### Email Message related to SR #: 1-2408921250 

### Account: British Airways



### Activity #: 1-13UX7KN 

### Timestamp: 19-Apr-2013 02:23:34 PM



### Owner: Adil Khannoussa 

### Message Sent: 31-Jan-2013 12:04:29 AM ((GMT)
Greenwich Mean Time : Dublin, Edinburgh, Lisbon,
London)



### Message Number: BAB-BAB-13-0127-02B 

### Status: Done



### Type: Email - Outbound 

### Sub Type: Boeing Response



### From: Due:

Field Base: BFSLHR-London-United Kingdom



### To:
bfslhr@boeing.com,paul.x.murphy@ba.com,douglas.shaw@ba.com,claire.rowland@ba.com,matthew.brayley
@ba.com,francis.perks@ba.com,mark.tarrant@ba.com



### Cc:

Airplanes:

Registry # Variable # Serial # Hours Cycles

G-BNLP RT486 24058 97173 12447


### Inquiry Type: Airplane Repair DTA NOT REQUESTED



### FAA Form 8100-9 Requested: No 

### Repair Design Record Requested: No



### Subject: G-BNLP Main Entry Door 5 Left Cutout Aft Upper Corner Crack



### Body:

FROM: THE BOEING COMPANY
TO: British Airways (BAB)
[MESSAGE NUMBER:BAB-BAB-13-0127-02B] Boeing Response

MESSAGE DATE: 30 Jan 2013 1604 US PACIFIC TIME / 31 Jan 2013 0004 GMT

The following message is distributed to the following people at British Airways:
Paul Murphy, Douglas Shaw, Claire Rowland, Matthew Brayley, Francis Perks, Mark Tarrant

Field Service Base: BFSLHR -------------------------------------------------------------------------------------------------- Page 1 of ----Service Category: Airplane Model: 747Series/Product: 747-400 ATA: 5361-10

SUBJECT: G-BNLP Main Entry Door 5 Left Cutout Aft Upper Corner Crack

AIRPLANE (VARIABLE/SERIAL): RT486/24058 REGISTRY: G-BNLP Flight Hours: 97173 Flight
Cycles: 12447

INQUIRY TYPE: Airplane Repair DTA NOT REQUESTED FAA Form 8100-9 Requested: No Repair
Design Record Requested: No

REFERENCES:

/A/ BAB-BAB-13-0127-01C

/B/ SB747-53A2839

/C/ 015U1914-2
/D/ Repair Sketch

DESCRIPTION:

In Ref/A/ BAB intends to accomplish a repair in accordance with Ref/B/ SB however the Ref/C/ kit is not
available. BAB requested Boeing to provide drawings to enable fabrication of the kit parts or provide an
alternate repair.

RESPONSE:

Ref/A/ has been reviewed and we offer the following:

For the reported conditions, we have no technical objection to BAB fabricating the service bulletin modification
parts locally, for installation.
If this is done, then no additional approval would be required. We recommend that BAB start the SMAL
process, please submit a Purchase Order (P.O) to Boeing spares and request Spares Material Authorization
License (SMAL) approval to fabricate the repair parts per the production drawings. A separate SMAL request
must be submitted for each part number requested.

As an alternative, BAB could install the Ref/D/ attached repair, and fabricate those repair parts locally. If this
is done, then a FAA 8100 could be given. please follow the repair instructions below.

Please note that Ref/D/ repair is generic, and may need to be modified to account for the existing configuration
and reported conditions. -------------------------------------------------------------------------------------------------- Page 2 of ----Further, the existing external skin repair shown in the Ref/A/ photograph may have an impact on either a

service bulletin modification doubler or the Ref/D/ repair. But in order to determine this, we would need a
dimensioned lay-out for the subject area.

Further, please note whether the service bulletin or the alternate repair is done, additional work may be
required when an AD is released for the bulletin.

Please address those items above as required for our further review.

Alternate repair instructions ( See ref/D/ sketch):

1.Fabricate a repair doubler from 0.090 inch gage 2024-T3 clad sheet.
2.Fabricate two repair doublers each from 0.080 inch gage 15-5PH cres SHEET. Heat treat to 150-170 Ksi.
3.Assemble the parts and drill the fastener holes as shown in attached sketch.
4.Apply Alodine to the aluminum repair parts and the bare surfaces of the original aluminum parts per 747-

400 SRM 51-20-01.
5.Apply one layer of BMS 10-79 Type II primer to the aluminum repair parts and bare surfaces of the original
aluminum parts per SOPM 20-44-04.
6.Brush or bath cadmium plate CRES (steel) parts per SOPM 20-42-05 and prime with two coats of BMS 10-
11 Type I primer per SOPM 21-41-02 as required for touch up.
7.Shim to limit clamp-up to 0.010 inch prior to fastener installation. Fabricate fillers/tapered shims from 2024-

T3 or 7075-T6.
8.Install the repair parts with BMS 5-95 sealant between the faying surfaces per 747-400 SRM 51-20-05.
9.Maintain 2D edge margin and 4-6D center to center spacing for all new fasteners and use existing hole
location as applicable.
10.Install all fasteners and associated collars per 747-400 SRM 51-40-02. Replace existing fastener with same
type and size except as noted. Oversize up to 1/32 inch if required.
11.Install all Hi-Loks in aluminum structure in transition fit holes, and in steel or a stack-up combination of
aluminum and steel in close ream holes, all per 747-400 SRM 51-40-05 and 51-40-02.
12.Apply a fillet seal to the exposed edge of the overlapped skin per 747-400 SRM 51-20-05.
13.Apply BMS 10-60, Type II finish to the repair area per AMM 51-24-11.
14.After completion of repair, apply BMS 3-23 corrosion preventative compound followed by BMS 3-26 per

747-400 SRM 51-20-01.

If attachments are referred to, and are not present, please reply to this e-mail or contact your Boeing Field
Service Representative.

Enhanced Controls Required?:No

Summary Notes: -------------------------------------------------------------------------------------------------- Page 3 of ----Adil Khannoussa

Service Engineer - Structures

Commercial Aviation Services

The following files are attached to this message:
BAB-BAB-13-0127-Repair Sketch.pdf -------------------------------------------------------------------------------------------------- Page 4 of ----