[Federal Register Volume 61, Number 50 (Wednesday, March 13, 1996)]
[Proposed Rules]
[Pages 10292-10294]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-5944]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-256-AD]
Airworthiness Directives; Piaggio Model P-180 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 Piaggio Model P-180
airplanes. This proposal would require replacement of outflow/safety
valves 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 April 22, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-256-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 Allied Signal 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-256-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-256-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/
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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 Piaggio
Model P-180 series airplanes. Therefore, the FAA has determined that
the latter airplane model also is subject to the unsafe condition
described previously.
The FAA has reviewed and approved Allied Signal Aerospace Service
Bulletins 103742-21-4059 (for airplanes equipped with valves having
part number 103742) and 103744-21-4060 (for airplanes equipped with
valves having part number 103744), both dated March 31, 1995, which
describe procedures for replacement of certain discrepant outflow/
safety valves with serviceable valves.
This airplane model is manufactured in Italy and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement.
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the 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, although the service bulletins
recommend accomplishing the replacement within 300 flight hours or six
months (after the release of the service bulletins), whichever occurs
first, 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.
The FAA estimates that 10 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 this proposal on U.S.
operators is estimated to be $7,200, or $720 per airplane.
The cost impact figure discussed above is based on assumptions that
no 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:
I.A.M. Rinaldo Piaggio S.P.A.: Docket 95-NM-256-AD.
Applicability: Model P-180 airplanes equipped with Allied Signal
outflow/safety valves, as identified in Allied Signal Aerospace
Service Bulletins 103742-21-4059 and 103744-21-4060, both dated
March 31, 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 would 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 103742-21-4059 (for airplanes equipped
with valves having part number 103742), or 103744-21-4060 (for
airplanes equipped with valves having part number 103744), both
dated March 31, 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 103742-21-
4059 (for airplanes equipped with valves having part number 103742)
or 103744-21-4060 (for airplanes equipped with valves having part
number 103744), both dated March 31, 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
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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 March 7, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-5944 Filed 3-12-96; 8:45 am]
BILLING CODE 4910-13-U
