[Federal Register Volume 59, Number 76 (Wednesday, April 20, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9473]


[[Page Unknown]]

[Federal Register: April 20, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 91-CE-83-AD]

 

Airworthiness Directives: Cessna Aircraft Company Models 421C and 
425 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise 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. The 
proposed action would provide 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 the 
proposed action. The actions specified by the proposed AD are intended 
to prevent wing failure caused by excessive wing spar cracking.

DATES: Comments must be received on or before June 30, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 91-CE-83-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 through Friday, 
holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from the Cessna Aircraft Company, Customer Services, P.O. Box 1521, 
Wichita, Kansas 67201. This information also may be examined at the 
Rules Docket at the address above.

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:

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. 91-CE-83-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. 91-CE-83-AD, room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    AD 91-25-08, Amendment 39-8109 (56 FR 60056, November 27, 1991), 
currently requires repetitively inspecting both wing front spar upper 
caps for cracks on certain Cessna Models 421C and 425 airplanes, and 
repairing any crack found that exceeds certain limits. The action is 
accomplished in accordance with the instructions in Cessna Service 
Bulletin (SB) MEB91-7 or SB CQB91-8, both dated October 18, 1991, as 
applicable.
    Since issuance of AD 91-25-08, Cessna has developed certain wing 
front spar upper cap service kits. The FAA has determined that these 
service kits, if incorporated, would either eliminate the need or 
extend the time necessary for the currently required repetitive 
inspections.
    Cessna has revised both SB MEB91-7 and SB CQB91-8 to include 
reference of the service kits mentioned above. Cessna has also issued 
attachments to these service bulletins that specify procedures for 
incorporating the service kits.
    After examining the circumstances and reviewing all available 
information related to the proposed action, the FAA has determined 
that: (1) The repetitive inspections can be either eliminated or 
extended (depending on whether cracks are found) if the service kits 
referenced above are incorporated; and (2) AD action should be taken to 
prevent wing failure because of excessive wing spar cracking.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Cessna Models 421C and 425 airplanes of the 
same type design, the proposed AD would revise AD 91-25-08 by 
maintaining the 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 kit that are included as an attachment to the 
above-referenced service bulletins.
    The FAA estimates that 551 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 3 
workhours per airplane to accomplish the proposed inspection, and that 
the average labor rate is approximately $55 an hour. Based on these 
figures, the total cost impact of the proposed inspection 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 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.
    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. 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:

Cessna Aircraft Company: 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.         
------------------------------------------------------------------------

    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 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) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to the Cessna Aircraft 
Company, P.O. Box 7704, Wichita, Kansas 67277; or may examine this 
document at the FAA, Central Region, Office of the Assistant Chief 
Counsel, room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
    (h) This amendment revises AD 91-25-08, Amendment 39-8109.

    Issued in Kansas City, Missouri, on April 14, 1994.
Barry D. Clements,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 94-9473 Filed 4-19-94; 8:45 am]
BILLING CODE 4910-13-U