Exemption No. 10521 UNITED STATES OF AMERICA DEPARTMENT OF TRANSPORTATION FEDERAL AVIATION ADMINISTRATION WASHINGTON, DC 20591

In the matter ofthe petition of AMERICAN EUROCOPTER for an exemption from 14 CFR part 60 Appendix C, Table C2A Title 14, Code of Federal Regulations Regulatory Docket No
. FAA-2011-0824

GRANT OF EXEMPTION By letter dated August 4, 201 1, Mr. Tim McAdams, Manager, American Eurocopter, 2701 Forum Drive, Grand Prairie, TX 75052 petitioned the Federal Aviation Administration (FAA) on behalfofAmerican Eurocopter Flight Simulation Center (AEFSC) for an exemption from part 60, Appendix C, Table C2A, 4.b.3 ofTitle 14, Code ofFederal Regulations (14 CFR). The proposed exemption, ifgranted, would permit a geometric error ofup to 12 degrees between the image generator (IG) eye point and the pilot eye point for the Eurocopter (EC) 175 Level D full flight simulator (FFS). The petitioner requests relieffrom the following regulation: Part 60, Continuous Field

-of

-View (Fo V) tests as stated in Table C2A paragraph 4.b.3, require any geometric error between the image generator eyepoint and the pilot eyepoint to be 

### go or J ess. The petitioner supports its request with the following information: The petitioner states American Eurocopter is seeking an exempt ion to 14 CFRpart 60, Appendix C, Table C2A, 4.b.3, specifically, allowing a geometric error greater than 

### go_ In order to produce a realistic helicopter training experience, thepilot 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 t he dome be as close as possible to the pilot. However, moving the dome closer increases the geometric error. The petitioner believes
AFS-11-413-E2 that the trade offofaccepting a higher geometric error in orderto 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. A technical description follows: EC175 Full Flight Simulator, Level

-D Technical Note Visual Display System (VDS) Parallax Error & Dome Screen Size. Introduction It is accepted that wide visual fields ofview, both horizontal and vertical, with coverage for peripheral view, look down on side-door window and chin window areas, greatly contribute to simulator acceptance by pilots and training effectiveness
. As for today's technology status, the only feasible solution for FoV in excess of210°x 60° is direct projection on a dome screen, which combined with adequate scene content and texture details also provide for a highly accurate perception ofheight above ground and ground speed magnitude and direction, as required for ground operations and low level hover and flight tasks. Formulti-crew helicopters, a significant contribution to the VDS error is the so called parallax errorto distant objects because ofdifferent crewmember and Image Generator /Projection System eye point reference positions. The VDS typically includes a switching capability to set the IG viewpoint to the pilot-flying eye point for critical tasks so the parallax error is effectively cancelled out (to the expense ofa higherparallax error for the pilot

-not-flying)
. Forgeneral tasks, or when both pilot and copilot are involved, a center view is selected (mid

-point between design eye point positions) so the parallax error for both crew members simultaneously is minimized.II 

### Conclusions There is no single VDS solution that is optimal from all points ofview atthe same time. As a result, there will always be a trade-offto achieve regulatory compliance, while meeting training aspects and practical simulator design considerations. The proposed VDS design provides an excellent coverage ofECI75 cockpit FoV and pretty good heightperception for ground operations and low level hovers and flight tasks. While in strict sense, 3.25m (10.7ft) dome radius parallax error for distant objects in centerview is overthe current 8° requirement by 14 CPRpart 60, it is still kept within practical acceptable values, and in any case, view point switching allows for pilot-flying error cancellation for critical flight tasks. The petitioner believes the trade

-offofaccepting a higher geometric error in order to provide an enhanced hover and landing experience greatly improves the helicopter training experience. The petitioner states a grant ofexemption would result in a better trained pilot. Better training enhances safety and safe helicopter operations are a substantial benefitto the public as a whole. A summary ofthe petition was published in the Federal Register on October 4, 20II (76 FR 6I473). 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 ofexemption would be in the public interest and woul d provide a level of safety equivalent to thatprovided by the current regulations. The FAA finds that there is no single visual display system (VDS) solution that is optimal, for purposes ofhelicopter simulator visual systems, from all points ofview at the same time. As a result, there will be a trade-offto 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 

### go requirement by I4 CFRpart 60 for typical VDS dome sizes ofwider bodied helicopter simulators (such as the Eurocopter ECI75). 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.12 As the petitioner has remarked, the FAA is aware ofand has participated in the ongoing work ofthe 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 minor deviations from the 

### goparallax 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 through eye point switching and /or training task restrictions on flight simulation training device (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 ofFSTD users with collimated VDS 's (required for FSTDs qualified priorto part 60 becoming effective) and could also be problematic on a direct view VDS with a large dome radius. Since much ofa helicopter pilot's eye is focused on objects in closeproximity 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 tradeoffin geometric error. The FAA agrees with the assertion that allowing a geometric error greater than 

### go will allow for an improved design that improves training for hovering and close proximity to objects operations. Improved training can significantly enhance safety. The FAA'sDecision In consideration ofthe foregoing, I find that a grant ofexemption is in the public interest. Therefore, pursuantto the authority contained in 49 U.S.C. §§ 40113 and 44701, delegated to me by the Administrator, American Eurocopter Flight Simulation Center is granted an exemption from 14 CFR part 60, Continuous Field-of-View tests as stated in Table C2A paragraphs 4.b.3 to the extent necessary to allow (AEFSC) to manufacture and obtain FAA qualification ofits Level D FSTD. This grant ofexemption is further subjectto the following conditions and limitations: Conditions and Limitations 1. A geometric error ofno greater than 12° is allowed subject to evaluation by a National Simulator Program (NSP) Aviation Safety Inspectorby conducting ground and flight maneuvers to validate the geometric/parallax error does not negatively affect qualified training, testing, or checking tasks.

### 13 2. Ifthe objective/subjective testing is successful, the NSP Inspector will 

### make a recommendation to the National Simulator Program Manager (NSPM) for final approval
. 3. Any training maneuver found to not be subj ectively acceptable due to geometric/ parallax error will 

### be task restricted on the FSTD' s Statement of Qualification as determined appropriate by the NSPM.
This exemption terminates onMay 31 , 2014, unless sooner superseded or rescinded. Issued in Washington, D.C., on April30, 2012.

JohnS
. Duncan Deputy Director, Flight Standards

Service