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Operations Manual Bulletin No. ILF2-13(R2), Dated April 1, 1999 (continued)
Boeing previously advised internal leakage of fuel into the oil system should be suspected if the oil quantity indication was at or approaching 20 or more quarts after engine start. However, since issue of the original bulletin, several operators have reported oil quantity indications of approximately 21 quarts after engine start which, when investigated, were not due to fuel/oil contamination. The increase in oil quantity was due to a slight over-servicing, oil expansion due to temperature increase, or an increase in scavenge efficiency with the engine at idle. For these reasons, the oil quantity check after engine start has been increased to 22 quarts (21 liters).
Information from these events has shown inconsistent indications for fuel in the oil system which cannot provide a sound basis for in-flight crew procedures. Since flight crews do not continuously monitor oil system indications, changes in oil system parameters may not be noticed. However, if the oil quantity is observed to be increasing during steady state operation or if at any time during engine operation the oil quantity indication is at or approaching 21 liters or more, internal leakage of fuel into the oil system should be suspected. This condition should be entered in the Flight Log for maintenance action prior to the next flight.
The first cockpit indication of a fuel-contaminated oil system may be an increasing or overfilled oil tank quantity. The rate of oil quantity increase depends on the severity of the fuel leak. Leaks are normally detected by maintenance personnel during required checks, or while investigating flight crew complaints of increasing oil quantity. An extreme overfilled condition may be accompanied by increasing oil temperature, fluctuating or decreasing oil pressure, or fuel/oil fumes in the cabin. The Smoke Air Conditioning procedures was issued to handle smoke or fumes in the cabin.
Additional maintenance checks have been implemented following servicing of oil tanks or after maintenance on the engine oil or fuel system to detect fuel contamination of the oil. This results in more frequent checks of the oil system.
Operating Procedure
Since data on at least one uncontained failure indicates the oil tank was overfilled at engine start, accomplish the following check until GE SB 72-648 is incorporated.
At least 30 seconds after the engine reaches stabilized idle and prior to taxi:
OIL QUANTITY ..............CHECK

If the oil quantity indicates 21 liters or more, maintenance investigation is required prior to takeoff.
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Operations Manual Bulletin No. ILF2-13(R2), Dated April 1, 1999 (continued)
Administrative Information
Insert this bulletin behind the Bulletin Record page in Volume 1 of your Operations Manual. Amend the Bulletin Record to show bulletin ILF2-13(R2) IN EFFECT (IE).
This Operations Manual Bulletin will be cancelled after Boeing is notified all affected airplanes in your fleet have been modified by GE Service Bulletin 72-648. If you do not plan to modify all your airplanes and would like to have the contents of this Bulletin incorporated in your Operations Manual, please advise Boeing accordingly. Please send all correspondence regarding Operations Manual Bulletin status to one of the following addresses:
Mailing Address: Manager, Flight Technical Publications (747-400)
Boeing Commercial Airplane Group P.O. Box 3707 MS 20-89 
Seattle, WA 98124-2207 USA 
Fax: Telex:  (206) 662-7812 32-9430 Station 627 
SITA:  SEABO7X 

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Operations Manual Bulletin No. ILF2-13(R2), Dated April 1, 1999 (continued)
Intentionally
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Operations Manual Bulletin
for
International Lease Finance Corp.

The Boeing Company Seattle, Washington 98124-2207

Number: ILF2-28(R2)
Date: April 1, 1999 Document Effectivity: D6-30151-425 Subject: ENGINE OPERATION IN HEAVY RAIN OR HAIL Reason: To inform flight crews of revised procedures for use of autothrottle in
heavy rain or hail. Revised for administrative purposes.
Information in this 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 GE engine flameout and subsequent engine recovery while operating in heavy rain. In one dual engine flameout incident, digital flight data recorder (DFDR) information revealed the autothrottle was engaged and commanding a thrust increase from approach idle when the flameouts occurred. While the reported flameouts occurred in heavy rain, water ingestion by itself has been ruled out as the sole cause of these events. Engineering analysis of DFDR data has determined the most likely cause to be rapid variable bleed valve (VBV) closure resulting from autothrottle thrust increases during sustained engine ingestion of supercooled water and ice.
　
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