1400 North Hurstbourne Parkway louisville, KY 40223 502.329.3000 Tel October 20, 2014

Federal Aviation Administration C/0 U.S. Department ofTransportation Docket Operations, M-30 West Building GroundFloor Room W12-140 1200 New Jersey Avenue SE Washington, DC 20590
SUBJECT: Notice ofProposed Rule Making (NPRM) 2013-NM-136-AD Docket No. FAA-2014-0648; Directorate Identifier 2013-NM-136-AD

To Whom ItMay Concern:
The Federal Aviation Administrationreleased the subject Notice ofProposed Rulemaking (NPRM) for comments on September22, 2014, viaFederal RegisterVolume 79, Number 183,pp. 56526-56532. The NPRM proposes to supersede Airworthiness Directive (AD) 2010-06-04which requires repetitive inspections to detect cracks ofthe pylon side panels (upper section) at rib 8 in accordance with Airbus SB A300-54-6015, Revision 03. Since AD 2010-06-04 issuance, additional analysis has shown that reduced compliance times and repeat inspection intervals are needed to ensure the structural integrity ofthe inspected area. United Parcel Service Co. (UPS Airlines) has reviewed the referencedproposedrule and offers the follow·ing comments regarding use ofAverage FlightTime (AFT) methodology for the proposedmandatory action threshold and repetitive intervals.
Theproposed rule identifies compliance times for the inspection threshold and repeat intervals using the Average Flight Time (AFT) methodology. Review ofpriorFAA AD -:omments notes, including AD 98- 18-02, that the FAAdoes not concur with the AFT compliance time methodology as"

...such adjustments may not address the unsafe condition in a timely manner" and"

...they (AFT compliance times) do not fit into the AD tracking process for operators or for Principle Maintenan..:.e Inspectors (PMI's) attempting to ascertain compliance with AD's." UPS shares the FAA concern with using the AFT compliance methodology.Federal Aviation Administration October 20, 2014 Page 2 of2

Under the proposedthresholds for aircraft utilization equal to or less than 1.5 AFT value, the aircraft is flight cycle limited as the flight hourlimit cannot be reached (reference Figure 1). Whenconsidering AFT values greaterthan 1.5, the aircraft is still flight cycle limited until an AFT value of2.16 is achieved. At a utilizationratio of2.16 and greater, the aircraft is flight hour limited. Therefore, variable flight hour limits add an unnecessary complexity to the threshold table and subsequent inspection actions.
Use ofthe complex AFT methodology combined withthe lack ofprocedures for the AFT methodusage (lifetime AFT value orrecent operational period, how often is AFT re-calculated, etc.) provides an opportunity for tracking errors and places an undue burden on aircraft operators andtheregulatory authority to monitor compliance. UPS believes a more consistent and simplified compliance requirement (i.e. defined threshold andrepeat intervals) achieves the safety intent ofthis ruling, provides for timely detection ofpossible damage and eliminates continuous AFT monitoring that is necessary to comply with the inspection interval compliancerequirements inthe proposed rule. Referto Table 1 for proposed inspection threshold andrepeat inspection intervals for this proposed ruling basedon Airbus SB A300- 54-6015 data and use ofthe simplified threshold and repeat inspection interval approach. UPS acknowledges the need for thepylon side skin panel inspection detailed in Airbus SB A300-54- 60 15. UPS believes the proposed inspectionthreshold and repeat inspection intervals proposed in Table 1 provides an equivalent level ofsafety and minimizes risks associated with the AFT compliance time methodology. Thank you for your time in considering these comments. Ifyou have any questions regarding this response, please contact MarkHilborn at 502-329-6020 orbye-mail at mhilbom@ups.com. Sincerely, UNITED PARCEL SERVICE CO.

EdwardM. Walton Director ofEngineering EW:MRH:mm Attachment
c: Ed Walton DanHaddix BruceNord1/) Q) 

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### FIGURE 1: NPRM2013-NM-136-AD Inspection Threshold Determination using AFT Methodology

NPRM 2013-NM-136-AD Conf 002 Post Mod Repeat Inspection 6,500 6,000 5,500 5,000 4,500 4,000

3,000 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 Average Flight Time (AFT) -FitCycles (AFT<= 1.5) -FitCycles (AFT> 1.5) -FC Limit (AFT<= 1.5) -FC Limit (AFT> 1.5)
ForConfiguration 002 (PWpowered aircraft) after incorporation ofSB A300-54-6021 as a repair (crack found during inspection), the chart shows thatthe repeat inspection interval is flight cycle limited. The flight hourrepeat inspection limits (5,600 FHfor AFT <= 1.5 and 7,500 FH for AFT > 1.5),the aircraft is flight cycle limited. Forexample, at an AFTvalue of 1.5, the aircraft will accumulate 3,733 flight cycles when accumulating 5,600 flight hours. Atthe AFTvalue of 1.5, the FHthreshold values change to 7,500 FH or 3,400 FC. Thusthe aircraft is limited bythe flight cycle value until the AFTvalue= 2.16. This is true for both Configuration 001 (GE powered aircraft) and Configuration 002 aircraft. Therefore, use ofthe AFTmethodology does notprovide any safety enhancement ortimely detection of damage based on the aircraft utilization.

## I TABLE 1: NPRM 2013-NM-136-AD Proposed Inspection Threshold and Repeat Intervals Table 1 identifies threshold and repeat inspection intervals for aircraft with various repair 

### I modification embodiment status and engine type installation. 

### Inspection Effectivity Engine Type Threshold Repeat Interval Interval General Electric All aircraft with SB A300-54-6021 not (GE) CF6-80 accomplished (pre mod 10431S20462) and Pratt & Whitney 4,200 FC 3,600 FC with no priorrepairs. (PW) 4000 Pratt & Whitney (PW)JT9D General Electric 9,300 FC after 8,200 FH

(GE) CF6-80 repair 4,100 FC All aircraft with SB A300-54-6021 with SB accomplishment A300-54-6021 accomplished as a repair Pratt & Whitney (PW) 4000 . 9,300 FC after (crack found during inspection). repair 7,500 FH Pratt & Whitney accomplishment 3,700 FC (PW) JT9D General Electric 10,100 FC after 8,200 FH repair (GE) CF6-80 4,100 FC All aircraft with SB A300-54-6021 accomplishment accomplished as preventative mod (no Pratt & Whitney cracking found during inspection). (PW) 4000 10,100 FC after 7,500 FH repair 3,700 FC Pratt & Whitney accomplishment (PW) JT9D