[Federal Register Volume 63, Number 41 (Tuesday, March 3, 1998)]
[Rules and Regulations]
[Pages 10297-10299]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-5198]



[[Page 10297]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-37-AD; Amendment 39-10365; AD 98-05-04]
RIN 2120-AA64


Airworthiness Directives; American Champion Aircraft Corp. Model 
8GCBC Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes 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 Corp. (ACAC) Model 8GCBC airplanes, and repairing or 
replacing any wood spar with compression cracks. This AD requires 
repetitively inspecting the front and rear wood spars for damage, 
including installing any necessary inspection holes; and repairing or 
replacing any damaged wood spar. Damage is defined as cracks; 
compression cracks; longitudinal cracks through the bolt holes or nail 
holes; or loose or missing nails. This 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, 
plus 4 other ACAC Model 8GCBC accidents and 11 service difficulty 
reports (SDR's) of compression cracked spars. The actions specified by 
this AD are intended to detect compression cracks and other damage in 
the wood spar wing, which, if not corrected, could eventually result in 
in-flight structural failure of the wing with consequent loss of the 
airplane.

DATES: Effective April 17, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 17, 1998.

ADDRESSES: Service information that applies to this AD may be obtained 
from the American Champion Aircraft Corp., P.O. Box 37, 32032 
Washington Avenue, Highway D, Rochester, Wisconsin 53167. This 
information may also be examined at the Federal Aviation Administration 
(FAA), Central Region, Office of the Regional Counsel, Attention: Rules 
Docket No. 97-CE-37-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. 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:

Events Leading to the Issuance of This AD

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an AD that would apply to ACAC Model 8GCBC 
airplanes was published in the Federal Register as a notice of proposed 
rulemaking (NPRM) on September 26, 1997 (62 FR 50527). The NPRM 
proposed to:
    --Supersede AD 87-18-09, Amendment 39-5725, which currently 
requires inspecting (one-time) the sides of the front and rear wood 
spars for compression cracks, repairing or replacing any wood spar with 
compression cracks, and re-inspecting immediately after any incident 
involving wing damage; and
    --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 as specified in the NPRM 
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) 43-13-1A, Acceptable Methods, Techniques and 
Practices; or other data that the FAA has approved for spar repair and 
replacement.
    The NPRM was the result of 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, plus 4 other ACAC Model 8GCBC 
accidents and 11 service difficulty reports (SDR's) of compression 
cracked spars.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. One comment was received in support of 
the NPRM, and another comment was received that suggests that the FAA 
reconsider the NPRM. Due consideration has been given to the comment 
that suggests that the FAA reconsider the NPRM. No comments were 
received on the FAA's determination of the cost impact upon the public.

Comment Disposition

    The commenter believes that, based on years of experience and 
involvement with operating the Model 8GCBC airplane, the NPRM is not 
justified. The commenter explains that after 60,000 hours time-in-
service (TIS) over 9 years (roughly about 7,000 hours TIS annually), 4 
of the 6 airplanes in the fleet that the commenter operates were 
rebuilt to improve aesthetics and to give piece of mind that the 
airplanes were in good operating condition. Upon refurbishing, 
including inspections of the wood spars, no compression cracks in the 
wing spars were found. The commenter went on to state that damage was 
found as a result of a previous ground incident, but revealed no 
compression cracking. The commenter feels the FAA should withdraw the 
AD as currently written.
    The FAA does not concur. Based on all data received, the FAA 
believes that wood spar compression cracks can occur with or 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. The FAA does not issue 
AD's based on individual operator's experiences. The FAA issues AD's 
after analyzing all safety information that is based on the design of 
the affected aircraft, such as testing, accident/incident reports, etc. 
Based on all of this data, the FAA believes that repetitive inspections 
are necessary and the proposed AD is necessary to assure the continued 
airworthiness of these airplanes. No changes have been made to the 
final rule based on this comment.

Revision to the Service Information

    Based on information received from the field, ACAC has revised 
Service Letter 417 to the Revision B level (dated February 10, 1998). 
This revision retains the pertinent information presented in the 
original version of the service letter and Revision A to the service 
letter, and adds optional borescope inspections and fabric patches in 
place of removable covers. A recommendation to use optional removable 
inspection covers is included in the service bulletin. The FAA has 
determined that this revised service letter should be incorporated into 
the AD.

The FAA's Determination

    After careful review of all available information related to the 
subject

[[Page 10298]]

presented above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed except for the 
addition of the service information described above and minor editorial 
corrections. The FAA has determined that this addition and these minor 
corrections will not change the meaning of the AD and will not add any 
additional burden upon the public than was already proposed.

Difference Between This AD and ACAC Service Letter 406

    ACAC Service Letter 406, dated March 28, 1994, specifies the same 
inspections as are required in this AD. The differences between the 
service letter and the AD are:
    --The service letter specifies the required 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 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 TIS, whichever 
occurs first; and
    --The service letter applies to all ACAC 7 and 8 series airplanes, 
whereas the AD applies only to ACAC Model 8GCBC airplanes. The FAA is 
currently considering additional rulemaking action on the airplane 
models other than the Model 8GCBC airplanes.

Compliance Time of This AD

    The compliance time of this AD is presented in calendar time and 
hours TIS. Although the unsafe condition specified in this AD is a 
result of airplane operation, the affected airplanes are utilized 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 
will then 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 will be 
affected by this AD, that it will take approximately 8 workhours 
(Installations: 7 workhours; Initial Inspection: 1 workhour) per 
airplane to accomplish the required and optional action, and that the 
average labor rate is approximately $60 an hour. Parts cost 
approximately $170 per airplane, provided that each airplane would only 
need 6 additional standard inspection hole covers per wing bottom 
surface (total of 12 new covers per airplane) and 4 upper surface wing 
covers. 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 this AD on U.S. operators is estimated to be 
$169,650, or $650 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.
    This 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 repetitive inspection will cost 
substantially less than the initial inspection if accomplishing the 
optional inspection hole and cover installations. The optional 
inspection covers allow easy access for the inspection of the wood 
spars, and the 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 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 copy of the final 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, 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:

98-05-04  American Champion Aircraft Corp.: Amendment 39-10365; 
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.


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    Compliance: Required as indicated in the body of this AD, unless 
already accomplished.
    To detect possible compression cracks and other damage in the 
wood spar wing, which, if not corrected, could eventually result in 
in-flight structural failure of the wing with consequent loss 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/or bottom surface of 
each wing in accordance with American Champion Aircraft Corporation 
(ACAC) Service Letter 417, Revision B, dated February 10, 1998. No 
further action is required by this paragraph (paragraph (a)(1) of 
this AD) if inspection holes are installed in accordance with ACAC 
Service Letter 417, Revision A, dated October 2, 1997; or ACAC 
Service Letter 417, dated August 14, 1997.
    (2) Inspect (detailed visual) both the front and rear wood wing 
spars for cracks; compression cracks; longitudinal cracks through 
the bolt holes or nail holes; and loose or missing 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) 43-13-1A, 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 or fabric patches, as 
required, on the top and bottom surface of the wing in accordance 
with ACAC Service Letter 417, Revision B, dated February 10, 1998. 
No further action is required by this paragraph (paragraph (a)(4) of 
this AD) if inspection hole covers are installed in accordance with 
ACAC Service Letter 417, Revision A, dated October 2, 1997; or ACAC 
Service Letter 417, dated August 14, 1997.
    (b) Within 12 calendar months or 500 hours time-in-service (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 
aerobatic maneuvers. AD 87-18-09 required a placard prohibiting 
aerobatic 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 
or accident 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) The installation required by this AD shall be done in 
accordance with American Champion Aircraft Corp. Service Letter 417, 
Revision B, dated February 10, 1998; American Champion Aircraft 
Corp. Service Letter 417, Revision A, dated October 2, 1997; or 
American Champion Aircraft Corp. Service Letter 417, dated August 
14, 1997. The inspections required by this AD shall be done in 
accordance with American Champion Aircraft Corp. Service Letter 406, 
dated March 28, 1994. 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 the American 
Champion Aircraft Corp., P.O. Box 37, 32032 Washington Avenue, 
Highway D, Rochester, Wisconsin 53167. 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 (39-10365) supersedes AD 87-18-09, Amendment 
39-5725.
    (h) This amendment (39-10365) becomes effective on April 17, 
1998.

    Issued in Kansas City, Missouri, on February 23, 1998.
Marvin R. Nuss,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-5198 Filed 3-2-98; 8:45 am]
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