E6-14628. Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This proposed AD would require repetitive cleaning/inspecting of the drain hole of each pitot static probe and repetitive cleaning of the pitot lines in the pitot static system. This proposed AD results from reports of incidents of airspeed mismatch between the pilot, co-pilot, and standby airspeed indications caused by contamination in the pitot static system. We are proposing this AD to prevent erroneous/misleading altitude and airspeed information from a contaminated pitot static system to the flightcrew, which could reduce the ability of the flightcrew to maintain the safe flight and landing of the airplane.

DATES:

We must receive comments on this proposed AD by October 5, 2006.

ADDRESSES:

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.
• Fax: [phone].
• 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.

Contact Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Ezra Sasson, Aerospace Engineer, Systems Flight Test Branch, ANE-172, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York 11590; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-25723; Directorate Identifier 2006-NM-007-AD” at the beginning 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 received 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 Web site, 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 may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may 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 [phone]) 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 Docket Management System receives them.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified us that an unsafe condition may exist on certain Bombardier Model DHC-8-400 series airplanes. TCCA advises that it has received reports of incidents of airspeed mismatch between the pilot, co-pilot, and standby airspeed indications. The cause of these incidents is believed to be contamination in the pitot lines and/or blockage in the pitot static probes. Blockage of a probe's pitot drain may allow enough moisture to enter the tube's internal pitot line, which could freeze under certain conditions, causing a blockage of the pitot line. This condition, if not corrected, could result in erroneous/misleading altitude and airspeed information to the flightcrew, which could reduce the ability of the flightcrew to maintain the safe flight and landing of the airplane.

Relevant Service Information

Bombardier has issued Task 20-00-40-170-801 in the Bombardier Dash 8 Q400 Aircraft Maintenance Manual (AMM), PSM 1-84-2, Part 2, Revision 21, dated December 5, 2005. This task describes procedures for cleaning the drain hole of the pitot static probes and examining the hole for blockage. Bombardier has also issued Task 34-11-00-170-801 in the Bombardier Dash 8 Q400 AMM, PSM 1-84-2, Part 2, Revision 21, dated December 5, 2005. Task 34-11-00-170-801 describes procedures for cleaning the pitot and static lines of the pitot static system. TCCA mandated the service information and issued Canadian airworthiness directive CF-2005-15, dated May 18, 2005, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

These airplane models are manufactured in Canada 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, TCCA has kept the FAA informed of the situation described above. We have examined TCCA's findings, evaluated all pertinent information, and determined that we need to issue an AD for airplanes of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.

Clarification of Compliance Times

The compliance time for inspecting the drain holes of the pitot static probes is before further flight following the cleaning of the drain holes. This is not made clear in paragraph A.1.b. of the Canadian airworthiness directive.

The compliance time for repeating the cleaning and inspection of blocked drain holes of the pitot static probes is before further flight. This is also not made clear in paragraph A.1.c. of the Canadian airworthiness directive.

Clarification of Certain Actions

Task 34-11-00-170-801 in the Bombardier Dash 8 Q400 AMM, PSM 1-84-2, Part 2, describes procedures for cleaning both the pitot and static lines of the pitot static system. This proposed AD would only require cleaning of the pitot lines; cleaning of the static lines is not necessary to address the unsafe condition that is the subject of this proposed AD. The Canadian airworthiness directive also requires cleaning of only the pitot lines of the pitot static system.

Interim Action

We consider this proposed AD interim action. The manufacturer is currently developing a modification that will address the unsafe condition identified in this proposed AD. Once this modification is developed, approved, and available, we may consider additional rulemaking.

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this proposed AD. There are about 181 airplanes of U.S. registry.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per airplane	Fleet cost
Clean/inspect pitot drain holes	1, per clean/inspection cycle	$80	$80, per clean/inspection cycle	$14,480, per clean/inspection cycle.
Clean pitot lines	2, per clean cycle	80	$160, per clean cycle	$28,960, per clean 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.

Regulatory Findings

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 and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2006-25723; Directorate Identifier 2006-NM-007-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by October 5, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies Bombardier Model DHC-8-400, DHC-8-401, and DHC-8-402 airplanes, certificated in any category; serial numbers 4001 and 4003 and subsequent.

Unsafe Condition

(d) This AD results from reports of incidents of airspeed mismatch between the pilot, co-pilot, and standby airspeed indications caused by contamination in the pitot static system. We are issuing this AD to prevent erroneous/misleading altitude and airspeed information from a contaminated pitot static system to the flightcrew, which could reduce the ability of the flightcrew to maintain the safe flight and landing of the airplane.

Compliance

(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.

Initial and Repetitive Cleaning and Inspection of the Pitot Static Drain Holes

(f) Within 30 days after the effective date of this AD, do paragraphs (f)(1) and (f)(2) of this AD. Thereafter, repeat the actions in paragraphs (f)(1) and (f)(2) of this AD at intervals not to exceed 70 flight hours.

(1) Clean the drain holes of all the pitot static probes in accordance with a method approved by the Manager, New York Aircraft Certification Office (ACO), FAA. Paragraph 4.B., Procedure 2, subparagraphs (1) through (3) of Bombardier Task 20-00-40-170-801 in the Bombardier Dash 8 Q400 Aircraft Maintenance Manual (AMM), PSM 1-84-2, Part 2, is one approved method for accomplishing the requirements of this paragraph.

(2) Before further flight after cleaning the drain holes of the pitot static probes, as specified in paragraph (f)(1) of this AD, do a general visual inspection of the drain holes of all the pitot static probes for blockages, in accordance with a method approved by the Manager, New York ACO. Paragraph 4.A., Procedure 1, of Bombardier Task 20-00-40-170-801 in the Bombardier Dash 8 Q400 AMM, PSM 1-84-2, Part 2, is one approved method for accomplishing the requirements of this paragraph.

Note 1:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(g) If any blockage is found in the drain hole of any pitot static probe during the inspection required in paragraph (f)(2) of this AD, before further flight, repeat the cleaning and inspection specified in paragraphs (f)(1) and (f)(2) of this AD on the affected pitot static probe.

Cleaning of the Pitot Static Lines

(h) Within 30 days after the effective date of this AD, clean the pitot lines of the pitot static system in accordance with a method approved by the Manager, New York ACO. Bombardier Task 34-11-00-170-801 in the Bombardier Dash 8 Q400 AMM, PSM 1-84-2, Part 2, is one approved method for accomplishing the actions required by this paragraph. Thereafter, repeat the cleaning of the pitot lines at intervals not to exceed 600 flight hours.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, New York ACO, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Related Information

(j) Canadian airworthiness directive CF-2005-15, dated May 18, 2005, also addresses the subject of this AD.

Issued in Renton, Washington, on August 23, 2006.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.