Airworthiness Directives; Boeing Model 737 Airplanes

[Federal Register Volume 73, Number 218 (Monday, November 10, 2008)]
[Rules and Regulations]
[Pages 66512-66514]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-26373]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1166; Directorate Identifier 2008-NM-179-AD; 
Amendment 39-15728; AD 2008-23-07]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Boeing Model 737 airplanes. This AD requires revising the airplane 
flight manual to include a new flightcrew briefing that must be done 
before the first flight of the day and following any change in 
flightcrew members, and to advise the flightcrew of this additional 
briefing. This AD results from continuing reports that flightcrews have 
failed to recognize and react properly to the cabin altitude warning 
horn. We are issuing this AD to prevent failure of the flightcrew to 
recognize and react properly to a valid cabin altitude warning horn, 
which could result in incapacitation of the flightcrew due to hypoxia 
(lack of oxygen in body) and consequent loss of airplane control.

DATES: This AD is effective November 25, 2008.
    We must receive comments on this AD by January 9, 2009.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> 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.

Examining the AD Docket

    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 AD, the regulatory evaluation, 
any comments received, and other information. The street address for

[[Page 66513]]

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: Gregg Nesemeier, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6479; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Discussion

    On June 15, 2006, we issued related AD 2006-13-13, amendment 39-
14666 (71 FR 35781, June 22, 2006). (A correction of that AD was 
published in the Federal Register on July 3, 2006 (71 FR 37980).) That 
AD applies to all Boeing Model 737 airplanes. That AD requires revising 
the airplane flight manual (AFM) to advise the flightcrew of improved 
procedures for pre-flight setup of the cabin pressurization system, as 
well as improved procedures for interpreting and responding to the 
cabin altitude/configuration warning horn. That AD resulted from 
reports that airplanes had failed to pressurize, and that the 
flightcrews failed to react properly to the cabin altitude warning 
horn. The actions specified in that AD are intended to prevent failure 
of the airplane to pressurize and subsequent failure of the flightcrew 
to recognize and react to a valid cabin altitude warning horn, which 
could result in incapacitation of the flightcrew due to hypoxia (lack 
of oxygen in body) and consequent loss of airplane control.

Actions Since Related AD Was Issued

    Since we issued AD 2006-13-13, we have received continuing reports 
of in-service events involving failure of the flightcrew to recognize 
and react properly to valid cabin altitude warning horns. Therefore, we 
have determined that a new flightcrew briefing before the first flight 
of the day and following any change in flight crewmembers, in addition 
to the existing AFM procedures, is necessary to mitigate the risk of 
additional events.

FAA's Determination and Requirements of This AD

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the(se) same type 
design(s). This AD requires revising the AFM to include a new 
flightcrew briefing that must be done before the first flight of the 
day and following any change in flightcrew members, and to advise the 
flightcrew of this additional briefing.

Interim Action

    We consider this AD interim action. The manufacturer has advised 
that it currently is developing a design change in the cabin altitude 
warning system that will address the unsafe condition identified by 
this AD. Once this design change is developed, approved, and available, 
we might consider additional rulemaking.

FAA's Justification and Determination of the Effective Date and 
Compliance Time

    We are issuing this AD to prevent failure of the flightcrew to 
recognize and react to a valid cabin altitude warning horn, which could 
result in incapacitation of the flightcrew due to hypoxia (lack of 
oxygen in body) and consequent loss of airplane control. This action 
follows related rulemaking action we took in response to a report 
resulting from the investigation by the Air Accident Investigation and 
Aviation Safety Board of Greece into the August 14, 2005, Helios 
Airways accident near Athens, Greece. This action affects the entire 
fleet of Boeing Model 737 airplanes (nearly 5,000 airplanes worldwide); 
these airplanes have a very high utilization rate. Because of our 
requirement to promote safe flight of civil aircraft and thus the 
critical need to assure that the flightcrew recognizes and reacts 
properly to a valid cabin altitude warning horn and the compliance time 
involved with this action, this AD must be issued immediately.
    We acknowledge that a compliance time of 120 days is unusually long 
for an AFM-change/immediately adopted rule. However, in this case, we 
have determined that it is necessary to provide sufficient time for 
operators to adequately prepare to meet the requirements of the AD. 
This preparation includes obtaining regulatory acceptance (from 
principal operations inspectors) of the required flightcrew preflight 
briefing aids, publication of flightcrew briefing aids in sufficient 
quantities, and familiarization of flightcrews with the AD briefing 
requirements. The time required to prepare to implement the AD 
requirements is increased by the size of the affected fleet. We have 
further determined that a 120-day compliance time will provide an 
adequate level of safety. Therefore, a compliance time of 120 days has 
been specified in order to provide operators with sufficient time to 
accomplish the requirements of this AD.
    Because an unsafe condition exists that requires the immediate 
adoption of this AD, we find that notice and opportunity for prior 
public comment hereon are impracticable and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2008-1166; Directorate Identifier 2008-NM-179-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
AD. We will consider all comments received by the closing date and may 
amend this 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 AD.

Authority for This Rulemaking

    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

    This AD will not have federalism implications under Executive Order 
13132. This AD 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

[[Page 66514]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    (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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

0
2. The FAA amends 39.13 by adding the following new AD:

2008-23-07 Boeing: Amendment 39-15728. Docket No. FAA-2008-1166; 
Directorate Identifier 2008-NM-179-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective November 25, 
2008.

Affected ADs

    (b) This AD is related to AD 2006-13-13, amendment 39-14666; 
paragraph (a) of AD 2003-03-15 R1, amendment 39-13366; and paragraph 
(a) of AD 2003-14-08, amendment 39-13227. This AD does not supersede 
the requirements of AD 2006-13-13, AD 2003-03-15 R1, or AD 2003-14-
08.

Applicability

    (c) This AD applies to all Boeing Model 737-100, -200, -200C, -
300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series 
airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from continuing reports that flightcrews 
have failed to recognize and react properly to the cabin altitude 
warning horn. We are issuing this AD to prevent failure of the 
flightcrew to recognize and react to a valid cabin altitude warning 
horn, which could result in incapacitation of the flightcrew due to 
hypoxia (lack of oxygen in body) and consequent loss of airplane 
control.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Revising the Airplane Flight Manual (AFM)

    (f) Within 120 days after the effective date of this AD, revise 
the Limitations Section of the applicable Boeing 737 AFM to include 
the following statement. This may be done by inserting a copy of 
this AD into the applicable AFM.

``CABIN ALTITUDE WARNING TAKEOFF BRIEFING (required by AD 2008-23-
07)

    With the CABIN ALTITUDE and TAKEOFF CONFIG lights not installed, 
or installed but not activated:
    As part of the Takeoff Briefing before engine start for the 
first flight of the day or following any change of either flightcrew 
member, the pilot-in-command will ensure the Cabin Altitude Warning 
indications and procedures are briefed in accordance with the 
procedures contained in the Normal Procedures section of this 
manual.''

    (g) Within 120 days after the effective date of this AD, revise 
the Normal Procedures Section of the applicable Boeing 737 AFM to 
include the following statement. This may be done by inserting a 
copy of this AD into the applicable AFM.

``CABIN ALTITUDE WARNING TAKEOFF BRIEFING (required by AD 2008-23-
07)

    The following briefing is important to further reduce the risk 
of flightcrew incapacitation due to hypoxia. Because of the dual 
purpose of the intermittent cabin altitude/takeoff configuration 
warning horn, this briefing serves to remind flightcrews that the 
sounding of the cabin altitude warning horn in flight requires 
immediate action, beginning with the immediate donning of oxygen 
masks. Upon completion of the applicable WARNING HORN--CABIN 
ALTITUDE OR CONFIGURATION non-normal checklist memory items, other 
alerts and indications on the flight deck (e.g., air/ground sensing 
system failures, equipment cooling OFF, etc.) may then be addressed.
    Memory item cabin altitude warning indications and procedures 
must be briefed on airplanes in which the CABIN ALTITUDE and TAKEOFF 
CONFIG lights are not installed, or are installed but not activated. 
This will be included as an additional item on the Takeoff briefing 
before engine start for the first flight of the day, or following 
any change of either flightcrew member.
    The briefing must include the following items.

--Whenever the intermittent warning horn sounds in flight:
    1. Immediately, don oxygen masks and set regulators to 100%.
    2. Establish crew communications.
    3. Do the CABIN ALTITUDE WARNING OR RAPID DEPRESSURIZATION 
checklist.
--Both pilots must verify on the overhead Cabin Altitude Panel that 
the cabin altitude is stabilized at or below 10,000 feet before 
removing oxygen masks.''

Special Flight Permit

    (h) Special flight permits are prohibited.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, ATTN: Gregg Nesemeier, Aerospace Engineer, Systems and 
Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
telephone (425) 917-6479; fax (425) 917-6590; has the authority to 
approve AMOCs for this AD, if requested using 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.

Material Incorporated by Reference

    (j) None.

    Issued in Renton, Washington, on October 24, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-26373 Filed 11-7-08; 8:45 am]
BILLING CODE 4910-13-P

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