Bombardier Service Bulletin 84-54-14

Revision ‘K’ 07 Aug 2018 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 --- 1 4 Nacelles - - - Rear Spar Attachment Fitting P/N 85414663- - - *** - - - Special Inspection and Rectification This page transmits Revision ‘K’ of Service Bulletin 84- - -54- - -14, pages 1 thru 26, dated 07 Aug 2018.

This service bulletin is re- - -issued in its entirety for the reasons that follow:

--- t h eEffectivity section has been revised from ‘4001 thru 4999’ to ‘4001, 4003, 4004, 4006, 4008 thru 4380’ and to add two notes --- t h eReason section is revised to remove reference to SB 84- - -54- - -15 and add reference to SB 84- - -54- - -16.

--- t h eDescription section is revised to remove reference to SB 84- - -54- - -15 and add reference to SB 84- - -54- - -16.

- - - components of theCompliance section are revised to reflect the changes in the Effectivity section. Also, an AD statement is added --- t h eManpower section is revised to remove reference to SB 84- - -54- - -15 and add reference to SB 84- - -54- - -16.

--- t h eReferences section is revised to convey the latest revision of the service bulletin and engineering documentation

- - - several locations inProcedure section are revised to remove reference to S B 8 4 --- 5 4 --- 1 5 a n d a d d r e f e r e n c e t o S B 8 4 --- 5 4 --- 1 6 f o r f i t t i n g r e p l a c e m e n t --- t h eClose Out section is revised to add a Note The Compliance in the previous issue(s) of this service bulletin is affected by this revision. Additional rework to the aircraft is introduced by this revision.

Remove the previous revision of Service Bulletin 84- - -54- - -14 and replace with attached.

Previous issue(s) of Service Bulletin 84- - -54- - -14:

Initial issue - - - Pages 1 thru 16 dated 16 Apr 2010 Revision ‘A’ - - - Pages 1 thru 16 dated 22 Apr 2010

Revision ‘B’ - - - Pages 1 thru 16 dated 11 Jun 2010 Revision ‘C’ - - - Pages 1 thru 16 dated 30 Jun 2010 Revision ‘D’ - - - Pages 1 thru 15 dated 05 Jul 2010 Revision ‘E’ - - - Pages 1 thru 22 dated 19 Aug 2010 Revision ‘F’ - - - Pages 1 thru 22 dated 20 Aug 2010 Revision ‘G’ - - - Pages 1 thru 22 dated 09 Sep 2010 Revision ‘H’ - - - Pages 1 thru 22 dated 10 Sep 2010 Revision ‘J’ - - - Pages 1 thru 24 dated 17 Sep 2010

D S . B . 8 4 --- 5 4 --- 1 4 Page 1 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM

SERVICE BULLETIN Customer Support ATA SYSTEM: 5431 NUMBER: 84- - -54- - -14

BOMBARDIER AEROSPACE CONSIDER THIS

SERVICE BULLETIN TO BE PARTICULARL Y SIGNIFICANT AND

URGE OPERATORS TO PROMPTL Y EVALUATE THE CONTENTS SUBJECT : Nacelles - - - Rear Spar Attachment Fitting P/N 85414663- - - *** - - - Special Inspection and Rectification

1. PLANNING INFORMA TION A. Effectivity Aircraft Affected:

In- - -Service: DHC- - -8 Aircraft Models 401 and 402 Serial Numbers 4001, 4003, 4004, 4006, 4008 thru 4380.

NOTE: For S/N 4003, 4004, 4006, 4008 thru 4380, if the fittings have been replaced per SB 84- - - 54- - - 15 (refer to previous revisions of this SB) fittings must be replaced per SB 84- - - 54- - - 16. No further inspections are required when the SB 84- - - 54- - - 16 is accomplished. Please note that SB 84- - - 54- - - 15 is now superceded by the SB 84- - - 54- - - 16.

NOTE: SB 84- - - 54- - - 16 is the terminating action to this SB 84- - - 54- - - 14.

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 2 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM 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 of the Q400 aircraft have reported finding cracked rear spar attachment fittings p/n 85414663 (refer to Figure 4 thru 7). Multiple cracks were found during a normal visual inspection (refer to Figure 1).

Cause: The cause of the problem is related to Stress Corrosion Cracking (SCC).

Solution: This service bulletin gives the instructions to do a detailed visual inspection and a conductivity test of each attachment fitting p/n 85414663 (qty. 2 per nacelle, inboard and outboard side). If any attachment fitting is determined to be cracked or the conductivity of any fitting is outside specified limits, follow instructions contained within this SB. Replacement instructions are a v a i l a b l e i n S B 8 4 --- 5 4 --- 1 6 .

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 to gain accessto each attachment fitting p/n 85414663 (left and right side in each nacelle)

- - - each attachment fitting (inboard and outboard) is located and is prepared (cleaned) for inspection

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 3 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM

- - - a detailed visual inspection is accomplished followed by a conductivity test (if required) with specific attention required at zones identified on Figure 1, Sheet 1 and Figure 2 in region of Note 1. All results to be recorded and passed to BA for evaluation

- - - if any attachment fitting is found to be cracked or the conductivity is outside specified limits the fitting must be replaced. Replacement instructions are available in SB 84- - -54- - -16. Contact Bombardier Aerospace for additional instructions

- - - If the fitting is cracked, a ferry flight may be supported, but the conditions must be reviewed by Bombardier on a case by case basis

- - - close out.

D. Compliance Bombardier Inc. highly recommends that opera tors inspect their aircraft to determine the condition of each rear spar attachment fitting p/n 85414663- - -*** (qty. 2 attachment fittings in each nacelle) as follows:

For S/N 4003, 4004, 4006, 4008 thru 4304 a detailed visual inspection and a conductivity check are required within 100 flight hours upon receipt of this service bulletin.

For S/N 4305 thru 4313 and 4316 thru 4380 a threshold detailed visual inspection is required for A/C with a T .A.T . (T otal Airframe Time) of 1200 hours or greater.

For S/N 4003, 4004, 4006, 4008 thru 4380 if the fitting has been replaced thru SB 84- - -54- - -15, then the initial detailed visual inspection is not required for 1200 flight hours from the time of replacement for that fitting only.

For S/N 4003, 4004, 4006, 4008 thru 4313 and 4316 thru 4380, after the first detailed visual inspection, a repeat detailed visual inspection is required every 300 flight hours for each fitting, including all fittings already replaced.

For S/N 4314 and 4315 a repeat detailed visual inspection is required every 300 flight hours. A threshold detailed visual inspection does not apply to the fittings initially installed on these aircraft. Threshold inspection is not applicable because conductivity reading taken by Bombardier show reading between 38.0 % IACS but less than 40.0 % IACS.

For S/N 4003, 4004, 4006, 4008 thru 4380, if the fittings have been replaced per SB 84- - -54- - -16, no further action is required.

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 4 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM For S/N 4003, 4004, 4006, 4008 thru 4380, if the fittings have been replaced per SB 84- - -54- - -15, fittings must be replaced per 84- - -54- - -16. No further inspections are r e q u i r e d w h e n t h e S B 8 4 --- 5 4 --- 1 6 i s a c c o m p l i s h e d .

Transport Canada Airworthiness Directive CF- - -2010- - -30R1 has been issued.

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 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 3.0 man- - -hours to inspect / record the condition of all 4 attachment fittings p/n 85414663.

Manpower to replace each attachment fitting assembly p/n 85414663 is specified in S e r v i c e B u l l e t i n 8 4 --- 5 4 --- 1 6 .

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 None H. T ooling - - - Price and Availability None I. Weight and Balance Not affected

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 5 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM J. Electrical Load Data Not affected K. Publications Affected None L. References Revision ‘K’ of this service bulletin was prepared to the engineering drawings and related data that follows:

PCR 43228 Revision 1 (for internal reference only) Transport Canada Airworthiness Directive CF- - -2010- - -30R1 PSM 1- - -84- - -7A Nondestructive T esting Manual ModSum IS4Q5400012

2. MATERIAL INFORMA TION A. Parts Required Per Aircraft

(1) Detailed Parts List:

Quantity Per Aircraft Part Number Description 4 85414663- - -*** Attachment Assembly (fitting), Rear Spar B. Parts Required to Modify Spares None C. Special T ools and Equipment Required Refer to Page 9 of this service bulletin, Procedure to Measure the Conductivity of the

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 6 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM Nacelle Fittings, Para B., C. and D.

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 85414663- - -*** Attachment Assembly (fitting), Rear Spar No. 1 Nacelle 2 C DIS 85414663- - -*** S 85414663- - -*** Attachment Assembly (fitting), Rear Spar - - - No.2 Nacelle 2 C DIS 85414663- - -*** S IC Interchangeability Code A Not interchangeable.

B Removed Part. 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.

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 7 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM PNC Part Number Code N No equivalent Bombardier Inc. 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 Bombardier in the CRC at 1- - -844- - -272- - -2720 (1- - -844- - -CRC- - -CRCO) or email at thd.qseries@aero.bombardier.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 THAT ALL HYDRAULIC AND ELECTRICAL POWER IS OFF . MAKE SURE THAT LOCKPINS ARE INSTALLED IN THE DOOR

MECHANISMS AND THE MAIN LANDING GEAR BEFORE YOU DO MAINTENANCE IN OR AROUND THE MAIN GEAR WHEEL. THE

DOOR MECHANISMS CAN ACCIDENTL Y CLOSE, THE LANDING

GEAR CAN ACCIDENTL Y RETRACT AND CONTROL SURFACES COULD MOVE. INJURY TO PERSONNEL AND/OR DAMAGE TO EQUIPMENT CAN OCCUR.

(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.

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 8 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM

(5) Make sure that the hydraulic system is de- - -pressurized.

(6) Position a ladder or a workstand behind the rear spar adjacent the left and right side of the No.1 and or No.2 nacelle to permit access to each attachment fitting p/n 85414663. Make sure the ladder or workstand is electrically grounded.

(7) Remove the access panels that follow (refer to AMM TASK 06- - -41- - -00- - -992- - -806 f o r l o c a t i o n o f p a n e l s a n d A M M T A S K 5 4 --- 2 1 --- 0 6 --- 0 0 0 --- 8 0 1 f o r r e m o v a l instruction).

ACCESS DESIGNATION 413BL Panel, Access, Rear Spar 413BR Panel, Access, Rear Spar 423BL Panel, Access, Rear Spar 423BR Panel, Access, Rear Spar B. Procedure Part A - - - Inspection

(1) Locate each attachment fitting p/n 85414663 in the No.1 and No.2 nacelle. Clean all debris and unwanted materials from ea ch attachment fitting before conducting the inspection . Make sure that each fitting is clean and any visible fay sealant is removed prior to inspection (refer to Figure 2, Sheet 1).

(2) Using adequate lighting and a magnifier lens (and/or optional use of borescope) do a detailed visual inspection of each atta chment fitting as required (from within the nacelle and externally thru the area of the removed access panel). Pay special attention in areas of sloping strut attachment (refer to Figure 1 and area marked as Figure 2, Sheet 1 in region of Note 1).

If there are any signs of cracking, remove and replace part in accordance with SB 84- - -54- - -16 before next flight. Refer to Figure 3 thru Figure 7 for typical crack locations. Inspections are not limited to typical crack locations, the suspected part should be fully DVI inspected to the extent that is practical without disassembly.

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 9 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM

(3) For Aircraft Serial Numbers 4001 thru 4304, measure and record the conductivity in accordance with the enclosed Procedure to Measure the Conductivity of the Nacelle Fittings on each attachment fitting 85414663 as follows: (2 per nacelle, 4 per aircraft) (refer to Figure 2, Sheet 4 & 5). For Aircraft Serial Numbers 4305 thru 4999 electrical conductivity inspection is not required because conductivity readings have been confirmed by Bombardier, and subsequently, it is not necessary to repeat conductivity measurements.

PROCEDURE TO MEASURE THE CONDUCTIVITY OF THE NACELLE FITTINGS A. Purpose

1.Conductivity measurements as required by SB 84- - -54- - -14 B. Equipment

1. Bombardier Aerospace used the following equipment for conductivity measurements:

a) Instrument Phasec 2200, Eddy current with co nductivity measurement capability, made by Hocking

b) Eddy current probe 47P001, 60kHz, made by Hocking

c) Cable 33A135, made by Hocking

d) Calibration standards (secondary) made by Fischer T echnology Inc. 45.33% IACS and 28.71% IACS (”A ” standards)

e) Calibration standard (secondary) made by Fischer T echnology Inc. 39.54%IACS (”B” standard)

f) DIGI TEMP 16 Level Thermometers, range 10- - -40 degrees C made by LCR Hallcrest

g) Instrument instruction manual C. Equivalent Equipment

1. Instruments

a) Conductivity meters or eddy current instruments, probes and cable combinations with or without temperature sensor that meet the following requirements:

I. Measure conductivity at 60kHz II. Display the conductivity as a numerical value to at least one decimal place III. Can be calibrated using at least two conductivity standards (”A ” standards) IV . Can measure a third standard within the accuracy specified by the conductivity standard manufacturer (”B” standard)

S E R V I C E B U L L E T I N 8 4 --- 5 4 --- 1 4 S . B . 8 4 --- 5 4 --- 1 4 Page 10 of 26 16 Apr 2010 Revision ‘K’ 07 Aug 2018 MG/PM NOTE: Conductivity meters with a temperature sensor are preferred.

These instruments are available free of charge from Bombardier Aerospace T oronto, In - - - Service Engineering

2. Calibration standards

a) T wo ”A ” standards (secondary standards only) as follows:

I. One that has the conductivity equal to or less than 30% IACS. Calibration standards with the conductivity in the range of 25% IACS to 30% IACS are preferred II. The other standard must have the conductivity equal to or greater than 41% IACS.

Calibration standards with conductivity in the range of 41% IACS to 50% IACS are preferred.

NOTE: The secondary standards are stand ards that are certified by the standards manufacturer. The conductivity value of the standards must have a trueness of 0.35% IACS or 1% of the measured conductivity value, whichever is less at 20 degrees C

b) One ”B” standard made of aluminum (secondary or Bombardier certified standards) with conductivity between 37% IACS and 40% IACS NOTE: Bombardier certified standards are certified by comparison to the secondary standards. These standards are available free of charge from Bombardier Aerospace T oronto, In - - - Service Engineering NOTE: All equipment and calibration standards must have a valid certificate of calibration D. Preparation

1. Clean all inspection surfaces with approved materials and according to an approved method until clean paint can be seen. Refer to Structural Repair Manual (SRM), Ch 51 (PSM 1- - -84- - -3)

2. Inspect the paint. No flakes, bumps or obvious unevenness is allowed at the points of measurement. Uneven surface, flakes and bumps in the paint may result in erroneous results. These conditions may be removed by lightly abrading the inspection surface using Scotch- - -Brite NOTE: If improvement in the inspection surface cannot be achieved, remove the paint.

3. If cracks are detected during preparation, remove and replace fitting in accordance with SB 84- - -54- - -16.