[Federal Register: April 23, 2007 (Volume 72, Number 77)]
[Rules and Regulations]
[Page 20029-20030]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23ap07-1]
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Rules and Regulations
Federal Register
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[[Page 20029]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM376; Special Conditions No. 25-352-SC]
Special Conditions: McDonnell Douglas Models DC-10-10, 10-15, 10-
30, 10-30F, 10-40, and 10-40F Airplanes; High-Intensity Radiated Fields
(HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: The FAA issues these special conditions for McDonnell Douglas
Models DC-10-10, 10-15, 10-30, 10-30F, 10-40, and 10-40F airplanes
modified by Canard Aerospace Corporation. These modified airplanes will
have novel or unusual design features when compared with the state of
technology envisioned in the airworthiness standards for transport
category airplanes. The modification consists of installing electronic
flight and engine instrument systems. The applicable airworthiness
regulations do not contain adequate or appropriate safety standards for
protecting these systems from 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 April 16,
2007. We must receive your comments on or before May 23, 2007.
ADDRESSES: You may mail or deliver comments on these special conditions
in duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attention: Rules Docket (ANM-113), Docket No. NM376, 1601
Lind Avenue SW., Renton, Washington 98057-3356. You must mark your
comments Docket No. NM376.
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
98057-3356; telephone (425) 227-2799; facsimile (425) 227-1320.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment for these special conditions is impracticable because these
procedures would significantly delay certification and delivery of the
affected aircraft. In addition, the substance of these special
conditions has been subject to the public comment process in several
prior instances with no substantive comments received. We therefore
find that good cause exists for making these special conditions
effective upon issuance. However, we invite interested persons to take
part in this rulemaking by submitting written comments. 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
about these special conditions. You may inspect the docket 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 based on the comments we receive.
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 October 24, 2006, Canard Aerospace Corporation, 250 South Fuller
Street, Shakopee, Minnesota, 55379, applied for a supplemental type
certificate (STC) to modify McDonnell Douglas Models DC-10-10, 10-15,
10-30, 10-30F, 10-40, and 10-40F airplanes. The McDonnell Douglas Model
DC-10 airplanes are powered by three turbofan engines, with maximum
takeoff weights of up to 590,000 pounds. These airplanes operate with a
2-pilot crew and can seat up to 380 passengers. The modification
consists of installing electronic flight and engine instrument systems.
These systems have a potential to be vulnerable to high-intensity
radiated fields (HIRF) external to the airplane.
Type Certification Basis
Under provisions of 14 CFR 21.101, Canard Aerospace Corporation
must show that the McDonnell Douglas Models DC-10-10, 10-15, 10-30, 10-
30F, 10-40, and 10-40F airplanes, as changed, continue to meet the
applicable provisions of the regulations incorporated by reference in
Type Certificate No. A22WE 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 specific regulations are 14
CFR part 25, as amended by Amendments 25-1 through 25-22. In addition,
the certification basis includes certain special conditions and
exemptions that are not relevant to these special conditions.
If the Administrator finds that the applicable airworthiness
regulations (part 25, as amended) do not contain adequate or
appropriate safety standards for the McDonnell Douglas Model DC-10
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 McDonnell Douglas Model DC-10 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.
[[Page 20030]]
The FAA issues special conditions, as defined in Sec. 11.19, under
Sec. 11.38, and they become part of the type certification basis under
the provisions of Sec. 21.101.
Novel or Unusual Design Features
As noted earlier, the McDonnell Douglas Model DC-10 airplanes
modified by Canard Aerospace will incorporate the Astronautics
Electronic Flight Information System (EFIS) that will perform critical
functions. This system may be vulnerable to high-intensity radiated
fields external to the airplane. Current airworthiness standards of
part 25 do not contain adequate or appropriate safety standards for
protecting this equipment from adverse effects of HIRF. So this system
is considered to be a novel or unusual design feature.
Discussion
As previously stated, there is no specific regulation that
addresses protection for electrical and electronic systems from HIRF.
Increased power levels from radio frequency transmitters and the
growing use of sensitive avionics/electronics and electrical 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 McDonnell Douglas Model DC-10 airplanes
modified by Canard Aerospace Corporation. 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 because of HIRF.
High-Intensity Radiated Fields (HIRF)
High-power radio frequency transmitters for radio, radar,
television, and satellite communications can adversely affect operation
of airplane electric and electronic systems. Therefore, the immunity of
critical avionics/electronics and electrical systems to HIRF must be
established.
Based on surveys and an analysis of existing HIRF emitters, an
adequate level of protection exists when airplane system immunity is
demonstrated when exposed to the HIRF environments in either paragraph
1 OR 2 below:
1. A minimum environment of 100 volts rms (root-mean-square) per
meter electric field strength from 10 KHz to 18 GHz.
a. System elements and their associated wiring harnesses must be
exposed to the environment without benefit of airframe shielding.
b. Demonstration of this level of protection is established through
system tests and analysis.
2. An environment external to the airframe of the field strengths
shown in the table below for the frequency ranges indicated. Immunity
to both peak and average field strength components from the table must
be demonstrated.
------------------------------------------------------------------------
Field strength
(volts per meter)
Frequency -------------------
Peak Average
------------------------------------------------------------------------
10 kHz-100 kHz...................................... 50 50
100 kHz-500 kHz..................................... 50 50
500 kHz-2 MHz....................................... 50 50
2 MHz-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
4 GHz-6 GHz......................................... 3000 200
6 GHz-8 GHz......................................... 1000 200
8 GHz-12 GHz........................................ 3000 300
12 GHz-18 GHz....................................... 2000 200
18 GHz-40 GHz....................................... 600 200
------------------------------------------------------------------------
The field strengths are expressed in terms of peak of the root-mean-
square (rms) over the complete modulation period.
The environment levels identified above are the result of an FAA
review of existing studies on the subject of HIRF and of the work of
the Electromagnetic Effects Harmonization Working Group of the Aviation
Rulemaking Advisory Committee.
Applicability
These special conditions are applicable to McDonnell Douglas Model
DC-10 airplanes modified by Canard Aerospace Corporation. Should Canard
Aerospace apply at a later date for a supplemental type certificate to
modify any other model included on Type Certificate No. A22WE to
incorporate the same or similar novel or unusual design feature, these
special conditions would apply to that model as well under provisions
of Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on McDonnell Douglas Model DC-10 airplanes modified by Canard Aerospace
Corporation. 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 airplane.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
0
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
0
Therefore, under the authority delegated to me by the Administrator,
the following special conditions are issued as part of the supplemental
type certification basis for the McDonnell Douglas Models DC-10-10, 10-
15, 10-30, 10-30F, 10-40, and 10-40F airplanes modified by Canard
Aerospace Corporation.
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 continued safe flight and
landing of the airplane.
Issued in Renton, Washington, on April 16, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-7699 Filed 4-20-07; 8:45 am]
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