AD Amdt-39-10524

[Federal Register Volume 63, Number 94 (Friday, May 15, 1998)]
[Rules and Regulations]
[Pages 26964-26965]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-12625]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-48-AD; Amendment 39-10524; AD 98-10-12]
RIN 2120-AA64


Airworthiness Directives; REVO, Incorporated Models Colonial C-2, 
Lake LA-4, Lake LA-4A, Lake LA-4P, and Lake LA-4-200 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to all REVO, Incorporated (REVO) Models Colonial C-2, Lake LA-
4, Lake LA-4A, Lake LA-4P, and Lake LA-4-200 airplanes. This action 
requires measuring for a clearance of \5/32\ of an inch between the 
attachment fitting and the horizontal stabilizer rear beam, and a 
clearance of \1/16\ of an inch between the attachment fitting and the 
stabilizer skin. If either area does not meet these minimum 
measurements, this AD requires removing the affected horizontal tail 
half from the airplane and inspecting the attachment fitting for any 
evidence of fretting, cracking, or corrosion. If cracks, fretting, or 
corrosion are present, the attachment fitting must be replaced with a 
new fitting, and the stabilizer skin must be trimmed to provide a 
positive clearance for the fitting. This action is prompted by an 
incident report of an airplane losing control during flight after the 
attachment fitting to the horizontal stabilizer fractured. The actions 
specified by this AD are intended to prevent fatigue cracks to the 
horizontal and vertical stabilizer attachment fitting, which could 
result in loss of control of the airplane.

DATES: Effective June 8, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 8, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before July 8, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 98-CE-48-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.
    Service information that applies to this AD may be obtained from 
REVO, Incorporated, 50 Airport Road, Laconia Airport, Laconia, New 
Hampshire, 03246. This information may also be examined at the Federal 
Aviation Administration (FAA), Central Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-CE-48-AD, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106; or at the Office of the 
Federal Register, 800 North Capitol Street, NW, suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Mr. Richard B. Noll, Aerospace 
Engineer, FAA, Aircraft Certification Office, 12 New England Executive 
Park, Burlington, Massachusetts 01803, telephone: (781) 238-7160; 
facsimile: (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA recently received a report of loss of control on a REVO, 
Incorporated Lake LA-4 series airplane during flight. The report 
indicated that during climb-out following take-off, the pilot heard a 
loud bang, and the airplane pitched over into a vertical dive, with 
loss of elevator control. During the pilot's efforts to regain control, 
another loud bang was heard and sufficient control was regained to 
manage a safe landing. Further investigation of the incident and 
inspection of the subject airplane revealed interference between the 
horizontal stabilizer skin and the attachment fitting. This 
interference caused fretting, which led to fatigue cracking and 
associated corrosion of the attachment fitting. The fracture of the 
attachment fitting resulted in loss of directional control of the 
airplane.

Relevant Service Information

    REVO has issued Service Bulletin B-78, dated April 3, 1998, 
applicable to Models Colonial C-2, Lake LA-4, Lake LA-4A, Lake LA-4P, 
and Lake LA-4-200 airplanes, which specifies procedures for:

--Measuring the gap between the horizontal stabilizer rear beam and the 
attachment fitting for a clearance of \5/32\ of an inch,
--If the gap between the stabilizer rear beam and the attachment 
fitting is less than \5/32\-inch, removing the fitting and visually 
inspect for cracks, fretting, or corrosion,
--If cracks, fretting, or corrosion is present, replacing the 
attachment fitting with a new fitting,
--Measuring the gap between the attachment fitting and the horizontal 
stabilizer skin for a clearance of \1/16\ of an inch, and
--If the clearance between the horizontal stabilizer skin and the 
attachment fitting is less than \1/16\ of an inch, but the other 
measurement is at or greater than \5/32\ of an inch, trimming the 
stabilizer skin to provide at least \1/16\ of an inch clearance.

The FAA's Determination

    After examining the circumstances and reviewing all available 
information related to the incidents described above, including the 
relevant service information, the FAA has determined that AD action 
should be taken to prevent fatigue cracks in the horizontal stabilizer 
attachment fitting, which if not detected and corrected, could result 
in loss of control of the airplane.

Explanation of the Provisions of the AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other REVO Colonial C-2, Lake LA-4, Lake LA-4A, 
Lake LA-4P, Lake LA-4-200 airplanes of the same type design, this AD 
requires measuring the gap between the horizontal stabilizer rear beam 
and the attachment fitting for correct clearance, and measuring the gap 
between the attachment fitting and the horizontal stabilizer skin for 
correct clearance. If the gap between the stabilizer rear beam and the 
attachment fitting is not the correct clearance, the action requires 
removing the horizontal tail half to gain access to the fitting, and 
visually inspecting for cracks, fretting, or corrosion. If cracks, 
fretting, or corrosion are present, the action requires replacing the 
attachment fitting with a new fitting. If the clearance between the 
horizontal stabilizer skin and the attachment fitting is not the 
correct clearance, but the other measurement is correct, the action 
requires trimming the stabilizer skin to provide acceptable clearance. 
The actions are to be done in accordance with the instructions in REVO 
Service Bulletin B-78, dated April 3, 1998.

Determination of the Effective Date of the AD

    Since a situation exists (loss of directional control of the 
airplane) that requires the immediate adoption of this regulation, it 
is found that notice and opportunity for public prior comment hereon 
are impracticable, and that good cause exists for making this amendment 
effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting immediate flight safety and, thus, was not 
preceded by notice and opportunity to comment, comments are invited on 
this rule. Interested persons

[[Page 26965]]

are invited to comment on this rule by submitting such written data, 
views, or arguments as they may desire. Communications should 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 will be considered, and this rule may be amended in 
light of the comments received. Factual information that supports the 
commenter's ideas and suggestions is extremely helpful in evaluating 
the effectiveness of the AD action and determining whether additional 
rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 98-CE-48-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a significant regulatory action under 
Executive Order 12866. It has been determined further that this action 
involves an emergency regulation under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979). If it is determined that 
this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket (otherwise, an evaluation is 
not required). A copy of it, if filed, may be obtained from the Rules 
Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, 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 a new airworthiness directive 
(AD) to read as follows:

98-10-12  Revo, Incorporated: Amendment 39-10524; Docket No. 98-CE-
48-AD.

    Applicability: Models Colonial C-2, Lake LA-4, Lake LA-4A, Lake 
LA-4P, and Lake LA-4-200 airplanes, all serial numbers, 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 (e) 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 within the next 25 hours time-in-service 
(TIS) after the effective date of this AD, unless already 
accomplished.
    To prevent fatigue cracks in the horizontal and vertical 
stabilizer attachment fitting, which could result in loss of control 
of the airplane, accomplish the following:
    (a) Measure the gap between the horizontal stabilizer rear beam 
and the attachment fitting for a clearance of \5/32\ of an inch in 
accordance with the PROCEDURE section in REVO Service Bulletin B-78, 
dated April 3, 1998.
    (1) If the gap between the stabilizer rear beam and the 
attachment fitting is less than \5/32\-inch, prior to further 
flight, remove the fitting and visually inspect or inspect using a 
dye penetrant method for cracks, fretting, or corrosion in 
accordance with the INSPECTION AND REPAIR section in REVO Service 
Bulletin B-78, dated April 3, 1998.
    (2) If any crack, fretting, or corrosion is present, prior to 
further flight, replace the attachment fitting with a new fitting in 
accordance with the INSPECTION AND REPAIR section in REVO Service 
Bulletin B-78, dated April 3, 1998.
    (b) Measure the gap between the attachment fitting and the 
horizontal stabilizer skin for a clearance of \1/16\ of an inch in 
accordance with the PROCEDURE section in REVO Service Bulletin B-78, 
dated April 3, 1998.
    (c) If the clearance between the horizontal stabilizer skin and 
the attachment fitting is less than \1/16\ of an inch, but the 
measurement required in paragraph (a) of this AD is at or greater 
than \5/32\ of an inch, prior to further flight, trim the stabilizer 
skin to provide at least \1/16\-inch clearance in accordance with 
the PROCEDURE section in REVO Service Bulletin B-78, dated April 3, 
1998.
    (d) 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.
    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Boston Aircraft Certification Office, 12 
New England Executive Park, Burlington, Massachusetts 01803. The 
request shall be forwarded through an appropriate FAA Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Boston ACO.

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

    (f) The inspection, modification, and replacement required by 
this AD shall be done in accordance with REVO Service Bulletin B-78, 
dated April 3, 1998. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies may be obtained from REVO, 
Incorporated, 50 Airport Road, Laconia Airport, Laconia, New 
Hampshire, 03246. Copies may be inspected at the FAA, Central 
Region, Office of the Regional Counsel, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri, or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.
    (g) This amendment becomes effective on June 8, 1998.

    Issued in Kansas City, Missouri, on May 1, 1998.
Michael Gallagher,
Manager, Small Aircraft Directorate, Aircraft Certification Service.
[FR Doc. 98-12625 Filed 5-14-98; 8:45 am]
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