1. Flap Carriage Solution
737 Classic Trailing Edge
Flap Carriage Solution

2. 737C Carriage Installation
The left schematic and picture illustrates the OB flap system fully retracted.
The right schematic and picture illustrates the OB flap system fully extended. Note the location of the main carriage in the extended views.

3. TE Flap Carriage Spindle Fractures
737 Classic Fleet Concern
TE Flap Carriage Spindle Fractures
Fracture of both inboard and outboard flap carriage spindles in the critical “A” location or through the “B” location to the cross bolt on an outboard flap may preclude continued safe flight and landing of the airplane.
Southwest Airlines experienced the first reported “dual fracture” during approach for landing in November 2003.
Fractures in this area are caused primarily by corrosion on the carriage spindles. B
Southwest Airlines experienced a dual flap spindle fracture at 500 feet above ground level on approach for landing. When this occurs the affected outboard flap may disconnect producing asymmetrical lift, and a potential loss of control for the pilot. In the SWA incident the pilot was able to recover the aircraft following the dual fracture, potentially avoiding catastrophe during landing. A

4. FAA Notice of Proposed Rule Making 2009-NM-076-AD
AD states that the FAA considered the requirements given “interim action” and that they were considering further rulemaking. The FAA has now determined that further rulemaking is necessary.
Effectivity: /-200/-200C/-300/-400/-500 Series Aircraft
Actions:
Would supersede AD
Comply with Gap Check and NDT inspections described in SB 57A1277.
Comply with spindle diameter limits specified in SB 57A1218.
Overhaul carriage spindles > 12,000 cycles or 8 years of service.
Life limit of 48,000 cycles mandatory.

5. FAA Notice of Proposed Rule Making 2009-NM-210-AD
AD states that the FAA considered the requirements given “interim action” and that they were considering further rulemaking. The FAA has now determined that further rulemaking is necessary.
Effectivity: /-200/-200C/-300/-400/-500 Series Aircraft
Actions:
Would supersede AD
Same requirements of AD with one exception.
Optional Terminating action to replace or rework suspect HVOF bases would be made mandatory IAW SB A1304 (Within 4 years after Aug 11th 2009).

6. Boeing / FAA Action SB 737-57A1304 Rev 1, 8/11/09
Issued to provide instructions for the inspection of the HVOF coated carriage spindles for corrosion and thermal spray flaking.
Effectivity: , -400, -500 Series Aircraft (carriages installed during overhaul or replacement after February 2006)
Inspections:
Review of records to determine if applicable carriage has been installed
Detailed or borescope inspection of applicable carriage spindle
Gap check or NDT (ultrasonic) inspection of applicable carriage spindle
Applicable carriages require rework or replacement. Contact Boeing for part disposition.
SB A1304 is made mandatory by FAA AD (Supersedes AD ).
CMM includes instructions for rework and/or replacement of all suspect carriages.
-FAA Airworthiness Directives are issued to address unsafe aircraft operating conditions and are equivalent to federal law. All US domestic and many international airlines must comply with AD requirements.

7. Boeing / FAA Action AD 2009-23-10 Effective: 11/24/09
Inspection Intervals
Condition
Action
Compliance Time
Repeat Interval
(Not to Exceed)
All Airplanes
Records inspection to find suspect HVOF carriage spindles (refer to applicable S/N’s)
Within 30 days after Aug 5th, 2008.
Not Applicable
Airplanes with applicable HVOF carriage spindles (refer to applicable S/N’s)
Detailed inspection or borescope inspection of carriage spindle
Within 30 days after Nov 24th 2009 or 90 days from installation of a HVOF carriage spindle, whichever occurs later;
90 Day
If No Corrosion is Found
Gap check or NDT (ultrasonic) inspection per SB 57A1277
Before Further Flight
15 days or 150 flight cycles, whichever occurs later
If Potential Indications are Found
Detailed inspection of entire spindle surface
If Corrosion is Found
Replace Carriage
If Severed Spindle is Indicated
Replace or refurbish the carriage. Refurbished carriages have “R” added to S/N
Within 4 years after 11-Aug-2009
Replacement or refurbishment terminates inspections.
Frequent inspections will severely impact operator schedule options for aircraft high time or cycle carriages.
Optional Terminating Action*
* FAA NPRM 2009-NM-210-AD would make the optional terminating action mandatory if adopted.

8. Boeing / FAA Action SB 737-57A1218 Rev 5, 2/9/09
Issued to provide instructions for removal, inspection, and overhaul of outboard carriage spindles. Revision 4 of this SB (6/19/07) recommends a finite life limit for carriage sub-assemblies. Prior to Revision 4, carriages were not life limited.
Effectivity: /-200/-200C/-300/-400/-500 Series Aircraft
Actions:
Records inspection for carriage spindle life limit
Detailed inspection of carriage spindle for corrosion
Overhaul carriage spindles > 12,000 cycles or 8 years of service.
Fractured or severed spindles require replacement, corroded spindles may be overhauled per CMM (-200 series) or (-300 series)
FAA Notice of Proposed Rule Making: 2009-NM-076-AD.
The proposed AD would supersede AD and require both repetitive inspections and compliance with the Life Limit recommended by SB 757A1218.
FAA has issued an NPRM (2009-NM-076-AD) against SB 57A1218 which would supersede AD and require compliance with the life limit suggested in SB 57A Currently, there is no AD officially requiring compliance with the life limit, however AD requires compliance with SB 57A1277 which requires compliance with SB 57A1218.
Comments are due in response to the NPRM by April 15, 2010.

9. Boeing / FAA Action SB 737-57A1218 Rev 5, 2/9/09 Life Limit Compliance
Condition
Action
Compliance Time
/-200/-200C
/-400/-500
Airplanes with an undocumented carriage or a documented carriage > 48,000 total cycles
Replace carriage with a new or documented carriage
Within 3 years from 19-Jun-2007 or within 7,500 flight cycles from 19-Jun-2007, whichever occurs first
Within 6 years from 19-Jun-2007 or within 15,000 flight cycles from 19-Jun-2007, whichever occurs first.
Airplanes with a documented carriage having < 48,000 total cycles
Replace carriage with new or documented carriage
Prior to carriage accumulating 48,000 cycles or as defined by one of the compliance criteria above, whichever is later.
New (zero time) carriages shall not go over 48,000 cycles.
FAA has issued an NPRM (2009-NM-076-AD) against SB 57A1218 which would supersede AD and require compliance with the life limit suggested in SB 57A Currently, there is no AD officially requiring compliance with the life limit, however AD requires compliance with SB 57A1277 which requires compliance with SB 57A1218.
Comments are due in response to the NPRM by April 15, 2010.

10. Boeing / FAA Action SB 737-57A1277 Rev 1, 11/25/03
Issued to provide instructions for the inspection of the outboard midflap carriage spindles to detect fractured, severed, or corroded carriage spindles.
Effectivity: , -200, -200C, -300, -400, -500 Series Aircraft
Inspections:
NDT Inspection (Ultrasonic Inspection)
Gap Check
Fractured or severed spindles require replacement, corroded spindles require overhaul per CMM (-200 series) or (-300 series) and SB A1218 Rev 5 (or later).
SB A1277 is made mandatory by FAA AD
-The Ultrasonic check is non-destructive check in place to detect material anomalies and corrosion which can lead to in-flight fracture.
-The Gap Check is a manual check where two mechanics must measure flap deflection by manually moving each flap. This check is intended to detect fractured spindles.
-FAA Airworthiness Directives are issued to address unsafe aircraft operating conditions and are equivalent to federal law. All US domestic and many international airlines must comply with AD requirements.

11. New Carriages (Never Been Overhauled)
Boeing / FAA Action
SB A1277 Rev 1, 11/25/03
Inspection Intervals
New Carriages (Never Been Overhauled)
thru -500
Days
Cycles
> 20,000 Cycles or 8 years in service, whichever is less
Gap Check 3 30
Ultrasonic NDT 60
600
12,000 to 20,000 Cycles 15
150
180
1500
< 12,000 Cycles
N/A
Gap Checks will severely impact operator schedule options for aircraft high time or cycle carriages.

12. Previously Overhauled Carriages
Boeing / FAA Action
SB A1277 Rev 1, 11/25/03
Inspection Intervals
Previously Overhauled Carriages
/-200
/-400/-500
Days
Cycles
> 20,000 Cycles
Gap Check 1 20 3 30
Ultrasonic NDT 6 60 15
150
12,000 to 20,000 Cycles or 8 years in service since last OH, whichever is less
3,000 to 11,999 Cycles 7 70 14
140
500
180
1500
< 3,000 Cycles
N/A
Daily Gap Checks will severely impact operator schedule options for aircraft high time or cycle carriages.

13. Effectivity: 300/-400/-500 Series Aircraft, Line Positions 1001-3132
Other Boeing Action…
SB Rev 2, 5/16/06
Issued to provide instructions to rework applicable carriages by replacing roller bearings with new, self-lubricated bearings.
Effectivity: 300/-400/-500 Series Aircraft, Line Positions
Actions:
Remove existing roller bearings and replace with new self-lubricated bearings
No Compliance Time is Given
No AD issued against SB

14. Effectivity: 300/-400 Series Aircraft, Line Positions 1001-1698
Other Boeing Action…
SB Rev 6, 6/22/95
Issued to provide instructions to rework applicable carriages by machining clearance chamfers on the carriage detents and side roller assemblies.
Effectivity: 300/-400 Series Aircraft, Line Positions
Actions:
Chamfer detent lugs and side roller fittings
No Compliance Time is Given
No AD issued against SB

15. Ongoing Industry Issue
Base Carriage Replacement and Identification
Many 737C TE Flap Carriage Bases are being removed from service due to undersize spindle ODs. Boeing no longer allows any repair to spindles that are out of CMM limits.

16. Base Carriage Interchangeability
Position
Old Carriage Sub Assy
New Carriage Sub
Assy
Outboard Flap,
Outboard
Carriage
WBL 355
65C
65C
65C
65C
65C
65C
Inboard Carriage
WBL 254
65C
65C
65C
65C
65C
65C
65C
Note: Interchangeabilities listed above based on PN 65C and -31 APL.

17. Typical Re-Part Marking of Carriages Used by Some Airlines
New Carriage Sub Assy
New Carriage PNs (Bearings that need Lubrication)
New Carriage PNs (Bearings that are Self-Lubricated)
65C
XXX (L/H) XXX (R/H)
XXX (L/H) XXX (R/H)
65C
XXX (L/H) XXX (R/H)
XXX (L/H) XXX (R/H)
Note: (L/H) or (R/H) designates position of carriage on the aircraft. Do not mark (L/H) or (R/H) on reworked carriages.
**XXX is customer assigned suffix showing that a new base carriage has been used.
*Example Only*
New Carriage Sub Assy
New Carriage PNs
65C
65C XXX (L/H) 65C XXX (R/H)
65C
65C XXX (L/H) 65C XXX (R/H)
Note: (L/H) or (R/H) designates position of carriage on the aircraft. Do not mark on reworked carriages.
**XXX is customer assigned suffix showing that a new base carriage has been used.

18. extension or retraction.
737C Flap Carriage Summary
Part Numbers –
/ (CMM )
thru -8
thru -86, -95, -96
/-400/-500 (CMM )
65C thru -8
thru -94, -97 thru -136,
-144 thru -150
Major Service Bulletins
737-57A1304 – HVOF Spindle Inspection
737-57A1218 – Spindle OH / Life Limit
737-57A1277 – Spindle Inspection
– Self-lubricated Bearings
– Toggle Interference
FAA Directives
2009-NM-076-AD – SB A1218/1277
AD – SB A1304
AD – SB A1277
Curtiss-Wright Repair Station Capability
Complete spindle overhaul capability
Turn Around Time
Multiple scenarios, but normally 17
calendar days or less
Flat-Rate overhaul pricing available:
Greased bearing configurations
Greaseless bearing configurations
Exchange Units Available
Basic carriage configuration, functionality, and aftermarket work scope summary.
The Outboard Flap Carriage Assy. supports the Flap on the Flap Track and moves the Flap during
extension or retraction.