SL525C-27-05 - Cessna Support

SERVICE LETTER
Citation
SL525C-27-05
TITLE
FLIGHT CONTROLS - GROUND SPOILER ULTRASONIC INSPECTION
EFFECTIVITY
MODEL
SERIAL NUMBERS
525C (CJ4)
-0152 thru -0166
All nondestructive inspections must be performed by a qualified facility and meet the requirements defined
in the Cessna Model 525C Nondestructive Testing Manual, Part 1 – Personnel and Facilities - General.
REASON
The core material used to build the ground spoiler assemblies may be contaminated with oil preventing a
proper bond.
DESCRIPTION
This service letter provides instructions to accomplish an ultrasonic NDT inspection of the ground spoilers
and established a recurring inspection every 10 flights or 15 flight hours thereafter, whichever occurs first.
COMPLIANCE
MANDATORY. This service letter must be accomplished as follows:
•
•
A one-time positioning flight is permitted to move the airplane to a location at which the inspection will be
accomplished. The following limitations apply to the positioning flight:
•
Only required crew-members on-board (no passengers permitted).
•
Maximum altitude of FL250.
•
Maximum airspeed of 200 KIAS.
•
Day VMC only.
This inspection must be accomplished prior to the next flight after the positioning flight.
LABOR HOURS
WORK PHASE
MAN-HOURS
Inspection
2.0
CONSUMABLE MATERIAL
You must use the consumable materials that follow, or their equivalent, to complete this service letter.
NAME
Couplant
NUMBER
Sonotrace 30 or
equivalent
MANUFACTURER
Commercially Available
USE
Provides a medium for the
ultrasonic transducer.
SL525C-27-05
Page 1 of 7
October 25, 2014
Cessna Aircraft Company, Cessna Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800
This document contains technical data and is subject to U.S. export regulations. This information has been exported from the United States
in accordance with export administration regulations. Diversion contrary to U.S. law is prohibited. ECCN: 9E991
COPYRIGHT © 2014
SERVICE LETTER
Citation
SL525C-27-05
TOOLING
NAME
NUMBER
MANUFACTURER
USE
Ultrasonic Instrument
(Note 1)
Commercially Available
Used to determine if
delamination is present.
Transducer (Note 2)
Commercially Available
Tool for the Ultrasonic
Instrument.
Note 1: The ultrasonic instrument must have A-scan display capability. A GE Inspection Technologies
USN58L was used to develop these procedures.
Note 2: Transducer specifications - 5MHz, 0.375 inch (10 mm) diameter, contact transducer.
WARRANTY
Eligibility:
Affected airplanes that were still within the Cessna five-year/5,000 hour airframe warranty
period on the original issue date of this service letter.
Parts:
Authorized Citation Service Facilities, individual operators, or other maintenance facilities
may submit a Credit Claim Form for the parts kit(s) required for accomplishment of this
service letter, provided the work is completed and the claim submitted by the expiration
date shown below.
Labor:
Authorized Citation Service Facilities may submit a Credit Claim Form for accomplishment
of this service letter, on eligible airplanes, provided the work is completed and the claim
submitted by the expiration date shown below.
Expiration:
October 31, 2016
REFERENCES
Cessna Model 525C Nondestructive Testing Manual
PUBLICATIONS AFFECTED
None
ACCOMPLISHMENT INSTRUCTIONS
1.
Do an inspection of the ground spoiler panel serial numbers.
A.
Ground spoilers with serial numbers listed in the table that follows will require an ultrasonic
inspection.
SL525C-27-05
Page 2
October 25, 2014
Citation
SERVICE LETTER
SL525C-27-05
Suspect Ground Spoiler Panel Serial Numbers
PRD-00106788
PRD-00111218
PRD-00112357
PRD-0012370
PRD-00124623
PRD-00110980
PRD-00111219
PRD-00112358
PRD-00123667
PRD-00124625
PRD-00110981
PRD-00111220
PRD-00112359
PRD-00123953
PRD-00124626
PRD-00111034
PRD-00111221
PRD-00112360
PRD-00124551
PRD-00124630
PRD-00111185
PRD-00111222
PRD-00115429
PRD-00124582
PRD-00124631
PRD-00111186
PRD-00112325
PRD-00117599
PRD-00124586
PRD-00124632
PRD-00111187
PRD-00112326
PRD-00118112
PRD-00124587
PRD-00124635
PRD-00111188
PRD-00112327
PRD-00118644
PRD-00124588
PRD-00124636
PRD-00111189
PRD-00112328
PRD-00120372
PRD-00124592
PRD-00124637
PRD-00111190
PRD-00112329
PRD-00120379
PRD-00124593
PRD-00124638
PRD-00111191
PRD-00112330
PRD-00120689
PRD-00124595
PRD-00124639
PRD-00111192
PRD-00112331
PRD-00120992
PRD-00124596
PRD-00124640
PRD-00111193
PRD-00112332
PRD-00120993
PRD-00124598
PRD-00124641
PRD-00111194
PRD-00112333
PRD-00120995
PRD-00124600
PRD-00125367
PRD-00111195
PRD-00112334
PRD-00120996
PRD-00124601
PRD-00125371
PRD-00111196
PRD-00112335
PRD-00121000
PRD-00124602
PRD-00125373
PRD-00111197
PRD-00112336
PRD-00121001
PRD-00124603
PRD-00125375
PRD-00111198
PRD-00112343
PRD-00121002
PRD-00124605
PRD-00125377
PRD-00111199
PRD-00112344
PRD-00121003
PRD-00124606
PRD-00125378
PRD-00111205
PRD-00112345
PRD-00121004
PRD-00124607
PRD-00125620
PRD-00111207
PRD-00112346
PRD-00121005
PRD-00124608
PRD-00125624
PRD-00111208
PRD-00112347
PRD-00121006
PRD-00124609
PRD-00125625
PRD-00111209
PRD-00112348
PRD-00121007
PRD-00124610
PRD-00125626
PRD-00111210
PRD-00112349
PRD-00121008
PRD-00124611
PRD-00125628
PRD-00111211
PRD-00112350
PRD-00121689
PRD-00124613
PRD-00125848
PRD-00111212
PRD-00112351
PRD-00121690
PRD-00124617
PRD-00125897
PRD-00111213
PRD-00112352
PRD-00121691
PRD-00124618
PRD-00125900
PRD-00111214
PRD-00112353
PRD-00121693
PRD-00124619
PRD-00127335
PRD-00111215
PRD-00112354
PRD-00121694
PRD-00124620
PRD-00111216
PRD-00112355
PRD-00122949
PRD-00124621
PRD-00111217
PRD-00112356
PRD-00122950
PRD-00124622
2.
Make sure that the ground spoilers are retracted.
3.
Prepare the airplane for maintenance.
A.
Make sure that the airplane is electrically grounded.
B.
Make sure that all switches are in the OFF/NORM position.
October 25, 2014
SL525C-27-05
Page 3
Citation
SERVICE LETTER
SL525C-27-05
C.
D.
Disconnect electrical power from the airplane.
(1)
Disconnect the airplane battery.
(2)
Disconnect external electrical power.
Attach maintenance warning tags to the battery and external power receptacle that have "DO NOT
CONNECT ELECTRICAL POWER - MAINTENANCE IN PROGRESS" written on them.
4.
Clean the upper surface of all six ground spoilers.
5.
Set
•
•
•
•
6.
Do an ultrasonic inspection of the ground spoiler panel leading edges.
the ultrasonic inspection device as follows:
Frequency 5 MHz
Range 0.20 inch (5 mm)
Velocity approximately 0.10 in/µsec
Full-wave rectification
NOTE: This inspection is to detect disbonding in the leading edge of each ground spoiler assembly
between the upper and lower laminates. The inspection will cover an area that spans the width of
each spoiler and extends aft approximately 0.25 inch from the leading edge.
A.
Adjust the ultrasonic instrument GAIN setting.
NOTE: This step will have to be repeated for each ground spoiler. The GAIN setting must be
calibrated for each ground spoiler panel.
(1)
Position the transducer on the upper surface of the ground spoiler leading edge.
(2)
Identify the back-wall signal from the laminate.
•
Additional information about the ground spoiler panel construction. The ground spoilers
consist of two precured laminates around a nomex core. The perimeter of the spoilers
consists of a secondary bond between the upper and lower laminates.
SL525C-27-05
Page 4
October 25, 2014
SERVICE LETTER
Citation
SL525C-27-05
•
B.
The signal from the interface between the upper and lower laminates will be evident at
approximately 2.5 major divisions on the baseline. The back-wall from the lower laminate
will occur at approximately the 5th major division on the instrument baseline. You can
confirm this signal by finger damping the lower surface of the lower laminate.
(3)
Take measurements at four equally spaced locations on the leading edge. (Do not use a
hinge location to establish the gain settings.)
(4)
Adjust the ultrasonic instrument GAIN to achieve amplitude at 100% full-screen height at
each of the four locations.
(5)
Set the ultrasonic instrument GAIN to an average gain setting from the four measured locations.
(6)
Test a random location on the leading edge to confirm the GAIN setting and adjust if necessary.
Ground spoiler inspection.
(1)
Apply couplant to the leading edge of the ground spoiler.
(2)
Scan the entire leading edge with the ultrasonic instrument from the leading edge to 0.25
inch (7 mm) aft of the leading edge.
(3)
Mark all areas where the back-wall signal at the fifth major division drops below the 50%
full-screen height as suspect.
NOTE: Any reduction in the back-wall signal will be accompanied by an increase in the
laminate interface back-wall signal at 2.5 major divisions.
October 25, 2014
SL525C-27-05
Page 5
Citation
SERVICE LETTER
SL525C-27-05
(4)
C.
D.
Make sure that any reduction in back-wall signal is not due to a lack of couplant between
the transducer and ground spoiler.
Map the suspect area on the ground spoiler.
(1)
Move the transducer around the suspect areas and monitor the signal amplitude.
(2)
Place a mark at the center of the transducer when the signal amplitude from the spoiler
back-wall reaches 50% full screen height.
(3)
Continue until all of the boundaries of the disbonded area are identified.
Do Step 6 again on all installed ground spoilers with a suspect serial number.
7.
Inspection results:
•
The airplane may continue operations if the ultrasonic inspection of the suspect serial number
ground spoiler panels did not show any disbonding. Follow-up inspection are required every 10 flight
or 15 flight-hours, whichever occurs first, until the ground spoiler panel(s) are replaced.
•
The airplane may not resume operations until the disbonded ground spoiler panel is repaired or
replaced.
8.
Remove the maintenance warning tags and connect the airplane battery.
NOTE: Cessna recommends that you contact CESCOM to set up a personal inspection item for the
ground spoiler ultrasonic inspection due in 10 flights or 15 flight-hours whichever occurs first.
SL525C-27-05
Page 6
October 25, 2014
Citation
SERVICE LETTER
SL525C-27-05
9.
Record that this service letter has been completed.
A.
Complete a Maintenance Transaction Report.
B.
Put a copy of the completed Maintenance Transaction Report in the airplane logbook.
C.
Send a copy of the completed Maintenance Transaction Report to: CESCOM C/O Camp Systems
International Incorporated, 8201 East 34th Street North, Building 1100 Suite 1101 Wichita, KS 67226.
October 25, 2014
SL525C-27-05
Page 7

Download Report