Exemption No. 10518 

UNITED STATES OF AMERICA 

DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRATION 

WASHINGTON, DC 20591 

 

In the matter of the petition of 

 

CAE INC. Regulatory Docket No. FAA-2011-0814

 

for an exemption from part 60, 

Appendix C, Table C2A, 

paragraph 4.b.1, 4.b.2, and 4.b.3 

of Title 14, Code of 

Federal Regulations 

 

GRANT OF EXEMPTION 

 By letter dated July 25, 2011, Mr. Itash Samani, Head of Global FSTD Regulations, CAE, 

Inc. (CAE), P.O. Box 619119, 2929 W. Airfield Drive, DFW Airport, Texas 75261, 

petitioned the Federal Aviation Administration (FAA) on behalf of CAE for an exemption 

from part 60, Appendix C, Table C2A, paragraph 4.b.1, 4.b.2, and 4.b.3 of Title 14, Code of 

Federal Regulations (14 CFR). The proposed exemption, if granted, would permit a 

geometric error between the image generator eye point and the pilot eye point up to 12° for 

the Agusta-Westland AW-139 and Sikorsky S-76C++ Level D Full Flight Simulators (FFS). 

The petitioner requests relief from the following regulation:

Part 60, Continuous Field-of-View tests as stated in Table C2A paragraphs 4.b.1, 4.b.2 and 

4.b.3, require any geometric error between the image generator eyepoint and the pilot 

eyepoint to be 8° or less. 

AFS-11-409-E 
2

The petitioner supports its request with the following information:

The petitioner states it is seeking an exemption to 14 CFR Part 60, Continuous Fieldof-View tests as stated in Table C2A paragraphs 4.b.1, 4.b.2 and 4.b.3, specifically, 

allowing a geometric error greater than 8 degrees. In order to produce a realistic 

helicopter training experience, the pilot must be able to accurately hover in close 

proximity to objects and landing areas. To design a visual system that realistically 

replicates this requirement requires that the dome be as close as possible to the pilot. 

However, moving the dome closer increases the geometric error. The petitioner 

believes that the trade off of accepting a higher geometric error in order to provide an 

enhanced hover and landing experience greatly improves the helicopter training 

experience. This exemption will allow an improved design that improves training for 

hovering and close proximity to objects operations. Improved training will 

significantly enhance safety. 

The petitioner states the Helicopter International Working Group (H-IWG), 

performing work under the auspices of the Royal Aeronautical Society (RAeS), is 

currently working on the development of the standards for the ICAO 9625 Revision 3. 

In the opinion of the H-IWG, the acceptable tolerance for this error is 12°. The 

petitioner’s technical and training analysis supports the H-IWG position. 

The petitioner requests the privileges of this exemption be extended outside the United 

States. FAA has Bilateral Aviation Safety Agreements (BASA) with a number of 

countries and a number of CAE simulators have been qualified under the BASA Flight 

Standards Agreements, Simulator Implementation Procedures (SIP). This extension of 

privileges is therefore necessary for operations based within foreign countries for 

equipment which has been qualified under FAA 14 CFR Part 60 and in use under an 

FAA approved training program or for operations having bilateral agreements with the 

United States accepting FAA 14 CFR Part 60 as their standard for the qualification of 

Flight Simulation Training equipment. 

The petitioner states the change from the standards in FAA Advisory Circular (AC) 

120-63 to the standards in 14 CFR Part 60 for the qualification and use of flight 

simulation training devices (FSTD) with regards to helicopter simulators included the 

removal of the requirement for collimated display systems for rotorcraft simulators 

along with the addition of a requirement for a maximum allowable geometric error. 

This requirement did not exist in the previous FAA AC 120-63 standard nor does it 

exist in the current JAR/EASA FSTD-H. 

The effect of these changes is to eliminate the requirement for collimation (allowing 

use of direct projection/dome displays) while limiting the allowable angular error seen 

by the pilot(s) that results from the removal of the collimation. 
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Parallax Error 

The petitioner further supports its request with the following information: The 

angular error in a dome display is a function of the distance between the design 

eyepoint (DEP, the position for which the system geometry has been optimized) and 

the pilot eyepoint (PEP), as well as the distances from each eyepoint to the dome 

surface. This geometric (parallax) error is also a function of which point in the field of 

view (FOV) is being tested and the modeled distance to the point of the scene in view. 

In general, however, the maximum error is typically seen for distant objects that are 

positioned ahead of the eyepoint as depicted in the below diagram. Furthermore, as 

seen in the below diagram, with the DEP placed equidistant between the PEP and the 

co-pilot eyepoint (CPEP), equivalent angular parallax errors will be evident from both 

the PEP and CPEP. While it is technically possible to shift the DEP to overlay either 

the PEP or CPEP position (effectively optimizing the parallax error to zero for that 

eyepoint), the non-optimized eyepoint will experience an angular parallax error of 

roughly double that of a centered DEP. 
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The petitioner states a grant of exemption would not result in an adverse effect on 

safety and would allow for the most cost-effective construction of an FSTD. The 

petitioner states that experiments conducted by the H-IWG support the view that 

expected errors, limited to 12°, do not adversely affect the performance of maneuvers 

by either pilot. 

The petitioner says a grant of exemption is in the public interest because it would 

permit more pilots to be trained in an FSTD. Direct projections systems allow for 

more cost-effective solutions to build rotary-wing FSTD. Larger domes are inherently 

more expensive to build and to operate. It is preferable to use smaller domes, when 

possible, as they are more cost-effective. A grant of exemption would permit a more 

cost-effective build of these FSTDs, while maintaining the standards required to 

perform the necessary training, which benefits the public because more crews are able 

to complete such training due to affordability. 
5

A summary of a similar petition was published in the Federal Register on 

October 4, 2011 (76 FR 61473). No comments were received. 

The FAA’s analysis is as follows: 

The FAA has fully considered the petitioner’s request and supporting information. 

The FAA finds that a grant of exemption would be in the public interest and would 

provide a level of safety equivalent to that provided by the current regulations. 

The FAA finds that no single visual display system (VDS) solution is optimal, for 

purposes of helicopter simulator visual systems, from all points of view at the same 

time. As a result, there will be a trade-off to achieve regulatory compliance and 

training capabilities, while meeting practical simulator design considerations. In a 

strict sense, the computed geometric error for distant objects in center view may 

exceed the current 8o requirement by part 60 for typical visual display system dome 

sizes of wider bodied helicopter simulators (such as the Agusta-Westland AW-139 

and the Sikorsky S-76C++). It is recognized, however, that the geometric error may 

still be kept within subjectively acceptable values through optimizing the design eye 

point position and view point switching that allows for pilot-flying error cancellation 

for critical flight tasks. 

As the petitioner has remarked, the FAA is aware of and has participated in the 

ongoing work of the Royal Aeronautical Society in proposing updates to the 

ICAO 9625 standards for helicopter simulators. While the ICAO document has not 

yet been completed, the FAA agrees with the conclusion that deviations from the 8° 

parallax error tolerance will have minor effects that are limited to specific training 

tasks which may be susceptible to parallax error (such as running landings). These 

effects can easily be mitigated though eye point switching and/or training task 

restrictions on FSTD use as determined through subjective assessment. 

Furthermore, the FAA also agrees with the petitioner’s argument that height 

perception of objects in close proximity is a common complaint of FSTD users with 

collimated visual display systems (required for FSTDs qualified prior to part 60 

becoming effective) and could also be problematic on a direct view VDS with a large 

dome radius. Since much of a helicopter pilot’s eye is focused on objects in close 

proximity during critical training maneuvers (such as hover and landing), 

improvements in height perception cues are likely to improve the overall training 

experience and are worth the relatively minor tradeoff in geometric error. 

The FAA agrees with the assertion that allowing a geometric error greater than 8° 

could allow for an improved design that improves training for hovering and close 

proximity to objects operations. Improved training can significantly enhance safety. 
6

The FAA further concurs with the petitioner’s request to use this exemption outside of 

the United States. The FAA provides both initial and annual evaluations of FSTDs, 

regardless of their location. 

The FAA’s Decision 

 In consideration of the foregoing, I find that a grant of exemption is in the public interest. 

Therefore, pursuant to the authority contained in 49 U.S.C. §§ 40113 and 44701, delegated to 

me by the Administrator, CAE, Inc. is granted an exemption from part 60, continuous fieldof-view tests as stated in Table C2A paragraphs 4.b.1, 4.b.2 and 4.b.3 to the extent necessary 

to allow CAE to manufacture and obtain FAA qualification of the applicable FSTDs to the 

qualification level requested. This grant of exemption is further subject to the following 

conditions and limitations. 

Conditions and Limitations 

1. A geometric error of no greater than 12 degrees is allowed subject to evaluation by 

a National Simulator Program (NSP) Aviation Safety Inspector by conducting 

ground and flight maneuvers to validate the geometric/parallax error does not 

negatively affect qualified training, testing, or checking tasks. 

2. If the objective/subjective testing is successful, the NSP Inspector will make a 

recommendation to the National Simulator Program Manager for final approval.

3. Any training maneuver found to not be subjectively acceptable due to 

geometric/parallax error will be task restricted on the FSTD’s Statement of 

Qualification (SOQ) as determined appropriate by the NSPM.

This exemption terminates on April 30, 2014, unless sooner superseded or rescinded. 

Issued in Washington, D.C., on April 30, 2012. 

/s/ 

John S. Duncan 

Deputy Director, Flight Standards 

 Service .