[Federal Register: October 13, 2004 (Volume 69, Number 197)]
[Rules and Regulations]
[Page 60797-60798]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13oc04-2]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM291; Special Conditions No. 25-273-SC]
Special Conditions: Raytheon Aircraft MU-300-10 and 400
Airplanes; High Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for Raytheon Aircraft
Company Model MU-300-10 and 400 airplanes modified by ARINC Inc. These
airplanes will have novel and unusual design features when compared to
the state of technology envisioned in the airworthiness standards for
transport category airplanes. The proposed modification incorporates
the installation of a Dual Thommen AD-32 Air Data Display Units. The
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for the protection of these systems from
the effects of high-intensity-radiated fields (HIRF). These special
conditions contain the additional safety standards that the
Administrator considers necessary to establish a level of safety
equivalent to that established by the existing airworthiness standards.
DATES: The effective date of these special conditions is November 12,
2004. Comments must be received on or before November 12, 2004.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM291, 1601 Lind
Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate
to the Transport Airplane Directorate at the above address. Comments
must be marked: Docket No. NM291. Comments may be inspected in the
Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4
p.m.
FOR FURTHER INFORMATION CONTACT: Greg Dunn, FAA, Airplane and Flight
Crew Interface Branch, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington, 98055-4056; telephone (425) 227-2799; facsimile (425) 227-
1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment hereon is unnecessary as the substance of these special
conditions has been subject to the public comment process in several
prior instances with no substantive comments received. The FAA,
therefore, finds that good cause exists for making these special
conditions effective upon issuance; however, we invite interested
persons to participate in this rulemaking by submitting written
comments, data, or views. The most helpful comments reference a
specific portion of the special conditions, explain the reason for any
recommended change, and include supporting data. We ask that you send
us two copies of written comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
concerning these special conditions. The docket is available for public
inspection before and after the comment closing date. If you wish to
review the docket in person, go to the address in the ADDRESSES section
of this preamble between 7:30 a.m. and 4 p.m. Monday through Friday,
except Federal holidays.
We will consider all comments we receive on or before the closing
date for comments. We will consider comments filed late if it is
possible to do so without incurring expense or delay. We may change
these special conditions in light of the comments received.
If you want the FAA to acknowledge receipt of your comments on
these special conditions, include with your comments a pre-addressed,
stamped postcard on which the docket number appears. We will stamp the
date on the postcard and mail it back to you.
Background
On March 1, 2004, ARINC Inc., 1632 South Murray Blvd. Colorado
Springs, CO 80916, applied for a supplemental type certificate (STC) to
modify Raytheon Aircraft Company Models MU-300-10 (Diamond II) and 400
(Beechjet) airplanes. The Raytheon airplanes are small transport
category airplanes powered by two turbojet engines, with maximum
takeoff weights of up to 15,780 pounds. These airplanes operate with a
2-pilot crew and can seat up to 9 passengers. The proposed modification
incorporates the installation of a Dual Thommen AD-32 Air Data Display
Units. The information this equipment presents is flight critical. The
avionics/electronics and electrical systems to be installed on these
airplanes have the potential to be vulnerable to high-intensity
radiated fields (HIRF) external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR 21.101, ARINC Inc. must show that
the Raytheon Aircraft Company Model MU-300-10 and 400 airplanes, as
changed, continue to meet the applicable provisions of the regulations
incorporated by reference in Type Certificate No. A16SW, or the
applicable regulations in effect on the date of application for the
change. The regulations incorporated by reference in the type
certificate are commonly referred to as the ``original type
certification basis.''
The regulations incorporated by reference in Type Certificate No.
A16SW include 14 CFR part 25, as amended by Amendments 25-1 through 25-
40; Sec. 25.1351(d), 25.1353(c)(5), and 25.1450 as amended by
Amendment 25-41; Sec. Sec. 25.29, 25.255, and 25.1353(c)(6) as amended
by Amendment 25-42; Sec. 25.361(b) as amended by Amendment 25-46; and
14 CFR part 36 as amended by Amendment 36-1 through 36-12.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for modified Model MU-300-10 and 400
airplanes, because of a novel or unusual design feature, special
conditions are prescribed under the provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Raytheon Model MU-300-10 and 400 airplanes must comply
with the fuel vent and exhaust emission requirements of 14 CFR part 34
and the noise certification requirements of 14 CFR part 36.
Special conditions, as defined in 14 CFR 11.19, are issued in
accordance with Sec. 11.38, and become part of the type certification
basis in accordance with Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should ARINC Inc. apply at a later date for
supplemental type certificate to modify any other model included on the
same type certificate to incorporate the same novel or unusual design
feature, these special conditions would also apply to the other model
under the provisions of Sec. 21.101.
[[Page 60798]]
Novel or Unusual Design Features
The modified Model MU-300-10 and 400 airplanes will incorporate
avionics/electrical systems that will perform critical functions. These
systems may be vulnerable to HIRF external to the airplane.
Discussion
There is no specific regulation that addresses protection
requirements for electrical and electronic systems from HIRF. Increased
power levels from ground-based radio transmitters and the growing use
of sensitive avionics/electrical and electronic systems to command and
control airplanes have made it necessary to provide adequate
protection.
To ensure that a level of safety is achieved equivalent to that
intended by the regulations incorporated by reference, special
conditions are needed for the Model MU-300-10 and 400 airplanes. These
special conditions require that new avionics/electronics and electrical
systems that perform critical functions be designed and installed to
preclude component damage and interruption of function due to both the
direct and indirect effects of HIRF.
High-Intensity Radiated Fields (HIRF)
With the trend toward increased power levels from ground-based
transmitters, plus the advent of space and satellite communications,
coupled with electronic command and control of the airplane, the
immunity of critical digital avionics/electronics and electrical
systems to HIRF must be established.
It is not possible to precisely define the HIRF to which the
airplane will be exposed in service. There is also uncertainty
concerning the effectiveness of airframe shielding for HIRF.
Furthermore, coupling of electromagnetic energy to cockpit-installed
equipment through the cockpit window apertures is undefined. Based on
surveys and analysis of existing HIRF emitters, an adequate level of
protection exists when compliance is shown with either HIRF protection
special condition paragraph 1 or 2 below:
1. A minimum threat of 100 volts rms (root-mean-square) per meter
electric field strength from 10 KHz to 18 GHz.
a. The threat must be applied to the system elements and their
associated wiring harnesses without the benefit of airframe shielding.
b. Demonstration of this level of protection is established through
system tests and analysis.
2. A threat external to the airframe of the field strengths
indicated in the following table for the frequency ranges indicated.
Both peak and average field strength components from the table are to
be demonstrated.
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Field strength
(volts per meter)
Frequency -------------------
Peak Average
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10 kHz-100 kHz...................................... 50 50
100 kHz-500 kHz..................................... 50 50
500kHz-2 MHz........................................ 50 50
2MHz-30 MHz......................................... 100 100
30 MHz-70 MHz....................................... 50 50
70 MHz-100 MHz...................................... 50 50
100 MHz-200 MHz..................................... 100 100
200 MHz-400 MHz..................................... 100 100
400 MHz-700 MHz..................................... 700 50
700 MHz-1 GHz....................................... 700 100
1 GHz-2 GHz......................................... 2000 200
2 GHz-4 GHz......................................... 3000 200
4GHz-6 GHz.......................................... 3000 200
6GHz-8 GHz.......................................... 1000 200
8GHz-12 GHz......................................... 3000 300
12 GHz-18 GHz....................................... 2000 200
18 GHz-40 GHZ....................................... 600 200
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The field strengths are expressed in terms of peak of the root-mean-
square (rms) over the complete modulation period.
The threat levels identified above are the result of an FAA review
of existing studies on the subject of HIRF, in light of the ongoing
work of the Electromagnetic Effects Harmonization Working Group of the
Aviation Rulemaking Advisory Committee.
Applicability
As discussed above, these special conditions are applicable to the
Raytheon Aircraft Company Model MU-300-10 and 400 airplanes. Should
ARINC Inc. apply at a later date for a change to the type certificate
to include another model incorporating the same novel or unusual design
feature, these special conditions would apply to that model as well
under the provisions of 14 CFR 21.101.
Conclusion
This action affects only certain novel or unusual design features
on the Raytheon Aircraft Company Model MU-300-10 and 400 airplanes. It
is not a rule of general applicability and affects only the applicant
who applied to the FAA for approval of these features on the airplanes.
The substance of the special conditions for these airplanes has
been subjected to the notice and comment procedure in several prior
instances and has been derived without substantive change from those
previously issued. Because a delay would significantly affect the
certification of the airplane, which is imminent, the FAA has
determined that prior public notice and comment are unnecessary and
impracticable, and good cause exists for adopting these special
conditions immediately. The FAA is requesting comments to allow
interested persons to submit views that may not have been submitted in
response to the prior opportunities for comment described above.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the supplemental type certification basis for Raytheon Aircraft Company
Model MU-300-10 and 400 airplanes modified by ARINC Inc.
1. Protection from Unwanted Effects of High-Intensity Radiated
Fields (HIRF). Each electrical and electronic system that performs
critical functions must be designed and installed to ensure that the
operation and operational capability of these systems to perform
critical functions are not adversely affected when the airplane is
exposed to high intensity radiated fields.
2. For the purpose of these special conditions, the following
definition applies: Critical Functions: Functions whose failure would
contribute to or cause a failure condition that would prevent the
continued safe flight and landing of the airplane.
Issued in Renton, Washington, on October 1, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-22946 Filed 10-12-04; 8:45 am]
BILLING CODE 4910-13-P