Special Conditions: Dassault Aviation Model Falcon 7X; Enhanced Flight Visibility System (EFVS), 47176-47180 [2010-19073]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 75, Number 150 (Thursday, August 5, 2010)]
[Rules and Regulations]
[Pages 47176-47180]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-19073]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM432; Special Conditions No. 25-410-SC]


Special Conditions: Dassault Aviation Model Falcon 7X; Enhanced 
Flight Visibility System (EFVS)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for certain Dassault 
Aviation Model Falcon 7X airplanes. This airplane will have an 
advanced, enhanced flight-visibility system (EFVS), which is a novel or 
unusual design feature consisting of a head-up display (HUD) system 
modified to display forward-looking infrared (FLIR) imagery. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. 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 July 27, 2010. 
We must receive your comments by August 25, 2010.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM432, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. You may deliver two copies to the Transport 
Airplane Directorate at the above address. You must mark your comments: 
Docket No. NM432. 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: Dale Dunford, FAA, Transport Standards 
Staff, ANM-111, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
telephone (425) 227-2239; fax (425) 227-1320; e-mail: 
dale.dunford@faa.gov.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of and 
opportunity for prior public comment on these special conditions is 
impracticable and would significantly delay issuance of the design 
approval and thus delivery of the affected aircraft. These particular 
special conditions were recently issued and only three non-substantive 
comments were received during the public-comment period. The FAA 
therefore finds that good cause exists for making these special 
conditions effective upon issuance.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a

[[Page 47177]]

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 can 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 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive by 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 us to let you know we received your comments on these 
special conditions, send us a self-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 15, 2009, Dassault Aviation applied for a change to Type 
Certificate A59NM for the installation of an EFVS in the Dassault Model 
Falcon 7X airplane, a 19-passenger, transport-category airplane powered 
by three aft-mounted Pratt & Whitney PW307A high-bypass-ratio turbofan 
engines. Maximum takeoff weight is 69,000 pounds, and maximum certified 
altitude will be 51,000 feet with a range of 5,700 nautical miles.
    The electronic infrared image displayed between the pilot and the 
forward windshield represents a novel or unusual design feature in the 
context of Title 14, Code of Federal Regulations (14 CFR) 25.773. 
Section 25.773 was not written in anticipation of such technology. The 
electronic image has the potential to enhance the pilot's awareness of 
the terrain, hazards, and airport features. At the same time, the image 
may partially obscure the pilot's direct, outside-compartment view. 
Therefore, the FAA needs adequate safety standards to evaluate the EFVS 
to determine that the imagery provides the intended visual enhancements 
without undue interference with the pilot's outside-compartment view. 
The FAA intends that the pilot is able to use a combination of the 
information seen in the image and the natural view of the outside 
scene, as seen through the image as safely and effectively as a pilot-
compartment view without an EVS image, and that is compliant with Sec.  
25.773.
    Although the FAA has determined that the existing regulations are 
not adequate for certification of EFVSs, we believe that EFVSs could be 
certified through application of appropriate safety criteria. 
Therefore, the FAA has determined that special conditions should be 
issued for certification of EFVS to provide a level of safety 
equivalent to that provided by the standard in Sec.  25.773.

    Note: The term ``enhanced vision system'' (EVS) commonly refers 
to a system comprised of a head-up display (HUD), imaging sensor(s), 
and avionics interfaces that display the sensor imagery on the HUD 
and overlay it with alpha-numeric and symbolic flight information. 
However, the term has also commonly refers to systems that display 
the sensor imagery, with or without other flight information, on a 
head-down display. To avoid confusion, the FAA created the term 
``enhanced flight visibility system'' (EFVS) to refer to certain EVS 
systems that meet the requirements of the new operational rules--in 
particular, the requirement for a HUD and specified flight 
information--and can be used to determine ``enhanced flight 
visibility.'' EFVSs can be considered a subset of systems otherwise 
labeled EVSs.

    On January 9, 2004, the FAA published revisions to operational 
rules in 14 CFR parts 1, 91, 121, 125, and 135 to allow aircraft to 
operate below certain altitudes during a straight-in instrument 
approach while using an EFVS to meet visibility requirements.
    Prior to this rule change, the FAA issued Special Conditions No. 
25-180-SC, which approved the use of an EVS on Gulfstream Model G-V 
airplanes. Those special conditions addressed the requirements for the 
pilot-compartment view and limited the scope of the intended functions 
permissible under the operational rules at the time. The intended 
function of the EVS imagery was to aid the pilot during the approach 
and allow the pilot to detect and identify the visual references for 
the intended runway down to 100 feet above the touchdown zone. However, 
the EVS imagery alone was not to be used as a means to satisfy 
visibility requirements below 100 feet.
    The recent operational rule change expands the permissible 
application of certain EVSs that are certified to meet the new EFVS 
standards. The new rule will allow the use of EFVSs for operation below 
the minimum descent altitude (MDA) or decision height (DH) to meet new 
visibility requirements of Sec.  91.175(l). The purpose of these 
special conditions is not only to address the issue of the ``pilot 
compartment view,'' as was done by Special Conditions No. 25-180-SC, 
but also to define the scope of intended function consistent with Sec.  
91.175(l) and (m).

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Dassault Aviation must show 
that the Model Falcon 7X airplane, as changed, continues to meet the 
applicable provisions of the regulations incorporated by reference in 
Type Certificate A59NM 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 A59NM are as follows:
    Title 14, Code of Federal Regulations (CFR) part 25, as amended by 
Amendment 25-1 through 25-111. The certification basis includes certain 
special conditions and exemptions that are not relevant to these 
special conditions.
    If the regulations incorporated by reference do not provide 
adequate standards regarding the change, the applicant must comply with 
certain regulations in effect on the date of application for the 
change. Dassault must show that the Falcon 7X, as modified, complies 
with 14 CFR part 25, as amended by Amendments 25-112 through 25-129.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25 as amended) do not contain adequate or 
appropriate safety standards for the Dassault Aviation Model Falcon 7X 
changed by Dassault Aviation, 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 Dassault Aviation Model Falcon 7X airplane 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.
    The FAA issues special conditions, as defined in 14 CFR 11.19, 
under Sec.  11.38 and they become part of the type certification basis 
under Sec.  21.101.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, or should any other model already 
included on the same type certificate be modified to

[[Page 47178]]

incorporate the same or similar novel or unusual design feature, the 
special conditions would also apply to the other model under Sec.  
21.101.

Novel or Unusual Design Features

    The Dassault Aviation Model Falcon 7X airplane will incorporate an 
EFVS, which is a novel or unusual design feature because the EFVS 
projects a video image derived from a forward-looking infrared (FLIR) 
camera through the HUD. The EFVS image is projected in the center of 
the ``pilot-compartment view,'' which is governed by Sec.  25.773. The 
image is displayed with HUD symbology and overlays the forward outside 
view. Therefore, Sec.  25.773 does not contain appropriate safety 
standards for the EFVS display.
    Operationally, during an instrument approach, the EFVS image is 
intended to enhance the pilot's ability to detect and identify ``visual 
references for the intended runway'' [see 14 CFR 91.175(l)(3)] to 
continue the approach below decision height or minimum descent 
altitude. Depending on atmospheric conditions and the strength of 
infrared energy emitted and/or reflected from the scene, the pilot can 
see these visual references in the image better than can be seen 
through the window without EFVS.
    Scene contrast detected by infrared sensors can be much different 
from that detected by natural pilot vision. On a dark night, thermal 
differences of objects which are not detectable by the naked eye are 
easily detected by many imaging infrared systems. On the other hand, 
contrasting colors in visual wavelengths may be distinguished by the 
naked eye but not by an imaging infrared system. Where thermal contrast 
in the scene is sufficiently detectable, the pilot can recognize shapes 
and patterns of certain visual references in the infrared image. 
However, depending on conditions, those shapes and patterns in the 
infrared image can appear significantly different than they would with 
normal vision. Considering these factors, the EFVS image needs to be 
evaluated to determine that it can be accurately interpreted by the 
pilot.
    The EFVS image may improve the pilot's ability to detect and 
identify items of interest. However, the EFVS needs to be evaluated to 
determine that the imagery allows the pilot to perform the normal 
duties of the flight crew and adequately see outside the window through 
the image, consistent with the safety intent of Sec.  25.773(a)(2).
    Compared to a HUD displaying the EFVS image and symbology, a HUD 
that only displays stroke-written symbols is easier to see through. 
Stroke symbology illuminates a small fraction of the total display area 
of the HUD, leaving much of that area free of reflected light that 
could interfere with the pilot's view out the window through the 
display. However, unlike stroke symbology, the video image illuminates 
most of the total display area of the HUD (approximately 30 degrees 
horizontally and 25 degrees vertically) which is a significant fraction 
of the pilot-compartment view. The pilot cannot see around the larger 
illuminated portions of the video image, but must see the outside scene 
through it.
    Unlike the pilot's external view, the EFVS image is a monochrome, 
two-dimensional display. Many, but not all, of the depth cues found in 
the natural view are also found in the image. The quality of the EFVS 
image and the level of EFVS infrared-sensor performance could depend 
significantly on conditions of the atmospheric and external light 
sources. The pilot needs adequate control of sensor gain and image 
brightness, which can significantly affect image quality and 
transparency (i.e., the ability to see the outside view through the 
image). Certain system characteristics could create distracting and 
confusing display artifacts. Finally, because this is a sensor-based 
system intended to provide a conformal perspective corresponding with 
the outside scene, the system must be able to ensure accurate 
alignment.
    Therefore, safety standards are needed for each of the following 
factors:
     An acceptable degree of image transparency;
     Image alignment;
     Lack of significant distortion; and
     The potential for pilot confusion or misleading 
information.
    Section 25.773, Pilot compartment view, specifies that ``Each pilot 
compartment must be free of glare and reflection that could interfere 
with the normal duties of the minimum flight crew * * *.'' In issuing 
Sec.  25.773, the FAA did not anticipate the development of the EFVS 
and does not consider Sec.  25.773 to be adequate to address the 
specific issues related to such a system. Therefore, the FAA has 
determined that special conditions are needed to address the specific 
issues particular to the installation and use of an EFVS.

Discussion

    The EFVS is intended to function by presenting an enhanced view 
during the approach. This enhanced view would help the pilot to see and 
recognize external visual references, as required by Sec.  91.175(l), 
and to visually monitor the integrity of the approach, as described in 
FAA Order 6750.24D (``Instrument Landing System and Ancillary 
Electronic Component Configuration and Performance Requirements,'' 
dated March 1, 2000).
    Based on this approved functionality, users would seek to obtain 
operational approval to conduct approaches, including approaches to 
Type I runways, in visibility conditions much lower than those for 
conventional Category I.
    The purpose of these special conditions is to ensure that the EFVS 
to be installed can perform the following functions:
     Present an enhanced view that would aid the pilot during 
the approach.
     Provide enhanced flight visibility to the pilot that is no 
less than the visibility prescribed in the standard instrument approach 
procedure.
     Display an image that the pilot can use to detect and 
identify the ``visual references for the intended runway'' required by 
Sec.  91.175(l)(3) to continue the approach with vertical guidance to 
100 feet height above the touchdown-zone elevation.
    Depending on the atmospheric conditions and the particular visual 
references that happen to be distinctly visible and detectable in the 
EFVS image, these functions would support its use by the pilot to 
visually monitor the integrity of the approach path.
    Compliance with these special conditions does not affect the 
applicability of any of the requirements of the operating regulations 
(i.e., 14 CFR parts 91, 121, and 135). Furthermore, use of the EFVS 
does not change the approach minima prescribed in the standard 
instrument-approach procedure being used; published minima still apply.
    The FAA certification of this EFVS is limited as follows:
     The infrared-based EFVS image will not be certified as a 
means to satisfy the requirements for descent below 100 feet height 
above touchdown (HAT).
     The EFVS may be used as a supplemental device to enhance 
the pilot's situational awareness during any phase of flight or 
operation in which its safe use has been established.
    An EFVS image may provide an enhanced image of the scene that may 
compensate for any reduction in the clear outside view of the visual 
field framed by the HUD combiner. The pilot must be able to use this 
combination of information seen in the image and the natural view of 
the outside scene, as seen through the image as safely and effectively 
as the pilot would use a pilot-compartment view without an EVS

[[Page 47179]]

image, and that is compliant with Sec.  25.773. This is the fundamental 
objective of the special conditions.
    The FAA will also apply additional certification criteria, not as 
special conditions, for compliance with related regulatory 
requirements, such as Sec. Sec.  25.1301 and 25.1309. These additional 
criteria address certain image characteristics, installation, 
demonstration, and system safety.
    Image-characteristic criteria include the following:
     Resolution,
     Luminance,
     Luminance uniformity,
     Low level luminance,
     Contrast variation,
     Display quality,
     Display dynamics (e.g., jitter, flicker, update rate, and 
lag), and
     Brightness controls.
    Installation criteria address visibility and access to EFVS 
controls and integration of EFVS in the cockpit.
    The EFVS demonstration criteria address the flight and 
environmental conditions that need to be covered.
    The FAA also intends to apply certification criteria relevant to 
high-intensity radiated fields (HIRF) and lightning protection.

Applicability

    As discussed above, these special conditions are applicable to 
Dassault Aviation Model Falcon 7X airplanes. Should Dassault Aviation 
apply at a later date for a change to the type certificate to include 
another model incorporating the same novel or unusual design feature, 
the special conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on Dassault Aviation Model Falcon 7X changed by Dassault Aviation. It 
is not a rule of general applicability.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, 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 upon issuance. 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.

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

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type-certification basis for Dassault Aviation Model Falcon 7X.
    1. The EFVS imagery on the HUD must not degrade the safety of 
flight or interfere with the effective use of outside visual references 
for required pilot tasks during any phase of flight in which it is to 
be used.
    2. To avoid unacceptable interference with the safe and effective 
use of the pilot-compartment view, the EFVS device must meet the 
following requirements:
    a. The EFVS design must minimize unacceptable display 
characteristics or artifacts (e.g., noise, ``burlap'' overlay, running 
water droplets) that obscure the desired image of the scene, impair the 
pilot's ability to detect and identify visual references, mask flight 
hazards, distract the pilot, or otherwise degrade task performance or 
safety.
    b. Control of EFVS display brightness must be sufficiently 
effective in dynamically changing background (ambient) lighting 
conditions to prevent full or partial blooming of the display that 
would distract the pilot, impair the pilot's ability to detect and 
identify visual references, mask flight hazards, or otherwise degrade 
task performance or safety. If automatic control for image brightness 
is not provided, it must be shown that a single manual setting is 
satisfactory for the range of lighting conditions encountered during a 
time-critical, high-workload phase of flight (e.g., low-visibility 
instrument approach).
    c. A readily accessible control must be provided that permits the 
pilot to immediately deactivate and reactivate display of the EFVS 
image on demand.
    d. The EFVS image on the HUD must not impair the pilot's use of 
guidance information or degrade the presentation and pilot awareness of 
essential flight information displayed on the HUD, such as alerts, 
airspeed, attitude, altitude and direction, approach guidance, 
windshear guidance, TCAS resolution advisories, or unusual-attitude-
recovery cues.
    e. The EFVS image and the HUD symbols, which are spatially 
referenced to the pitch scale, outside view and image, must be scaled 
and aligned (i.e., conformal) to the external scene. In addition, the 
EFVS image and the HUD symbols--when considered singly or in 
combination--must not be misleading, cause pilot confusion, or increase 
workload. Some airplane attitudes or cross-wind conditions may cause 
certain symbols (e.g., the zero-pitch line or flight-path vector) to 
reach field of view limits such that they cannot be positioned 
conformally with the image and external scene. In such cases, these 
symbols may be displayed, but with an altered appearance which makes 
the pilot aware that they are no longer displayed conformally (for 
example, ``ghosting'').
    f. A HUD system used to display EFVS images must, if previously 
certified, continue to meet all of the requirements of the original 
approval.
    3. The safety and performance of the pilot tasks associated with 
the use of the pilot-compartment view must be not be degraded by the 
display of the EFVS image. These tasks include the following:
    a. Detection, accurate identification, and maneuvering, as 
necessary, to avoid traffic, terrain, obstacles, and other hazards of 
flight.
    b. Accurate identification and utilization of visual references 
required for every task relevant to the phase of flight.
    4. Compliance with these special conditions will enable the EFVS to 
be used during instrument approaches in accordance with Sec.  91.175(l) 
such that it may be found acceptable for the following intended 
functions:
    a. Presenting an image that would aid the pilot during a straight-
in instrument approach.
    b. Enabling the pilot to determine that there is sufficient 
``enhanced flight visibility,'' as required by Sec.  91.175(l)(2), for 
descent and operation below minimum descent altitude/decision height.
    c. Enabling the pilot to use the EFVS imagery to detect and 
identify the ``visual references for the intended runway,'' required by 
Sec.  91.175(l)(3), to continue the approach with vertical guidance to 
100 feet height above touchdown-zone elevation.
    5. Use of EFVS for instrument-approach operations must be in 
accordance with the provisions of Sec.  91.175(l) and (m). Appropriate 
limitations must be stated in the Operating Limitations section of the 
airplane flight manual to prohibit the

[[Page 47180]]

use of the EFVS for functions that have not been found to be 
acceptable.

    Issued in Renton, Washington, on July 27, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-19073 Filed 8-4-10; 8:45 am]
BILLING CODE 4910-13-P