[Federal Register Volume 59, Number 180 (Monday, September 19, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-23078]
[[Page Unknown]]
[Federal Register: September 19, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 91-CE-83-AD; Amendment 39-9024; AD 91-25-08 R1]
Airworthiness Directives; Cessna Aircraft Company Models 421C and
425 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment revises Airworthiness Directive (AD) 91-25-08,
which currently requires repetitively inspecting both wing front spar
upper caps for cracks on certain Cessna Aircraft Company (Cessna)
Models 421C and 425 airplanes, and repairing cracks that exceed certain
limits. This action provides the option of incorporating a certain wing
spar upper cap service kit as either terminating action or as an
extension to the repetitive inspections currently required. Wing front
spar upper cap cracks at the main landing gear actuating cylinder
attachment fitting on three of the affected airplanes prompted this
action. The actions specified by this AD are intended to prevent wing
failure caused by excessive wing spar cracking.
DATES: Effective November 4, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 4, 1994.
ADDRESSES: Service information that applies to this AD may be obtained
from the Cessna Aircraft Company, Customer Services, P.O. Box 1521,
Wichita, Kansas 67201. This information may also be examined at the
Federal Aviation Administration (FAA), Central Region, Office of the
Assistant Chief Counsel, 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. Larry Abbott, Aerospace Engineer,
FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room
100, Wichita, Kansas 67209; telephone (316) 946-4123; facsimile (316)
946-4407.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an AD that would apply
to certain Cessna Models 421C and 425 airplanes was published in the
Federal Register on April 20, 1994 (59 FR 18768). The action proposed
to revise AD 91-25-08 by maintaining the wing front spar upper cap
repetitive inspection and possible crack repair requirement, and adding
the option of incorporating the applicable Cessna service kits to
either eliminate or extend the inspection time interval (depending on
whether cracks are found) of the repetitive inspections. The proposed
inspections would be accomplished in accordance with the ACCOMPLISHMENT
INSTRUCTIONS section of ATTACHMENT TO SERVICE BULLETIN (SB) to Cessna
SB CQB91-8R1, or the ACCOMPLISHMENT INSTRUCTIONS attachment to Cessna
SB MEB91-7R1, as applicable. The proposed inspection-extending or
inspection-terminating modifications (optional) would be accomplished
in accordance with the instructions to the applicable service kits that
are included as an attachment to the above-referenced service
bulletins.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the one comment received.
The commenter states that, although the proposal does not apply to
the serial number airplanes that the commenter owns, all 16 hi-lock
pins of each aft main landing gear support (part number 5122724-1 and
5122724-2) were found loose during an annual inspection. The commenter
believes that the above-referenced main landing gear supports are
located in the same general area as the area referenced in the
proposal, and that these areas share the same structural loads. For
these reasons, the commenter proposes expanding the rule to include an
inspection of these main landing gear supports as well as the wing
front spar upper caps. The FAA concurs that the referenced main landing
gear supports are in the same general area as the wing front spar upper
caps (between the main landing gear actuating cylinder attachment and
the front spar wing attach fittings); however, the two do not share the
same structural loads. The main landing gear supports incur loads from
the landing gear while the upper spar caps incur loads from the gear
retraction cylinder. This AD is written only to detect and correct wing
front spar upper cap cracking because the FAA identified this as an
unsafe condition that needed AD corrective action. The FAA will
evaluate service difficulty reports on the main landing gear supports,
and, if found necessary, will initiate applicable rulemaking at that
time. The AD is unchanged as a result of this comment.
After careful review of all available information including the
comment referenced above, the FAA has determined that air safety and
the public interest require the adoption of the rule as proposed except
for minor editorial corrections. The FAA has determined that these
minor corrections will not change the meaning of the AD nor add any
additional burden upon the public than was already proposed.
The FAA estimates that 551 airplanes in the U.S. registry will be
affected by this AD, that it will take approximately 3 workhours per
airplane to accomplish the required action, and that the average labor
rate is approximately $55 an hour. Based on these figures, the total
cost impact of the AD on U.S. operators is estimated to be $90,915.
This figure does not take into account the cost of repetitive
inspections nor the cost of the optional inspection-extending or
inspection-terminating service kit installations. The FAA has no way of
determining how many repetitive inspections each operator would incur
over the lifetime of the airplane.
In addition, the FAA estimates 52 workhours to install service kits
on the spar caps at an average labor rate of approximately $55 an hour,
and $1,050 cost per airplane for service kit parts. Based on these
figures, the cost for the optional service kit installations on U.S.
operators would be $2,154,410 or $3,910 per airplane. After
incorporation of these kits, the repetitive inspections would be
terminated or the number of repetitive inspections would be reduced
depending on whether the spar was cracked.
The Cessna Aircraft Company has informed the FAA that 67 SK421-142
(-1 or -2) or SK425-44 (-1 or -2) service kits have been sold, thus
reducing or terminating the inspections for the particular airplane
wing front spar upper cap that the kit is installed on. Repetitive
inspections are no longer required on the airplane if both wing front
spar upper caps have service kits incorporated, and these kits are
incorporated without cracks present. The FAA has no reasonably
available means of finding out how many inspection reductions (kit
incorporated with cracks) and how many inspection terminations (kit
incorporated without cracks) are involved, or how many airplanes
incorporated a left wing kit (-1) and a right wing kit (-2). With this
in mind, the FAA does not know exactly how much this reduces the cost
of the inspections and optional modification portion of this AD on U.S.
operators; however, the FAA would estimate this cost reduction at
around $125,000, thus reducing the optional modification portion of
this AD from a fleetwide cost impact of $2,154,410 to $2,029,410. This
estimate is based on taking the average workhour per wing of 26
workhours (2 wings = 52 workhours) times the average labor rate of $55
per hour plus the average cost of the different kits.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing AD 91-25-08, Amendment 39-
8109 (56 FR 60056, November 27, 1991), and by adding a new
airworthiness directive to read as follows:
91-25-08 R1 Cessna Aircraft Company: Amendment 39-9024; Docket No.
91-CE-83-AD; Revises AD 91-25-08, Amendment 39-8109.
Applicability: The following model and serial number airplanes,
certificated in any category:
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Model Serial Nos.
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421C............ 421C0801 through 421C1807.
425............. 425-0002 through 425-0236.
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Compliance: Required initially upon the accumulation of 3,000
hours time-in-service (TIS) or within the next 50 hours TIS after
the effective date of this AD, whichever occurs later, unless
already accomplished within the last 300 hours TIS, and thereafter
as indicated in the body of this AD.
Note 1: The compliance times specified in this AD take
precedence over those referenced in the applicable service
information.
To prevent wing failure caused by excessive wing spar cracking,
accomplish the following:
(a) Fluorescent penetrant inspect both the left and right wing
front spar upper caps for cracks between the main landing gear
actuating cylinder attachment and the front spar wing attach
fittings in accordance with the ACCOMPLISHMENT INSTRUCTIONS section
of ATTACHMENT TO SERVICE BULLETIN (SB) to Cessna SB CQB91-8R1, or
the ACCOMPLISHMENT INSTRUCTIONS attachment to Cessna SB MEB91-7R1,
as applicable.
(b) If any crack is found that is parallel (inboard--outboard)
to the top of the spar cap, install the applicable SK421-142 or
SK425-44 service kit (-1 for left spar cap and -2 for right spar
cap) in accordance with instructions to the applicable service kit
(included with the service bulletins referenced in paragraph (a) of
this AD) at the times that correspond with the following crack
lengths, and reinspect (as applicable) as specified in paragraph (d)
of this AD:
(1) If equal to or less than 2.0 inches in length, within the
next 200 hours TIS;
(2) If more than 2.0 inches and less than 2.5 inches in length,
within the next 50 hours TIS; or
(3) If 2.5 or more inches in length, prior to further flight.
(c) If any crack (regardless of length) is found that is not
parallel (inboard - outboard) to the top of the spar cap, prior to
further flight, obtain a repair scheme from the manufacturer through
the Wichita Aircraft Certification Office (ACO), incorporate this
repair scheme, and reinspect as specified in paragraph (d) of this
AD.
(d) Reinspect (fluorescent penetrant) the left and right wing
front spar upper caps for cracks in accordance with those procedures
specified in paragraph (a) of this AD at intervals presented within
the applicable criteria below:
(1) With cracks less than or equal to 2.0 inches in length that
are parallel (inboard--outboard) to the top of the spar cap, at 50-
hour TIS intervals until the applicable service kit is installed in
accordance with paragraph (b) of this AD, and then reinspect
thereafter at intervals not to exceed 600 hours TIS.
(2) With cracks found and the applicable SK421-142 or SK425-44
service kit (-1 for left spar cap and -2 for right spar cap)
incorporated, at 600-hour TIS intervals.
(3) With no cracks found and the applicable SK421-142 or SK425-
44 service kit (-1 for left spar cap and -2 for right spar cap) not
incorporated, at 300-hour TIS intervals; or
(4) With no cracks found and the applicable SK421-142 or SK425-
44 service kit (-1 for left spar cap and -2 for right spar cap)
incorporated, no repetitive inspections required.
(e) Special flight permits may be issued in accordance with
Secs. 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.
(f) An alternative method of compliance or adjustment of the
compliance time that provides an equivalent level of safety may be
approved by the Manager, Wichita ACO, 1801 Airport Road, Room 100,
Mid-Continent Airport, Wichita, Kansas 67209. The request shall be
forwarded through an appropriate FAA Maintenance Inspector, who may
add comments and then send it to the Manager, Wichita ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Wichita ACO.
(g) The inspections and modifications required by this AD shall
be done in accordance with ATTACHMENT TO SERVICE BULLETIN to Cessna
Service Bulletin CQB91-8R1, or the ACCOMPLISHMENT INSTRUCTIONS
attachment to Cessna Service Bulletin MEB91-7R1, as applicable. The
modification required by this AD shall be accomplished in accordance
with Cessna SERVICE KIT SK421-142, dated July 3, 1993, or Cessna
SERVICE KIT SK425-44, dated November 6, 1992, as applicable. 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 Cessna Aircraft Company, P.O. Box
7704, Wichita, Kansas 67277. Copies may be inspected at the FAA,
Central Region, Office of the Assistant Chief 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.
(h) This amendment (39-9024) revises AD 91-25-08, Amendment 39-
8109.
(i) This amendment (39-9024) becomes effective on November 4,
1994.
Issued in Kansas City, Missouri, on September 12, 1994.
Barry D. Clements,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 94-23078 Filed 9-16-94; 8:45 am]
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