[Federal Register Volume 60, Number 11 (Wednesday, January 18, 1995)]
[Proposed Rules]
[Pages 3592-3593]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-1135]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-220-AD]
Airworthiness Directives; Raytheon Corporate Jets Models DH/BH/
HS/BAe 125-1 to -700 Series Airplanes; BAe 125-800A Airplanes; and
Hawker 800 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 Raytheon Corporate Jets
Models DH/BH/HS/BAe 125-1 to -700 series, BAe 125-800A, and Hawker 800
series airplanes. This proposal would require replacement of the
existing standby static inverter with an inverter that incorporates a
circuit board assembly sealed with a conformal coating. This proposal
is prompted by reports of failure of the standby static inverter caused
by electrical shorting from moisture condensing on the printed circuit
boards (PCB), due to aberrations in the PCB conformal coating. The
actions specified by the proposed AD are intended to prevent
malfunction of the standby static inverter due to exposure to moisture
caused by inadequate insulation coating of the circuit board assembly.
Malfunction or failure of the standby static inverter, when its use is
necessary, could result in the loss of electric power for certain
equipment critical to safety of flight.
DATES: Comments must be received by February 27, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-220-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 Raytheon Corporate Jets, Inc., 3 Bishops Square, St.
Albans Road West, Hatfield, Hertfordshire, AL109NE, United Kingdom.
This information may be examined at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2148; fax (206) 227-1320.
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 94-NM-220-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. 94-NM-220-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness
authority for the United Kingdom, recently notified the FAA that an
unsafe condition may exist on certain Raytheon Corporate Jets Models
DH/BH/HS/BAe 125-1 to -700, BAe 125-800A, and Hawker 800 series
airplanes. The CAA advises that it has received reports of failure of
the standby static inverter on certain of these airplanes. Failure was
caused by electrical shorting from moisture condensing on the printed
circuit boards (PCB), due to aberrations in the PCB's conformal
coating. Investigation has revealed that certain circuit boards in the
inverters have conformal coatings that were applied improperly. The
purpose of this coating is to protect the electric/electronic circuits
from moisture. Improper coating of the circuit boards can allow
moisture to condense on the PCB; this could cause an electrical short
that, subsequently, could result in a malfunction or failure of the
standby static inverter. This condition, if not corrected, could result
in the loss of all alternating current (AC) electric power for
equipment that is critical to safety of flight.
Raytheon Corporate Jets has issued Hawker Service Bulletin SB.24-
308-7673A, Revision 1, dated July 11, 1994, which describes procedures
for removing the existing standby static inverter and replacing it with
a printed circuit board assembly that is properly sealed with a
conformal coating. The CAA classified this service bulletin as
mandatory and issued British airworthiness directive 005-05-94 in order
to assure the continued [[Page 3593]] airworthiness of these airplanes
in the United Kingdom.
This airplane model is manufactured in the United Kingdom 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. Pursuant
to this bilateral airworthiness agreement, the CAA has kept the FAA
informed of the situation described above. The FAA has examined the
findings of the CAA, reviewed all available information, and determined
that AD action is necessary for products of this type design that are
certificated for operation in the United States.
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require replacement of the
existing standby static inverters with a printed circuit board assembly
that is properly sealed with a conformal coating. The actions would be
required to be accomplished in accordance with the service bulletin
described previously.
As a result of recent communications with the Air Transport
Association (ATA) of America, the FAA has learned that, in general,
some operators may misunderstand the legal effect of AD's on airplanes
that are identified in the applicability provision of the AD, but that
have been altered or repaired in the area addressed by the AD. The FAA
points out that all airplanes identified in the applicability provision
of an AD are legally subject to the AD. If an airplane has been altered
or repaired in the affected area in such a way as to affect compliance
with the AD, the owner or operator is required to obtain FAA approval
for an alternative method of compliance with the AD, in accordance with
the paragraph of each AD that provides for such approvals. A note has
been included in this notice to clarify this requirement.
The FAA estimates that 450 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 4 work
hours per airplane to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Required parts would cost
approximately $410 per airplane. Based on these figures, the total cost
impact of the proposed AD on U.S. operators is estimated to be
$292,500, or $650 per airplane.
The total 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 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 adding the following new
airworthiness directive:
Raytheon Corporate Jets, Inc. (Formerly de Havilland; Hawker
Siddeley; British Aerospace, plc): Docket 94-NM-220-AD.
Applicability: Model DH/BH/HS/BAe 125-1 to -700 series
airplanes, inclusive, on which Modification 252740 has been
installed; Model BAe 125-800A series airplanes, having constructor's
numbers prior to number 258248; and Hawker 800 series airplanes,
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 use the authority
provided in paragraph (b) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition; or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent an electrical short in the standby static inverter
due to the printed circuit boards being exposed to condensed
moisture, accomplish the following:
(a) Within 5 months of the effective date of this AD, remove the
existing standby static inverter (type PC 250) and replace it with a
Mod C Marathon/Flitetronics Inverter (type PC 250), in accordance
with Raytheon Corporate Jets Hawker Service Bulletin SB.24-308-
7673A, Revision 1, dated July 11, 1994.
(b) 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, Standardization Branch, ANM-113,
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,
Standardization Branch, ANM-113.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(c) 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 January 11, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-1135 Filed 1-17-95; 8:45 am]
BILLING CODE 4910-13-U
