03-17675. Airworthiness Directives; Boeing Model 737-600, 737-700, 737-700C, 737-800, 737-900, 757, and 767 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD); applicable to all Boeing Model 737-600, 737-700, 737-700C, 737-800, 737-900, 757, and 767 series airplanes; that requires revising the Airplane Flight Manual (AFM) to advise the flightcrew to don oxygen masks as a first and immediate step when a cabin altitude warning occurs. This action is necessary to prevent incapacitation of the flightcrew due to lack of oxygen, which could result in loss of control of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective August 18, 2003.

ADDRESSES:

Information pertaining to this AD may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Donald Eiford, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Boeing Model 737-600, 737-700, 737-700C, 737-800, 737-900, 757, and 767 series airplanes was published in the Federal Register on February 24, 2003 (68 FR 8560). That action proposed to require revising the Airplane Flight Manual (AFM) to advise the flightcrew to don oxygen masks as a first and immediate step when a cabin altitude warning occurs.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. The FAA has duly considered the comments received.

Support for the Proposed AD

One commenter concurs with the proposed AD, and several other commenters had no objection to the proposed AD.

Request To Modify Cabin Altitude Warning System

One commenter notes that there is no “CABIN ALT” or “CABIN ALTITUDE” warning light in the Boeing Model 737-800 series airplanes that it operates, and for this reason, the commenter suspects that the proposed AD does not apply to its airplanes. The commenter states that the only warning of excessive cabin altitude is the intermittent warning horn. The commenter suggests that the cabin altitude warning system installed on the airplane could be greatly enhanced by a modification that would give the flightcrew a visual warning of improper altitude. The commenter also suggests that the cabin altitude warning should be duplicated in the forward and aft galley areas.

We infer that the commenter is requesting clarification of the applicability and requirements of this proposed AD. We agree that such clarification is needed. Our intent was for this AD to apply to all airplanes listed in the applicability, regardless of the equipment associated with the cabin altitude warning system. We have confirmed with the airplane manufacturer that the Model 737-600, -700, -700C, -800, and -900 series airplanes subject to this AD have a cabin altitude warning horn instead of a warning light. Thus, we have revised Figure 1 of this AD to replace the reference to the illumination of the cabin altitude light with a reference to the sounding of the cabin altitude warning horn.

Further, with regard to the commenter's specific requests to add a cabin warning light on the flight deck and duplicate the cabin altitude warning in the forward and aft galley areas, we acknowledge the concerns of the commenter. While there may be merit to the commenter's suggestions, this AD is not the appropriate context in which to evaluate those suggestions. We have determined that the cabin altitude warning horn is an adequate means to alert the flightcrew to an unsafe condition and provides an acceptable level of safety when combined with the changes to procedures required by this AD. No further change to the AD is necessary in this regard.

Request To Coordinate Rulemaking Activity

One commenter notes that its understanding is that AD 2003-03-15, amendment 39-13039 (68 FR 4892, January 31, 2003), may be revised in the future. (The proposed AD explains that the proposed actions are similar to those in AD 2003-03-15.) The commenter asks us to consider establishing a common compliance time between the proposed AD and any future revision of AD 2003-03-15. The commenter states that it would like to accomplish all AFM changes in a one-time effort to ensure consistency and standardization among its manuals, especially for similar airplane fleets. Related to consistency and standardization, the commenter is also concerned about the variations in operational procedures in the AFM revisions. The commenter states that, while the AFM may differ in format from one model to another, there should not be procedural differences related to responding to a cabin altitude warning.

We acknowledge the commenter's concerns but do not concur with the commenter's request. We find that it is not possible to establish a common compliance time between this AD and a possible future proposed AD, because the timelines for these rulemaking actions are different. We have already proposed this AD and allowed opportunity for the public to comment, but, at this time, we are still considering further rulemaking to revise AD 2003-03-15. In light of the identified unsafe condition, we find that it would be inappropriate to delay issuance of this action indefinitely to wait for development of a proposal to revise AD 2003-03-15.

We also acknowledge the commenter's concerns about ensuring consistency among its AFMs, and we agree that it may be desirable to have the same wording in the AFMs for all models. However, the effort to achieve commonality is compromised by differences in the terminology used to identify similar equipment on different models, and the subtle differences in existing procedures between models. In developing the AFM changes contained in this AD, we limited the scope of changes within each affected AFM to avoid introducing standardized wording that may be incompatible with equipment on the airplane model or may contradict other procedures in the AFM.

No further change to the final rule is necessary in this regard.

Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Changes to 14 CFR Part 39/Effect on the AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. However, for clarity and consistency in this final rule, we have retained the language of the NPRM regarding that material.

Explanation of Change to Cost Impact

After the proposed AD was issued, we reviewed the figures we use to calculate the labor rate to do the required actions. To account for various inflationary costs in the airline industry, we find it appropriate to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The economic impact information, below, has been revised to reflect this increase in the specified hourly labor rate.

Cost Impact

There are approximately 3,107 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,599 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required AFM revision, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of this AD on U.S. operators is estimated to be $103,935, or $65 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

2003-14-08 Boeing: Amendment 39-13227. Docket 2002-NM-282-AD.

Applicability: All Model 737-600, 737-700, 737-700C, 737-800, 737-900, 757, and 767 series airplanes; certificated in any category.

Note 1:

The requirements of this AD are similar to those in AD 2003-03-15, amendment 39-13039, which applies to various Boeing and McDonnell Douglas transport category airplanes.

Compliance: Required as indicated, unless accomplished previously.

To prevent incapacitation of the flightcrew due to lack of oxygen, which could result in loss of control of the airplane, accomplish the following:

Revision to the Airplane Flight Manual

(a) Within 90 days after the effective date of this AD: For the applicable airplane models listed in the “For—” column of Table 1 of this AD, revise the procedures regarding donning oxygen masks in the event of rapid depressurization, as contained in the Emergency Procedures or Non-Normal Procedures section of the Airplane Flight Manual (AFM), as applicable, by replacing the text in the “Replace—” column of Table 1 of this AD with the information in the applicable figure referenced in the “With the Information In—” column of Table 1 of this AD. This may be accomplished by recording the AD number of this AD on the applicable figure and inserting it into the AFM. Table 1 and Figures 1 through 3 follow:

Table 1.—AFM Revisions

For—	Replace—	With the Information in—
Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes	“Rapid Depressurization (With airplane altitude abvoe 14,000 feet M.S.L.)	Figure 1 of this AD.
	Oxygen Masks & Regulators—ON, 100%”
Boeing Model 757-200, -200PF, -200CB; and Boeing Model 767-200, -300, and -300F series airplanes	“Rapid Depressurization Recall Oxygen Masks and Regulators—ON”	Figure 2 of this AD.
Boeing Model 757-300 series airplanes	“Rapid Depressurization Put on oxygen masks, and establish crew communications”	Figure 3 of this AD.
Boeing Model 767-400ER series airplanes	“Rapid Depressurization Turn on oxygen masks, and establish crew communications”	Figure 3 of this AD.

Figure 1

For Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

Insert the information in this figure into the “Non-Normal Procedures” section of the FAA-approved Airplane Flight Manual.

“Cabin Altitude Warning or Rapid Depressurization

Condition: The cabin altitude warning horn sounds:

Oxygen Masks & Regulators ON, 100%''

The rest of the steps under this heading in the AFM are unchanged.

Figure 2

For Boeing Model 757-200, -200PF, and -200CB; and Model 767-200, -300, and -300F Series Airplanes

Insert the information in this figure into the “Emergency Procedures” section of the FAA-approved Airplane Flight Manual.

“Cabin Altitude Warning or Rapid Depressurization

Condition: The CABIN ALT or CABIN ALTITUDE light illuminated indicates cabin altitude is excessive:

RECALL

Oxygen Masks & Regulators ON, 100%''

The rest of the steps under this heading in the AFM are unchanged.

Figure 3

For Boeing Model 757-300 and 767-400ER Series Airplanes

Insert the information in this figure into the “Non-Normal Procedures” section of the FAA-approved Airplane Flight Manual.

“Cabin Altitude Warning or Rapid Depressurization

Condition: The CABIN ALT or CABIN ALTITUDE light illuminated indicates cabin altitude is excessive:

Put on oxygen masks and establish crew communications.”

The rest of the steps under this heading in the AFM are unchanged.

Alternative Methods of Compliance

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Operations Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Effective Date

(d) This amendment becomes effective on August 18, 2003.

Issued in Renton, Washington, on July 7, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.