Skip to Content
Proposed Rule

Airworthiness Directives; Boeing Model 707 Airplanes and Model 720 and 720B Series Airplanes

Action

Notice Of Proposed Rulemaking (Nprm).

Summary

The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 707 airplanes and Model 720 and 720B series airplanes. This proposed AD would require repetitive inspections for any cracking of or damage to the left side and right side flight deck No. 2, No. 4, and No. 5 windows, as necessary, and corrective actions if necessary. This proposed AD results from reports of in-flight departure and separation of the flight deck windows. We are proposing this AD to detect and correct cracking in the vinyl interlayer or damage to the structural inner glass panes of the flight deck No. 2, No. 4, and No. 5 windows, which could result in loss of a window and rapid loss of cabin pressure. Loss of cabin pressure could cause crew communication difficulties or crew incapacitation.

Unified Agenda

Airworthiness Directives

1 action from November 2013

  • November 2013
    • Actions Will Continue Through
 

Table of Contents Back to Top

DATES: Back to Top

We must receive comments on this proposed AD by January 17, 2008.

ADDRESSES: Back to Top

You may send comments by any of the following methods:

  • Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
  • Fax: 202-493-2251.
  • Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
  • Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Examining the AD Docket Back to Top

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Back to Top

Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6577; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: Back to Top

Comments Invited Back to Top

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2007-0264; Directorate Identifier 2007-NM-212-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion Back to Top

We have received one report of in-flight departure of the flight deck No. 3 window, on a Boeing Model 747 series airplane, which resulted in rapid loss of cabin pressure and an emergency landing. That airplane had accumulated 36,131 total flight hours and 5,607 total flight cycles. We have also received two reports of in-flight separation of the left side flight deck No. 5 window, on two Boeing Model 737 series airplanes. One of the Model 737 series airplanes experienced cabin pressure loss at 12,500 feet due to separation of the forward, aft, and upper edges of the left side flight deck No. 5 window. That airplane had accumulated 25,673 total flight hours and 15,669 total flight cycles. The other Model 737 series airplane experienced a pressure leak at 29,000 feet due to partial separation of the upper aft corner of the left side flight deck No. 5 window. That airplane had accumulated 28,139 total flight hours and 16,566 total flight cycles. Vinyl interlayer cracking of the flight deck No. 2, No. 4, and No. 5 windows could decrease the load carrying capability of the affected windows during cabin pressurization if the structural glass pane of the window becomes broken. Vinyl interlayer cracking could also decrease the bird impact resistance capability of the flight deck No. 2 and No. 4 windows. Cracking in the vinyl interlayer or damage to the structural inner glass panes of the flight deck No. 2, No. 4, and No. 5 windows, if not corrected, could result in loss of a window and rapid loss of cabin pressure. Loss of cabin pressure could cause crew communication difficulties or crew incapacitation.

The window construction and operating environment on the Model 737 airplanes and Model 747 airplanes are similar to those on the affected Boeing Model 707 airplanes and Model 720 and 720B series airplanes. Therefore, all of these models are also subject to the same unsafe condition.

Other Related Rulemaking Back to Top

On July 18, 2007, we issued AD 2007-15-10, amendment 39-15139 (72 FR 41438, July 30, 2007), to address the unsafe condition on all Model 747 airplanes. A correction was issued on September 10, 2007 (72 FR 53923, September 21, 2007), to fix a typographical error in AD 2007-15-10. That AD requires an inspection of the No. 2 and No. 3 windows on the left and right sides of the airplane to determine their part numbers, and related investigative and corrective actions if necessary. On October 5, 2007, we issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on October 17, 2007 (72 FR 58766). That NPRM proposed to require repetitive inspections for any cracking of or damage to the left side and right side flight deck No. 2, No. 4, and No. 5 windows and corrective actions if necessary.

Relevant Service Information Back to Top

We have reviewed Boeing 707 Alert Service Bulletin A3526, dated June 4, 2007. The service bulletin describes procedures for doing repetitive internal and external detailed inspections for any cracking of or damage to the left side and right side flight deck No. 2, No. 4, and No. 5 windows, as applicable, that exceeds the limits given in the Accomplishment Instructions of the service bulletin. The service bulletin specifies an initial compliance time ranging between 6 months and 24 months, depending on the window location and number of window flight hours. If a replacement window is not new or has an unknown number of flight hours, the service bulletin specifies accomplishing the initial inspections before installation. If a replacement window is new or has zero flight hours, the service bulletin specifies accomplishing the initial inspections at the following times: (1) 7,500 window flight hours or 36 months, whichever occurs first, for flight deck No. 2 windows, and (2) 6,000 window flight hours or 24 months, whichever occurs first, for flight deck No. 4 and No. 5 windows. The service bulletin also specifies a repetitive interval of (1) 7,500 window flight hours or 36 months, whichever occurs first, for flight deck No. 2 windows, and (2) 6,000 window flight hours or 24 months, whichever occurs first, for flight deck No. 4 and No. 5 windows.

The service bulletin also describes procedures for accomplishing corrective actions if necessary. The corrective actions include replacing any cracked or damaged window with a new or serviceable window. The service bulletin specifies accomplishing the corrective actions before further flight.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD Back to Top

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.

Costs of Compliance Back to Top

There are about 238 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 83 airplanes of U.S. registry. The proposed actions would take about 2 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $13,280, or $160 per airplane, per inspection cycle.

Authority for This Rulemaking Back to Top

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings Back to Top

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify that the proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39 Back to Top

The Proposed Amendment Back to Top

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

begin regulatory text

PART 39—AIRWORTHINESS DIRECTIVES Back to Top

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. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-0264; Directorate Identifier 2007-NM-212-AD.

Comments Due Date Back to Top

(a) The FAA must receive comments on this AD action by January 17, 2008.

Affected ADs Back to Top

(b) None.

Applicability Back to Top

(c) This AD applies to all Boeing Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; Model 707-300, -300B, -300C, and -400 series airplanes; and Model 720 and 720B series airplanes, certificated in any category.

Unsafe Condition Back to Top

(d) This AD results from reports of in-flight departure and separation of the flight deck windows. We are issuing this AD to detect and correct cracking in the vinyl interlayer or damage to the structural inner glass panes of the flight deck No. 2, No. 4, and No. 5 windows, which could result in loss of a window and rapid loss of cabin pressure. Loss of cabin pressure could cause crew communication difficulties or crew incapacitation.

Compliance Back to Top

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Repetitive Inspections and Replacement Back to Top

(f) At the applicable times specified in Tables 1, 2, and 3 of paragraph 1.E. of Boeing 707 Alert Service Bulletin A3526, dated June 4, 2007, except as provided by paragraph (g) of this AD: Do the internal and external detailed inspections for any cracking of or damage to the left side and right side flight deck No. 2, No. 4, and No. 5 windows, as applicable, and do the applicable corrective actions before further flight, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3526, dated June 4, 2007. Repeat the inspections thereafter at the applicable interval specified in paragraph 1.E. of Boeing 707 Alert Service Bulletin A3526, dated June 4, 2007.

Exception to Compliance Times Back to Top

(g) Where Tables 1, 2, and 3 of paragraph 1.E. of Boeing 707 Alert Service Bulletin A3526, dated June 4, 2007, specify counting the compliance time from “* * * the date on this service bulletin,” this AD requires counting the compliance time from the effective date of this AD.

Alternative Methods of Compliance (AMOCs) Back to Top

(h)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

Issued in Renton, Washington, on November 7, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

end regulatory text

[FR Doc. E7-23337 Filed 11-30-07; 8:45 am]

BILLING CODE 4910-13-P

Site Feedback