Federal Aviation Administration, DOT.
Final rule; request for comments.
This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53, DC-8-55, DC-8-61, DC-8-61F, DC-8-62, DC-8-62F, DC-8-63, DC-8-63F, DC-8F-54, and DC-8F-55 series airplanes. This action requires modification of the flow control system by rerouting the bleed air ducts to warm the pitot tube lines. This action is necessary to prevent the pitot lines from freezing, which could result in erroneous or total loss of airspeed indications to the flight crew, and consequent loss of control of the airplane. This action is intended to address the identified unsafe condition.
Effective March 21, 2001.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of March 21, 2001.
Comments for inclusion in the Rules Docket must be received on or before May 7, 2001.
Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-26-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: firstname.lastname@example.org. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-26-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 this AD may be obtained from National Aircraft Service, Inc., 9133 Tecumseh-Clinton Road, Tecumseh, Michigan 49286. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Chicago Aircraft Certification Office, 2330 East Devon Avenue, Room 323, Des Plaines, Illinois; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Roy Boffo, Aerospace Engineer, Systems and Flight Test Branch, ACE-117C, FAA, Chicago Aircraft Certification Office, 2350 East Devon Avenue, Room 323, Des Plaines, Illinois 60018; telephone (847) 294-7564; fax (847) 294-7834.End Further Info End Preamble Start Supplemental Information
The FAA has received reports of erroneous airspeed readings, including those from the airspeed indicator and Machmeter, after a McDonnell Douglas Model DC-8 series airplane had flown through visible moisture. The original airplane design included a turbo compressor system. The turbo compressors generated enough heat to prevent freezing of any trapped moisture in the lines running from the pitot tubes. The turbo compressors were removed during installation of Supplemental Type Certificate (STC) ST466CH, which incorporated a flow control system that Start Printed Page 13415uses bleed air from the engines. However, the flow control system did not generate enough heat in the area of the pitot tube lines to prevent freezing. Frozen pitot lines could generate erroneous or total loss of airspeed indications to the flight crew, which could result in loss of control of the airplane
A modification to positively address this unsafe condition was subsequently developed, and applicable parts and procedures were provided to operators of the affected airplanes. However, a recent fleetwide inspection revealed that not all of those airplanes had been modified.
Explanation of Relevant Service Information
National Aircraft Service, Inc., issued Service Bulletin SB-98-01R1, dated January 26, 1999, which the FAA reviewed and approved. The service bulletin describes procedures to modify the flow control system by rerouting the bleed air ducts to warm the pitot tube lines. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent the pitot lines from freezing, which could result in erroneous or total loss of airspeed indications to the flight crew, and consequent loss of control of the airplane. This AD requires accomplishment of the actions specified in the service bulletin described previously, except as discussed below.
Difference Between AD and Service Bulletin
The service bulletin recommends the modification within 500 flight hours after March 1, 1999; this AD requires the modification within 30 days after the effective date of this AD. In light of the urgency of the unsafe condition and the fact that the revised service bulletin has been available to affected operators for nearly two years, the FAA finds that the required compliance time represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.
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.
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.
Submit comments using the following format:
- 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.
- For each issue, state what specific change to the AD is being requested.
- 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 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 filed in 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 2001-NM-26-AD.” The postcard will be date stamped and returned to the commenter.
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 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.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
Adoption of the AmendmentStart Amendment Part
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (End Amendment Part Start Part
PART 39—AIRWORTHINESS DIRECTIVESEnd Part Start Amendment Part
1. The authority citation for part 39 continues to read as follows:End Amendment Part
2. Section 39.13 is amended by adding the following new airworthiness directive:End Amendment Part
2001-04-15 McDonnell Douglas: Amendment 39-12135. Docket 2001-NM-26-AD.
Applicability: The following Model DC-8 series airplanes that have been modified in accordance with Supplemental Type Certificate (STC) ST466CH, certificated in any category:Start Printed Page 13416
|DC-8-31 DC-8-32 DC-8-33 DC-8-41 DC-8-42 DC-8-43 DC-8-51 DC-8-52 DC-8-53||DC-8-55 DC-8-61 DC-8-61F DC-8-62 DC-8-62F DC-8-63 DC-8-63F DC-8F-54 DC-8F-55|
This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (b) 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 the pitot lines from freezing, which could result in erroneous or total loss of airspeed indications to the flight crew, and consequent loss of control of the airplane, accomplish the following:
(a) Within 30 days after the effective date of this AD, modify the flow control system to reroute the bleed air ducts, in accordance with National Aircraft Service, Inc., Service Bulletin SB-98-01R1, dated January 26, 1999.
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, Chicago Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Chicago ACO.
Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Chicago 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.
Incorporation by Reference
(d) The actions shall be done in accordance with National Aircraft Service, Inc., Service Bulletin SB-98-01R1, dated January 26, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from National Aircraft Service, Inc., 9133 Tecumseh-Clinton Road, Tecumseh, Michigan 49286. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Chicago Aircraft Certification Office, 2330 East Devon Avenue, Room 323, Des Plaines, Illinois; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(e) This amendment becomes effective on March 21, 2001.Start Signature
Issued in Renton, Washington, on February 22, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 01-4933 Filed 3-5-01; 8:45 am]
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