[Federal Register Volume 69, Number 100 (Monday, May 24, 2004)]
[Proposed Rules]
[Pages 29477-29480]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11644]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-CE-48-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc. Model DHC-3 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Bombardier, Inc. Model DHC-3 airplanes modified with A. M. 
Luton's Supplemental Type Certificate (STC) number SA3777NM. This 
proposed AD would require you to inspect the wiring for the heating 
blankets on P3 and PY pneumatic lines and the 
push-to-test function lights to ensure that they are wired to the 
correct schematic; replace the circuit breaker switch as applicable; 
and replace the flight manual supplement currently in use with Revision 
G, dated March 28, 2001 (incorporates Revision I of Sheet I of Drawing 
20075, ``Electrical System Schematic,'' dated October 10, 2000). This 
proposed AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for Canada. We 
are issuing this proposed AD to detect and correct wiring installed in 
accordance with an incorrect drawing, which shows the pneumatic heating 
blankets to the P3 and PY pneumatic lines wired 
in series with the indicator lights, rather than parallel. This can 
result in reduced current for the heating blankets and loss of 
pneumatic line heating, which can lead to loss of engine power or 
reverse propeller overspeed governing protection and ultimately loss of 
control of the airplane.

DATES: We must receive any comments on this proposed AD by July 15, 
2004.

ADDRESSES: Use one of the following to submit comments on this proposed 
AD:
     By mail: FAA, Central Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2003-CE-48-AD, 901 Locust, Room 
506, Kansas City, Missouri 64106.
     By fax: (816) 329-3771.
     By e-mail: [email protected]. Comments sent 
electronically must contain ``Docket No. 2003-CE-48-AD'' in the subject 
line. If you send comments electronically as attached electronic files, 
the files must be formatted in Microsoft Word 97 for Windows or ASCII.
    You may get the service information identified in this proposed AD 
from A. M. Luton, 3025 Eldridge Ave., Bellingham, WA 98225.
    You may view the AD docket at FAA, Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 2003-CE-48-AD, 901 
Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. 
to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Richard Simonson, Aerospace Engineer, 
Special Certification Branch; telephone: 425-917-6507; facsimile: 425-
917-6590.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    How do I comment on this proposed AD? We invite you to submit any 
written relevant data, views, or arguments regarding this proposal. 
Send your comments to an address listed under ADDRESSES. Include ``AD 
Docket No. 2003-CE-48-AD'' in the subject line of your comments. If you 
want us to acknowledge receipt of your mailed comments, send us a self-
addressed, stamped postcard with the docket number written on it. We 
will date-

[[Page 29478]]

stamp your postcard and mail it back to you.
    Are there any specific portions of this proposed AD I should pay 
attention to? We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of this 
proposed AD. If you contact us through a nonwritten communication and 
that contact relates to a substantive part of this proposed AD, we will 
summarize the contact and place the summary in the docket. We will 
consider all comments received by the closing date and may amend this 
proposed AD in light of those comments and contacts.

Discussion

    What events have caused this proposed AD? Transport Canada, which 
is the airworthiness authority for Canada, recently notified FAA that 
an unsafe condition may exist on all Bombardier, Inc. Model DHC-3 
airplanes modified with an A. M. Luton Supplemental Type Certificate 
(STC) number SA3777NM. Transport Canada reports a drawing error on 
Revisions G and H of Sheet I of the Electrical System Schematic Drawing 
20075, which shows the pneumatic heating blankets to the P3 
and PY pneumatic lines wired in series with the indicator 
lights, rather than parallel. This can result in severely reduced 
electrical energy going to the heating blankets with loss of pneumatic 
line heating, which can lead to loss of engine power or reverse 
propeller overspeed governing protection.
    What are the consequences if the condition is not corrected? 
Electrical installation using incorrect wiring configurations could 
result in the electrical energy being absorbed by the light bulbs with 
insufficient electrical energy for the heating blankets, which would 
allow ice to form in these lines due to condensation even though the 
indication lights show the lines being heated. This could result in 
loss of engine power or reverse propeller overspeed governing 
protection and lead to loss of control of the airplane.
    Is there service information that applies to this subject? A. M. 
Luton has issued Service Information Letter SIL-00-10-10, Electrical 
Systems, dated March 22, 2001.
    What are the provisions of this service information? The service 
letter includes procedures for:
    --Replacing the flight manual supplement with Revision G, dated 
March 28, 2001. This flight manual revision corrects the drawing error 
on Revisions G and H of Sheet I of the Electrical System Schematic 
Drawing 20075, by incorporating Revision I of Sheet I of Drawing 20075, 
``Electrical System Schematic,'' dated October 10, 2000;
    --Inspecting the push-to-test indicator light for correct wiring; 
and
    --Replacing the circuit breaker switch for the P3 and 
PY pneumatic heating lines, depending on whether the engine 
uses one or both heating lines.
    What action did Transport Canada take? Transport Canada classified 
this service bulletin as mandatory and issued Canadian AD Number CF-
2002-38, dated August 29, 2002, to ensure the continued airworthiness 
of these airplanes in Canada.
    Did Transport Canada inform the United States per the bilateral 
airworthiness agreement? These Bombardier, Inc. DHC-3 airplanes 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.
    Under this bilateral airworthiness agreement, Transport Canada has 
kept us informed of the situation described above.

FAA's Determination and Requirements of This Proposed AD

    What has FAA decided? We have examined Transport Canada's findings, 
reviewed all available information, and determined that AD action is 
necessary for products of this type design that are certificated for 
operation in the United States.
    Since the unsafe condition described previously is likely to exist 
or develop on other Bombardier, Inc. DHC-3 airplanes of the same type 
design modified with A. M. Luton's STC number SA3777NM and are 
registered in the United States, we are proposing AD action to detect 
and correct incorrect wiring configuration. This can result in the 
electrical energy being absorbed by the light bulbs with insufficient 
electrical energy for the heating blankets, which would allow ice to 
form in these lines due to condensation even though the indication 
lights show the lines being heated. This could result in loss of engine 
power or reverse propeller overspeed governing protection and lead to 
loss of control of the airplane.
    What would this proposed AD require? This proposed AD would require 
you to incorporate the actions in the previously-referenced service 
information letter.
    How does the revision to 14 CFR part 39 affect this proposed AD? On 
July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 
47997, July 22, 2002), which governs FAA's AD system. This regulation 
now includes material that relates to altered products, special flight 
permits, and alternative methods of compliance. This material 
previously was included in each individual AD. Since this material is 
included in 14 CFR part 39, we will not include it in future AD 
actions.

Costs of Compliance

    How many airplanes would this proposed AD impact? We estimate that 
this proposed AD affects 32 airplanes in the U.S. registry.
    What would be the cost impact of this proposed AD on owners/
operators of the affected airplanes? We have no way of determining the 
number of airplanes that may need the proposed rewiring or circuit 
breaker switch replacement. We estimate the following costs to 
accomplish this proposed inspection:

----------------------------------------------------------------------------------------------------------------
                                                                                 Total cost per   Total cost on
                          Labor cost                              Parts cost        airplane      U.S. operators
----------------------------------------------------------------------------------------------------------------
1 workhour est. $65 per hour = $65...........................            $100             $165           $5,280
----------------------------------------------------------------------------------------------------------------

Regulatory Findings

    Would this proposed AD impact various entities? 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.
    Would this proposed AD involve a significant rule or regulatory 
action? For the reasons discussed above, I certify that this proposed 
AD:
    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

[[Page 29479]]

    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 summary of the costs to comply with this proposed AD 
and placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 2003-CE-48-AD'' in your request.

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

Bombardier, Inc.: Docket No. 2003-CE-48-AD

When Is the Last Date I Can Submit Comments on This Proposed AD?

    (a) We must receive comments on this proposed airworthiness 
directive (AD) by July 15, 2004.

What Other ADs Are Affected by This Action?

    (b) None.

What Airplanes Are Affected by This AD?

    (c) This AD affects the Model DHC-3 airplanes, all serial 
numbers, that are:
    (1) Modified with STC number SA3777NM; and
    (2) Certificated in any category.

What Is the Unsafe Condition Presented in This AD?

    (d) This AD is the result of a drawing error on Revisions G and 
H of Sheet I of Drawing 20075, Electrical System Schematic. The 
actions specified in this AD are intended to detect and correct 
wiring installed according to an incorrect drawing, which shows the 
pneumatic heating blankets to the P3 and PY 
pneumatic lines wired in series with the indicator lights, rather 
than parallel. This can result in insufficient electrical energy for 
the heating blankets and loss of pneumatic heating, which can lead 
to loss of engine power or reverse propeller overspeed governing 
protection and ultimately loss of control of the airplane.

What Must I Do To Address This Problem?

    (e) To address this problem, you must do the following:

------------------------------------------------------------------------
             Action                   Compliance          Procedures
------------------------------------------------------------------------
(1) Inspect the electrical        Inspect within 4    Follow the
 wiring to the P3 and PY engine    months after the    procedures in the
 pneumatic line heating blankets   effective date of   A.M. Luton
 and the P3 heater warning light   this AD or 300      Service
 to determine if they are wired    hours time in       Information
 in a parallel configuration. If   service (TIS)       Letter SIL-00-10-
 they are not wired in a           after the           10, revision
 parallel configuration, they      effective date of   dated, March 22,
 must be rewired.                  this AD,            2001.
                                   whichever occurs
                                   first. Rewire
                                   prior to further
                                   flight after the
                                   inspection.
---------------------------------
(2) Replace Flight Manual         Replace within 4    Follow the
 Supplement currently in use       months after the    procedures in the
 with Revision G, dated March      effective date of   A.M. Luton
 28, 2001. This flight manual      this AD or 300      Service
 revision corrects the drawing     hours TIS after     Information
 error on Revisions G and H of     the effective       Letter SIL-00-10-
 Sheet I of the Electrical         date of this AD,    10, revision
 System Schematic Drawing 20075    whichever occurs    dated, March 22,
 by incorporating Revision I of    first.              2001.
 Sheet I of Drawing 20075,
 ``Electrical System
 Schematic,'' dated October 10,
 2000.
(i) The owner/operator holding
 at least a private pilot
 certificate as authorized by
 section 43.7 of the Federal
 Aviation Regulations (14 CFR
 43.7) may accomplish the flight
 manual replacement requirement
 of this AD.
(ii) Make an entry into the
 aircraft records showing
 compliance with this portion of
 the AD in accordance with
 section 43.9 of the Federal
 Aviation Regulations (14 CFR
 43.9).
---------------------------------
(3) Inspect circuit breaker       Inspect within 4    Follow the
 switch for heated engine          months after the    procedures in the
 pneumatic lines circuit. If an    effective date of   A.M. Luton
 engine is installed that uses     this AD or 300      Service
 both P3 and PY heated pneumatic   hours TIS after     Information
 lines, circuit breaker switch,    the effective       Letter SIL-00-10-
 Part Number (P/N) 20075-3 (5      date of this AD,    10, revision
 amp), must be replaced with       whichever occurs    dated, March 22,
 circuit breaker switch P/N        first. Replace      2001.
 20075-59 (7.5 amp).               prior to further
                                   flight after the
                                   inspection.
------------------------------------------------------------------------

May I Request an Alternative Method of Compliance?

    (f) You may request a different method of compliance or a 
different compliance time for this AD by following the procedures in 
14 CFR 39.19. Unless FAA authorizes otherwise, send your request to 
your principal inspector. The principal inspector may add comments 
and will send your request to the Manager, Special Certifications 
Branch, Transport Airplane Directorate, FAA. For information on any 
already approved alternative methods of compliance, contact Richard 
Simonson, Aerospace Engineer, Special Certifications Branch, 
Transport Airplane Directorate, 1601 Lind Avenue, SW. Renton, WA 
98055; telephone: 425-917-6507; facsimile: 816-917-6590.

May I Get Copies of the Documents Referenced in This AD?

    (g) You may get copies of the documents referenced in this AD 
from A.M. Luton, 3025 Eldridge Ave., Bellingham, WA 98225. You may 
view these documents at FAA, Central Region, Office of the Regional 
Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

[[Page 29480]]

Is There Other Information That Relates to This Subject?

    (h) Airworthiness Directive CF-2002-38, dated August 29, 2002, 
and Service Information Letter SIL-00-10-10, revision dated March 
22, 2001, also pertain to the subject of this AD.

    Issued in Kansas City, Missouri on May 18, 2004.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-11644 Filed 5-21-04; 8:45 am]
BILLING CODE 4910-13-P