AD 2000-25-02

[Federal Register Volume 65, Number 243 (Monday, December 18, 2000)]
[Rules and Regulations]
[Pages 78905-78912]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-31450]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-121-AD; Amendment 39-12036; AD 2000-25-02]
RIN 2120-AA64


Airworthiness Directives; American Champion Aircraft Corporation 
7, 8, and 11 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 98-05-
04, which currently requires you to repetitively inspect the front and 
rear wood spars for damage (including installing any as-needed 
inspection holes) and repair or replace any damaged wood spar on 
certain American Champion Aircraft Corporation (ACAC) Model 8GCBC 
airplanes. Damage is defined as cracks, compression cracks, 
longitudinal cracks through the bolt holes or nail holes, or loose or 
missing nails. This AD retains the actions of AD 98-05-04 for the ACAC 
Model 8GCBC airplanes; extends the actions to all ACAC 7, 8, and 11 
series airplanes (except the inspections are not repetitive for certain 
7 and 11 series airplanes); incorporates

[[Page 78906]]

alternative methods of accomplishing the actions; and requires 
reporting any damage found. This AD is the result of a review of the 
service history of the affected airplanes that incorporate wood wing 
spars where damage was found in this area and consideration of all 
public comments received. The actions specified by this AD are intended 
to detect and repair or replace damaged wood wing spars. Continued 
operation with such damage could progress to in-flight structural 
failure of the wing with consequent loss of control of the airplane.

DATES: This amendment becomes effective on January 19, 2001.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the regulation as of 
January 19, 2001.

ADDRESSES: You may get service information referenced in this AD from 
the American Champion Aircraft Corporation, P.O. Box 37, 32032 
Washington Avenue, Highway D, Rochester, Wisconsin 53167; internet 
address: <a href="http://www.amerchampionaircraft.com">www.amerchampionaircraft.com</a>. You may examine this information 
at the Federal Aviation Administration (FAA), Central Region, Office of 
the Regional Counsel, Attention: Rules Docket No. 98-CE-121-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:

Discussion

    What prior AD action did FAA take on this subject? A review of the 
service history of ACAC 7, 8, and 11 series airplanes that incorporate 
wood wing spars caused FAA to initiate AD rulemaking action. In-flight 
wing structural failures on ACAC Model 8GCBC airplanes and several 
incidents and accidents on other affected airplane models where damage 
was found on the front and rear wood spars prompted this review. Those 
rulemaking actions are:

--AD 98-05-04, Amendment 39-10365 (63 FR 10297, March 3, 1998), which 
applies to ACAC Model 8GCBC airplanes, and requires you to accomplish 
the following: (1) inspect (repetitively) the front and rear wood spars 
for damage (including installing any necessary inspection holes); and 
(2) repair or replace any damaged wood spar; and
--a notice of proposed rulemaking (NPRM) (Docket No. 97-CE-79-AD) that, 
if followed by a final rule, would have required the same actions as AD 
98-05-04 on all ACAC 7, 8, and 11 series airplanes (excluding the Model 
8GCBC airplanes). This NPRM was published in the Federal Register on 
November 3, 1997 (62 FR 59310).

    What is the potential impact if FAA took no action? Continued 
operation with such cracks and damage could progress to in-flight 
structural failure of the wing with consequent loss of the airplane.
    Did we receive comments on the NPRM (Docket No. 97-CE-79-AD)? The 
FAA encouraged interested persons to participate in the rulemaking 
aspects of this subject. We received numerous comments on the NPRM 
(Docket No. 97-CE-79-AD). Many of these comments proposed that we 
combine the actions of the NPRM and AD 98-05-04 into one AD that would 
affect all ACAC 7, 8, and 11 series airplanes and incorporate 
recommended alternative methods for complying with the actions. Based 
on these comments, FAA:

--Withdrew the NPRM Docket No. 97-CE-79-AD (64 FR 29969, June 4, 1999); 
and
--Issued an NPRM that proposed to supersede AD 98-05-04 with a new AD 
that would combine the actions of AD 98-05-04 and Docket No. 97-CE-79-
AD; and incorporate recommended alternative methods for complying with 
those actions. This NPRM was published in the Federal Register on June 
4, 1999 (64 FR 29972).

    Accomplishment of the proposed inspection as specified in the NPRM 
would be required in accordance with ACAC Service Letter 406, Revision 
A, dated May 6, 1998.
    Was the public invited to comment on the NPRM? The FAA encouraged 
interested persons to participate in the making of this amendment. At 
the request of several commenters, FAA reopened the comment period for 
the NPRM on July 29, 1999. This action was published in the Federal 
Register on August 4, 1999 (64 FR 42297). A summary of the comments on 
both the original NPRM and the reopening of the comment period follow, 
along with FAA's responses.

Comment Issue No. 1: Extend the Comment Period to 60 Days

    What is the commenters' concern? Several commenters request an 
extension to the comment period in order to have more time to provide 
information on the proposed rule.
    What is FAA's response to the concern? As discussed previously, FAA 
reopened the comment period to give the public an additional 30 days to 
respond.
    We are not changing the final rule as a result of these comments.

Comment Issue No. 2: Only Require a One-Time Inspection for Certain 
7 and 11 Series Airplanes

    What is the commenters' concern? Numerous commenters agree with the 
AD pertaining to ACAC airplane models. However, the commenters state 
that certain lightweight 7 and 11 series airplanes with low horsepower 
engines should only be subject to a one-time spar inspection because 
they are not certificated for aerobatic flight and are not subjected to 
the same operations as the heavier high horsepower airplanes.
    What is FAA's response to the concern? The FAA has determined that 
wing damage incidents are the major cause of compression cracks and 
other spar damage in low horsepower and lightweight airplanes. 
Therefore, a one-time inspection is acceptable for ACAC Models 7AC, 
7ACA, S7AC, 7BCM (L-16A), 7CCM (L-16BA), S7CCM, 7DC, S7DC, 7EC, S7EC, 
7FC, 7JC, 11AC, S11AC, 11BC, S11BC, 11CC, and S11CC airplanes. These 
airplanes have engines that are 90 horsepower and lower (includes 60- 
to 90-horsepower engines). You must repetitively inspect airplanes that 
are modified with engines greater than 90 horsepower.
    You must also accomplish the inspection any time one of the 
affected airplanes is involved in any accident or incident where the 
wing is involved.
    We are changing the final rule AD to only require an initial 
inspection on certain ACAC 7 and 11 series airplanes, with any 
subsequent inspections required for any affected airplane involved in 
an incident/accident (that happens after the effective date of this AD) 
where wing damage occurs (e.g., surface deformations such as abrasions, 
gouges, scratches, or dents, etc.).

Comment Issue No. 3: Exclude Certain Airplanes From the Proposed AD

    What is the commenters' concern? Numerous commenters request that 
FAA remove lightweight and low horsepower airplanes from the 
Applicability of the AD. The commenters state that these airplanes are 
not certificated for aerobatic operation and, therefore, do not receive 
the stress levels in the spar that caused the need for this AD.

[[Page 78907]]

    What is FAA's response to the concern? We do not concur that these 
lightweight and low horsepower airplanes should be removed from the AD. 
We have received compression crack and spar damage reports on 
lightweight and low horsepower airplane models (i.e., Model 7AC). The 
following is a synopsis from a service difficulty report (SDR) for a 
Model 7AC airplane:

    During annual inspection, found rear spar right wing cracked 
across width of spar outboard rear strut attach point next to 
doubler. Defect was found using an inspection mirror and strong 
light through an inspection hole. The removal of fabric material on 
the bottom of the wing in the area of suspicion verified the defect. 
Submitter suggests immediate inspection of all Aeronca Champ 7AC 
aircraft both on the top and bottom of the aft wing strut spar 
attach points outboard.

    This information caused us to propose (in the NPRM) a requirement 
for submitting all findings of airplane wing damage. You can accomplish 
this by describing the damage in a Malfunction or Defect Report (M or 
D), FAA Form 8010-4, and sending a copy of the report to the Chicago 
Aircraft Certification Office. (You may submit M or D reports 
electronically through the FAA AFS-600 web page at <a href="http://www.mmac.jccbi.gov/afs/afs600">http://www.mmac.jccbi.gov/afs/afs600</a>. Because you will lose access to the 
report once you electronically submit it, we recommend that you print 
two copies prior to submitting the report and forward one to the 
Chicago ACO and keep the other for your records). We will evaluate the 
data as it is received and initiate further rulemaking action, if 
necessary.
    We are not changing the AD based on these comments. However, as 
discussed in the previous comment, the AD will only require an initial 
inspection on the airplanes equipped with low horsepower engines. 
Subsequent inspections are required for any affected airplane involved 
in an incident/accident (that happens after the effective date of this 
AD) where wing damage occurs (e.g., surface deformations such as 
abrasions, gouges, scratches, or dents, etc.).

Comment Issue No. 4: The AD Should Only Apply to Aerobatic Aircraft

    What is the commenters' concern? Two commenters state that spar 
damage is a direct result of aerobatic flight. The commenters suggest 
that FAA change the proposal to affect only aircraft certificated for 
aerobatic activity.
    What is FAA's response to the concern? We do not concur. Reports 
indicate that spar damage occurs on low horsepower airplane models that 
are not certificated for aerobatic flight. We have determined that wing 
damage incidents are the primary cause of compression cracks on the 
lower horsepower airplanes.
    We are not changing the AD based on these comments.

Comment Issue No. 5: Exclude Airplanes With Damaged Spars That Can 
Still Support the Required Load

    What is the commenter's concern? One commenter requests that FAA 
exclude airplanes from the Applicability of the AD if any wing with a 
compression crack can still pass testing to 150-percent of design limit 
load.
    What is FAA's response to the concern? We do not concur. 
Compression cracked test spar specimens may not represent wood spars 
where compression cracks occur randomly along the spar length. The only 
assurance that the specimen was in a ``Pass'' condition was if the 
specimen's compression crack was identical to that of a failed spar. 
All compression cracks are not identical. Even slight compression 
cracks may seriously reduce the strength of the material. The approved 
type design of the affected airplanes does not allow cracked spars.
    We are not changing the AD based on these comments.

Comment Issue No. 6: Properly Performed Annual Inspections are 
Sufficient

    What is the commenters' concern? Several commenters state that, if 
you accomplish a proper annual inspection, then there is no need for 
this AD. These commenters state that the required maintenance programs 
provide the procedures to detect spar damage. These commenters also 
state that part 43 of the Federal Aviation Regulations (14 CFR part 43) 
requires inspection of the wing spars.
    What is FAA's response to the concerns? We concur that maintenance 
manuals for the ACAC 7, 8, and 11 series airplanes and part 43 of the 
Federal Aviation Regulations (14 CFR part 43) specify inspecting the 
wing spars for cracks during annual and 100-hour inspections, 
particularly at the butt ends and strut attach points. However, this 
existing guidance does not provide instructions for sufficiently 
accessing the spar or identifying damage. For example, compression 
cracks appear as barely visible, minute, and jagged series of lines 
that run across the grain on the top or bottom of the spar. If not 
viewed with detailed instructions and the proper equipment, you could 
overlook them. SDR's submitted since the issuance of AD 98-05-04 have 
confirmed the importance of inspecting the wing spars in accordance 
with ACAC Service Letter 406, Revision A, dated May 6, 1998. We can 
only require compliance with service information through AD action.
    We are not changing the AD based on these comments.

Comment Issue No. 7: Exempt Airplanes With Wings That Were Recently 
Rebuilt

    What is the commenters' concern? Two commenters request that FAA 
exempt from the AD airplanes where the wing spars were recently 
inspected and found to be free of damage or where the spars were 
replaced.
    What is FAA's response to the concern? We do not concur. To 
adequately inspect the wing spars for cracks and compression cracks, 
you must utilize the detailed inspection procedures in ACAC Service 
Letter 406, Revision A, dated May 6, 1998 (or procedures approved by 
FAA). Information available to FAA reveals that mechanics have 
overlooked compression cracks when not following these procedures.
    We are not changing the AD based on these comments

Comment Issue No. 8: Eliminate, Minimize, or Provide Alternatives 
to Installing Top Inspection Covers

    What is the commenters' concerns? Several commenters request that 
FAA remove from this AD the option of installing inspection covers on 
the top surface of the wings of the ACAC 7, 8, and 11 series airplanes. 
Specific concerns are as follows:
    1. Top wing inspection covers could leak, cause water damage to the 
spar, and result in structural degradation of the wing;
    2. Top wing inspection covers could come off during flight due to 
the negative pressure on the top surface, and result in wing damage; 
and
    3. Top wing inspection covers will cause aerodynamic and 
performance concerns.
    What is FAA's response to the concerns? We do not concur with 
removing the option of installing top inspection covers from the AD. 
ACAC Service Letter 406, Revision A, dated May 6, 1998, allows the 
mechanic to utilize a variety of procedures and techniques (including 
the installation of top inspection covers) to perform a thorough 
inspection depending on his/her experience, equipment, and the aircraft 
configuration without mandating a specific number, type, or

[[Page 78908]]

location of inspection holes/covers. The service information only 
specifies the installation of additional FAA-approved holes/covers as 
needed to accomplish a thorough spar inspection. The mechanic 
performing the inspection is in the best position to determine the 
minimum number, type, and location of inspection holes/covers needed to 
accomplish a thorough spar inspection. We also do not concur that the 
installation of these covers will cause other safety concerns. Our 
response to each specific concern is as follows:
    1. Water damage to the spar: The manufacturer designed and tested 
an FAA-approved watertight seal for the as-needed wing inspection cover 
installation. This minimizes the potential for water damage.
    2. Wing damage: The manufacturer designed the covers specifically 
to not cause damage to the reinforced cutout if the eight screws that 
attach the covers are inadvertently left off or not tightened, and the 
covers come off the airplane. Testing indicates that the covers easily 
flip backward off the wing if all screws are omitted.
    3. Aerodynamic and performance concerns: FAA flight test personnel 
have evaluated these as-needed top inspection covers. As of the 
issuance of this document, we have not received any reports of 
decreased performance or service difficulty reports concerning any of 
the over 200 sets (400 inspection covers) that have already been 
delivered to the field.
    We are not changing the AD based on these comments.

Comment Issue No. 9: Require the Installation of Top Inspection 
Covers

    What is the commenter's concerns? One commenter requests that we 
not require the mechanics to inspect with a high intensity light source 
and mirrors. The commenter states that compression cracks are extremely 
difficult to detect and are easily overlooked.
    The commenter also states that the initial inspection method 
described in ACAC Service Letter 406, Revision A, dated May 6, 1998, is 
inadequate and the best way to detect compression cracks is by removing 
a section of the leading edge and looking directly at the top of the 
spar. This commenter suggests requiring the installation of FAA-
approved inspection holes/covers that are better situated on top of the 
wing than the holes/covers referenced in ACAC Service Letter 417, 
Revision C, dated May 6, 1998.
    What is FAA's response to the concern? ACAC Service Letter 406, 
Revision A, dated May 6, 1998, allows the mechanic to utilize a variety 
of procedures and techniques to perform a thorough inspection depending 
on his/her experience, equipment, and the aircraft configuration 
without mandating a specific number, type and/or location of inspection 
holes/covers. The service information only specifies the installation 
of additional FAA-approved holes/covers as needed to accomplish a 
thorough spar inspection. The mechanic performing the inspection is in 
the best position to determine the type, number, and location of 
inspection holes/covers needed to accomplish a thorough spar 
inspection.
    Mechanics utilizing ACAC Service Letter 406, Revision A, dated May 
6, 1998, have detected compression cracks on the wing spars that were 
not detected during previous annual inspections. We have determined 
that the procedures in the service letter, as proposed in the NPRM, 
provide sufficient information to detect compression cracks in the wing 
spars of ACAC 7, 8, and 11 series airplanes.
    We are not changing the AD based on these comments.

Comment Issue No. 10: Cost Impact Is Too Low

    What is the commenter's concern? One commenter believes that the 
cost of installing inspection covers will be significantly greater than 
we estimated in the NPRM. We infer that the commenter is referring to 
the additional costs associated with cosmetic paint refinishing costs 
after the installation of any needed inspection holes/covers.
    What is FAA's response to the concern? The cost impact of this AD 
reflects 11 as-needed inspection holes installed in the bottom of each 
wing (a total of 22) and 2 as-needed inspection holes/covers installed 
in the top of each wing. The decision on the number and location of any 
as-needed inspection holes/covers is at the discretion of the inspector 
in order to adequately inspect the entire surface of both wing spars.
    Cosmetic considerations are not reflected. If you utilize the 
alternative inspection method referenced in ACAC Service Letter 406, 
Revision A, dated May 6, 1998, the number of as-needed inspection 
holes/covers would be reduced. This would further reduce the cost 
impact of this AD.
    We are not changing the AD based on these comments.

Comment Issue No. 11: Provide Additional Inspection Guidance to 
Service Letter 406A and/or Require Additional Training for 
Inspectors

    What is the commenters' concerns? Five commenters state that 
compression cracks are extremely difficult to detect and are easily 
overlooked. Because of this, the commenters believe that FAA should:

--Include additional guidance to the AD to assure a thorough inspection 
is performed; and
--Require mechanics to obtain additional training in the detection of 
compression cracks on ACAC 7, 8, and 11 series airplanes.

    What is FAA's response to the concerns? We concur that the 
compression cracks are difficult to detect and mechanics could easily 
overlook them if they are not experienced in detecting damage specific 
to wood structure. ACAC Service Letter 406, Revision A, dated May 6, 
1998, contains a detailed description of compression cracks. This 
service letter also:

--Includes a recommendation that mechanics should have previous 
compression crack detection experience to perform certain methods of 
inspection; and
--Allows the mechanic to utilize different procedures and techniques to 
perform a thorough inspection depending on his/her experience, 
equipment, and the aircraft configuration without mandating a specific 
number, type, and/or location of inspection holes/covers.

    Mechanics have detected compression cracks in aircraft while 
utilizing ACAC Service Letter 406, Revision A, dated May 6, 1998. We 
have determined that the procedures in the service letter, as proposed 
in the NPRM, provide sufficient information to detect compression 
cracks in the wing spars of ACAC 7, 8, and 11 series airplanes.
    We are not changing the AD based on these comments.

Comment Issue No. 12: Proposed Inspection Is Too Broad.

    What is the commenters' concern? Two commenters suggest that FAA 
narrow the areas of inspection for compression cracks. These commenters 
state that this will not affect the inspection results.
    What is FAA's response to the concern? We do not concur. The 
Inspection: (Bottom/Top) section of ACAC Service Letter 406, Revision 
A, contains the following:

    Both front and rear spars need to be inspected. The key areas to 
be concerned with are shown in figure 1.

Figure 1 of this service letter depicts an isolated area that requires 
inspection of the top and bottom surfaces of the spar (near the strut 
attachments). The service

[[Page 78909]]

letter only includes procedures for the installation of top inspection 
covers in this area for the front spar. However, as stated as a warning 
in the service letter, loose rib nails may indicate compression cracks 
behind the rib flanges and you need to inspect these.
    Compression cracks have been detected in locations other than the 
strut attachment area. The forward or aft face of the spar needs to be 
inspected for indication of damage. This position has also been 
supported by an SDR on an ACAC Model 7GCBC airplane on the aft spar. 
This SDR contains the following information:

    Subject spar indicated irregular lines across the grain at 163 
inches from the root end. Fore and aft spar faces cleaned and sanded 
& the vertical lines remained. Pressure applied to the spar each 
side indicated slight movement. A hard downward pressure force 
caused the spar to crack along the apparent fault lines. Submitter 
enclosed a copy of the page taken from the wood encyclopedia, which 
describes compression failures in wood. Submitter suggests that this 
could have been caused by ground contact of the wing tip, sometime 
in the aircraft's history.

    We also have received photos of a badly cracked front spar from an 
ACAC Model 7GCAA airplane. This compression crack occurred just 
outboard of the first rib outboard and adjacent to the fuel tank bay 
and it extended 2/3 upward from the bottom of the spar. The report 
specifies that the aircraft had just over 500 hours time-in-service 
(TIS).
    We are not changing the AD based on these comments.

Comment Issue No. 13: Improper Wing Rigging Causes Many Compression 
Cracks

    What is the commenter's concern? One commenter believes improper 
rigging of the aircraft wings causes many compression cracks. This 
commenter requests additional service information.
    What is FAA's response to the concern? While FAA agrees that 
improper rigging could lead to compression cracks, all information 
available to us indicates the problem does not result from improper 
rigging alone. The reporting requirement in the AD will allow us to 
continue to collect data and investigate the cause of compression 
cracks and other reported damage. We may initiate further rulemaking 
action on this subject based on the information received.
    We are always open for groups such as the manufacturer and type 
clubs to work together to come up with valuable information, such as 
standardized rigging criteria and procedures.
    We are not changing the AD based on these comments.

Comment Issue No. 14: Change the Wording in the AD

    What is the commenters' concern? Two commenters suggest that the 
phrase ``to prevent possible compression cracks and other * * *'' that 
is included in the NPRM be changed to read ``to detect possible 
compression cracks and other * * *''
    What is FAA's response to the concern? We concur that the word 
detect should be added. We are changing this part of the final rule AD 
to read:

    * * * to detect and repair or replace damaged wood wing spars. 
Continued operation with such damage could progress to in-flight 
structural failure of the wing with consequent loss of control of 
the airplane.

Comment Issue No. 15: Use Carbon Tetrachloride in the Compression 
Crack Inspection Method

    What is the commenter's concern? One commenter states that use of 
carbon tetrachloride would improve the compression crack inspection 
method.
    What is FAA's response to the concern? The FAA agrees that the use 
of carbon tetrachloride may enhance the inspection of unvarnished wood 
and may have limited benefit if used on varnished spars. However, the 
Environmental Protection Agency (EPA) has classified carbon 
tetrachloride as a carcinogen. Health concerns and the availability of 
this substance prevent us from requiring its use through this AD.
    If desired, the application of any commercially-available ``light 
weight'' (not thick or viscous) wood stain instead of carbon 
tetrachloride may enhance the inspection process.
    We obtained this information from the Forest Products Laboratory, 
which is a unit of the research organization of the Forest Service, 
U.S. Department of Agriculture.
    We have determined that the application of a high intensity light 
source directly on the varnished surface, as specified in Service 
Letter 406, Revision A, dated May 6, 1998, adequately highlights 
compression cracks.
    We are not changing the AD based on these comments.

Comment Issue No. 16: Only Require Inspection During Fabric 
Recovering

     What is the commenters' concern? Two commenters suggest that FAA 
only require inspection during fabric recovering. These commenters 
state that this should be adequate to detect wing spar damage.
    What is FAA's response to the concern? The FAA does not concur. 
Information tells us differently. For example, Advisory Circular (AC) 
43.13-1B, paragraph 2.2.a., contains the following:

    Polyester fabric deteriorates only by exposure to ultraviolet 
radiation as used in aircraft covering environment. When coatings 
completely cover the fabric, its service life is infinite.

    Therefore, the special instructions contained in ACAC Service 
Letter 406, Revision A, dated May 6, 1998, are required to identify 
certain types of damage that may occur in the span of 10, 20, or more 
years of service. Additionally, the above-referenced AC also specifies 
``Therefore, it is very important to * * * provide adequate inspection 
access to all areas of (man-made) fabric covered components * * *''
    We are not changing the AD based on these comments.

Comment Issue No. 17: Preflight of Aircraft Should Include Wing 
Flexing

    What is the commenter's concern? One commenter states that he was 
taught to always ``jack the wings back and forth'' during the preflight 
inspection. The commenter recommends we consider adding this preflight 
technique to the AD. Since the commenter did not elaborate on the 
reason for this technique, we infer that the commenter believes this 
technique will help to audibly detect wing spar damage.
    What is FAA's response to the concern? The FAA does not concur. 
This technique may not detect most types of damage and may actually 
initiate damage if performed too aggressively.
    We are not changing the AD based on these comments.

The FAA's Determination and an Explanation of the Provisions of the 
AD

    What have we decided? After careful review of all available 
information related to the subject presented above, including the 
above-referenced comments, FAA has determined that:

--Air safety and the public interest require the adoption of the rule 
as proposed except for the changes described in the above comment 
disposition and minor editorial corrections; and
--These changes and minor corrections will not add any additional 
burden upon the public than was already proposed.

    What does this AD require? This AD retains the inspection and 
repair or

[[Page 78910]]

replacement requirements of AD 98-05-04 for the ACAC Model 8GCBC 
airplanes; extends all these actions to all ACAC 7, 8, and 11 series 
airplanes, except the inspections are not repetitive for certain 7 and 
11 series airplanes; requires that all damage be reported to FAA; and 
incorporates alternative methods of accomplishing certain actions.
    Why is the compliance time in calendar time instead of hours time-
in-service? The compliance time of this AD is presented in calendar 
time and TIS. We are utilizing repetitive inspection compliance times 
that will coincide with the owner's/operator's annual inspection 
program. This should have the least impact upon operators because the 
costs of having the airplane out of service can be absorbed with 
regularly scheduled down-time.
    To assure that compression cracks do not go undetected in the wood 
spars of the affected airplanes, we are using the following compliance 
times:
    1. The initial inspection at the first annual inspection that 
occurs 30 calendar days or more after the effective date of the AD or 
within 13 calendar months after the effective date of the AD, whichever 
occurs later; and
    2. The repetitive inspections (for those airplanes affected) 
thereafter at intervals not to exceed 12 calendar months or 500 hours 
TIS, whichever occurs first.

Cost Impact

    How did we determine the cost impact of this AD? The following cost 
analysis is based on the presumption that 26 as-needed inspection 
holes/covers (11 per wing on the bottom surface and 2 per wing on the 
top surface) will be installed on each affected airplane, in order to 
complete a thorough inspection in accordance with ACAC Service Letter 
406, Revision A, dated May 6, 1998. All of these inspection holes/
covers may not be needed, which will reduce the cost impact upon U.S. 
operators of the affected airplanes.
    How many airplanes are impacted by this AD? The FAA estimates that 
6,701 airplanes in the U.S. registry will be affected by this AD.
    What is the cost impact of the initial inspection on owners/
operators of the affected airplanes? We estimate that it will take 
approximately 6 workhours (Installations: 5 workhours; Initial 
Inspection: 1 workhour) per airplane to accomplish this action, and 
that the average labor rate is approximately $60 an hour. Parts cost 
approximately $292 per airplane, provided that each airplane will have 
11 as-needed standard inspection holes/covers per wing bottom surface 
and 2 as-needed inspection holes/covers per wing top surface (total of 
26 new covers per airplane) installed. If the airplane needs more 
inspection covers installed (e.g., 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 $4,369,052, or $652 per airplane.
    What about the cost of repetitive inspections and possible repairs 
and replacements? These cost figures are based on the presumption that 
no affected Model 8GCBC airplane owner/operator has accomplished the 
installations or the initial inspection as currently required by AD 98-
05-04, and do 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 because the initial cost of the as-needed 
inspection hole/cover installations will not be repetitive. If 
installed, as-needed inspection holes/covers allow easy access for the 
inspection of the wood spars, and the compliance time will enable the 
owners/operators of the affected airplanes to accomplish the repetitive 
inspections at regularly scheduled annual inspections.

Regulatory Impact

    Does this AD impact various entities? The regulations adopted 
herein will not have a substantial direct effect 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, it is determined that this final rule does not 
have federalism implications under Executive Order 13132.
    Does this AD involve a significant rule or regulatory action? 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, under 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. FAA amends Sec. 39.13 by removing Airworthiness Directive (AD) 
98-05-04, Amendment 39-10365 (63 FR 10297, March 3, 1998), and by 
adding a new AD to read as follows:

2000-25-02  American Champion Aircraft Company (ACAC): Amendment 39-
12036; Docket No. 98-CE-121-AD; Supersedes AD 98-05-04, Amendment 
39-10365.

    (a) What airplanes are affected by this AD? This AD applies to 
the following airplane models, all serial numbers, certificated in 
any category, that are equipped with wood wing spars:
    (1) Group 1 airplanes: ACAC Models 7AC, 7ACA, S7AC, 7BCM (L-
16A), 7CCM (L-16B), S7CCM, 7DC, S7DC, 7EC, S7EC, 7FC, 7JC, 11AC, 
S11AC, 11BC, S11BC, 11CC, and S11CC airplanes that have not been 
modified to incorporate an engine with greater than 90 horsepower.
    (2) Group 2 airplanes: ACAC Models 7ECA, 7GC, 7GCA, 7GCAA, 7GCB, 
7GCBA, 7GCBC, 7HC, 7KC, 7KCAB, 8GCBC, and 8KCAB airplanes; and any 
of the airplane models referenced in paragraph (a)(1) of this AD 
that have been modified to incorporate an engine with greater than 
90 horsepower.
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the above airplanes must comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to detect and repair or replace damaged wood 
wing spars. Continued operation with such cracks and damage could 
progress to an in-flight structural failure of the wing with 
consequent loss of control of the airplane.
    (d) What actions must be accomplished on all Group 1 airplanes 
to address this problem? For any Group 1 airplane as referenced in 
paragraph (a)(1) of this AD, the following must be accomplished to 
address the problem:

[[Page 78911]]



----------------------------------------------------------------------------------------------------------------
                Action                          Compliance time                        Procedures
----------------------------------------------------------------------------------------------------------------
(1) Inspection Requirements: Inspect    Initially inspect at the first  Accomplish in accordance with the
 (detailed visual) the entire length     annual inspection that occurs   instructions in ACAC Service Letter No.
 of the front and rear wood wing spars   30 calendar days or more        406, Revision A, dated May 6, 1998.
 for cracks, compression cracks,         after January 19, 2001 (the     This service bulletin specifies as an
 longitudinal cracks through the         effective date of this AD),     FAA-approved inspection option using a
 boltholes or nail holes, or loose or    whichever occurs later.         high-intensity flexible light (e.g.,
 missing rib nails. We will refer to                                     ``Bend-A-Light''). A regular flashlight
 these conditions as damage throughout                                   must not be used for this portion of
 the rest of this section.                                               the inspection. Alternative FAA-
                                                                         approved inspection options are listed
                                                                         in this service bulletin.
(2) Additional Inspection               Prior to further flight after   Accomplish in accordance with the
 Requirements: If, after January 19,     each accident/incident that     instructions in ACAC Service Letter No.
 2001 (the effective day of this AD),    involved wing damage.           406, Revision A, dated May 6, 1998.
 any airplane is involved in an                                          This service bulletin specifies as an
 accident/incident that involves wing                                    FAA-approved inspection option using a
 damage (e.g., wing surface                                              high-intensity flexible light (e.g.,
 deformations such as abrasions,                                         ``Bend-A-Light''). A regular flashlight
 gouges, scratches, or dents, etc.),                                     must not be used for this portion of
 accomplish the inspection required in                                   the inspection. Alternative FAA-
 paragraph (d)(1) of this Ad.                                            approved inspection options are listed
                                                                         in this service bulletin.
(3) Replacement Requirements: If any    Prior to further flight after   In accordance with Advisory Circular
 damage is found during any inspection   the inspection where the        (AC) 43.13-1B, Acceptable Methods,
 required by this AD, repair or          damage is found.                Techniques, and Practices; or other
 replace the wood spar.                                                  data that is FAA-approved for wing spar
                                                                         repair or replacement.
 (4) Reporting Requirements: If any     Within 10 days after the        Mail the information to: FAA, Chicago
 damage is found during any inspection   inspection where the damage     Aircraft Certification Office (ACO),
 required by this AD, submit a           was found or within 10 days     Attention: Docket No. 98-CE-121-AD,
 Malfunction or Defect Report (M or      after January 19, 2001 (the     2300 E. Devon avenue, Des Plaines,
 D), FAA Form 8010-4, to the FAA.        effective date of this AD),     Illinois 60018; facsimile: (847) 294-
                                         whichever occurs later.         7834. You may also file electronically
                                                                         as discussed in this AD.
(i) Include the airplane model and
 serial number, the extent of the
 damage (location and type), and the
 number of total hours time-in-service
 (TIS) on the damaged wing.
(ii) You may submit M or D reports
 electronically by accessing the FAA
 AFS-600 web page at <a href="http://www.mmac.jccbi.gov/afs/afs600">http://www.mmac.jccbi.gov/afs/afs600</a>.
 Because you will lose access to the
 report once you electronically submit
 it, we recommend that you print two
 copies prior to submitting the report
 and forward one to the Chicago ACO
 and keep the other for your records.
(iii) The Office of Management and
 Budget (OMB) approved the information
 collection requirements contained in
 this regulation under the provisions
 of the Paperwork Reduction Act of
 1980 (14 U.S.C. 3501 et seq.). The
 OMB assigned this approval Control
 Number 2120-0056.
----------------------------------------------------------------------------------------------------------------

    (e) What actions must be accomplished on all Group 2 airplanes 
to address this problem? For any Group 2 airplane as referenced in 
paragraph (a)(2) of this AD, the following must be accomplished to 
address the problem:

------------------------------------------------------------------------
            Action               Compliance time          Procedures
------------------------------------------------------------------------
 (1) Inspection               Initially inspect at  Accomplish in
 Requirements: Inspect         the first annual      accordance with the
 (detailed visual) the         inspection that       instructions in
 entire length of the front    occurs 30 calendar    American Champion
 and rear wood wing spars      days or more after    Aircraft
 for cracks, compression       January 19, 2001      Corporation (ACAC)
 cracks, longitudinal cracks   (the effective dae    Service Letter No.
 through the boltholes or      of this AD) or        406, Revision A,
 nail holes, or loose or       within the next 13    dated May 6, 1998.
 missing rib nails. We will    calendar months       This service
 refer to these conditions     after January 19,     bulleting specifies
 as damage throughout the      2001 (the effective   an FAA-approved
 rest of this section.         date of this AD),     inspection option
                               whichever occurs      using a high-
                               later. Repetitively   intensity flexible
                               inspect thereafter    light (e.g., ``Bend-
                               at intervals not to   A-Light''). A
                               exceed 500 hours      regular flashlight
                               time-in-service       must not be used
                               (TIS) or 12           for this portion of
                               calendar months,      the inspection.
                               whichever occurs      Alternative FAA-
                               first.                approved inspection
                                                     options are listed
                                                     in this service
                                                     bulletin.

[[Page 78912]]

 
 (2) Additional Inspection    Prior to further      Accomplish in
 Requirements: If, after       flight after each     accordance with the
 January 19, 2001 (the         accident/incident     instuctions in
 effective date of this AD),   that involved wing    American Champion
 any airplane is involved in   damage.               Aircraft
 an accident/incident that                           Corporation (ACAC)
 involves wing damage (e.g.,                         Service Letter No.
 wing surface deformations                           406, Revision A,
 such as abrasions, gouges,                          dated May 6, 1998.
 scratches, or dents, etc.),                         This service
 accomplish the inspection                           bulletin specifies
 required in paragraph                               an FAA-approved
 (e)(1) of this AD.                                  inspection option
                                                     using a high-
                                                     intensity flexible
                                                     light (e.g., ``Bend-
                                                     A-Light''). A
                                                     regular flashlight
                                                     must not be used
                                                     for this portion of
                                                     the inspection.
                                                     Alternative FAA-
                                                     approved inspection
                                                     options are listed
                                                     in this service
                                                     bulletin.
 (3) Replacement              Prior to further      In accordance with
 Requirements: If any damage   flight after the      Advisory Circular
 is found during any           inspection where      (AC) 43.13-1B,
 inspection required by this   the damage is found.  Acceptable Methods,
 AD, repair or replace the                           Techniques, and
 wood spar.                                          Practices; or other
                                                     data that is FAA-
                                                     approved for wing
                                                     spar repair or
                                                     replacement.
 (4) Reporting Requirement:   Within 10 days after  Mail the information
 If any damage is found        the inspection        to: FAA, Chicago
 during any inspection         where the damage      Aircraft
 required by this AD, submit   was found or within   Certification
 a Malfunction or Defect       10 days after         Office (ACO),
 Report (M or D), FAA Form     January 19, 2001      Attention: Docket
 8010-4, to the FAA.           (the effective date   No. 98-CE-121-AD,
                               of this AD),          2300 E. Devon
                               whichever occurs      Avenue, Des
                               later.                Plaines, Illinois
                                                     60018; facsimile:
                                                     (847) 294-7834. You
                                                     may also file
                                                     electronically as
                                                     discussed in this
                                                     AD.
 (i) Include the airplane
 model and serial number,
 the extent of the damage
 (location and type), and
 the number of total TIS on
 the damaged wing.
 (ii) You may submit M or D
 reports electronically by
 accessing the FAA AFS-600
 web page at <a href="http://www.mmac.jccbi.gov/afs/afs600">http://www.mmac.jccbi.gov/afs/afs600</a> afs600. Because you will
 lose access to the report
 once you electronically
 submit it, we recommend
 printing two copies prior
 to submitting the report
 and forward one to the
 Chicago ACO and keep the
 other for your records.
 (iii) The Office of
 Management and Budget (OMB)
 approved the information
 collection requirements
 contained in this
 regulation under the
 provisions of the Paperwork
 Reduction Act of 1980 (14
 U.S.C. 3501 et seq.). The
 OMB assigned this approval
 Control Number 2120-0056.
------------------------------------------------------------------------

    (f) Can I comply with this AD in any other way?
    (1) You may use an alternative method of compliance or adjust 
the compliance time if:
    (i) Your alternative method of compliance provides an equivalent 
level of safety; and
    (ii) The Manager, Chicago Aircraft Certification Office, 
approves your alternative. Submit your request through an FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager.
    (2) ACAC Service Letter 406, Revision A, and ACAC Service Letter 
417, Revision C, both dated May 6, 1998, specify additional 
inspection and installation alternatives over that included in the 
original issue of these service letters. All inspection and 
installation alternatives presented in these service letters are 
acceptable for accomplishing the applicable actions of this AD.
    (3) Alternative methods of compliance approved in accordance 
with AD 98-05-04, which is superseded by this AD, are approved as 
alternative methods of compliance with this AD.

    Note: This AD applies to each airplane identified in paragraph 
(a) of this AD, 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 (f) 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 you have not eliminated the unsafe condition, specific 
actions you propose to address it.

    (g) Where can I get information about any already-approved 
alternative methods of compliance? Contact the Chicago Aircraft 
Certification Office, 2300 E. Devon Avenue, Des Plaines, Illinois 
60018; telephone: (817) 294-7697; facsimile: (817) 294-7834.
    (h) What if I need to fly the airplane to another location to 
comply with this AD? The FAA can issue a special flight permit under 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate your airplane to a location where you 
can accomplish the requirements of this AD.
    (i) Are any service bulletins incorporated into this AD by 
reference? The inspections required by this AD must be done in 
accordance with American Champion Aircraft Corporation (ACAC), 
Service Letter 406, Revision A, dated May 6, 1998. The Director of 
the Federal Register approved this incorporation by reference under 
5 U.S.C. 552(a) and 1 CFR part 51. You can get copies from the 
American Champion Aircraft Corporation, P.O. Box 37, 32032 
Washington Avenue, Highway D, Rochester, Wisconsin 53167; internet 
address: ``<a href="http://www.amerchampionaircraft.com">www.amerchampionaircraft.com</a>''. You can look at copies at 
FAA, Central Region, Office of the Regional Counsel, 901 Locust, 
Room 506, Kansas City, Missouri, or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.
    (j) Are other AD's affected by this action? This amendment 
supersedes AD 98-05-04, Amendment 39-10365.
    (k) When does this amendment become effective? This amendment 
becomes effective on January 19, 2001.

    Issued in Kansas City, Missouri, on December 4, 2000.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 00-31450 Filed 12-15-00; 8:45 am]
BILLING CODE 4910-13-P