Craig Amadeo General Manager Engineering Standards & Chief Engineer Delta Air Lines, Inc. 1775 Aviation Blvd Atlanta, Ga. 30320 T. +1 404 714 1312 F. +1 404 773 3675 craig.amadeo @delta.com

March 22, 2013

U.S. Department of Transportation Docket Operations, M

- 30, West Building Ground Floor, Room W12

- 140 1200 New Jersey Avenue SE Washington, DC 20590 Fax: (202) 493

- 2251

Subject : Docket No. FAA

- 2013

- 0090 ; Directorate Identifier 2012

- NM

- 149

- AD

– Proposed Rule

Reference: /A/ Notice of Proposed Rule Making (NPRM): Docket No. FAA

- 2013

- 0090 ; Directorate Identifier 2

- 13

- NM

- 149

- AD /B/ Boeing Service Bulletin 747

- 25

- 3428, Revision 3, dated 14 June 2012 / C / Boeing Message: DAL

- DAL

- 13

- 0578

- 03B, Sub ject: 747

- 25

- 3428 Compliance Time

, dated 18 March 2013

SUMMARY :

Ref. /A/ was prompted by reports of worn or incorrect ly assembled latches on main dec k escape slides installed on airplane doors. This NPRM was issued to prevent a latch hook moving from closed to open in an escape slide/raft or escape slide not deploying correctly in an emergency or releasing/inflating into the passenger cabin and causing injury to passengers and crew.

Compliance with R ef. /A/ requires the inspection and modification of the latch assembl y, in accordance with Ref. /B/ within 48 months of the AD effective date

.

DELTA’S COMMENT S

Delta requests that the 48 month compliance time for the proposed AD be extended up to 60 months. This will allow for the modification to be accom plished at the next scheduled overhaul for Delta’s affected slides. By allowing this compliance time extension, it would decrease the financial effect to Delta and other operators by removing the need to schedule early removal of the slide/raft and slide p acks. At Ref. /B/ creation, a risk assessment was performed to determine if modification needed to be expedited. There were too few instances to perform a proper analysis, so Boeing determined that it was acceptable to set the compliance time to correspond with the recommended slide overhaul cycle at the time of release. The unsafe condition reported in this NPRM and Ref. /B/ has not resulted in injury to passengers

or crew , thus the modification can be scheduled to coordinate with routine maintenance witho ut an undue risk to
passengers or crew. Ref. /C/ provides Boeing’s concurrence to the compliance time extension.

Additionally, Delta requests that the proposed AD allow the replacement of affected slides with slides that have completed the inspection an d modification requirements of Ref. /B/ as an acceptable means of compliance

. This will allow Delta and other operators to bypass the installation and removal procedures of Ref. /B/ while addressing the unsafe condition in the same manner as the proposed A D

. Tracking c ompliance with Ref. /B/ is possible, because the slide pack assy. is identified to indicate completion of SB 747

- 25

- 3428 Rev. 3.

Alternatively, if replacement is deemed unacceptable, Delta requests that the proposed AD include a statement not ing that remov al and install ation of the slide p er the SB is not an AD mandated task, but accomplishment by means of an approved routine maintenance item would also be acceptable . This would not affect the modification of the slide,March 22, 2013 Page 2 of 2

because Ref. /B/ refers to a door

- specific AMM section or “an accept ed alternative procedure” for these process es

. It would allow Delta and other operators to track compliance at the slide level and ensure fleet

- wide compliance by attrition. It will also provide an elegant method to ensure spares are modified.

If you have any further questions or require additional information, please contact Kendra Johnson

- Aerospace Engineer, Interiors Engineer, at (404)714

- 1207 or email at kendra.johnson@delta.com

. Thank you,

Peter Lauria ODA Lead administrator and Acting Chief Engineer Dept. 574 for Craig Amade o General Manager

– Engineering Standards & Chief Engineer Dept. 567