[Federal Register Volume 59, Number 125 (Thursday, June 30, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-15597]
[[Page Unknown]]
[Federal Register: June 30, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-01-AD; Amendment 39-8955; AD 94-14-03]
Airworthiness Directives; Nordskog Water Heaters and Coffee
Makers as Installed in Various Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Nordskog water heaters and coffee makers. This
amendment requires an inspection to determine whether certain
discrepant pressure relief valves have been installed in certain galley
water heaters and coffee makers; and either replacement of the
discrepant valves, or discontinued use of the water heaters or coffee
makers and installation of placards indicating that these units are not
to be used. This amendment is prompted by reports of injuries to cabin
crew members that resulted from explosions of galley water heaters. The
actions specified by this AD are intended to prevent explosions of
galley water heaters and coffee makers, and subsequent injuries to
passengers or cabin crew members.
DATES: Effective August 1, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 1, 1994.
ADDRESSES: The service information referenced in this AD may be
obtained from Aircraft Products Company, 12807 Lake Drive, P.O. Box
130, Delray Beach, Florida 33447-0130. This information may be examined
at the Federal Aviation Administration (FAA), Transport Airplane
Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington;
or at the FAA, Los Angeles Aircraft Certification Office (ACO), 3229
East Spring Street, Long Beach, California; or at the Office of the
Federal Register, 800 North Capitol Street, NW., suite 700, Washington,
DC.
FOR FURTHER INFORMATION CONTACT: Walter Eierman, Systems and Equipment
Branch, ANM-131L, FAA, Transport Airplane Directorate, Los Angeles ACO,
3229 East Spring Street, Long Beach, California 90806-2425; telephone
(310) 988-5336; fax (310) 988-5210.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Nordskog water heaters and
coffee makers was published in the Federal Register on March 16, 1994
(59 FR 12203). That action proposed to require an inspection to
determine whether certain discrepant pressure relief valves have been
installed in certain galley water heaters and coffee makers; and either
replacement of the discrepant valves, or discontinued use of the water
heaters or coffee makers and installation of placards indicating that
these units are not to be used.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Several commenters support the proposal.
Another commenter supports the proposed AD action, but requests
that it be issued as an immediately adopted rule, in light of the
potential for serious injury to passengers and cabin crew members that
is associated with exploding water heaters and coffee makers. This
commenter points out that AD 93-23-01, amendment 39-8735 (58 FR 61618,
November 22, 1993), addressed this same problem in other water heaters
and coffee makers using the same pressure relief valves, and it was
made effective immediately, without prior opportunity for notice and
public comment. This commenter questions whether the unsafe condition
is any ``less'' for the units addressed by the proposal than for those
addressed by AD 93-23-01. The FAA responds by noting that the incident
reports that prompted the issuance of AD 93-23-01 involved units
equipped with an integral check valve; AD 93-23-01 applies only to
units with the integral check valve installation. At the time that AD
93-23-01 was issued, the FAA was in the process of evaluating the need
for additional AD action to address other installations that
incorporate the same pressure relief valve design. The FAA found that
Nordskog water heaters and coffee makers without the integral check
valve could use the same pressure relief valve in other applications
and, therefore, could also be subject to the same unsafe condition.
However, because there had been no service history of incidents
involving units without the integral check valve, the FAA could not
demonstrate that the safety concern was so critical that it should
preclude the opportunity for prior notice and public comment on this
rule.
Two commenters do not consider that AD action is appropriate to
address a ``non-critical'' application of the subject valve. These
commenters point out that AD 93-23-01 implemented the recommendations
of Nordskog Service Bulletin 93-34, which targeted the ``critical''
valve installations. However, the proposed AD would implement the
recommendations of Nordskog Service Bulletin 93-35, which addresses
``non-critical'' installations of the valve. In light of this, the
commenters contend that the AD is unnecessary. The FAA does not concur.
The FAA acknowledges that AD 93-23-01 addresses units that incorporate
the subject valve as an integral check valve, which may be viewed as a
``critical'' application of the valve; it was a unit equipped with this
integral check valve that exploded during the incident that prompted
issuance of that AD. However, as discussed in the previous comment, the
FAA has determined that water heaters and coffee makers that are not
equipped with the integral check valve but use the same pressure relief
valve addressed by AD 93-23-01, may also be subject to the same unsafe
condition addressed by that AD. Although the commenters may view the
component design of the units addressed by this AD action as ``less
critical'' than those addressed by AD 93-23-01, the FAA has received no
data to demonstrate that the subject relief valve is not necessary to
assure system safety. Therefore, the FAA considers this AD action to be
both appropriate and warranted.
One commenter requests that the proposed rule be revised the permit
the installation of the discrepant NUPRO pressure relief valve after
the effective date of the AD and until the compliance time for
inspection. This commenter points out that proposed paragraph (b) would
require that, as of the effective date of the rule, no operator would
be allowed to install a discrepant valve on any airplane; however,
operators would have up to 12 months to remove any discrepant valve
that is currently installed on the airplane. The FAA does not concur in
this case. Removing an unsafe condition that already exists on an
airplane necessarily involves performing maintenance on the airplane,
and the FAA always provides some kind of ``grace period'' in order to
minimize disruption of operations. On the other hand, prohibiting
installation of spares that have been determined to create an unsafe
condition does not require any additional maintenance activity; it
simply requires use of one part rather than another. In general, once
an unsafe condition has been determined to exist, it is the FAA's
normal policy not to allow that condition to be introduced into the
fleet. In developing the technical information on which every AD is
based, one of the important considerations is the availability of parts
that the AD will require to be installed. When it is determined that
those (safe) parts are immediately available to operators, it is the
FAA's policy to prohibit installation of the unsafe parts after the
effective date of the AD.
Further, the FAA considers that the period of time between
publication of the final rule AD in the Federal Register and the
effective date of the final rule (usually 30 days) is sufficient to
provide operators with an opportunity to determine their immediate need
for modified spares and to obtain them. Of course, in individual cases
where this is not possible, every AD contains a provision that allows
an operator to obtain an extension of compliance time based upon a
specific showing of need. The FAA considers that this policy does
increase safety and does not impose undue burdens on operators.
One commenter is concerned about the thermostat installed on the
water heaters and coffee makers equipped with the subject NUPRO
pressure relief valves, and its involvement in the incident of
explosion of the water heater. This commenter assumes that the incident
was the result of one of two possible failure paths: Either the
thermostat failed closed and the pressure relief valve failed closed;
or the power relay failed closed and the pressure relief valve failed
closed. This commenter indicates that the proposed rule does not
address these possible failure paths or the fact that failures of the
thermostat or relay are non-indicating by themselves. The FAA
acknowledges that this commenter's assumptions about the failure paths
is reasonable. Although a failure other than that of the relief valve
could not be identified, some failure apparently occurred in the
temperature control system to cause the pressure to build up beyond its
normal level. Generally, it is expected that the temperature control
system will fail sometime during its service life; the relief valve is
in the system to address that failure. Although increased redundancy
and failure monitoring in the temperature control system would be two
ways of improving system safety, those methods are not considered
necessary in this case. Replacement of the discrepant valve with the
improved valve will address the failure scenario that actually
occurred.
This commenter also is concerned about part identification of
inserts in the affected water heaters and coffee makers, and the need
for a possible design change of NUPRO relief valves that have a common
design type. Since these issues do not directly concern this rulemaking
action, the FAA has passed the commenter's suggestions on to the
appropriate manufacturer. -
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule as proposed.
The FAA is aware that the subject water heaters and coffee makers
are installed in various airplanes. There are approximately 300 of
these airplanes in the worldwide fleet, the FAA estimates that 200
airplanes are of U.S. registry. It will take approximately 2 work hours
per airplane to accomplish the proposed actions, and the average labor
rate is $55 per work hour. (There are approximately 4 water heaters
and/or coffee makers installed on each airplane.) The cost of required
parts is expected to be negligible. Based on these figures, the total
cost impact of this AD on U.S. operators is estimated to be $22,000, or
$110 per airplane.
The total cost impact figure discussed above is based on
assumptions that no operator has yet accomplished any of the
requirements of this AD action, and that no operator would accomplish
those actions in the future if this AD were not adopted.
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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from 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.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
94-14-03 Nordskog Industries, Inc.: Amendment 39-8955. Docket 94-
NM-01-AD.
Applicability: Nordskog water heaters and coffee makers, as
listed in Nordskog Industries, Inc., Service Bulletin SB-93-35,
dated October 21, 1993; as installed in, but not limited to, Boeing
Model 727, 737, 747, 757, and 767 series airplanes; McDonnell
Douglas Model DC-9, DC-9-80, and DC-10 series airplanes, and MD-11
airplanes; Lockheed Model L-1011 series airplanes; Airbus Industrie
Model A300, A310, and A320 series airplanes; Gulfstream Model G-1159
series airplanes and Model G-IV airplanes; de Havilland, Inc., Model
DHC-8 series airplanes; Dassault-Aviation Model Mystere-Falcon 50,
200, and 900 series airplanes; Canadair Model CL-600-1A11 (CL-600),
CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and -3R) and CL-
600-2B19 series airplanes; and Fokker Model F27 and F28 series
airplanes; certificated in any category.
To prevent explosions of galley water heaters and coffee makers,
and subsequent injuries to passengers or cabin crew members,
accomplish the following:
(a) Within 12 months after the effective date of this AD,
perform a one-time inspection to determine whether a NUPRO pressure
relief valve having part number (P/N) SS-2C4-65 has been installed,
in accordance with Nordskog Industries, Inc., Service Bulletin SB-
93-35, dated October 21, 1993. If any NUPRO pressure relief valve
having P/N SS-2C4-65 has been installed, prior to further flight,
accomplish either paragraph (a)(1) or (a)(2) of this AD.
(1) Remove the NUPRO pressure relief valve having P/N SS-2C4-65
and install a new, improved NUPRO pressure relief valve having P/N
SS-CHF2-65, in accordance with the service bulletin. Or
(2) Deactivate any Nordskog water heater or coffee maker listed
in the service bulletin on which a NUPRO pressure relief valve
having P/N SS-2C4-65 has been installed, and install a placard
stating, ``Not to be used.''
(b) As of the effective date of this AD, no person shall install
a NUPRO pressure relief valve having P/N SS-2C4-65 on any airplane.
(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: 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.
(e) The inspection and installation shall be done in accordance
with Nordskog Industries, Inc., Service Bulletin SB-93-35, dated
October 21, 1993. 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 Aircraft
Products Company, 12807 Lake Drive, P.O. Box 130, Delray Beach,
Florida 33447-0130. Copies may be inspected at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or
at the FAA, Los Angeles Aircraft Certification Office (ACO), 3229
East Spring Street, Long Beach, California; or at the Office of the
Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
(f) This amendment becomes effective on August 1, 1994.
Issued in Renton, Washington, on June 22, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-15597 Filed 6-29 -94; 8:45 am]
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