E6-21267. Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires 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 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.

DATES:

This AD becomes effective January 19, 2007.

ADDRESSES:

You may examine the 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., Nassif Building, Room PL-401, Washington, DC.

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

FOR FURTHER INFORMATION CONTACT:

Ezra Sasson, Aerospace Engineer, Systems and 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:

Examining the Docket

You may examine the airworthiness directive (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 street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Bombardier Model DHC-8-400 series airplanes. That NPRM was published in the Federal Register on September 5, 2006 (71 FR 52300). That NPRM proposed to 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.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the single comment received.

Request To Include Terminating Action for the Repetitive Inspections of the Pitot Static Drain Holes

Horizon Air has no objection to the NPRM, but requests that we add a terminating action for the repetitive inspections of the pitot static drain holes specified in paragraph (f) of the NPRM. Horizon states that Bombardier has issued Service Bulletin 84-34-59, Revision A, dated January 9, 2006, to correct the moisture in the pitot static system. Horizon states that the service bulletin specifies installing new tube assemblies with a larger diameter; these tube assemblies are designed to improve the water drainage characteristics of the pitot static system and reduce airspeed mismatch events.

We do agree that the procedures provided in Bombardier Service Bulletin 84-34-59, Revision A, dated January 9, 2006, would improve drainage; however, we have learned that Bombardier is in the process of revising this service bulletin. Once this service bulletin is revised and approved, we may consider issuing additional rulemaking to mandate the actions specified in the revised service bulletin, along with a modification to prevent the freezing of moisture once the modification is developed, approved, and available, which will be provided in a separate service bulletin. Together, the actions in these service bulletins are intended to terminate the requirements of this AD. We have made no change to the final rule in this regard.

Conclusion

We have carefully reviewed the available data, including the single comment received, and determined that air safety and the public interest require adopting the AD as proposed.

Interim Action

We consider this AD interim action. The manufacturer is currently developing a modification that will address the unsafe condition identified in this 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 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 AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under 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 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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):

2006-25-17 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 39-14858. Docket No. FAA-2006-25723; Directorate Identifier 2006-NM-007-AD.

Effective Date

(a) This AD becomes effective January 19, 2007.

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.

Material Incorporated by Reference

(k) None.

Issued in Renton, Washington, on December 7, 2006.

Michael J. Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.