[Federal Register Volume 64, Number 151 (Friday, August 6, 1999)]
[Proposed Rules]
[Pages 42870-42872]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-20326]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-153-AD]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F27 Mark 100, 200, 300, 
400, 500, 600, and 700 Series Airplanes and Model F27 Mark 050 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain Fokker Model F27 Mark 100, 200, 
300, 400, 500, 600, and 700 series airplanes and Model F27 Mark 050 
series airplanes, that would have required revising the Airplane Flight 
Manual (AFM) to include requirements for activation of the airframe 
pneumatic deicing boots. That proposal was prompted by reports of 
inflight incidents and an accident that occurred in icing conditions 
where the airframe pneumatic deicing boots were not activated. The 
actions specified by that proposed AD are intended to ensure that 
flightcrews activate the pneumatic wing and tail deicing boots at the 
first signs of ice accumulation. This new proposed action revises the 
proposed rule by specifying that, at the first signs of ice 
accumulation, ``heavy'' automatic cycling mode must be used during 
operation of the deicing boots. The actions specified by this new 
proposed AD are intended to prevent reduced controllability of the 
aircraft due to adverse aerodynamic effects of ice adhering to the 
airplane prior to the first deicing cycle.

DATES: Comments must be received by August 31, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-153-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Norman Martenson, Aerospace Engineer, 
Manager, International Branch, ANM-116, FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-153-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 99-NM-153-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 
series airplanes and Model F27 Mark 050 series airplanes, was published 
as a notice of proposed rulemaking (NPRM) in the Federal Register on 
July 16, 1999 (64 FR 38345). That NPRM would have required revising the 
Airplane Flight Manual (AFM) to include requirements for activation of 
the airframe pneumatic deicing boots. That NPRM was prompted by reports 
of inflight incidents and an accident that occurred in icing conditions 
where the airframe

[[Page 42871]]

pneumatic deicing boots were not activated. That condition, if not 
corrected, could result in reduced controllability of the aircraft due 
to adverse aerodynamic effects of ice adhering to the airplane prior to 
the first deicing cycle.

Actions Since Issuance of Previous Proposal

    The FAA has determined that further definition is necessary to 
specify the automatic cycling mode of activation of the deicing boots. 
These airplanes may operate deicing boots in either a ``light'' or a 
``heavy'' automatic cycling mode; however, the FAA finds that at the 
first sign of ice accumulation, required activation of the deicing 
boots in ``heavy'' mode is warranted. The FAA considers that the 
required activation in ``heavy'' mode is necessary to assure the 
capability of the system to shed ice with a low pressure indication 
setting of 8 pounds per square inch gage (psig).
    However, the manufacturer has advised the FAA that requiring 
activation of the deicing boots in ``heavy'' automatic cycling mode 
would cause the boots to wear at a rate higher than anticipated. The 
manufacturer further states that, consequently, such a high wear rate 
would require replacement of the deicing boots sooner than anticipated. 
The manufacturer concludes, therefore, that the additional costs 
associated with such additional replacement of the deicing boots would 
impose an additional burden to operators.
    The FAA acknowledges that the activation of the deicing boots using 
the ``heavy'' automatic cycling mode may require costs that were not 
originally anticipated. The FAA recognizes that the obligation to 
maintain aircraft in an airworthy condition is vital, but sometimes 
expensive. Because AD's require specific actions to address specific 
unsafe conditions, they appear to impose costs that would not otherwise 
be borne by operators. However, because of the general obligation of 
operators to maintain aircraft in an airworthy condition, this 
appearance is deceptive. Attributing those costs solely to the issuance 
of this AD is unrealistic because, in the interest of maintaining safe 
aircraft, prudent operators would accomplish the required actions even 
if they were not required to do so by the AD. In this case, the FAA has 
determined that direct and incidental costs are still outweighed by the 
safety benefits of the AD.
    Therefore, this supplemental NPRM revises paragraph (a) of the 
original proposal by adding the words ``heavy'' to specify that in the 
Airplane Flight Manual revision the deicing boot system must be 
operated in the ``heavy'' automatic cycling mode. Additionally, since 
these airplanes are all equipped with an automatic cycling mode, the 
FAA has removed the phrase ``if available'' in the same AFM paragraph. 
The proposed actions will prevent reduced controllability of the 
aircraft due to adverse aerodynamic effects of ice adhering to the 
airplane prior to the first deicing cycle.

Conclusion

    Since this change expands the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Cost Impact

    The FAA estimates that 34 airplanes of U.S. registry would be 
affected by this proposed AD.
    The FAA estimates that it would take approximately 1 work hour per 
airplane to accomplish the proposed AFM revisions, at the average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the proposed AD on U.S. operators is estimated to be $2,040, or $60 per 
airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed 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 proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Fokker Services B.V.: Docket 99-NM-153-AD.

    Applicability: Model F27 Mark 100, 200, 300, 400, 500, 600, and 
700 series airplanes and Model F27 Mark 050 series airplanes 
equipped with pneumatic deicing boots, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To ensure that flightcrews activate the wing and tail pneumatic 
deicing boots at the first signs of ice accumulation on the 
airplane, accomplish the following:
    (a) Within 10 days after the effective date of this AD: Revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following requirements for activation of the 
ice protection systems. This may be accomplished by inserting a copy 
of this AD in the AFM.
    `` Except for certain phases of flight where the AFM 
specifies that deicing boots should not be used (e.g., take-off, 
final approach, and landing), compliance with the following is 
required.
     Wing and Tail Leading Edge Pneumatic Deicing Boot 
System, if installed, must be activated:

--At the first sign of ice formation anywhere on the aircraft, or 
upon annunciation from an ice detector system, whichever occurs 
first; and
--The system must either be continued to be operated in the 
``heavy'' automatic cycling mode; or the system must be manually 
cycled as needed to minimize the ice accretions on the airframe.

     The wing and tail leading edge pneumatic deicing boot 
system may be deactivated only after leaving icing conditions and 
after the airplane is determined to be clear of ice.''
    (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, Manager,

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International Branch, ANM-116, FAA, Transport Airplane Directorate. 
The request shall be forwarded through an appropriate FAA Operations 
Inspector, who may add comments and then send it to the Manager, 
International Branch, ANM-116 ACO.

    Note 1: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116 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.

    Issued in Renton, Washington, on July 30, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-20326 Filed 8-5-99; 8:45 am]
BILLING CODE 4910-13-U