94-17194. Airworthiness Directives; Jetstream Model 4101 Airplanes  

  • [Federal Register Volume 59, Number 135 (Friday, July 15, 1994)]
    [Unknown Section]
    [Page 0]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 94-17194]
    
    
    [[Page Unknown]]
    
    [Federal Register: July 15, 1994]
    
    
    =======================================================================
    -----------------------------------------------------------------------
    
    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 94-NM-66-AD]
    
     
    
    Airworthiness Directives; Jetstream Model 4101 Airplanes
    
    AGENCY: Federal Aviation Administration, DOT.
    
    ACTION: Notice of proposed rulemaking (NPRM).
    
    -----------------------------------------------------------------------
    
    SUMMARY: This document proposes the adoption of a new airworthiness 
    directive (AD) that is applicable to certain Jetstream Model 4101 
    airplanes. This proposal would require installation of additional 
    venting between the flight deck and the passenger compartment. This 
    proposal is prompted by results of an engineering analysis that 
    revealed there was insufficient venting in the forward stowage and 
    wardrobe assembly. The actions specified by the proposed AD are 
    intended to prevent injury to the crew resulting from structural 
    failure of the bulkhead between the flight deck and the passenger 
    compartment in the event of windshield failure and subsequent rapid 
    decompression.
    
    DATES: Comments must be received by September 20, 1994.
    
    ADDRESSES: Submit comments in triplicate to the Federal Aviation 
    Administration (FAA), Transport Airplane Directorate, ANM-103, 
    Attention: Rules Docket No. 94-NM-66-AD, 1601 Lind Avenue, SW., Renton, 
    Washington 98055-4056. Comments may be inspected at this location 
    between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
    holidays.
        The service information referenced in the proposed rule may be 
    obtained from Jetstream Aircraft, Inc., P. O. Box 16029, Dulles 
    International Airport, Washington, D.C. 20041-6029. This information 
    may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
    Avenue, SW., Renton, Washington.
    
    FOR FURTHER INFORMATION CONTACT: Bud Schroeder, Aerospace Engineer, 
    Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
    1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
    227-2148; fax (206) 227-1320.
    
    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 notice may be changed in 
    light of the comments received.
        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 notice must submit a self-addressed, 
    stamped postcard on which the following statement is made: ``Comments 
    to Docket Number 94-NM-66-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-103, Attention: Rules 
    Docket No. 94-NM-66-AD, 1601 Lind Avenue, SW., Renton, Washington 
    98055-4056.
    
    Discussion
    
        The Civil Aviation Authority (CAA), which is the airworthiness 
    authority for the United Kingdom, recently notified the FAA that an 
    unsafe condition may exist on certain Jetstream Model 4101 airplanes. 
    The CAA advises that results of an engineering analysis have revealed 
    that there is insufficient venting in the left and right forward 
    stowage and the right forward wardrobe assembly between the flight deck 
    and the passenger compartment. This condition, if not corrected, could 
    result in injury to the crew due to structural failure of the bulkhead 
    between the flight deck and the passenger compartment in the event of 
    windshield failure and subsequent rapid decompression. Although the 
    forward flight attendant seat is attached to this bulkhead, integrity 
    of the airplane hull is not a risk factor in this situation.
        Jetstream Aircraft Limited has issued Service Bulletin J41-25-018, 
    dated March 15, 1994, that describes procedures for installing 
    additional venting in the left and right forward stowage and the right 
    forward wardrobe assembly. This additional venting would provide faster 
    pressure equalization between the flight deck and the passenger 
    compartment in the event of a sudden depressurization of the pilots' 
    compartment. Faster pressure equalization will prevent structural 
    failure of the bulkhead in the event of rapid depressurization. The CAA 
    classified this service bulletin as mandatory in order to assure the 
    continued airworthiness of these airplanes in the United Kingdom.
        This airplane model is manufactured in the United Kingdom and is 
    type certificated for operation in the United States under the 
    provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 
    21.29) and the applicable bilateral airworthiness agreement. Pursuant 
    to this bilateral airworthiness agreement, the CAA has kept the FAA 
    informed of the situation described above. The FAA has examined the 
    findings of the CAA, 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.
        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 installation of 
    additional venting between the flight deck and the passenger 
    compartment. The actions would be required to be accomplished in 
    accordance with the service bulletin described previously.
        The FAA estimates that 10 airplanes of U.S. registry would be 
    affected by this proposed AD, that it would take approximately 40 work 
    hours per airplane to accomplish the proposed actions, and that the 
    average labor rate is $55 per work hour. Required parts would be 
    provided by the manufacturer at no cost to the operators. Based on 
    these figures, the total cost impact of the proposed AD on U.S. 
    operators is estimated to be $22,000, or $2,200 per airplane.
        The total 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 AD were not adopted.
        The regulations proposed herein would not have substantial direct 
    effects 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, in 
    accordance with Executive Order 12612, it is determined that this 
    proposal would not have sufficient federalism implications to warrant 
    the preparation of a Federalism Assessment.
        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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
    106(g); and 14 CFR 11.89.
    
    
    Sec. 39.13  [Amended]
    
        2. Section 39.13 is amended by adding the following new 
    airworthiness directive:
    
    Jetstream Aircraft Limited: Docket 94-NM-66-AD.
    
        Applicability: Model 4101 airplanes; constructors numbers 41005 
    through 41015 inclusive, 41019 through 41024 inclusive, 41028, and 
    41029; certificated in any category.
        Compliance: Required as indicated, unless accomplished 
    previously.
        To prevent injury to the crew resulting from structural failure 
    of the bulkhead between the flight deck and the passenger 
    compartment in the event of windshield failure and subsequent rapid 
    decompression, accomplish the following:
        (a) Within 525 hours time-in-service after the effective date of 
    this AD, install additional decompression vents in the left and 
    right stowage and the right forward wardrobe assembly bulkhead 
    between the flight deck and passenger compartment, in accordance 
    with Jetstream Service Bulletin J41-25-018, dated March 15, 1994.
        (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, Standardization Branch, ANM-113, 
    FAA, Transport Airplane Directorate. Operators shall submit their 
    requests through an appropriate FAA Principal Maintenance Inspector, 
    who may add comments and then send it to the Manager, 
    Standardization Branch, ANM-113.
    
        Note: Information concerning the existence of approved 
    alternative methods of compliance with this AD, if any, may be 
    obtained from the Standardization Branch, ANM-113.
    
        (c) Special flight permits may be issued in accordance with 
    Sec. Sec.  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 July 11, 1994.
    Darrell M. Pederson,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 94-17194 Filed 7-14-94; 8:45 am]
    BILLING CODE 4910-13-U
    
    
    

Document Information

Published:
07/15/1994
Department:
Federal Aviation Administration
Entry Type:
Uncategorized Document
Action:
Notice of proposed rulemaking (NPRM).
Document Number:
94-17194
Dates:
Comments must be received by September 20, 1994.
Pages:
0-0 (1 pages)
Docket Numbers:
Federal Register: July 15, 1994, Docket No. 94-NM-66-AD
CFR: (2)
14 CFR Sec
14 CFR 39.13