Administrative Information
This bulletin cancels Operations Manual Bulletin ELF-23, dated May 28, 1999. Insert this bulletin behind the Operations Manual Bulletin Record page in Volume 1 of your Operations Manual. Amend the FCOM Bulletin Record to show bulletin ELF-23 “CANCELLED” (CANC) and bulletin ELF-25 “IN EFFECT” (IE).
This bulletin will be cancelled after Boeing is notified that all affected airplanes in your fleet have been modified by SB 737-27A1206.
The Block Speeds provided by this Operations Manual Bulletin will be incorporated in a future revision to the Operations Manual.
Page 4 of 6
Flight Crew Operations Manual Bulletin No. ELF-25,dated December 03, 1999 (continued)
Please send all correspondence regarding FCOM bulletin status to one of the
following addresses: 
Mailing Address:  Manager 737, Flight Technical Integration & Data Boeing Commercial Airplane Group P. O. Box 3707 MS 20-89 Seattle, WA 98124-2207 USA 
Fax Number: Telex: SITA: E-MAIL:  (206) 662-7812 329430 Station 627 LKEBO7X FTID@Boeing.com 

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Flight Crew Operations Manual Bulletin No. ELF-25,dated December 03, 1999 (continued)
Intentionally
Blank

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Flight Crew Operations Manual Bulletin
for
 

The Boeing Company Seattle, Washington 98124-2207

737
Number: ILF-28 Date: November 17, 2003 Document Effectivity: 
Subject:  Trailing Edge Flaps -Outboard Flap Carriage Spindle Fractures 
Reason:  To inform flight crews of outboard trailing edge flap carriage spindle fractures that could cause mid-flap displacement with associated infight roll-off. In addition, to inform flight crews to report any unexpected roll-off condition to maintenance 

Information in this Flight Crew Operations Manual (FCOM) bulletin is recommended by The Boeing Company, but may not be FAA approved at the time of writing. In the event of conflict with the FAA approved Airplane Flight Manual (AFM), the AFM shall supersede. The Boeing Company regards the information or procedures described herein as having a direct or indirect bearing on the safe operation of this model airplane.
THE FOLLOWING PROCEDURE AND/OR INFORMATION IS EFFECTIVE UPON RECEIPT
Background Information
Boeing has received reports of outboard mid-flap carriage spindle fractures from operators of 737-100 through -500 airplanes. Two carriage assemblies move on independent flap tracks and connect each outboard trailing edge mid-flap to the wing. Fractures have been found in varying locations along the length of the carriage spindle, which connects the carriage assembly to the mid-flap. A fracture can result in the displacement of the associated flap from the carriage assembly.
This displacement can cause a change in the flap angle of attack resulting in airplane roll-off as the flaps extend. An airplane roll-off condition that requires one unit or more of rudder trim and/or 2.5 units or more of aileron trim to maintain wings level flight when the flaps are extended can be an indication of a spindle fracture. The flight deck flap indications are normal.
A fractured spindle will not cause roll changes when the trailing edge flaps are fully retracted. Roll changes should be minimal at flap positions 1, 2, 5, and 10. Depending upon the location of the fracture, roll changes are expected to be more pronounced as the flaps extend to 15 or greater. If one carriage spindle fractures at the critical location, the pilot can compensate for it with aileron and/or rudder
CS3-3341 Page 1 of 2
Flight Crew Operations Manual Bulletin No. ILF-28,dated November 17, 2003 (continued)
inputs. However, if both the inboard and outboard spindles on an outboard flap fracture in the critical location, a large potentially uncontrollable rolling moment could occur.
Operating Instructions
During flap operation at flaps 15 or greater with normal flap indications, if an unexpected roll-off occurs stop flap extension. If the roll-off requires one unit or more of rudder trim and/or 2.5 units or more of aileron trim to maintain wings level flight, retract flaps to flaps 5. Land using flaps 5 and Vref 40 + 30 knots. Report the roll-off condition to maintenance.
Administrative Information
Insert this bulletin behind the FCOM Bulletin Record Page in Volume 1 of your FCOM. Amend the FCOM Bulletin Record Page to show Bulletin ILF-28 "IN EFFECT" (IE).
This condition is under investigation. This FCOM bulletin remains in effect until further notice.
Page 2 of 2

Flight Crew Operations Manual Bulletin
　
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