[Federal Register Volume 71, Number 171 (Tuesday, September 5, 2006)]
[Proposed Rules]
[Pages 52300-52302]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-14628]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25723; Directorate Identifier 2006-NM-007-AD]
RIN 2120-AA64


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: (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.
    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 (516) 228-7320; fax (516) 794-5531.

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,

[[Page 52301]]

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

[[Page 52302]]

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.


Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  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 Sec.  
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.
 [FR Doc. E6-14628 Filed 9-1-06; 8:45 am]
BILLING CODE 4910-13-P