Airworthiness directives: C'' transponder(s) with single Gillham code altitude input,

[Federal Register: December 16, 1999 (Volume 64, Number 241)]

[Rules and Regulations]

[Page 70181-70184]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr16de99-3]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-328-AD; Amendment 39-11473; AD 99-23-22 R1]

RIN 2120-AA64

Airworthiness Directives; Various Transport Category Airplanes Equipped With Mode ``C'' Transponder(s) With Single Gillham Code Altitude Input

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

SUMMARY: This amendment revises an existing airworthiness directive (AD), applicable to various transport category airplanes equipped with certain Mode ``C'' transponder(s) with single Gillham code altitude input. That AD currently requires repetitive tests to detect discrepancies of the Mode ``C'' transponder(s), air data computer, and certain wiring connections; and corrective actions, if necessary. The existing AD is prompted by reports that, during level flight, the Traffic Alert Collision Avoidance System (TCAS II) issued false advisories that directed the flightcrew to change course and either climb or descend. The actions specified by that AD are intended to prevent such false advisories due to inaccurate airplane altitude reporting, which could result in the flightcrew deviating the airplane from its assigned flight path and a possible mid-air collision. This new action revises certain compliance times and limits the applicability of the existing AD.

DATES: Effective November 29, 1999.

Comments for inclusion in the Rules Docket must be received on or before February 14, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-328-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Information pertaining to this amendment may be obtained from or examined at the FAA, Transport Airplane Directorate, 1601 Lind Ave, SW., Renton, Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT: Peter Skaves, Aerospace Engineer, Airplane and Flight Crew Interface Branch, ANM-111, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington

[[Page 70182]]

98055-4056; telephone (425) 227-2795; fax (425) 227-1320.

SUPPLEMENTARY INFORMATION: On November 4, 1999, the FAA issued AD 99- 23-22, amendment 39-11418 (64 FR 61493, November 12, 1999), applicable to various transport category airplanes equipped with certain Mode ``C'' transponder(s) with single Gillham code altitude input. That AD requires repetitive tests to detect discrepancies of the Mode ``C'' transponder(s), air data computer, and certain wiring connections; and corrective actions, if necessary. That action was prompted by reports that, during level flight, the Traffic Alert Collision Avoidance System (TCAS II) issued false advisories that directed the flightcrew to change course and either climb or descend. The actions required by that AD are intended to prevent such false advisories due to inaccurate airplane altitude reporting, which could result in the flightcrew deviating the airplane from its assigned flight path and a possible mid-air collision.

Actions Since Issuance of Previous Rule

Since the issuance of AD 99-23-22, the FAA has determined that the existing AD should be revised as follows:

1. The applicability section of the existing AD has been revised to identify only airplane models used in the same type of operations as those involved in the reported incidents of reduced airplane separation. Specifically, the applicable airplane models have been limited to only those transport category airplanes that can be operated for extended periods in level flight cruise at altitudes greater than 24,000 feet and that are equipped with Mode ``C'' transponder(s) with single Gillham code altitude input. As the FAA has not yet determined the precise cause of the erroneous Mode ``C'' altitude reporting, investigations into the cause of the unsafe condition are continuing. The FAA has determined that the applicability of the existing AD should be limited to airplanes with more exposure to the potential risks of incorrect altitude reporting. Based on the review of the data received from these airplane inspections, the FAA may consider future rulemaking to expand the applicability of this AD.

2. A note has been added to the existing AD to clarify that the requirements of that AD DO NOT supersede the current airplane Master Minimum Equipment List (MMEL) requirements for deferral of repair of malfunctioning systems. The existing AD states that any malfunctioning Mode ``C'' altitude reporting system is to be repaired prior to further flight. Note 3 of this revised AD explains that Mode ``C'' transponder altitude reporting systems that have been determined to be malfunctioning must be turned off and placarded as inoperative, as specified in the MMEL. The airplane may then be operated in accordance with the MMEL.

3. The compliance time for accomplishment of the initial and repetitive tests required by paragraph (a) of the existing AD has been extended from 45 days to 90 days after the effective date of the existing AD. Test results received to date indicate that a substantial number of airplanes have already been tested without failures. Based on these test results and on the increased awareness of operators using Mode ``C'' altitude reporting, the FAA has determined that the risk of exposure to incorrect altitude reporting has been sufficiently reduced to allow extension of the compliance time for accomplishment of the initial and repetitive testing. Extended test intervals also will provide additional time for operators required to schedule and execute the tests. In addition, the reporting requirement specified in paragraph (c) of the existing AD has been extended from 10 days to 20 days after accomplishment of the initial and repetitive tests required by paragraph (a) of the existing AD.

4. The alternative method of compliance paragraph of the existing AD has been revised to identify the Manager, Airplane and Flight Crew Interface Branch, Transport Airplane Directorate, as the point of contact in lieu of the Manager, Seattle Aircraft Certification Office.

   Explanation of Requirements of Rule

   Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD revises AD 99-23-22 to continue to require repetitive tests to detect discrepancies of the Mode ``C'' transponder(s), air data computer, and certain wiring connections; and corrective actions, if necessary. This action revises certain compliance times and limits the applicability of the existing AD. This AD also includes a note which describes provisions for continued operation of the airplane in accordance with the provisions and limitations specified in the operator's FAA-approved Master Minimum Equipment List (MMEL).

   Interim Action

   This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

   Determination of Rule's Effective Date

   Since a situation exists that requires the immediate adoption of this regulation, it is found 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

   Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

   Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filedin the Rules Docket.

   Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 99-NM-328-AD.'' The postcard will be date stamped and returned to the commenter.

   Regulatory Impact

   The regulations adopted herein 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 responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

   The FAA has determined that this regulation is an emergency regulation

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   that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from 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.

   Adoption of the Amendment

   Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 removing amendment 39-11418 (64 FR 61493, November 12, 1999), and by adding a new airworthiness directive (AD), amendment 39-11473, to read as follows:

   099-23-22 R1 Transport Category Airplanes: Amendment 39-11473. Docket 99-NM-328-AD. Revises AD 99-23-22, Amendment 39-11418.

   Applicability: Transport category airplanes, as listed below, certificated in any category, equipped with any Mode ``C'' transponder with single Gillham code altitude input, including, but not limited to, the transponder part numbers listed below. Whether a Mode ``C'' transponder has a single Gillham code altitude input may be determined by reviewing the transponder installation instructions.

   Airplane Models

   Airbus Industrie

   A300

   A310 British Aerospace

   BAe Avro 146-RJ

   BAe ATP Fokker

   F28 Mark 0070

   F28 Mark 0100

   F28 Mark 1000-4000 Lockheed

   L-1011 TriStar

   L-188 Electra CASA

   CN-235 Dassault Aviation

   Mystere Falcon 50

   Mystere Falcon 900

   Mystere Falcon 200

   Fan Jet Falcon Series G Boeing (MDC)

   DC-10-30

   DC-10-40

   DC-9

   DC-9-81

   DC-9-82

   DC-9-83

   DC-9-87

   Boeing 707

   Boeing 727

   Boeing 737

   Boeing 747 Bombardier

   CL-215-1A10

   CL-215-6B11

   CL-600-1A11

   CL-600-2A12

   CL-600-2B16 Gulfstream

   G1159 (G-II)

   G-1159A (G-III)

   G-IV

   Mode ``C'' Transponder Part Numbers:

   Rockwell Collins

   622-2224-001

   622-2224-003

   522-2703-001

   522-2703-011

   787-6211-001

   787-6211-002 Bendix

   066-1056-00

   066-1056-01

   066-1123-00

   2041599-6508 Wilcox

   97637-201

   97637-301 IFF

   APX-100

   APX-101

   Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

   Compliance: Required as indicated, unless accomplished previously.

   To prevent false Traffic Alert Collision Avoidance System (TCAS II) advisories due to inaccurate airplane altitude reporting, which could result in the flightcrew deviating the airplane from its assigned flight path and a possible mid-air collision, accomplish the following:

   Repetitive Tests

   (a) Within 90 days after November 29, 1999 (the effective date of AD 99-23-22, amendment 39-11418): Perform the test procedures specified in paragraphs (a)(1) through (a)(9) of this AD to detect any discrepancies of the Mode ``C'' transponder(s), air data computer (ADC), or Gillham wiring connections, in accordance with the applicable ADC and Mode ``C'' transponder component maintenance manuals and airplane maintenance manual. Repeat the test procedures thereafter at intervals not to exceed 90 days.

   (1) Connect an air data test set to the Captain's (No. 1) Pitot/ Static system.

   (2) In the airplane flight deck, select Mode ``C'' transponder (1), or left Mode ``C'' transponder, depending on airplane flight deck configuration, and select ADC source (1).

   (3) Select the air data test set to the following altitude reporting values:

   1,000 feet; 4,100 feet; 15,700 feet; and 31,000 feet.

   (4) For each selected altitude, verify that the Mode ``C'' altitude reporting is within tolerance (+/-125 feet), and record the altitude output as follows: 1,000 feet (+/-125 feet); 4,100 feet (+/-125 feet); 15,700 (+/-125 feet); and 31,000 feet (+/-125 feet).

   (5) In the airplane flight deck, select ADC source (2) and repeat paragraphs (a)(3) and (a)(4) of this AD.

   (6) In the airplane flight deck, select Mode ``C'' transponder (2), or the right Mode ``C'' transponder, depending on airplane flight deck configuration, select ADC source (1), and repeat paragraphs (a)(3) and (a)(4) of this AD.

   (7) In the airplane flight deck, select ADC source (2) and repeat paragraphs (a)(3) and (a)(4) of this AD.

   (8) Connect an air data test set to the Captain's (No. 2) Pitot/ Static system.

   (9) Repeat paragraphs (a)(2) through (a)(7) of this AD.

   Note 2: The tests required by paragraph (a) of this AD examine the three primary sources of inaccurate airplane altitude reporting. These three sources are: ADC's, Mode ``C'' transponders, and the Gillham wiring connections between the ADC and Mode ``C'' transponder.

   Corrective Actions

   (b) Except as permitted by the Master Minimum Equipment List (MMEL): If any discrepancy is detected during any test required by paragraph (a) of this AD: Prior to further flight, repair in accordance with the applicable ADC and Mode ``C'' transponder component maintenance manual and airplane maintenance manual. If the repair information is not available in the applicable manual, except as permitted by the MMEL, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

   Note 3: The airplane may be operated in accordance with the provisions and

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   limitations specified in the FAA-approved MMEL, provided that only one Mode ``C'' transponder on the airplane is inoperative.

   Reporting Requirement

   (c) Within 20 days after accomplishing the initial and repetitive tests required by paragraph (a) of this AD, submit a report of the inspection and test results (both positive and negative findings) to: Peter Skaves, Aerospace Engineer, Airplane and Flight Crew Interface Branch, ANM-111, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; fax (425) 227-1320. The test results must include the Mode ``C'' transponder(s) and ADC part number(s), and must specify if any discrepancies of the Gillham wiring connections were detected, and if corrective action was required. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

   Alternative Methods of Compliance

   (d) 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, Airplane and Flight Crew Interface Branch, ANM-111, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance or Avionics Inspector, who may add comments and then send it to the Manager, ANM-111.

   Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Manager, ANM-111.

   Special Flight Permits

   (e) 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.

   (f) The effective date of this amendment remains November 29, 1999.

   Issued in Renton, Washington, on December 10, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-32584Filed12-15-99; 8:45 am]

   BILLING CODE 4910-13-P