[Federal Register Volume 62, Number 187 (Friday, September 26, 1997)]
[Proposed Rules]
[Pages 50527-50529]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-25607]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / 
Proposed Rules  

[[Page 50527]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-37-AD]
RIN 2120-AA64


Airworthiness Directives; American Champion Aircraft Corporation 
Model 8GCBC Airplanes

agency: Federal Aviation Administration, DOT.

action: Notice of proposed rulemaking (NPRM).

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summary: This document proposes to supersede Airworthiness Directive 
(AD) 87-18-09, which currently requires inspecting (one-time) the sides 
of the front and rear wood spars for compression cracks on certain 
American Champion Aircraft Corporation (ACAC) Model 8GCBC airplanes, 
and repairing or replacing any wood spar with compression cracks. The 
proposed AD would require installing inspection holes on the top and 
bottom wing surfaces, repetitively inspecting the front and rear wood 
spars for damage, repairing or replacing any damaged wood spar, and 
installing inspection covers. Damage is defined as cracks; compression 
cracks; longitudinal cracks through the bolt holes, spacer holes, or 
nail holes; or loose or missing rib nails. The proposed AD results from 
in-flight wing structural failure on one of the affected airplanes that 
was in compliance with the one-time inspection requirement of AD 87-18-
09. The actions specified by the proposed AD are intended to prevent 
damage in the wood spar wing from going undetected, which could result 
in in-flight structural failure of the wing with consequent loss of 
control of the airplane.

dates: Comments must be received on or before November 28, 1997.

addresses: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 97-CE-37-AD, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106. Comments may be inspected at 
this location between 8 a.m. and 4 p.m., Monday and Friday, holidays 
excepted.
    Service information that applies to the proposed AD may be obtained 
from American Champion Aircraft Corporation, P.O. Box 37, 32032 
Washington Avenue, Highway D, Rochester, Wisconsin 53167. This 
information also may be examined at the Rules Docket at the address 
above.

for further information contact: Mr. William Rohder, Aerospace 
Engineer, FAA, Chicago Aircraft Certification Office, 2300 E. Devon 
Avenue, Des Plaines, Illinois 60018; telephone (847) 294-7697; 
facsimile (847) 294-7834.

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 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, 
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 that summarizes 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 No. 97-CE-37-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, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 97-CE-37-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    AD 87-18-09, Amendment 39-5725, currently requires inspecting (one-
time) the sides of the front and rear wood spars for compression cracks 
on American Champion Aircraft Corporation (ACAC) Model 8GCBC airplanes, 
repairing or replacing any wood spar with compression cracks, and re-
inspecting immediately after any incident involving wing damage. AD 87-
18-09 was the result of three accidents involving ACAC Model 8GCBC 
airplanes where compression cracks in the wood spar caused in-flight 
structural failure of the wing.
    Wood compression cracks are failures of wood fibers on a plane 
perpendicular to the wood fiber longitudinal axis. Repetitive high 
stress can initiate these compression cracks on the top or bottom 
surface of the wing spar adjacent to doubler plate glue lines and rib 
nail holes. These high stress conditions can occur during crop dusting, 
banner and glider tow operations, turbulence, and rough field or float 
operations. Compression cracks can also initiate if the wing contacts 
the ground. Compression cracks can initiate at either the top or bottom 
surface of the spar depending on the bending loads (either upward or 
downward) at impact.

Actions Since Issuance of Previous Rule

    In-flight structural failure of the wing recently occurred on an 
ACAC Model 8GCBC airplane that was initially inspected as required by 
AD 87-18-09. A possible contributing factor of this accident was an 
undetected compression crack on the right wing front spar.
    Review of data acquired from inspections of several ACAC Model 
8GCBC airplanes indicate that wood spar compression cracks can occur 
without previous wing damage. The data indicates that detection of a 
compression crack on the sides of the spar is unlikely, unless the 
crack is in an advanced state of propagation. Based

[[Page 50528]]

on this data, the FAA believes that repetitive inspections are 
necessary.

Relevant Service Information

    The FAA has reviewed and approved the technical contents of ACAC 
Service Letter 406, dated March 28, 1994, and ACAC Service Letter 417, 
dated August 14, 1997. ACAC Service Letter 406 includes procedures for 
conducting a detailed visual inspection of both the front and rear wood 
wing spars for cracks; compression cracks; longitudinal cracks through 
the bolt holes, spacer holes, or nail holes; and loose or missing rib 
nails (referred to as damage hereon). ACAC Service Letter 417 includes 
procedures for installing inspection holes and surface covers and 
assuring that all applicable lower surface drain holes are installed.

The FAA's Determination

    After examining the circumstances and reviewing all available 
information related to the incidents and accidents described above, 
including the referenced service information, the FAA has determined 
that AD action should be taken to prevent damage in the wood spar from 
going undetected, which could result in in-flight structural failure of 
the wing with consequent loss of control of the airplane.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other ACAC Model 8GCBC airplanes of the same type 
design, the FAA is proposing an AD to supersede AD 87-18-09. The 
proposed AD would require installing inspection holes on the top and 
bottom wing surfaces, repetitively inspecting the front and rear wood 
spars for damage, repairing or replacing any damaged wood spar, and 
installing surface covers.
    Accomplishment of the proposed actions would be as follows:

--Installations: in accordance with ACAC Service Letter 417, dated 
August 14, 1997;
--Inspections: in accordance with ACAC Service Letter 406, dated March 
28, 1994; and
--Spar Repair and Replacement, as applicable: in accordance with 
Advisory Circular (AC) 43-13, Acceptable Methods, Techniques and 
Practices; or other data that the FAA has approved for spar repair and 
replacement

Difference Between This Proposed AD and ACAC Service Letter 406

    ACAC Service Letter 406, dated March 28, 1994, specifies the same 
inspections as are proposed in this notice of proposed rulemaking 
(NPRM). The differences between the service letter and NPRM are:

--The service letter specifies the proposed action within the next 30 
days or 10 flight hours and at each 100 hour/annual inspection 
thereafter. The FAA has determined that a more realistic compliance and 
enforceable compliance time would be to require the proposed action 
within 3 calendar months after the effective date of the AD, and 
thereafter at intervals not to exceed 12 calendar months or 500 hours 
time-in-service (TIS), whichever occurs first; and
--The service letter applies to all ACAC 7 and 8 series airplanes, 
whereas the NPRM applies only to ACAC Model 8GCBC airplanes. The FAA is 
currently reviewing the service history of all of the ACAC airplane 
models specified in ACAC Service Letter 406. Based on this review, the 
FAA may initiate additional rulemaking action in the future on the 
airplane models other than the Model 8GCBC airplanes. This potential 
action may propose the same actions as the proposed AD with either the 
same or different compliance times, or may propose entirely different 
actions altogether.

Compliance Time of the Proposed AD

    The compliance time of the proposed AD is presented in calendar 
time and hours TIS. Although the unsafe condition specified in the 
proposed AD is a result of airplane operation, operators of the 
affected airplanes utilize their airplanes in different ways.
    For example, an operator may utilize his/her airplane 50 hours TIS 
in a year while utilizing the aircraft in no or very little crop 
dusting operations, banner and glider tow operations, or rough field or 
float operations. This airplane operator would obviously experience 
less of a chance of high crack propagation than the airplane operator 
that utilizes his/her airplane 300 hours TIS in a year regularly in 
heavy crop dusting operations, banner and glider tow operations, or 
rough field or float operations. However, this airplane could have pre-
existing and undetected wood spar damage that occurred during previous 
operations. In this situation, the damage to the wood spar would 
propagate at a level that depends on the operational exposure of the 
airplane and severity of the wood spar damage.
    To assure that compression cracks do not go undetected on the wood 
spars of the affected airplanes, the FAA has determined that an initial 
3 calendar month compliance time should be used. Repetitive actions 
would be accomplished every 12 calendar months or 500 hours TIS, 
whichever occurs first.

Cost Impact

    The FAA estimates that 261 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 6 
workhours (Installations: 5 workhours; Initial Inspection: 1 workhour) 
per airplane to accomplish the proposed action, and that the average 
labor rate is approximately $60 an hour. Parts cost approximately $292 
per airplane, provided that each airplane would only need 11 additional 
standard inspection hole covers per wing (total of 22 additional 
standard covers per airplane). If the airplane would require the 
installation of more inspection covers (i.e., a result of previous non-
factory wing recover work), the cost could be slightly higher. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $170,172 or $652 per airplane.
    This cost figure is based on the presumption that no affected 
airplane owner/operator has accomplished the installations or the 
initial inspection. The FAA has no knowledge of any owner/operator of 
the affected airplanes that has already accomplished the installations 
and initial inspection.
    The cost figure also does not account for repetitive inspections. 
The FAA has no way of determining the number of repetitive inspections 
each owner/operator of the affected airplanes will incur over the life 
of his/her airplane. However, each proposed repetitive inspection would 
cost substantially less than the initial inspection because of the cost 
of the initial proposed inspection hole and cover installations. The 
inspection covers allow easy access for the inspection of the wood 
spars, and the proposed compliance time would enable the owners/
operators of the affected airplanes to accomplish the repetitive 
inspections at regularly scheduled annual inspections.

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.

[[Page 50529]]

    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) 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 has been placed 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 14 
CFR part 39 of the Federal Aviation Regulations 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 removing Airworthiness Directive 
(AD) 87-18-09, Amendment 39-5725, and by adding a new AD to read as 
follows:

American Champion Aircraft Company: Docket No. 97-CE-37-AD; 
Supersedes AD 87-18-09, Amendment 39-5725.

    Applicability: Model 8GCBC airplanes, all serial numbers, 
certificated in any category, that are equipped with wood wing 
spars.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, repaired, or reconfigured in the area subject to 
the requirements of this AD. For airplanes that have been modified, 
altered, repaired, or reconfigured 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 as indicated in the body of this AD, unless 
already accomplished.
    To prevent damage in the wood spar wing from going undetected, 
which could result in in-flight structural failure of the wing with 
consequent loss of control of the airplane, accomplish the 
following:
    (a) Within the next 3 calendar months after the effective date 
of this AD, accomplish the following:
    (1) Install inspection holes in the top and bottom surface of 
each wing in accordance with American Champion Aircraft Corporation 
(ACAC) Service Letter 417, dated August 14, 1997. Assure that all 
drainage holes are installed as depicted in this service letter, and 
install drainage holes as necessary.
    (2) Inspected (detailed visual) both the front and rear wood 
wing spars for cracks; compression cracks; longitudinal cracks 
through the bolt holes, spacer holes, or nail holes; and loose or 
missing rib nails (referred to as damage hereon). Accomplish these 
inspections in accordance with ACAC Service Letter 406, dated March 
28, 1994.
    (3) If any spar damage is found, prior to further flight, 
accomplish the following:
    (i) Repair or replace the wood wing spar in accordance with 
Advisory Circular (AC) 43-13, Acceptable Methods, Techniques and 
Practices; or other data that is approved by the FAA for wing spar 
repair or replacement.
    (ii) If the wing is recovered, accomplish the installations 
required by paragraph (a)(1) of this AD, as applicable.
    (4) Install inspection hole covers on the top and bottom surface 
of the wing in accordance with ACAC Service Letter 417, dated August 
14, 1997.
    (b) Within 12 calendar months or 500 hours TIS (whichever occurs 
first) after accomplishing all actions required by paragraph (a), 
all subparagraphs included, of this AD, and thereafter at intervals 
not to exceed 12 calendar months or 500 hours TIS, whichever occurs 
first, accomplish the inspection, repair, replacement, and 
installation required by paragraphs (a)(2), (a)(3) as applicable; 
including its subparagraphs; and (a)(4) of this AD.

    Note 2: The affected airplanes are not certificated for 
acrobatic maneuvers. AD 87-18-09 required a placard prohibiting 
acrobatic maneuvers in addition to the existing operational placard. 
The FAA encourages owners/operators of the affected airplanes to 
keep this placard installed on their airplanes.

    (c) If any of the affected airplanes are involved in an incident 
involving wing damage after the effective date of this AD, prior to 
further flight, accomplish the inspection, repair, replacement, and 
installation required by paragraphs (a)(2), (a)(3), as applicable; 
including its subparagraphs; and (a)(4) of this AD.
    (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 
initial or repetitive compliance time that provides an equivalent 
level of safety may be approved by the Manager, Chicago Aircraft 
Certification Office (ACO), 2300 E. Devon Avenue, Des Plaines, 
Illinois 60018.
    (1) The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Chicago ACO.
    (2) Alternative methods of compliance approved in accordance 
with AD 87-18-09 (superseded by this action) are not considered 
approved as alternative methods of compliance for this AD.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Chicago ACO.

    (f) All persons affected by this directive may obtain copies of 
the documents referred to herein upon request to American Champion 
Aircraft Corporation, P.O. Box 37, 32032 Washington Avenue, Highway 
D, Rochester, Wisconsin 53167; or may examine these documents at the 
FAA, Central Region, Office of the Assistant Chief Counsel, Room 
1558, 601 E. 12th Street, Kansas City, Missouri 64106.
    (g) This amendment supersedes AD 87-18-09, Amendment 39-5725.

    Issued in Kansas City, Missouri, on September 22, 1997.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-25607 Filed 9-25-97; 8:45 am]
BILLING CODE 4910-13-M