MG 16 Certification guidance for rotorcraft Night Vision Imaging System (NVIS) aircraft lighting systems

This AMC provides further guidance and acceptable means of compliance to supplement FAA AC 29-2C Change 7 MG 16, which is the EASA acceptable means of compliance, as provided for in AMC 29 General. However, some aspects of the FAA AC are deemed by EASA to be at variance with EASA’s interpretation or its regulatory system. EASA’s interpretation of these aspects is described below. Paragraphs of FAA AC 29-2C Change 7 MG 16 that are not amended below are considered to be EASA acceptable means of compliance.

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d. References (use the current versions of the following references).

(1) Regulatory (CS-29 paragraphs).

21.93	29.1321	29.1401
29.1	29.1322	29.1413
29.21	29.1331(a)(3)	29.1501
29.141(c)	29.1333	29.1523
29.561	29.1351	29.1525
29.771	29.1355	29.1529
29.773	29.1357	29.1541
29.777	29.1359	29.1543
29.779	29.1381	29.1545
29.785	29.1383	29.1549
29.803	29.1385	29.1553
29.811	29.1387	29.1555
29.812	29.1389	29.1557
29.853	29.1391	29.1559
29.1301	29.1393	29.1561
29.1303	29.1395	29.1581
29.1305	29.1397	29.1583
29.1307	29.1399	29.1585
29.1309

(2) Other references.

Document	Title
FAA AC 25-11B	Electronic Flight Displays
FAA AC 20-74	Aircraft Position and Anticollision Light Measurements
FAA AC 20-88A	Guidelines on the Marking of Aircraft Powerplant Instruments (Displays)
FAA AC 20-152	RTCA, Inc., Document RTCA/DO-254, Design Assurance Guidance for Airborne Electronic Hardware
RTCA DO-268	Concept of Operations, Night Vision Imaging System for Civil Operators
RTCA DO-275	Minimum Operational Performance Standards for Integrated Night Vision Imaging System Equipment
SAE ARP 4754A	Certification considerations for highly-integrated or complex aircraft systems

Document	Title
SAE ARP 4761	Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment
SAE ARP 5825A	Design Requirements and Test Procedures for Dual Mode Exterior Lights
ETSO-C4c	Bank and Pitch Instruments
ETSO-C8e	Vertical Velocity Instrument (Rate-of-Climb)
ETSO-C87a	Airborne Low-Range Radio Altimeter
ETSO-C164	Night Vision Goggles (NVG)

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e. Background.

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(7) Night vision goggles (NVGs) enhance a pilot’s night vision by amplifying certain energy frequencies. The NVGs for civil use are based on performance criteria in ETSO-C164 and RTCA Document DO-275. These NVGs are known as ‘Class B NVG’ because they have filters applied to the objective lenses that block energy below the wavelength of 665 nanometres (nm). The Class B objective lens filter allows more use of colour in the cockpit, with truer reds and ambers. The ETSO specifies Class B NVGs for civil use. Because NVGs will amplify energy that is not within the range of the filter, it is important that the NVIS lighting system keeps those incompatible frequencies out of the cockpit. However, there are NVGs in civil use that do not conform to the ETSO-C164 standard because they have Class A filters on their objective lenses. Class A filters block energy below the wavelength of 625 nm. As a result, Class A NVGs amplify more wavelengths of visible light, so they require special care in the use of colour in the cockpit. Applicants are advised that Class A NVGs are deemed to be not acceptable for certification by EASA.

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(9) Point 21.A.91 of Annex I to Regulation (EU) No 748/2012 contains the criteria for the classification of changes to a type certificate. For NVIS approved rotorcraft, experience has shown that some changes, which are classified as being minor according to the AMC to 21.A.91 for unaided flight, may have an appreciable effect on the cockpit/cabin lighting characteristics, and thus on crew vision through the NVGs. Therefore, the classification of design changes of NVIS approved rotorcraft should take into account the effects on cockpit/cabin lighting characteristics and the NVIS.

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f. Procedures.

[...]

(6) Required equipment, instrument arrangement and visibility.

(i) In addition to the instruments and equipment required for flight at night, the following additional instruments and equipment will typically be necessary for NVG operations (to be defined for each helicopter). The applicable operational regulations that specify aircraft equipment required for night and NVG operations should be reviewed.

(A) NVIS lighting.

(B) A helmet with suitable NVG mount for each pilot and crew member required to use NVGs.

(C) NVGs for each pilot and crew members required to use NVGs.

(D) Point SPA.NVIS.110(b) of Annex V (Part-SPA) to Regulation (EU) 965/2012 on air operations, and the associated AMC and GM, requires a radio altimeter with analogue representation. It is recommended that an applicant carries out a careful evaluation of the radio altimeter human-machine interface (including the presentation of height and the possibility of selecting the DH) to establish that it is able to provide the crew with the necessary information.

(E) A slip/skid indicator.

(F) A gyroscopic attitude indicator.

(G) A gyroscopic direction indicator or equivalent.

(H) Vertical speed indicator or its equivalent.

(I) Communications and navigation equipment necessary for the successful completion of an inadvertent IMC procedure in the intended area of operations.

(J) Any other aircraft or personal equipment required for the operation (e.g., curtains, NVG stowage, extra batteries for NVGs).

[Amdt No: 29/6]