[Federal Register Volume 68, Number 57 (Tuesday, March 25, 2003)]
[Proposed Rules]
[Pages 14353-14355]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-6996]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-01-AD]
RIN 2120-AA64


Airworthiness Directives; Israel Aircraft Industries, Ltd., Model 
1124 and 1124A 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 Israel Aircraft Industries, 
Ltd., Model 1124 and 1124A series airplanes. This proposal would 
require revising the airplane flight manual to advise the flightcrew to 
don oxygen masks as a first and immediate step following a cabin 
altitude alert. This action is necessary to prevent incapacitation of 
the flightcrew due to lack of oxygen. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by April 24, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-01-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. 2003-NM-01-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 Gulfstream Aerospace Corporation, P.O. Box 2206, Mail 
Station D25, Savannah, Georgia 31402. This information may be examined 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2141; fax (425) 227-1149.

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

[[Page 14354]]

statement is made: ``Comments to Docket Number 2003-NM-01-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. 2003-NM-01-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On October 25, 1999, a Learjet Model 35 series airplane operating 
under 14 CFR 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 
reported that the windows of the Model 35 series airplane were 
apparently frosted over, which prevented the flightcrews of the chase 
airplanes from observing the interior of the Model 35 series airplane. 
The flightcrews of the chase airplanes reported that they did not 
observe any damage to the airplane. Subsequently, the Model 35 series 
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 oxygen 
systems on Model 35 series 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 35/36 series 
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 Model 35A and 
36A series 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 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 horn could lead to incapacitation of the flightcrew.
    A review of the emergency procedures in the AFM for Model 1124 and 
1124A series airplanes revealed that the procedures for the flightcrew 
to don emergency oxygen masks is not the first and immediate step, but 
rather the second step when the warning horn sounds. Time spent 
troubleshooting the pressurization system following a cabin altitude 
alert may result in the flightcrew's incapacitation and consequent 
inability to continue to control the airplane before they are able to 
don oxygen masks. Therefore, these airplanes may be subject to the 
identified unsafe condition.

Explanation of Relevant Service Information

    Israel Aircraft Industries has issued Temporary Revision (TR) No. 3 
to the 1124 Westwind Airplane Flight Manual (AFM) and TR No. 5 to the 
1124A Westwind AFM. Both TRs are dated January 16, 2001. The TRs advise 
the flightcrew to don oxygen masks as a first and immediate step 
following a cabin altitude alert to prevent incapacitation of the 
flightcrew due to lack of oxygen. (Previously the AFMs advised the 
flightcrew to check the cabin altitude and differential pressure gauge 
before donning oxygen masks.) Accomplishment of the AFM revision is 
intended to adequately address the identified unsafe condition. The 
Civil Aviation Administration of Israel (CAAI), which is the 
airworthiness authority for Israel, approved these TRs and issued 
Israeli airworthiness directive 21-02-07-01, dated July 22, 2002, which 
mandates compliance with the TRs to ensure the continued airworthiness 
of these airplanes in Israel.

FAA's Conclusions

    These airplane models are manufactured in Israel and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the CAAI has kept the FAA informed 
of the situation described above. The FAA has examined the findings of 
the CAAI, reviewed all available information, and determined that AD 
action is necessary for products of this type design that are 
certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require an AFM revision to 
advise the flightcrew to don oxygen masks as a first and immediate step 
following a cabin altitude alert.

Cost Impact

    The FAA estimates that 198 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 actions, 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 
$11,880, 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

[[Page 14355]]

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.

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:

Israel Aircraft Industries, LTD.: Docket 2003-NM-01-AD.

    Applicability: All Model 1124 and 1124A series airplanes, 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent incapacitation of the flightcrew due to lack of 
oxygen, accomplish the following:

Revision to Airplane Flight Manual (AFM)

    (a) Within 1 month after the effective date of this AD, revise 
the Emergency Procedures section of the FAA-approved AFM, as 
specified in paragraph (a)(1) or (a)(2) of this AD, as applicable.
    (1) For Model 1124 series airplanes: Insert TR 3, dated January 
16, 2001, into the 1124 Westwind AFM.
    (2) For Model 1124A series airplanes: Insert TR 5, dated January 
16, 2001, into the 1124A Westwind AFM.
    (b) When the information in the TRs identified in paragraph (a) 
of this AD has been incorporated into the general revisions of the 
respective AFM, the general revisions may be incorporated into the 
AFMs, and these TRs may be removed from the AFM.

Alternative Methods of Compliance

    (c) 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, International Branch, ANM-116, 
Transport Airplane Directorate, FAA. Operators shall submit their 
requests through an appropriate FAA Principal Operations Inspector, 
who may add comments and then send it to the Manager, International 
Branch, ANM-116.

    Note 1: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

Special Flight Permits

    (d) 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.

    Note 2: The subject of this AD is addressed in Israeli 
airworthiness directive 21-02-07-01, dated July 22, 2002.


    Issued in Renton, Washington, on March 18, 2003.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-6996 Filed 3-24-03; 8:45 am]
BILLING CODE 4910-13-P