[Federal Register Volume 68, Number 36 (Monday, February 24, 2003)]
[Proposed Rules]
[Pages 8560-8562]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-4236]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-282-AD]
RIN 2120-AA64


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: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new 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. This 
proposal would 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. 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: Comments must be received by April 10, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-282-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-282-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 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 (425) 917-6465; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-282-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2002-NM-282-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On October 25, 1999, a Learjet Model 35 airplane operating under 
part 135 of the Federal Aviation Regulations (14 CFR part 135) departed 
Orlando International Airport en route to Dallas, Texas. Air traffic 
control lost communication with the airplane near Gainesville, Florida. 
Air Force and National Guard airplanes intercepted the airplane, but 
the flightcrews of the chase airplanes indicated that the windows of 
the Model 35 airplane were apparently frosted over, which prevented the 
flightcrews of the chase airplanes from observing the interior of the 
Model 35 airplane. The flightcrews of the chase airplanes reported that 
they did not observe any damage to the airplane. Subsequently, the 
Model 35 airplane ran out of fuel and crashed in South Dakota. To date, 
causal factors of the accident have not been determined. However, lack 
of the Learjet flightcrew's response to air traffic control poses the 
possibility of flightcrew incapacitation and raises concerns with the 
pressurization and oxygen systems.
    Recognizing these concerns, the FAA initiated a special 
certification review (SCR) to determine if pressurization and

[[Page 8561]]

oxygen systems on Model 35 airplanes were certificated properly, and to 
determine if any unsafe design features exist in the pressurization and 
oxygen systems.
    The SCR team found that there have been several accidents and 
incidents that may have involved incapacitation of the flightcrews 
during flight. In one case, the airplane flightcrew did not activate 
the pressurization system or don their oxygen masks and the airplane 
flew in excess of 35,000 feet altitude. In another case, the airplane 
flightcrews did not don their oxygen masks when the cabin altitude 
aural warning was activated. Further review by the SCR team indicates 
that the Airplane Flight Manual (AFM) of Learjet Model 35 and 36 
airplanes does not have an emergency procedure that requires donning 
the flightcrew oxygen masks when the cabin altitude aural warning is 
activated. Additional review has found that the AFMs of Learjet Model 
35A and 36A airplanes also do not contain appropriate flightcrew 
actions when the cabin altitude aural warning is activated. However, 
the AFMs do contain an abnormal procedure that allows the flightcrew to 
troubleshoot the pressurization system prior to donning the oxygen 
masks after the cabin altitude aural warning sounds. Troubleshooting 
may delay donning of the oxygen masks to the point that flightcrews may 
become incapable of donning their oxygen masks.
    The SCR findings indicated that the most likely cause for 
incapacitation was hypoxia (lack of oxygen). The only other plausible 
cause of incapacitation is exposure to toxic substances. However, no 
evidence was found to support the existence of toxic substances.
    Delayed response of the flightcrew in donning oxygen masks as a 
first and immediate action upon the activation of the cabin altitude 
warning could lead to incapacitation of the flightcrew and loss of 
control of the airplane.

Explanation of Applicability of Proposed AD

    We have previously issued AD 2003-03-15, amendment 13039 (68 FR 
4892, January 31, 2003). That AD revises the AFM for various Boeing and 
McDonnell Douglas transport category airplanes to advise the flightcrew 
to don oxygen masks as a first and immediate step when the cabin 
altitude aural warning sounds. Boeing Model 737-600, 737-700, 737-700C, 
737-800, 737-900, 757, and 767 series airplanes were not included in 
the applicability of that AD because we determined that appropriate 
instructions for donning oxygen masks were included in the Airplane 
Operations Manual for those airplanes.
    After the issuance of the NPRM for AD 2003-03-15, we repeated the 
review of the AFMs for Boeing Model 737-600, 737-700, 737-700C, 737-
800, 737-900, 757, and 767 series airplanes. Based on the results of 
this second review, we have determined that further rulemaking is 
necessary to ensure that the AFMs for those airplanes contain 
appropriate instructions for the flightcrew to immediately don 
emergency oxygen masks when a cabin altitude aural warning occurs. This 
proposed AD follows from that determination.

Other Related Rulemaking

    We have previously issued AD 2000-23-10, amendment 39-11980 (65 FR 
70294, November 22, 2000), which applies to all Lockheed Model 188A and 
188C series airplanes. That AD requires a revision of the AFM to add 
procedures for donning the flightcrew oxygen masks when the cabin 
altitude aural warning sounds. The requirements of that AD are intended 
to prevent incapacitation of the flightcrew as a result of lack of 
oxygen and consequent loss of control of the airplane.
    We have also previously issued AD 2001-22-10, amendment 39-12489 
(66 FR 54425, October 29, 2001), which applies to all Dassault Model 
Mystere-Falcon 50, Mystere-Falcon 900, and Falcon 900EX series 
airplanes. That AD requires revising the Emergency Procedures and 
Abnormal Procedures sections of the AFM to advise the flightcrew to 
immediately don oxygen masks in the event of significant pressurization 
or oxygen level changes. The requirements of that AD are intended to 
prevent incapacitation of the flightcrew due to lack of oxygen, which 
could result in their inability to continue to control the airplane.
    We are continuing to review emergency procedures in the AFMs for 
other airplane models to ensure that the AFMs contain appropriate 
instructions for donning the flightcrew oxygen masks. We may consider 
further rulemaking based on the results of these reviews.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require revising the Emergency Procedures or Non-
Normal Procedures section of the AFM, as applicable, to advise the 
flightcrew to don oxygen masks as a first and immediate step when the 
cabin altitude aural warning sounds.

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 would be affected by this proposed AD, that it would take 
approximately 1 work hour per airplane to accomplish the proposed AFM 
revision, and that the average labor rate is $60 per work hour. Based 
on these figures, the cost impact of the proposed AD on U.S. operators 
is estimated to be $95,940, or $60 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed 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 proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting 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.

[[Page 8562]]

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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.


Sec.  39.13  [Amended]

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

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

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

    Issued in Renton, Washington, on February 13, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-4236 Filed 2-21-03; 8:45 am]
BILLING CODE 4910-13-P