AD Amdt-39-10236

[Federal Register Volume 62, Number 236 (Tuesday, December 9, 1997)]
[Rules and Regulations]
[Pages 64680-64682]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 97-32112]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-37-AD; Amendment 39-10236; AD 97-25-12]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-44 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Bombardier Model CL-44 series airplanes, that 
requires revising the Airplane Flight Manual (AFM) to modify the 
limitation that prohibits positioning the power levers below the flight 
idle stop during flight, and to provide a statement of the consequences 
of positioning the power levers below the flight idle stop during 
flight. This amendment is prompted by incidents and accidents involving 
airplanes equipped with turboprop engines in which the ground propeller 
beta range was used improperly during flight. The actions specified by 
this AD are intended to prevent loss of airplane controllability, or 
engine overspeed and consequent loss of engine power caused by the 
power levers being positioned below the flight idle stop while the 
airplane is in flight.

DATES: Effective January 13, 1998.

ADDRESSES: This information may be examined at the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, Rules Docket, 
1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and 
Propeller Directorate, New York Aircraft Certification Office, 10 Fifth 
Street, Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: Peter LeVoci, Flight Test Pilot, 
Systems and Flight Test Branch, ANE-172, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7514; 
fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Bombardier Model CL-44 series 
airplanes was published in the Federal Register on May 28, 1997 (62 FR 
28813). That action proposed to require revising the Limitations 
Section of the FAA-approved Airplane Flight Manual (AFM) to modify the 
limitation that prohibits the positioning of the power levers below the 
flight idle stop while the airplane is in flight, and to add a 
statement of the consequences of positioning the power levers below the 
flight idle stop while the airplane is in flight.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due

[[Page 64681]]

consideration has been given to the comments received.

Request to Withdraw the Proposal

    One commenter, the manufacturer, considers that a revision to the 
Limitations Section of the AFM, issued on December 6, 1996, fully meets 
the intent of the proposed rule. Therefore, the manufacturer concludes 
that an AD for the Model CL-44 series airplane is not required.
    The FAA does not concur that inserting the AFM revision referenced 
by the commenter into the AFM provides an adequate method of compliance 
with the final rule. That revision does not contain reference to the 
fact that failure to observe the prohibition may cause loss of airplane 
control, and as such, does not completely meet the intent of the rule. 
The FAA acknowledges that revising the AFM to add the phrase ``loss of 
airplane control'' as a consequence of failure to observe the 
prohibition would provide adequate compliance with the requirements of 
the final rule. Therefore, the FAA will consider requests for approval 
of an alternative method of compliance in accordance with the 
provisions of paragraph (b) of this AD.

Request to Clarify That No Accidents Occurred on the CL-44

    This same commenter notes that the text of the proposed rule does 
not make it clear that no accidents have occurred on Model CL-44 series 
airplanes as a result of ground propeller beta range being used 
improperly during flight. The commenter requests that the FAA clarify 
this in the final rule.
    The FAA acknowledges that no accidents have occurred involving 
Model CL-44 series airplanes that have been attributed to ground 
propeller beta range being used improperly during flight. However, the 
FAA considers that the wording of the Summary section of the proposed 
rule that states, ``This proposal is prompted by incidents and 
accidents involving airplanes equipped with turboprop engines in which 
the ground propeller beta range was used improperly during flight,'' is 
correct. The fact that the FAA did not specifically name each 
manufacturer and airplane model on which those incidents or accidents 
occurred does not negate the fact that such incidents and accidents did 
occur on airplanes equipped with turboprop engines. The FAA finds that 
no change to the final rule is necessary.

Clarification of the Rule

    Since the issuance of the NPRM, the FAA has noted that operations 
manuals for certain airplanes equipped with Dart turboprop engines may 
contain reference to ``ground fine pitch'' rather than ``operations 
below the flight idle stop,'' as specified in the proposed rule. 
Although the operations manuals refer to both of those phrases, the FAA 
finds that some clarification is necessary. Therefore, the FAA has 
added the phrase ``(i.e., ground fine pitch)'' in paragraph (a) of the 
final rule as a parenthetical definition of ``operations below the 
flight idle stop'' in the final rule.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 1 Bombardier Model CL-44 series airplane of 
U.S. registry will be affected by this AD, that it will take 
approximately 1 work hour to accomplish the proposed actions, and that 
the average labor rate is $60 per work hour. Based on these figures, 
the cost impact of the AD on the single U.S. operator is estimated to 
be $60 for the one affected airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

97-25-12  Bombardier, Inc. (Formerly Canadair): Amendment 39-10236. 
Docket 97-NM-37-AD.

    Applicability: All Model CL-44 series airplanes, certificated in 
any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of airplane controllability, or engine overspeed 
and consequent loss of engine power caused by the power levers being 
positioned below the flight idle stop while the airplane is in 
flight, accomplish the following:
    (a) Within 30 days after the effective date of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following statements. This action may be 
accomplished by inserting a copy of this AD into the AFM.
    ``Positioning of power levers below the flight idle stop (i.e., 
ground fine pitch) while

[[Page 64682]]

the airplane is in flight is prohibited. Such positioning may lead 
to loss of airplane control or may result in an overspeed condition 
and consequent loss of engine power.''
    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, New York Aircraft Certification 
Office (ACO), FAA, Engine and Propeller Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, New York ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (d) This amendment becomes effective on January 13, 1998.

    Issued in Renton, Washington, on December 2, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-32112 Filed 12-8-97; 8:45 am]
BILLING CODE 4910-13-U