Federal Aviation Administration (FAA), DOT.
Notice of proposed rulemaking (NPRM).
The FAA proposes to adopt a new airworthiness directive (AD) for certain McDonnell Douglas transport category airplanes. This proposed AD would require doing repetitive detailed inspections for accumulation of debris (blockage) of the drain holes of the pitot tubes, and cleaning if any evidence of debris is found. This proposed AD is prompted by reports of blocked drain holes of the pitot tubes. We are proposing this AD to prevent blocked drain holes of the pitot tubes, which could result in the accumulation of water in the pitot-static system and consequent failure of that system. Failure of the pitot-static system could result in erroneous airspeed indications in the cockpit and consequent loss of airspeed control.
We must receive comments on this proposed AD by February 28, 2005.
Use one of the following addresses to submit comments on this proposed AD.
- DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
- Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
- Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
- By fax: (202) 493-2251.
- Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).
You can examine the contents of this AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2005-20034; the directorate identifier for this docket is 2004-NM-178-AD.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Technical information: Brett Portwood, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5350; fax (562) 627-5210.
Plain language information: Marcia Walters, firstname.lastname@example.org.End Further Info End Preamble Start Supplemental Information
Docket Management System (DMS)
The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2005-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2005-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.
We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-Start Printed Page 20632005-20034; Directorate Identifier 2004-NM-178-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that website, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.
We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.
Examining the Docket
You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.
On November 6, 1996, a McDonnell Douglas Model MD-11 airplane departed the end of the runway after landing in instrument meteorological conditions in Buenos Aires, Argentina. During approach to landing, the flight crew had several in-flight advisories, and the airplane excessively vibrated. The vibration was attributed to a flap overspeed condition caused by erroneous airspeed indications. Investigation revealed that the pitot-static system had accumulated a significant amount of water. The drain holes on two of the three pitot tubes were completely blocked by debris. The third pitot tube had one drain hole totally blocked and the other hole partially blocked.
In 1997, a similar incident of blocked drain holes of the pitot tubes occurred on another Model MD-11 airplane. Although the design of the pitot-static system was reviewed and found to meet FAA regulations, we determined that the maintenance task cards used by operators lacked sufficient detail about inspecting the drain holes of the pitot tubes. To correct this, in 2002, Boeing issued a report recommending additional maintenance actions. Since then there have been additional similar incidents, indicating that the manufacturer's recommendations have not been fully implemented.
Blocked drain holes of the pitot tubes, if not corrected, could result in the accumulation of water in the pitot-static system and consequent failure of that system. Failure of the pitot-static system could result in erroneous airspeed indications in the cockpit and consequent loss of airspeed control.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require doing repetitive detailed inspections (i.e., visual and forced-air checks) for accumulation of debris (blockage) of the drain holes of the pitot tubes, and cleaning if any evidence of debris is found. These inspections must be done by certificated maintenance personnel.
Costs of Compliance
There are about 314 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 216 airplanes of U.S. registry. The proposed inspections would take about 2 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $28,080, or $130 per airplane, per inspection cycle.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.
For the reasons discussed above, I certify that the 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. 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. We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):
McDonnell Douglas: Docket No. FAA-2005-20034; Directorate Identifier 2004-NM-178-AD. Start Printed Page 2064
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by February 28, 2005.
(c) This AD applies to all McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD-10-30F, MD-11, and MD-11F airplanes; certificated in any category.
(d) This AD was prompted by reports of blocked drain holes of the pitot tubes. We are issuing this AD to prevent blocked drain holes of the pitot tubes, which could result in the accumulation of water in the pitot-static system and consequent failure of that system. Failure of the pitot-static system could result in erroneous airspeed indications in the cockpit and consequent loss of airspeed control.
(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
(f) Within 90 days after the effective date of this AD, do a detailed inspection for accumulation of debris (blockage) of the drain holes of the pitot tubes in accordance with paragraphs (g) and (h) of this AD. The actions required by paragraph (g) must be done before those in paragraph (h) of this AD. Repeat the inspection thereafter at intervals not to exceed 650 flight hours.
For the purposes of this AD, a detailed inspection is “an intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required.”
(g) Do a visual check in accordance with paragraphs (g)(1) through (g)(3) of this AD. The visual check must be done by certificated maintenance personnel.
(1) Make certain that the pitot heat is off and the pitot tubes are not hot.
Caution. Exercise care in checking pitot tubes to prevent severe burns to your hands.
(2) Attempt to look through the left and right drain holes of each pitot tube.
(3) Make sure that ambient light (or flashlight) is visible through both drain holes of each pitot tube.
Forced Air Check
(h) Do a forced air check in accordance with paragraphs (h)(1) through (h)(3) of this AD. The forced air check must be done by certificated maintenance personnel.
Exercise care in checking pitot tubes to prevent severe burns to your hands.
(1) Make certain that the pitot heat is off and the pitot tubes are not hot.
Excessive, as well as sudden, pressurization or depressurization applied to a pitot system by either method can cause damage to instruments. Do not exceed 9.0 pounds per square inch (psi) or 550 knots when pressurizing the system. Do not exceed 1.0 psi per second or 90 knots per second when pressurizing or depressurizing the system.
(2) Three methods are given in Table 1 of this AD. Only one test must be done and all are equivalent.
|(i) 1||(A) Install a 9/16 inch (14 millimeter (mm)) inner diameter hose approximately three feet (1 meter) long to the end of the pitot tube; and|
|(B) Use the hose to carefully blow air (using your mouth) into the pitot tube.|
|(ii) 2||(A) Connect an air pressure source (dry Nitrogen) to the pitot tubes; and|
|(B) Adjust the pressure source to 5-psi maximum.|
|(iii) 3||(A) Connect a pitot static test set; and|
|(B) Adjust it to 450 knots at 0-feet altitude maximum.|
(3) Check for airflow out of each drain hole. Make sure that you do not cover the drain holes when checking.
Special Test Equipment
(i) If test method 3 in paragraph (h)(2)(iii) of this AD is used, an air data line tester with pitot and static port adapters is required.
(j) If any evidence of drain hole blockage (e.g., air exiting from any pitot drain hole cannot be felt on the hand) is found during any inspection required by paragraph (f), (g), or (h) of this AD, before further flight, clean the hole in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Chapter 34-11-02 of the applicable Boeing airplane maintenance manual is one approved method.
Alternative Methods of Compliance (AMOCs)
(k) The Manager, Los Angeles ACO, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.
Issued in Renton, Washington, on December 30, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 05-615 Filed 1-11-05; 8:45 am]
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