[Federal Register Volume 74, Number 207 (Wednesday, October 28, 2009)]
[Rules and Regulations]
[Pages 55443-55447]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-25493]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM416; Special Conditions No. 25-393-SC]


Special Conditions: Bombardier Model Challenger CL-600-2B16 (CL-
605, Ref. Note 9 of TC No. A21EA); Enhanced Flight Vision 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 the Bombardier Model 
CL-600-2B16 (CL-605) airplane. This airplane, as modified by Rockwell 
Collins Aerospace & Electronics, Inc., will have an Enhanced Flight 
Vision System (EFVS). The EFVS is a novel or unusual design feature 
which consists of a head-up display (HUD) system modified to display 
forward-looking infrared (FLIR) radar imagery. The airworthiness 
regulations applicable to pilot compartment view 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 October 9, 
2009. We must receive your comments by December 14, 2009.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM416, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356. You may deliver two copies to the Transport 
Airplane Directorate at the above address. You must mark your comments: 
Docket No. NM416. You can inspect comments in the Rules Docket 
weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Dale Dunford, FAA, ANM-111, Airplane 
and Flight Crew Interface, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2239; fax (425) 227-1320; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: The FAA has determined that the substance of 
these special conditions has previously

[[Page 55444]]

been subject to the public-comment process. 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 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 7:30 a.m. and 4 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 acknowledge receipt of your comments on these 
special conditions, include with your comments a self-addressed, 
stamped postcard on which you have written the docket number. We will 
stamp the date on the postcard and mail it back to you.

Background

    On November 28, 2008, Rockwell Collins Aerospace & Electronics, 
Inc., applied for a supplemental type certificate for installation of a 
HUD/EFVS system in the Bombardier Model CL-600-2B16 (CL-605). The Model 
No. CL-600-2B16 (CL-605) is a transport category airplane certified to 
carry a maximum of 19 passengers and a minimum of 2 crew members. The 
Model CL-605 is a marketing designation for the Challenger CL-600-2B16 
(CL-604 Variant) with Modsums 604DX10000, 604DX20000 and 604DX30000 
incorporated, beginning with aircraft S/N 5701 and subsequent numbers. 
The modification involves the installation of an EFVS. This system 
consists of a Rockwell Collins HUD system, modified to display FLIR 
imagery, and an FLIR camera.
    The electronic infrared image displayed between the pilot and the 
forward windshield represents a novel or unusual design feature in the 
context of 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 be able to use a combination of the information, seen in the 
image and the natural view of the outside scene appearing beyond and 
through the image, as safely and effectively as a pilot-compartment 
view without an EFVS 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, the FAA believes that EFVSs 
could be certified through the 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) has been 
commonly used to refer to a system comprised of a 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 been commonly used in 
reference 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 Vision 
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 vision.'' An EFVS can be 
considered a subset of systems otherwise labeled EVS.

    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 25-
180-SC, which approved the use of an EVS on Gulfstream Model G-V 
airplanes. These 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 instrument 
approach, and to 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 allows 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 this special 
condition is not only to address the issue of the ``pilot-compartment 
view,'' as was done by 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, Rockwell Collins Aerospace & 
Electronics, Inc., must show that the Bombardier Model CL-600-2B16 (CL-
605), as changed, continues to meet the applicable provisions of the 
regulations incorporated by reference in Type Certificate No. A21EA or 
the applicable regulations in effect on the date of application for 
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 
A21EA are as follows:
    Model CL-600-2B16 (604 Variant)
    Part 25 dated February 1, 1965, including Amendments 25-1 through 
25-78 with the following exceptions at Amendment:
     25-37 for Sec. Sec.  25.109, 25.149, 25.365, 25.561, 
25.625, 25.701, 25.772, 25.783 (except Sec.  25.783(f)), 25.785 (except 
Sec.  25.785(g)), 25.789, 25.791, 25.801, 25.803, 25.807, 25.809, 
25.811, 25.812, 25.813, 25.831, 25.853, 25.855, 25.857, 25.1307, 
25.1359, 25.1415, and 25.1419;
     25-37 for existing installations and Amendment 25-78 for 
new installations for Sec. Sec.  25.963, 25.965, 25.994, 25.997, and 
25.1438;
     25-38 for Sec. Sec.  25.787 and 25.1439;
     25-40 for Sec.  25.973;
     25-37 for Sec.  25.109 (see note 7);
     25-44 for Sec.  25.1413;
     25-54 for Sec.  25.851;
     25-80 for Sec.  25.1316.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Bombardier Model CL-600-2B16

[[Page 55445]]

(CL-605), 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 Bombardier Model CL-600-2B16 (CL-605) 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, in 
accordance with Sec.  11.38, and they become part of the type-
certification basis under Sec.  21.17(a)(2).
    Special conditions are initially applicable to the model for which 
they are issued. Should Rockwell Collins Aerospace & Electronics, Inc. 
(the applicant), apply for a supplemental type certificate to modify 
any other model, included on the same type certificate to incorporate 
the same novel or unusual design feature, the special conditions would 
also apply to the other model.

Novel or Unusual Design Features

    The Bombardier Model CL-600-2B16 (CL-605) airplanes will 
incorporate EFVS, which is a novel or unusual design feature, because 
it projects a video image derived from an 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 Sec.  91.175(l)(3)] to 
continue the approach below DH or MDA. 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 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, will 
be 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 the pilot can interpret 
it accurately.
    The 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 and beyond 
the EFVS 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 and beyond 
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 and 
beyond 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.
    Hence, safety standards are required 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 EFVSs 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 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 performs the following functions:
     Present an enhanced view that aids 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 instrument-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

[[Page 55446]]

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 displayed in the image and the natural view 
of the outside scene, seen through the image, as safely and effectively 
as the pilot would use a Sec.  25.773-compliant pilot-compartment view 
without an EVS image. This is the fundamental objective of the special 
conditions.
    The FAA also applies additional certification criteria, not as 
special conditions, for compliance with related regulatory 
requirements, such as Sec.  25.1301 and Sec.  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
     Gain 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 the 
Bombardier Model CL-600-2B16 (CL-605) airplane. Should Rockwell Collins 
Aerospace & Electronics, Inc., apply at a later date for a 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 apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on the Bombardier Model CL-600-2B16 (CL-605) airplane, as modified by 
Rockwell Collins Aerospace & Electronics, Inc. It is not a rule of 
general applicability and affects only the applicant that applied to 
the FAA for approval of these features on the airplane.
    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

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the amended type certification basis for Bombardier Model CL-600-2B16 
(CL-605) airplanes, modified by Rockwell Collins Aerospace & 
Electronics, Inc.:
    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 EFVS image display 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. 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 that makes the pilot aware 
they are no longer displayed conformally, such as with ``ghosting.''
    f. A HUD system that displays 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 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

[[Page 55447]]

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 14 CFR 
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 the ``enhanced flight 
visibility,'' as required by Sec.  91.175(l)(2), for descent and 
operation below MDA and DH.
    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 use of the EFVS for functions 
that have not been found to be acceptable.

    Issued in Renton, Washington, on October 9, 2009.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-25493 Filed 10-27-09; 8:45 am]
BILLING CODE 4910-13-P