9811-P2  - EMC <
- EMC <
ELECTRONIC CONTROL UNIT
REF
DUAL CHANNEL
CABLE ASS
8Z3023-011
829652-01
8Z9422-011
8z6499-011
8Z9652-013
8Z9422-013
8z6499-013
3251-P1
VIEW LKG AFT RHS  cg5633a01.dg. sk, apr24/2019
Routing of Cable Assembly
Figure 1 (Sheet 1 of 3)
S.B. 84-32-162
26 Aug 2019  Revision 'B' 13 Nov 2019  Page 19 of 28  FQ

### Page 20 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 20 of 32
SERVICE BULLETIN 84-32-162
-77.50  -84.20
- (SIDE CONSOLE)
PILOT HAND CONTROL
9811-P167
Z126.48
3251-P3
2350-TB1
REF
DUAL  _CHANNEL
CABLE  ASSY  W7, W12
8Z3023-019
TO W18 RUN
Z112.00
UP
LKG OUTBD ON CONSOLE, LHS  cg5633a02.dg. sk, apr24/2019
Routing of Cable Assembly
Figure 1 (Sheet 2 of 3)
S.B. 84-32-162
26 Aug 2019  Revision 'B' 13 Nov 2019  Page 20 of 28  FQ

### Page 21 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 21 of 32
SERVICE BULLETIN 84-32-162
STEERING CONTROL UNIT
cg5633a08.dg, sk, may06/2019
Routing of Cable Assembly
Figure 1 (Sheet 3 of 3)
S.B. 84-32-162
26 Aug 2019  Revision 'B' 13 Nov 2019  Page 21 of 28  FQ

### Page 22 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 22 of 32
SERVICE BULLETIN 84-32-162
REFER TO SHEET 2
- NEW WIRING  •-- EXISTING WIRING  * EXISTING WIRING RETERMINATED  > NEW WIRING TAPED & STOWED  W20B-22-6/BLK  W20B-22-6/WHT  W20B-22-6/RED  W21B-22-6/BLK  W21B-22-6/WHT  W21B-22-6/RED  -- W22B-22-6/BLK  W22B-22-6/WHT  -• W22B-22-6/RED
LEGEND  J2  FWD. PRESS. BLKHD. U/FLOOR RHS.
9811-  This sheet is applicable for POST MODSUM 4Q126600
P2  8Z3023-011
W20A-22-6/BLK  W20A-22-6/WHT  U- W20A-22-6/RED  W21A-22-6/BLK  W21A-22-6/WHT  W21A-22-6/RED  W22A-22-6/BLK  W22A-22-6/WHT  W22A-22-6/RED -  (4001, 4003-4469, 4471-4474, 4477).
3251-P1  777 <
STEERING CONTROL UNIT  NOSE BAY  RIGHT SIDE  LOWER  NOTE  cg5631a01.dg. sk, apr24/2019
Wiring Diagram
Figure 2 (Sheet 1 of 2)
S.B. 84-32-162
26 Aug 2019  Revision 'B' 13 Nov 2019  Page 22 of 28  FQ

### Page 23 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 23 of 32
SERVICE BULLETIN 84-32-162
EXISTING WIRING RETERMINATED  > NEW WIRING TAPED & STOWED  HANDWHEEL  CONTROL  POT
3251-P3  00100
₺**·**
NEW WIRING  EXISTING WIRING  RUDDER  PEDAL  CONTROL  POT  W21D-22-6/BLK  W21D-22-6/WHT  W21D-22-6/RED
LEGEND  P203
3251-P2  FWD FLT DECK ABV/FL  TO U/FLOOR DISC LHS  J203  9811  This sheet is applicable for POST MODSUM 4Q126600
FWD CKPT X-OVER, U/FLOOR  P180  W21C-22-6/BLK  W21C-22-6/WHT  W21C-22-6/RED -  (4001, 4003-4469, 4471-4474, 4477).
W20B-22-6/BLK -------------  W20B-22-6/WHT --------------  9811-
W20B-22-6/RED ----  J180  W21B-22-6/BLK -  W21B-22-6/WHT -  W21B-22-6/RED-  W22B-22-6/BLK -  W22B-22-6/WHT  W22B-22-6/RED -  NOTE
REFER TO SHEET 1  cg5631a02.dg. sk. apr24/2019
Wiring Diagram
Figure 2 (Sheet 2 of 2)
S.B. 84-32-162
26 Aug 2019  Page 23 of 28
Revision 'B' 13 Nov 2019  FQ

### Page 24 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 24 of 32
SERVICE BULLETIN 84-32-162
REFER TO SHEET 2
LEGEND  NEW WIRING  ----------- EXISTING WIRING  ................* EXISTING WIRING RETERMINATED  > NEW WIRING TAPED & STOWED  W22B-22-6/BLK  W22B-22-6/WHT  W22B-22-6/RED  FWD. PRESS. BLKHD. U/FLOOR RHS.  This sheet is applicable for POST MODSUMS 4Y 123998, 4Y 124024, 4Y 124501
9811-
W22A-22-6/BLK  W22A-22-6/WHT  W22A-22-6/RED  and 4Y124473 (4470, 4475, 4476, 4478-4608).
3251-P1  777 <
STEERING CONTROL UNIT  NOTE
NOSE BAY  RIGHT SIDE  LOWER  cg5632a01.dg, sk. apr24/2019
Wiring Diagram
Figure 3 (Sheet 1 of 2)
S.B. 84-32-162
26 Aug 2019  Page 24 of 28
Revision 'B' 13 Nov 2019  FQ

### Page 25 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 25 of 32
SERVICE BULLETIN 84-32-162
* EXISTING WIRING RETERMINATED  > NEW WIRING TAPED & STOWED  3251-P3  HANDWHEEL  CONTROL  POT
- NEW WIRING  - EXISTING WIRING  -- W22D-22-6/BLK  - W22D-22-6/WHT  -- W22D-22-6/RED -  This sheet is applicable for POST MODSUMS 4Y 123998, 4Y 124024, 4Y124501
LEGEND  P203
9811-  J203  FWD FLT DECK ABV/FL  TO U/FLOOR DISC LHS  and 4Y124473 (4470, 4475, 4476, 4478-4608).
•- W22C-22-6/BLK  - W22C-22-6/WHT --1  - - W22C_22_6/RED --
P180  FWD CKPT X-OVER, U/FLOOR
9811-
J180  W22B-22-6/BLK -  :: :  W22B-22-6/WHT--  W22B-22-6/RED--  NOTE  cg5632a02.dg. sk. apr24/2019
REFER TO SHEET 1
Figure 3 (Sheet 2 of 2)
S.B. 84-32-162
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S E R V I C E B U L L E T I N 8 4 --- 3 2 --- 1 6 2
S.B. 84- - -32- - -162
Page 26 of 2826 Aug 2019
FQRevision ‘B’ 13 Nov 2019
View of 9811- - - J2 Bulkhead Connector
F i g u r e4( S h e e t1o f2 )
9811- -J2
View looking FWD on Pressure Bulkhead
- - Location copilot side fwd access panel
located top right
View looking Aft on Pressure Bulkhead
- - Location copilot side fwd access panel
9811- -J2
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
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### Page 27 (OCR)

DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC VSB 406300-32-142 & 406330-32-143_Jun 24/19 Page 27 of 32
SERVICE BULLETIN 84-32-162
00800
SHEEP CLEAN AND FREEOF ALL
REFER TO CHAPTER 12-10-35 DHC
Tape and stowed provisional  RECHARGING INSTRUCTIONS
wires have shrink sleeve over  2 CREW - 1300 PSI MIN CHARGE
pins. To remove shrink sleeve
without damaging wires, appy
heat then using a cloth pull the
shrink sleeve out of the pin
STE NEL
KEEP CI  OILS AN  REFER TO  MAINTE  RECE
Removing Shrink Sleeve From Provisional Pins
Figure 4 (Sheet 2 of 2)
S.B. 84-32-162
26 Aug 2019  Page 27 of 28
Revision 'B' 13 Nov 2019  FQ

### Page 28

S E R V I C E B U L L E T I N 8 4 --- 3 2 --- 1 6 2
S.B. 84- - -32- - -162
Page 28 of 2826 Aug 2019
FQRevision ‘B’ 13 Nov 2019
This Page Intentionally Blank.
1
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
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### Page 29

Landing Systems - Landing Gear
Goodrich Aerospace Canada Ltd
1400 South Service Road West
Oakville, Ontario L6L 5Y7
Canada 
Tel: +1 905 825 1515
Fax: +1 905 825 1583
www.customers.utcaerospacesystems.com
CAGE: 02121
SERVICE BULLETIN
Page 1 of 2
Jun 24/19
EXPORT CLASSIFICATION
U.S. Export Classification: EAR ECCN - 9E991   EIPA Export Classification: NSCanR
PROPRIETARY INFORMATION
THIS DOCUMENT IS THE PROPERTY OF UTC AEROSPACE SYSTEMS. YOU MAY NOT POSSESS, USE, COPY OR DISCLOSE THIS DOCUMENT OR ANY
INFORMATION IN IT, FOR ANY PURPOSE, INCLUDING WITHOUT LIMITATION, TO DESIGN, MANUFACTURE OR REPAIR PARTS, OR OBTAIN ANY
GOVERNMENT APPROVAL TO DO SO, WITHOUT UTC AEROSPACE SYSTEM' S EXPRESS WRITTEN PERMISSION. NEITHER RECEIPT NOR POSSESSION OF
THIS DOCUMENT ALONE, FROM ANY SOURCE, CONSTITUTES SUCH PERMISSION . POSSESSION, USE, COPYING OR DISCLOSURE BY ANYONE WITHOUT
UTC AEROSPACE SYSTEM'S EXPRESS WRITTEN PERMISSION IS NOT AUTHO RIZED AND MAY RESULT IN CRIMINAL AND/OR CIVIL LIABILITY.
406300-32-142
DASH 8 Q400
NOSE LANDING GEAR - ST EERING CONTROL UNIT -
INTRODUCTION OF NEW STEERING CONT ROL UNIT COMPLEMENTARY WITH 
DUAL CHANNEL PILOT HAND CONTROL UNIT
1. PLANNING INFORMATION
A. Effectivity
All P/N 406300-03/-04/-05/-06 Nosewheel Steering Control Units manufactured by BAE
Systems Aircraft Controls Inc.
B. Concurrent Requirements
UTC Aerospace Systems Service Bulletin 406330-32-143.
C. Reason
The single channel pilot hand control unit may fail in a way such that an un-commanded
control signal is not detected as invalid by the steering control unit. A new steering
control unit is introduced in conjunction with the new dual channel pilot hand control un it.
D.
Description
A new steering control unit incorporates changes to accommodate the new dual channel
pilot hand control unit and eliminates the resistors installed in the aircraft wiring harness
(ref. SB 84-32-162). The new steering control unit replaces all previous configurations of
the steering control unit.
E. Compliance Recommendation
Incorporation per Operator discretion, TCCA AD pending.
F. Approval
The technical content of this service bul letin has been reviewed and accepted by De
Havilland Aircraft of Canada Limited.
G. Manpower
Not applicable.
H. Weight and Balance
Not applicable.
I. Electrical Load Data
Not applicable.
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
Page 29 of 32

### Page 30

Page 2 of 2
Jun 24/19
UTC AEROSPACE SYSTEMS PROPRIETARY 
U.S. Export Classification: EAR ECCN - 9E991 
EIPA Export Classification: NSCanR
406300-32-142
J. Software Accomplishment Summary
Does not apply.
K. References
De Havilland Aircraft of Canada Limited MODSUM 4N126579
L. Other Publications Affected
BAE Systems Component Main tenance Manual 32-50-03.
M. Interchangeability of Parts
Refer to aircraft bulletin.
2. MATERIAL INFORMATION
A. Material Cost & Availability
Refer to Goodrich Landing Gear Serv ice Information Letter (SIL) 02121-32-53 for
material cost and availability related to this Service Bulletin.
B. Material Required for each component
3. ACCOMPLISHMENT INSTRUCTIONS
A. Nosewheel Steering Control Unit Removal and Installation.
Refer to De Havilland Aircraft of Canada Limited Service Bulletin 84-32-162.
NEW PART NO.
QTY 
PER 
UNIT
KEYWORD OLD PART NO. DISPOSITION
406300-10-01 1 Control Unit 406300-03/-04/-05/-
06
Destroy
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19 
Page 30 of 32

### Page 31

Landing Systems - Landing Gear
Goodrich Aerospace Canada Ltd
1400 South Service Road West
Oakville, Ontario L6L 5Y7
Canada 
Tel: +1 905 825 1515
Fax: +1 905 825 1583
www.customers.utcaerospacesystems.com
CAGE: 02121
SERVICE BULLETIN
Page 1 of 2
Jun 24/19
EXPORT CLASSIFICATION
U.S. Export Classification: EAR ECCN - 9E991   EIPA Export Classification: NSCanR
PROPRIETARY INFORMATION
THIS DOCUMENT IS THE PROPERTY OF UTC AEROSPACE SYSTEMS. YOU MAY NOT POSSESS, USE, COPY OR DISCLOSE THIS DOCUMENT OR ANY  
INFORMATION IN IT, FOR ANY PURPOSE, INCLUDING WITHOUT LIMITATION, TO DESIGN, MANUFACTURE OR REPAIR PARTS, OR OBTAIN ANY  
GOVERNMENT APPROVAL TO DO SO, WITHOUT UTC AEROSPACE SYSTEM' S EXPRESS WRITTEN PERMISSION. NEITHER RECEIPT NOR POSSESSION OF  
THIS DOCUMENT ALONE, FROM ANY SOURCE, CONSTITUTES SUCH PERMISSION . POSSESSION, USE, COPYING OR DISCLOSURE BY ANYONE WITHOUT  
UTC AEROSPACE SYSTEM'S EXPRESS WRITTEN PERMISSION IS NOT AUTHO RIZED AND MAY RESULT IN CRIMINAL AND/OR CIVIL LIABILITY.
406330-32-143
DASH 8 Q400
NOSE LANDING GEAR - PI LOT HAND CONTROL UNIT -
INTRODUCTION OF DUAL CHANNEL PILOT HAND CONTROL UNIT 
1. PLANNING INFORMATION
A. Effectiv ity
All P/N 406330-03/-04 Nose Wheel Steering Pilot Hand Control Units manufactured by  
BAE Systems Aircraft Controls Inc.
B. Concurrent Requirements
UTC Aerospace Systems Service Bulletin 406300-32-142.
C. Reason
The single channel hand control unit may fail in a way such that an un-commanded  
control 
signal is not detected as invalid by the steering control unit.
D. Description
A new dual channel pilot hand control unit, with  t wo potentiometers, replaces all previous 
configurations of pilot hand control unit.
E. Compliance Recommendation
Incorporation per Operator discretion, TCCA AD pending.
F. Approval
The technical content of this service bul letin has been  reviewed and accepted by De  
Havilland Aircraft of Canada Limited.
G. Manpower
Not applicable.
H. Weight and Balance
Incorporation of this bulletin results in a 0.3 pound (0.14 kg) increase.
I. Electrical Load Data
Not applicable.
J. Software Accomplishment Summary
Does not apply.
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
Page 31 of 32

### Page 32

Page 2 of 2
Jun 24/19
UTC AEROSPACE SYSTEMS PROPRIETARY 
U.S. Export Classification: EAR ECCN - 9E991 
EIPA Export Classification: NSCanR
406330-32-143
K. References
De Havilland Aircraft of Canada Limited MODSUM 4N126579.
L. Other Publications Affected
BAE Systems Component Main tenance Manual 32-50-04.
M. Interchangeability of Parts
Refer to aircraft bulletin.
2. MATERIAL INFORMATION
A. Material Cost & Availability
Refer to Goodrich Landing Gear Serv ice Information Letter (SIL) 02121-32-53 for  
material cost and availability related to this Service Bulletin.
B. Material Required for each component
3. ACCOMPLISHMENT INSTRUCTIONS
A. Nose wheel Pilot Hand Control Unit Removal and Installation.
Refer to De Havilland Aircraft of Canada Limited Service Bulletin 84-32-162.
NEW PART NO.
QTY 
PE
R 
UNIT
KEYWORD OLD PART NO. DISPOSITION
406330-05-01 1 Control Unit 406330-03/-04 Destroy
DHC Merged Document SB 84-32-162B 13 Nov 2019 & UTC  VSB 406300-32-142 & 406330-32-143_Jun 24/19
Page 32 of 32

---
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