1. NDT INSPECTION A300 / A300-600 FR 47 upper radius
1. A319 / A320 / A321 STRUCTURE DESCRIPTION
1.3. FUSELAGE
SECTION 15 - CENTER FUSELAGE
Layout
Construction
Upper Region
Lower Fuselage assembly
Keel Beam
Slanded Panels
Pressure Boundaries
Floor Structure / Seat Rails
NDT INSPECTION
MENU
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2. UNDER NO CIRCUMSTANCE THE CD CONTENT SHOULD NOT SUPERSEDE
INTRODUCTION
SECTION 15 - CENTER FUSELAGE
general layout
The fuselage center section extends from frame 35 to frame 47 for A320, (from frame 35.8 to frame 47 for A321 and frame 35 to frame 47/51 for A319).
The purpose of this CD ROM is to assist NDT inspectors in
carrying out:
- FR 47 Upper radius inspection -
As per:
A300 NTM ( SB ) Or
A NTM (SB )
NOTE:
UNDER NO CIRCUMSTANCE THE CD CONTENT SHOULD NOT SUPERSEDE
THE NTM PROCEDURE OR
THE SERVICE BULLETIN
MENU
EXIT

3. FR 47 DESCRIPTION FR 47 FRONT FACE FR 47 REAR FACE CABIN CABIN FR47
Construction Gneeral
The section 15 provides part of the passenger cabin in the upper region and, beneath the floor, the air conditioning, hydraulic and main landing gear bays, together with the integration structure for the center wing box.
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
On the external surfaces, all around the wing profile attachment, provision is made for the belly fairing structure.
COMPARISON WITH A321
Section 15 of the A321 uses the same design principles as those employed for A320:
- moving of emergency exits in section 14A/16A,
- modified lower/upper lateral panels,
- changes of wing root cruciform shape,
- new thicknesses for most of the elements.
COMPARISON WITH A319
- deletion of one emergency exit.
FR 47 REAR FACE
CABIN
CABIN
FR47
Front side (LH)
CENTER TANK
WING TANK
CABIN
INSPECTED AREA
MLG BAY
WING TANK
CENTER TANK
MENU
EXIT

4. PICTURE OF UNASSEMBLED PART GIVEN FOR BETTER UNDERSTANDING
POSSIBLE DAMAGE
Construction Gneeral
The section 15 provides part of the passenger cabin in the upper region and, beneath the floor, the air conditioning, hydraulic and main landing gear bays, together with the integration structure for the center wing box.
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
On the external surfaces, all around the wing profile attachment, provision is made for the belly fairing structure.
COMPARISON WITH A321
Section 15 of the A321 uses the same design principles as those employed for A320:
- moving of emergency exits in section 14A/16A,
- modified lower/upper lateral panels,
- changes of wing root cruciform shape,
- new thicknesses for most of the elements.
COMPARISON WITH A319
- deletion of one emergency exit.
FR47
FRONT face
CRACK
LH SIDE
“A”
FR47
SIDE VIEW
“A”
CRACK
CRACK
LH SIDE
FR47
BACK face
“A”
PICTURE OF UNASSEMBLED PART GIVEN FOR BETTER UNDERSTANDING
Fatigue cracks emanating from the upper radius and propagating through the frame 47
MENU
EXIT

5. INSPECTION AREAS KEEL DOUBLER EDDY CURRENT FR 47 FUSELAGE LH side FWD
Construction Gneeral
The section 15 provides part of the passenger cabin in the upper region and, beneath the floor, the air conditioning, hydraulic and main landing gear bays, together with the integration structure for the center wing box.
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
On the external surfaces, all around the wing profile attachment, provision is made for the belly fairing structure.
COMPARISON WITH A321
Section 15 of the A321 uses the same design principles as those employed for A320:
- moving of emergency exits in section 14A/16A,
- modified lower/upper lateral panels,
- changes of wing root cruciform shape,
- new thicknesses for most of the elements.
COMPARISON WITH A319
- deletion of one emergency exit.
KEEL DOUBLER
FUSELAGE
LH side
EDDY CURRENT
WING
FWD
FR 47
KEEL DOUBLER
MENU
EXIT

6. INSPECTION AREAS NTM ULTRASONIC CABIN Click here to play again MENU
Construction Gneeral
The section 15 provides part of the passenger cabin in the upper region and, beneath the floor, the air conditioning, hydraulic and main landing gear bays, together with the integration structure for the center wing box.
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
On the external surfaces, all around the wing profile attachment, provision is made for the belly fairing structure.
COMPARISON WITH A321
Section 15 of the A321 uses the same design principles as those employed for A320:
- moving of emergency exits in section 14A/16A,
- modified lower/upper lateral panels,
- changes of wing root cruciform shape,
- new thicknesses for most of the elements.
COMPARISON WITH A319
- deletion of one emergency exit.
ULTRASONIC
CABIN
Click here
to play again
MENU
EXIT

7. INSPECTION AREAS NTM KEEL DOUBLER LATERAL PANEL CABIN CTR TANK
Construction Gneeral
The section 15 provides part of the passenger cabin in the upper region and, beneath the floor, the air conditioning, hydraulic and main landing gear bays, together with the integration structure for the center wing box.
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
On the external surfaces, all around the wing profile attachment, provision is made for the belly fairing structure.
COMPARISON WITH A321
Section 15 of the A321 uses the same design principles as those employed for A320:
- moving of emergency exits in section 14A/16A,
- modified lower/upper lateral panels,
- changes of wing root cruciform shape,
- new thicknesses for most of the elements.
COMPARISON WITH A319
- deletion of one emergency exit.
KEEL DOUBLER
LATERAL PANEL
CABIN
CTR TANK
WING TANK
RIB1
MENU
EXIT

8. ACCESS EC INSPECTION - FAIRINGS REMOVED LH side KEEL DOUBLER
Construction Gneeral
The section 15 provides part of the passenger cabin in the upper region and, beneath the floor, the air conditioning, hydraulic and main landing gear bays, together with the integration structure for the center wing box.
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
On the external surfaces, all around the wing profile attachment, provision is made for the belly fairing structure.
COMPARISON WITH A321
Section 15 of the A321 uses the same design principles as those employed for A320:
- moving of emergency exits in section 14A/16A,
- modified lower/upper lateral panels,
- changes of wing root cruciform shape,
- new thicknesses for most of the elements.
COMPARISON WITH A319
- deletion of one emergency exit.
EC INSPECTION
- FAIRINGS REMOVED
LH side
KEEL DOUBLER
US INSPECTION
LH side
FRAME 47
FRAME 47
WING TOP SURFACE
Inspection area
Inspection area
FWD
- FLOORS PANELS REMOVED
- PIPES REMOVED
CABIN FLOOR
MENU
EXIT

9. INSPECTION FLOW- CHART
EDDY CURRENT
INSPECTION
Upper Region
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
FRAMES
Typical frames in the pressurized area are only machined in their lower region, up to stringer 18 for frames 37, 43, 45 and 46 and up to stringer 8 for the emergency exit door frames. In their upper region these frames are formed from sheet metal.
At the interface with sections 13/14 and 17, frames 35 and 47 are machined up to stringer 29.
Frames 36 and 42, which provide attachment for the center wing box to the center fuselage, are completely machined.
SKINS AND STRINGERS
In the upper region and in the landing gear bay area skin panels are chemically lilled and have riveted stringers. In addition a riveted machined doubler reinforces the emergency exits cut-outs.
In the lower region, the panel riveted to the keel beam is integrally machined.
L < 8 mm (0.314 in)
CRACK
L > 8 mm (0.314 in)
ULTRASONIC
INSPECTION SB
Re-inspection
at xxx FC
MENU
EXIT

10. ULTRASONIC INSPECTION EDDY CURRENT INSPECTION
INSPECTION METHODS
Upper Region
In the upper region the structure incorporates the necessary reinforcements to allow for the installation of two type III emergency exits on each side, between frame 38 and 41 for A320 and none for A319.
FRAMES
Typical frames in the pressurized area are only machined in their lower region, up to stringer 18 for frames 37, 43, 45 and 46 and up to stringer 8 for the emergency exit door frames. In their upper region these frames are formed from sheet metal.
At the interface with sections 13/14 and 17, frames 35 and 47 are machined up to stringer 29.
Frames 36 and 42, which provide attachment for the center wing box to the center fuselage, are completely machined.
SKINS AND STRINGERS
In the upper region and in the landing gear bay area skin panels are chemically lilled and have riveted stringers. In addition a riveted machined doubler reinforces the emergency exits cut-outs.
In the lower region, the panel riveted to the keel beam is integrally machined.
ULTRASONIC
INSPECTION
EDDY CURRENT
INSPECTION
MENU
EXIT

11. EDDY CURRENT INSPECTION
Upper Region (cont’d)
A320 Emergency exit reinforcing panel (thickness examples)
SRM identification page extract.
EDDY CURRENT
INSPECTION
MENU
EXIT

12. EDDY CURRENT INSPECTION
Upper Region (cont’d)
A320 Emergency exit reinforcing panel (thickness examples)
SRM identification page extract.
Fatigue cracks emanating from the upper radius of frame 47
DAMAGE
MENU
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13. EDDY CURRENT INSPECTION EQUIPMENT AND MATERIALS
Upper Region (cont’d)
Details
Frame 42 details
A . The equipment used in the development of this procedure is as follows :
(1) Instrument : LOCATOR Type UH from HOCKING
(2) Probe : 206P4F, NFe, Shielded, 2MHz from HOCKING
(3) Calibration Standard : Al 29A029 from HOCKING
NOTE :Any comparable Eddy Current equipment may be used provided that it satisfies the requirements of this
procedure and is capable of resolving the reference slot in the calibration standard at the required level of
resolution.
EQUIPMENT AND MATERIALS
MENU
EXIT

14. EDDY CURRENT INSPECTION
Upper Region (cont’d)
Details
Frame 42 details
A . Set the required frequency (2 MHz).
B . Use the calibration standard Al 29A029 to calibrate the instrument for lift off and zero,
in accordance with the manufacturer’s instructions.
C . Position the probe directly over the 1 mm (0.039 in.) slot in the calibration standard
and adjust the instrument sensitivity so that the meter needle is at 100% of full scale.
CALIBRATION
MENU
EXIT

15. EDDY CURRENT INSPECTION
NTM
Upper Region (cont’d)
Details
Frame 42 details
Click here
to play again
- Position the probe near to the inspection area and adjust lift-off and zero as necessary.
- Carry out the inspection using the probe position and scanning movement as illustrated.
INSPECTION
MENU
EXIT

16. EDDY CURRENT INSPECTION
Upper Region (cont’d)
Details
Frame 42 details
CRACK
CRACK
CRACK
-A crack will be indicated by a sharp meter needle deflection to the right  25% of full scale.
INSPECTION
MENU
EXIT

17. EDDY CURRENT INSPECTION ULTRASONIC INSPECTIONSB
Upper Region (cont’d)
Details
Frame 42 details
CRACK
FWD
L < 8 mm (0.314 in)
Re-inspect L
L > 8 mm (0.314 in) L
ULTRASONIC INSPECTION
Note:
The crack length “ L” is taken from the back face of the frame.
MENU
EXIT

18. ULTRASONIC INSPECTION
Upper Region (cont’d)
Details
Frame 42 details
ULTRASONIC
INSPECTION
MENU
EXIT

19. ULTRASONIC INSPECTION -THE ULTRASONIC INSPECTION IS MADE IN 2 STEPS-
RECORDING OF CRACK
START
POSITION IN THE RADIUS
STEP 1
Upper Region (cont’d)
Details
Frame 42 details
RECORDING OF CRACK
DEPTH and END
POSITION IN THE FRAME
STEP 2
GENERAL
-THE ULTRASONIC INSPECTION IS MADE IN 2 STEPS-
STEP 1 : RECORDING OF CRACK START POSITION IN THE RADIUS
STEP 2 : RECORDING OF CRACK DEPTH and END POSITION IN THE FRAME
MENU
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20. STEP 1 ULTRASONIC INSPECTION
Upper Region (cont’d)
Details
Frame 42 details
KEEL DOUBLER
crack
Reference
RADIUS
STEP 1
RECORDING OF THE CRACK START POSITION IN THE RADIUS
The principle is to locate the crack relative to a reference line, which is the projection of
the keel doubler on the radius
MENU
EXIT

21. ULTRASONIC INSPECTION
NTM
Lower fuselage Assembly
MAIN LANDING GEAR BAY
Aft of the center wing box, beneath the cabin floor, space is provided for the main landing gear wheels when retracted.
Longitudinal structural continuity of the lower fuselage in this area is maintained by a keel beam which transmits the overall fuselage vertical bending loads. This beam is a box structure providing attachments for the main landing gear doors and door actuators. In its center region, the keel beam side walls are connected to the wing box aft lower panel.
The pressure ceiling of the bay is constructed from 6 drop forged portal frames on the flange of which are riveted pressure resisting curved diaphragms.
NTM
Click here
to play again
-Put the reference location tool PN 99A on the Keel Doubler and record
(with a fine permanent pen) the position in the radius of the reference line mark.
INSPECTION
MENU
EXIT

22. ULTRASONIC INSPECTION
NTM
Lower fuselage Assembly
MAIN LANDING GEAR BAY
Aft of the center wing box, beneath the cabin floor, space is provided for the main landing gear wheels when retracted.
Longitudinal structural continuity of the lower fuselage in this area is maintained by a keel beam which transmits the overall fuselage vertical bending loads. This beam is a box structure providing attachments for the main landing gear doors and door actuators. In its center region, the keel beam side walls are connected to the wing box aft lower panel.
The pressure ceiling of the bay is constructed from 6 drop forged portal frames on the flange of which are riveted pressure resisting curved diaphragms.
CRACK
REFERENCE LINE MARK
The crack position on the radius will be determined relative to this reference line mark
MENU
EXIT

23. ULTRASONIC INSPECTION
NTM
Lower fuselage Assembly
MAIN LANDING GEAR BAY
Aft of the center wing box, beneath the cabin floor, space is provided for the main landing gear wheels when retracted.
Longitudinal structural continuity of the lower fuselage in this area is maintained by a keel beam which transmits the overall fuselage vertical bending loads. This beam is a box structure providing attachments for the main landing gear doors and door actuators. In its center region, the keel beam side walls are connected to the wing box aft lower panel.
The pressure ceiling of the bay is constructed from 6 drop forged portal frames on the flange of which are riveted pressure resisting curved diaphragms.
Click here
to play again
-Place the transparency vernier PN 99A on the radius and adjust it’s position until
the zero of the transparency vernier coincides with the crack origin on the back face of the
fitting frame
INSPECTION
MENU
EXIT

24. ULTRASONIC INSPECTION
NTM
Lower fuselage Assembly
MAIN LANDING GEAR BAY
Aft of the center wing box, beneath the cabin floor, space is provided for the main landing gear wheels when retracted.
Longitudinal structural continuity of the lower fuselage in this area is maintained by a keel beam which transmits the overall fuselage vertical bending loads. This beam is a box structure providing attachments for the main landing gear doors and door actuators. In its center region, the keel beam side walls are connected to the wing box aft lower panel.
The pressure ceiling of the bay is constructed from 6 drop forged portal frames on the flange of which are riveted pressure resisting curved diaphragms.
CRACK
POINT1 12
LH RECORD SHEET
PN 99A
REFERENCE LINE MARK
INSPECTION
-Read on the transparency vernier the distance between the zero and the marked
line and record this value on the “record sheet” (12 in this example)
-This is Point 1-
MENU
EXIT

25. ULTRASONIC INSPECTION RECORDING OF CRACK DEPTH AND END POSITION.
Lower fuselage Assembly (cont’d) D
RECORDING OF CRACK DEPTH AND END POSITION.
STEP 2
MENU
EXIT

26. Note: Except for the instrument, none alternative equipment
ULTRASONIC INSPECTION
Keel beam
The keel beam is installed between frame 35 (35.8 for the A321) and frame 46.
It is attached tot he bottom of both frames and to the center wing box structure (section 21).
The keel beam achieves the longitudinal structural continuity of the lower part of section 15 and transmits the fuselage bending loads.
AIRBUS KIT PN 99A
EQUIPMENT AND MATERIALS
Note: Except for the instrument, none alternative equipment
(1) Instrument : USN 52 L from KRAUTKRAEMER GMBH
(2) AIRBUS kit :PN 99A including
-Search unit: A5068, Al, 5 MHz, 60° Transverse wave from Panametrics
-Cable LCMC 74-2 from Panametrics
-Reference standard PN 99A
-Search unit template PN 99A
-Transparency vernier PN 99A
LH search unit position template: PN 99A
-RH search unit position template: PN 99A
-LH record sheet: PN 99A
-RH record sheet: PN 99A
-Reference location tool PN 99A
MENU
EXIT

27. ULTRASONIC INSPECTION
Keel beam (cont’d)
FR 47
CABIN FLOOR
ACCESS
MENU
EXIT

28. ULTRASONIC INSPECTION
NTM
Keel beam (cont’d)
Click here
to play again
CALIBRATION
A . Adjust the instrument for a 100 mm (3.937 in.) range transverse wave in Aluminum (10 divisions on the screen).
B . Using the reference standard PN 99A , couple the search unit in line with the slot 1.
C . Adjust the search unit position to obtain a maximum amplitude signal from the slot and adjust
the delay to position the maximum slot echo at 6 divisions on the time base line.
MENU
EXIT

29. ULTRASONIC INSPECTION
Keel beam (cont’d)
100%
+ 12 dB
D . Adjust the instrument gain control to give a full screen height signal on the time base display.
For the inspection: Increase the instrument gain control by an additional 12 dB.
MENU
EXIT

30. ULTRASONIC INSPECTION
NTM
Keel beam (cont’d)
PROCEDURE
- The scanning will start pointing the search unit towards the radius direction, in order
to catch the crack at the origin. Then follow the crack, scanning inwards.
(No template is used during this first scan)
MENU
EXIT

31. ULTRASONIC INSPECTION - Start scanning with the search unit
NTM
Keel beam (cont’d)
Click here
to play again
PROCEDURE
- Start scanning with the search unit
MENU
EXIT

32. ULTRASONIC INSPECTION
NTM
Keel beam (cont’d)
Click here
to play again
PROCEDURE
The end of the crack is when the signal drops at 15% FSH
MENU
EXIT

33. ULTRASONIC INSPECTION PROCEDURE
NTM
Keel beam (cont’d)
CRACK END AT 15% FSH
CRACK END DIRECTION
PROCEDURE
NOTE THE SEARCH UNIT POSITION ON THE FITTING FRAME
MENU
EXIT

34. ULTRASONIC INSPECTION
NTM
Keel beam (cont’d)
Click here
to play again
-Put the search unit template in place and repeat the scanning.
The search unit template enables the crack direction to be recorded when the signal drops at 15% (crack end).
Note: It is recommended to cut the template to facilitate the scanning between holes A and B
PROCEDURE
MENU
EXIT

35. ULTRASONIC INSPECTION
NTM
Keel beam (cont’d)
CRACK END AT 6.2
ON TIME BASE
PROCEDURE
RECORD THE END OF THE CRACK AT POSITION” X” ON THE TIME BASE (~6.2 in this example)
MENU
EXIT

36. ULTRASONIC INSPECTION
NTM
Keel beam (cont’d)
CONSTRUCTION DETAILS
Click here
to play again
PROCEDURE
- Keeping the template in place with the fingers, remove the search unit
MENU
EXIT

37. ULTRASONIC INSPECTION
NTM
Slanded panels
Click here
to play again
PROCEDURE
- Put the “LH Search unit position template” on top of the “Search unit template” using the 2 holes A and B to locate the position
The “search unit position template” will enable the search unit position to be recorded relative to holes A and B
MENU
EXIT

38. ULTRASONIC INSPECTION
NTM
Slanded panels Y Z
Click here
to play again
PROCEDURE
- Mark on the “search unit position template” both axes Y and Z
MENU
EXIT

39. ULTRASONIC INSPECTION
Slanded panels (cont’d)
Click here
to play again
PROCEDURE
- Remove the “search unit position template”
MENU
EXIT

40. ULTRASONIC INSPECTION
Slanded panels (cont’d)
Click here
to play again
PROCEDURE
Draw Y and Z axes on the “search unit position template”
MENU
EXIT

41. ULTRASONIC INSPECTION
NTM
Slanded panels (cont’d) Y Z
Click here
to play again
PROCEDURE
-Place the “record sheet LH” on top of the “search unit position template”
-Extend the Y axis on the “record sheet” to report distance “d”
MENU
EXIT

42. ULTRASONIC INSPECTION
Slanded panels (cont’d)
X =6.2
NTM
NTM x d x
PROCEDURE
DETERMINATION OF “d ” (distance from the search unit to the crack end)
MENU
EXIT

43. ULTRASONIC INSPECTION
NTM
Slanded panels (cont’d) X
Click here
to play again
6.2
PROCEDURE
On the reference standard,
- Couple the search unit to be in line with the slot 2.
- Adjust the search unit position to get the slot signal at the same “x” position on the CRT
screen time base recorded ( 6.2 in our example )
MENU
EXIT

44. ULTRASONIC INSPECTION
Slanded panels (cont’d)
6.2
6.2
CRACK END
ON TIME BASE
PROCEDURE
The search unit position on the reference standard,corresponds to the same
location on the frame (I.e 6.2 )
MENU
EXIT

45. ULTRASONIC INSPECTION
Slanded panels (cont’d)
NTM
Click here
to play again
PROCEDURE
Measure the distance “ d” from the search unit to the slot
MENU
EXIT

46. ULTRASONIC INSPECTION
NTM
Slanded panels (cont’d) d
PROCEDURE
The distance “ d” to be reported on the “ Record sheet” is 53 mm in this example
MENU
EXIT

47. ULTRASONIC INSPECTION -Report this value on the record sheet
Slanded panels (cont’d)
Click here
to play again
PROCEDURE
-Report this value on the record sheet
This is point 2
MENU
EXIT

48. ULTRASONIC INSPECTION Measure the crack depth “D” on the”record sheet”
NTM
Slanded panels (cont’d) D
Click here
to play again
PROCEDURE
Measure the crack depth “D” on the”record sheet”
MENU
EXIT

49. 1.3.3.6. Slanded panels (cont’d)
AND NOW JUST DO IT
MENU
EXIT

50. THIS PAGE INTENTIONALLY LEFT BLANK
MENU
FR 47 PRESENTATION
EDDY CURRENT INSPECTION
ULTRASONIC INSPECTION
THIS PAGE INTENTIONALLY LEFT BLANK
EXIT