[Federal Register Volume 61, Number 73 (Monday, April 15, 1996)]
[Proposed Rules]
[Pages 16416-16418]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-9234]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-255-AD]
Airworthiness Directives; Beech Model 400, 400A, MU-300-10, and
2000 Airplanes, and Model 200, B200, 300, and B300 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Beech Model 400, 400A, MU-
300-10, and 2000 airplanes, and Model 200, B200, 300, and B300 series
airplanes. This proposal would require replacement of outflow/safety
valves
[[Page 16417]]
with serviceable valves. This proposal is prompted by a report of
cracking and subsequent failure of outflow safety valves in the
pressurization system. The actions specified by the proposed AD are
intended to prevent such cracking and subsequent failure of the
outflow/safety valves, which could result in rapid decompression of the
airplane.
DATES: Comments must be received by May 28, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-255-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from AlliedSignal Aerospace, Technical Publications, Dept. 65-
70, P.O. Box 52170, Phoenix, Arizona 85072-2170. This information may
be examined at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount
Boulevard, Lakewood, California.
FOR FURTHER INFORMATION CONTACT: Walter Eierman, Aerospace Engineer,
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft
Certification Office, 3960 Paramount Boulevard, Lakewood, California
90712; telephone (310) 627-5336; fax (310) 627-5210.
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 shall 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 summarizing 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 Number 95-NM-255-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, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 95-NM-255-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report of the failure of a safety valve in
the pressurization system on a Learjet Model 31A airplane. Failure of
the valve resulted in depressurization of the cabin. Investigation
revealed that the poppets of certain outflow/safety valves were
cracked. These discrepant valves, including the safety valve installed
on the incident airplane, had been manufactured since January 1, 1989.
Certain valves manufactured since that date have been found to be
susceptible to cracking due to an improper molding process during their
manufacture. Cracking in the poppets of the outflow/safety valves in
the pressurization system can result in an open valve with an effective
flow area of 4.4 square inches; additionally, the valve may close and
remain closed. This condition, if not corrected, could result in
cracking and subsequent failure of the airflow/safety valves, which
could lead to rapid decompression of the airplane.
On September 20, 1995, the FAA issued AD 95-20-03, amendment 39-
9381 (60 FR 51709, October 3, 1995), to address this unsafe condition
on certain Learjet Model 24, 25, 28, 29, 31, 35, 36, and 55 series
airplanes. Subsequently, on December 5, 1995, the FAA issued AD 95-25-
10, amendment 39-9456, (60 FR 66484, December 22, 1995), to address the
unsafe condition on certain Cessna Model 441, 500, 550, and 560 series
airplanes. The outflow/safety valves installed on these Cessna and
Learjet airplane models are similar to the valves installed on Beech
Model 400, 400A, MU-300-10, and 2000 airplanes, and Model 200, B200,
300, and B300 series airplanes. Therefore, the FAA has determined that
the latter airplane models also are subject to the unsafe condition
described previously.
The FAA has reviewed and approved Allied Signal Aerospace Service
Bulletins 103570-21-4012 (for airplanes equipped with valves having
part number 103570-25, 103570-26, or 103570-27) and 103648-21-4022 (for
airplanes equipped with valves having part number 103648-1, 103648-3,
103648-4, 103648-5, 103648-6, 103648-7, or 103648-13), both Revision 1,
both dated May 30, 1995, which describe procedures for replacement of
certain discrepant outflow/safety valves with serviceable valves.
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require replacement of certain discrepant outflow/
safety valves with serviceable valves. The actions would be required to
be accomplished in accordance with the service bulletins described
previously.
Operators should note that Allied Signal Aerospace Service Bulletin
103570-21-4012 recommends accomplishing the replacement within 150
flight hours (after the release of the service bulletin), but no later
than June 30, 1996. Allied Signal Aerospace Service Bulletin 103648-21-
4022 recommends accomplishing the replacement within 200 flight hours
(after the release of the service bulletin), but no later than June 30,
1996. However, the FAA has determined that an interval of 18 months
will address the identified unsafe condition in a timely manner. This
proposed compliance time of 18 months was determined to be appropriate
in consideration of the safety implications, the average utilization
rate of the affected fleet, the practical aspects of accomplishment of
the replacement during regular maintenance periods, and the
availability of required replacement parts.
There are approximately 150 Model 400, 400A, MU-300-10, and 2000
airplanes, and Model 200, B200, 300, and B300 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 105
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 12 work hours per airplane to accomplish
the proposed actions, and that the average labor rate is $60 per work
hour. The parts manufacturer has advised that it will provide
replacement parts at no cost to operators. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$75,600, or $720 per airplane.
The cost impact figure discussed above is based on assumptions that
no
[[Page 16418]]
operator has yet accomplished any of the proposed requirements of this
AD action, and that no operator would accomplish those actions in the
future if this AD were not adopted.
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 proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the 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 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, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Beech Aircraft Corporation: Docket 95-NM-255-AD.
Applicability: Model 400, 400A, MU-300-10, and 2000 airplanes,
Model 200 and B200 series airplanes having a maximum altitude
capability of greater than 31,000 feet, and Model 300 and B300
series airplanes; equipped with Allied Signal outflow/safety valves,
as identified in Allied Signal Aerospace Service Bulletins 103570-
21-4012 and 103648-21-4022, both Revision 1, both dated May 30,
1995; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, 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 (c) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent cracking and subsequent failure of the outflow/safety
valves, which could result in rapid decompression of the airplane,
accomplish the following:
(a) Within 18 months after the effective date of this AD,
replace the outflow/safety valve in accordance with Allied Signal
Aerospace Service Bulletin 103570-21-4012 (for airplanes equipped
with valves having part number 103570-25, 103570-26, or 103570-27),
or 103648-21-4022 (for airplanes equipped with valves having part
number 103648-1, 103648-3, 103648-4, 103648-5, 103648-6, 103648-7,
or 103648-13), both Revision 1, both dated May 30, 1995, as
applicable.
(b) As of the effective date of this AD, no person shall install
an outflow/safety valve, having a part number and serial number
identified in Allied Signal Aerospace Service Bulletin 103570-21-
4012 (for airplanes equipped with valves having part number 103570-
25, 103570-26, or 103570-27), or 103648-21-4022 (for airplanes
equipped with valves having part number 103648-1, 103648-3, 103648-
4, 103648-5, 103648-6, 103648-7, or 103648-13), both Revision 1,
both dated May 30, 1995, on any airplane unless that valve is
considered to be serviceable in accordance with the applicable
service bulletin.
(c) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Los Angeles Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Los Angeles ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(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.
Issued in Renton, Washington, on April 9, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-9234 Filed 4-12-96; 8:45 am]
BILLING CODE 4910-13-U
