VOLUME 4 AIRCRAFT EQUIPMENT AND OPERATIONAL AUTHORIZATIONS
CHAPTER 7 ROTORCRAFT AUTHORIZATIONS AND LIMITATIONS
Section 4 Safety Assurance System: Night Vision Imaging Systems
4-1125 GENERAL. The information outlined in the following paragraphs will be used by Principal Operations Inspectors (POI), Principal
Maintenance Inspectors (PMI), and Principal Avionics Inspectors (PAI) when evaluating a Title 14 of the Code of Federal Regulations (14 CFR) part
request for use of night vision goggles (NVG). This guidance covers the evaluation of the operator’s formal application, revision to the General Operations Manual
(GOM), the addition of an NVG training program, and minimum equipment list (MEL). This section is related to Safety Assurance System (SAS) Elements 2.2.1 (OP) Airmen
Duties/Flight Deck Procedures, 2.2.3 (OP) Pilot Operating Limitations/Recent Experience, and 4.2.2 (AW) Maintenance/Inspection Schedule.
A. Night Vision Enhancement Devices (NVED). In 1990, the Federal Aviation Administration (FAA) determined that NVEDs, including NVGs,
which are used or intended to be used in the navigation, operation, or control of an aircraft in flight, are appliances. As appliances, NVEDs/NVGs require FAA
certification and specific approval according to prescribed procedures outlined in 14 CFR part
may only be used in
part 135 operations
with specific FAA approval.
B. Night Vision Imaging Systems (NVIS). NVG is the common term used for NVIS operations. The limitations and provisions for conducting
Helicopter Night Vision Goggle Operations (HNVGO) are described in Operations Specification (OpSpec) A050. The complete description and performance standards of NVG and
cockpit lighting modifications appropriate to civil aviation are contained in RTCA DO-275, Minimum Operational Performance Standards for Integrated Night Vision Imaging
1) Currently, an NVIS consists of the following:
• Interior and exterior rotorcraft lighting;
• Cockpit windows (e.g., windshield, windows, and chin bubbles);
• Crew station design and components; and
• Radar altimeter.
2) Refer to the current editions of Advisory Circular (AC)
of Normal Category Rotorcraft, and AC
of Transport Category Rotorcraft, for additional information.
C. Civil Use of NVGs. The civil use of NVGs will be approved only for the purpose of enhancing operational safety. The 1994 FAA study
DOT/FAA/RD-94/21, Night Vision Goggles in Emergency Medical Service (EMS) Helicopters, summarized the need for NVGs by stating, “When properly used, NVGs can
increase safety, enhance situational awareness, and reduce the pilot workload and stress that are typically associated with night operations.” The hours of
darkness add to a pilot’s workload by decreasing those visual cues commonly used during daylight operations. The pilot has a decreased ability to see and avoid
obstructions at night. Since the 1970s, NVEDs, such as NVGs, have provided the military with some limited ability to see at night and therefore enhance operations.
Continual technological improvements have advanced the capability and reliability of NVGs and part
operators have requested use of NVGs in commercial operations as a tool for night flight. NVGs are used as an aid to night flight during visual meteorological conditions
(VMC), and operators are not to use NVGs during inadvertent instrument meteorological conditions (IIMC). This means that operators must comply with visual flight rules
(VFR) weather minimums during a flight. For air carrier operations, these weather minimums are prescribed in the air carrier’s OpSpecs. The use of NVGs will not
change or modify any of the existing regulations.
D. NVIS Approval. RTCA, Inc. has developed and published the Minimum Operational Performance Standards (MOPS) for NVGs in RTCA DO-275.
Technical Standard Order (TSO)-C164, Night Vision Goggles, was published on September 30, 2004. The approval for NVIS installation can only be accomplished through the
type certificate (TC), amended TC, or Supplemental Type Certification (STC) process. The FAA must determine that an appliance can perform its intended function after
installation and that its operation does not adversely affect the operation of the rotorcraft and its installed equipment. Flight deck lighting changes to support NVG
use, or any approvals related to NVGs must comply with the current edition of FAA Order
Repair and Alteration Data Approval, and the Major Repair and Alteration Data Approval Job Aid located on the Aircraft Maintenance Division (AFS-300) website under the
heading, “Aircraft Maintenance Division Job Aids” located at
job aid includes additional information for specific repairs or alterations and links to other guidance.
E. Additional Documents. In addition to RTCA DO-275, RTCA Special Committee 196 completed two other documents: RTCA DO-268, Concept of
Operations, Night Vision Imaging System for Civil Operators, and RTCA DO-295, Civil Operators’ Training Guidelines for Integrated Night Vision Imaging System
Equipment. These documents may provide operators with additional insight into the implementation of NVGs.
4-1127 OFFICE COORDINATION AND RESPONSIBILITIES. Direct coordination with the Rotorcraft Directorate, Aircraft Certification Office
(ACO), and the Flight Standards Inspector Resource Program (FSIRP) is essential for timely completion of the STC process. The operator must specify on the STC application
to the ACO whether approval is sought for a single rotorcraft or a series of rotorcraft, and under what operating rule the rotorcraft will be operated. Operations
inspectors assigned to evaluate, test, and check job functions using NVGs will be qualified and current in accordance with the current edition of FAA Order
Aircraft Management Program. Inspectors who maintain currency in military HNVGO may credit that experience toward currency requirements in accordance with Order
is recommended that the POI consult with an NVG national resource specialist (NRS) through the FSIRP process.
A. The ACO is Responsible For:
• Approving the STC for installation of NVG-compatible equipment
• Flight testing for NVIS compatibility; and
• Approving the Rotorcraft Flight Manual (RFM) NVG/NVIS supplement.
B. The POI is Responsible For:
• Evaluating the part
training program and GOM;
• Operational approval of NVGs through the issuance of OpSpec A050;
• Monitoring training; and
• Ensuring competency flights are conducted.
C. An NVG NRS May Assist the POI in the Following Areas:
• Monitoring training;
• Conducting competency flights; and
• Advising POIs on recommended changes to the training program and GOM.
4-1128 CERTIFICATION PROCESS. The standard five-phase certification process will be followed for NVG approval. The phases are:
• Formal Application,
• Document Conformity,
• Demonstration and Inspection, and
A. Preapplication Phase. During this phase, there are several important issues that the POI must present to the operator. These issues
1) OpSpec A050 authorizes approval for HNVGO and outlines additional NVG requirements, restrictions, and limitations.
2) Applicants should review the RFM NVG/NVIS supplement to ensure that the types of approved operations, crew requirements, and other
operational requirements and limitations are compatible with their intended NVG operations.
3) Applicants should note that NVGs with image intensifier tube(s), which are marked “Not for Aviation Use” or with other
similar marking(s), or whose serial number(s) is listed as not suitable for aviation use by the manufacturer, or whose tube data sheet(s) indicates that the tube(s) is
not suitable for aviation use, may not be used in HNVGO under OpSpec A050.
4) It is recommended that operators select NVG flight instructors from the most experienced pilots, preferably those with experience
as flight instructors and/or NVG pilots. Pilots with prior NVG qualifications with another certificated operator or who have military NVG training would typically be good
candidates for authorized company NVG flight instructors. See
Volume 3, Chapter 20, Section 1 for
additional information on air transportation flight instructors.
5) While NVGs provide great benefits for night operations, they have specific performance limitations that affect the visual cues
and references available to the pilot. Detailed technical descriptions of NVGs and NVG operations may be found in RTCA DO-268 and DO-275. Some of the general limitations
of NVGs referenced in these documents include:
a) The user’s visual acuity with NVGs is less-than-normal daytime visual acuity.
b) Both the reduced field of view (FOV) of the image and the resultant decrease in peripheral vision can increase the operator’s
susceptibility to misperceptions and illusions.
c) The NVG has a limited FOV but, because it is head mounted, that FOV can be scanned when viewing the outside scene. The total area that
the FOV can be scanned is the field of regard (FOR). The FOR will vary depending on both human limitations and rotorcraft design.
d) Depending on the level of ambient light, transition from aided (NVG) to unaided (no NVG) operations will require different time periods
to obtain dark adaptation and the best visual acuity. In brightly lit areas (urban areas and well-lit airports/heliports), transition to maximum unaided acuity may be
instantaneous. In dark areas, typically in remote areas with little cultural lighting, especially when lunar illumination is absent, dark adaptation may take
up to 5 minutes.
e) Night operations impose different stresses on pilots than day operations, and these factors may become worse in NVG operations, with a
resulting negative effect on crewmember performance. Included in these factors are fatigue, stresses, eyestrain, working outside the crewmember’s normal circadian
rhythm envelope, increased helmet weight, and the aggressive scanning techniques required to deal with reduced FOV. These limitations may be mitigated through proper
training and recognition, experience, adaptation, rest, risk management, and proper crew rest/duty cycles.
f) When flying, it is important for pilots to be able to accurately employ depth perception and distance estimation techniques. When viewing
an NVG image, monocular vision is used, even though the NVG used when flying is a binocular system. This has to do with the way the eyes function and the design of the
NVG. Typically, monocular vision is the type of vision used to support depth perception beyond 100 feet, not while flying a helicopter near the ground (e.g., takeoff,
landing, and hovering). Depth perception and distance estimation when viewing the surface or objects within 100 feet using NVGs is degraded to varying degrees, depending
on the quality of the NVG image.
6) Accordingly, NVG training programs and the associated qualification segment (pilot flight check) must include maneuvers and procedures
that are accomplished using external visual references (VFR maneuvers). Emphasis must be placed on maneuvers and procedures that rely on visual cues and references,
such as, but not limited to, high and low reconnaissance, approaches, landings, hovering maneuvers, slope operations, pinnacle operations, and confined area operations.
Training and checking must include hovering autorotations in single-engine helicopters and one-engine-inoperative operations (including landings) in multiengine
helicopters. Qualification segments (flight checks) will consist of the maneuvers and procedures identified in
Volume 3, Chapter 19, Section 7, Table
ModulesHelicopters, using the performance standards provided in the current edition of
Practical Test Standards
Practical Test Standards for
Rotorcraft (Helicopter and Gyroplane), and supplemented by guidance in this order and this chapter.
B. Formal Application and Document Conformity Phases. During these phases, the operator submits, and the POI reviews, appropriate
company manuals and training programs.
1) GOM. The standard guidance for a GOM is outlined in Volume 3, Chapter 32. Additional manual guidance is contained in Volume 4,
Chapter 5. A revision to an operator’s GOM will be required for NVG authorization. NVG operational control issues and responsibilities must be listed in the GOM.
Specific procedures for crewmembers (including flight nurses, emergency medical technicians (EMT), etc.) will be listed in the GOM for HNVGO. If there are changes in
these procedures and responsibilities between existing unaided operations and proposed NVG operations, the applicant should indicate that the procedures and
responsibilities are the same. Where changes are appropriate, the operator should annotate the basic procedures and responsibilities with the NVG operations differences.
2) NVG Revisions to the GOM. In addition to the requirements in Volume 4, Chapter 5, specific procedures and responsibilities will include:
• Pilot NVG currency requirements (e.g., category and class, and type
if a type rating is required);
• Proficiency check requirements;
• Pilot training requirements;
• Check pilot and company flight instructor requirements;
• Crewmember training and currency requirements for use of NVGs;
• Recordkeeping requirements;
• Minimum safe altitudes for HNVGO;
• NVG weather minimums;
• Rotorcraft equipment requirements for HNVGO and MEL deferrals;
• Use of rotorcraft external lighting;
• NVG-authorized area of operations;
• NVG maintenance and inspections;
• NVG preflight inspection procedures;
• Reporting of NVIS irregularities and discrepancies;
• Crew flight time and rest requirements;
• Crew Resource Management (CRM);
• Preflight planning, including rotorcraft performance requirements;
• Detailed crew briefings;
• Light discipline, internal and external;
• Scene landings (e.g., unimproved landing sites);
• Abort/go-around criteria;
• IIMC procedures; and
• Any additional information, as needed by the operator.
NOTE: The above items are intended as a guide for initial development of the NVG portion of a GOM.
3) MEL. MEL guidance is contained in Volume 4, Chapter 4. NVIS includes all of the elements (including the NVG, windshield, lighting
system, etc.) required to successfully and safely operate a rotorcraft with the aid of NVGs. Request for MEL relief should be made to the Southwest Region’s Fort
Worth Aircraft Evaluation Group (FTW-AEG), as specified in FAA guidance. Operators requesting an MEL revision or an interim global change Policy Letter (PL) addressing
NVIS may see the guidance outlined in Volume 4, Chapter 4. The installation of search lights, landing lights, and the rotorcraft’s internal lighting system will be
approved during the STC process. The FAA will not certify a helicopter for NVG operations without a radar altimeter.
4) Training Program. NVG training may be conducted within the initial new-hire, initial equipment, transition, upgrade, or recurrent
training programs or in a special qualification program for pilots already serving in the type of rotorcraft for which NVG qualification is desired.
a) The ground training for initial NVG qualification must include at least 5 hours of ground school. These hours must be added to existing
initial new-hire and initial equipment ground training curricula. In the case of transition, upgrade, or recurrent training, 1 hour of ground training is required.
b) See the following Table 4-21, NVG Flight Training Hours, to determine the national norm for flight training hours for training programs
that include NVG operations.
Table 4-21. NVG Flight Training Hours
IFR and VFR/NVG
SIC to PIC 5
SIC to PIC 3
Minimum NVG Flight Training Hours
*These categories assume that the pilot is already NVG-qualified.
Volume 3, Chapter 19, Section 6 applies
in cases where the pilot has demonstrated proficiency before accumulating the program flight-hours.
2. If a pilot is currently qualified as a pilot crewmember, but is not NVG-qualified, initial equipment, transition,
upgrade, and recurrent training hours are governed by the national norms identified in Table 3-60, Flight Training Hours (National Norms) Two PilotsFSTD, and
Table 3-61, Flight Training Hours (National Norms) One PilotFSTD or When All Training is Conducted in an Aircraft, found in
Volume 3, Chapter 19, Section 6, as
appropriate. If NVG qualification is desired, these training programs must be augmented by no less than 5 hours of ground training and 5 hours of flight training on
NOTE: These 5 hours of flight training may be integrated with rotorcraft-specific training, but in no case must programs contain less than
5 hours of NVG flight time.
3. If NVG training is conducted under a special qualification program, the minimum number of flight training hours
is 5. For subsequent transition, upgrade, or recurrent training programs, see Table 4-21.
4. For air transportation flight instructor and check pilot training, see
Volume 3, Chapter 20, Section 4.
c) Guidelines for the development of NVG training programs are contained in Volume 3, Chapter 19. During the Formal Application Phase, the
POI will review the training program for appropriate content. If the program requires additional information, the POI will inform the operator in writing. After the
satisfactory review of the training program, the POI will approve the NVG training program. If necessary, the POI may request an NVG NRS to assist in reviewing the
training program prior to POI approval. Initial and final approval processes are the same as for other training program approvals. Inspectors should ensure the elements
outlined in Volume 4, Chapter 5 are included in an operator’s training program for flightcrew and medical personnel in air ambulance operations. This chapter also
contains elements that inspectors should consider when making evaluations, as appropriate to the operator’s operations (see Volume 3, Chapter 19 for the types of
training categories that operators must use in training curricula in general).
d) All categories of training have both ground training and flight training curricula. Portions of ground training can be divided into
airman-specific and operator-specific segments, normally included in basic indoctrination.
1. Modules within the airman-specific segment include, appropriate to the crewmember position (e.g., pilot or medical
• Introduction to NVGs,
• Limitations/emergency procedures,
• NVG aeromedical consideration/aviation physiology (including visual
• NVG/night flight planning (including terrain interpretation), and
• Risk management tool for each phase of flight. (Refer to the current
edition of FAA‑H‑8083-21, Rotorcraft Flying Handbook, Chapter 14, Effective Aeronautical Decision-Making. This handbook may be found at
2. Modules within the operator-specific segment include:
• Authorized operations,
• Forms and records,
• Responsibilities of the duty position,
• Applicable regulations and OpSpecs, and
3. Modules within the rotorcraft ground training segment include:
• Lighting systems,
• Caution/warning systems, and
• Cockpit familiarization and NVG compatibility.
e) Detailed descriptions of the normal, abnormal, and emergency maneuvers must be a part of the NVG training program. These descriptions may
be the same as those used for unaided VFR operations. If differences exist, however, those differences should be noted in the basic description package.
Volume 3, Chapter 19, Section 7, Table
3-71 outlines the minimum maneuvers to be covered on a part
The POI will verify that an adequate amount of time is allocated to meet the flight training curriculum. It must be realistic in meeting the stated training objectives.
The company pilot must be proficient in recognizing visual illusions, spatial disorientation, and performing IIMC recovery procedures. The total time within the flight
training curriculum can only be determined by direct observation, as described in
Volume 3, Chapter 19, Section 6, Paragraph
3-1230, Training Hours.
f) In addition to pilot crewmembers, the additional crewmembers (e.g., flight nurses and EMTs) who perform duties in-flight are required to have
an approved training curriculum. This training includes 5 hours of ground training that must include 1 hour of NVG demonstration and use, which must be accomplished at
night and may be accomplished in-flight or on the ground. These crewmembers will receive the same ground training segments as the pilot crewmembers, including the
rotorcraft-specific and operator-specific segments. CRM will be emphasized during crewmember training.
g) If only one NVG crewmember is required for takeoff from unimproved sites, the operator must develop and use appropriate operational
procedures and training for dual NVG high and low reconnaissance, which must include the evaluation of egress route(s). The single pilot using NVGs, provided no
substantial change in conditions (wind, obstructions, and weather conditions) has occurred between the time of the reconnaissance and the departure, may use egress
routes selected during high and low reconnaissance.
h) It is highly recommended that personnel who support HNVGO also receive training regarding NVG operations. For example, ground ambulance
operators and local law enforcement officers should receive training to ensure appropriate light discipline is used when helicopters are landing in remote areas. While
encouraged to do so, records of such training are not required to be maintained by the certificate holder, as these personnel are not employees or agents of the certificate
holder. It is suggested that this training be conducted during county, city, or State first responder meetings or training seminars to cover the greatest possible audience.
Ground personnel should also be referred to the Aeronautical Information Manual (AIM), Chapter 10, Helicopter Operations, for landing zone guidance.
C. Demonstration and Inspection Phase. During this phase, the POI determines that an operator’s proposed procedures and programs
are effective. This is a total evaluation of the operator’s system to include crewmembers and maintenance personnel. Draft OpSpecs will be provided to the operator
for use in its ground and flight training curricula.
1) HNVGO is an advancing field of civil helicopter operations. Some certificated operators may not have the expertise to effectively
conduct an NVG ground curriculum without using a contract training provider. A training vendor, with special qualifications in HNVGO, may contract with an operator to
conduct the ground training in accordance with part
Volume 3, Chapter 54, Section 5.
2) Company flight instructors and check pilots must meet the requirements of §§
Volume 3, Chapter 20, Section 1, Paragraph
3-1387, Regulatory Requirements. A training vendor cannot conduct any flight training unless the vendor meets the requirements of §
section of the regulations states: “Other than the certificate holder, only another certificate holder certificated under this part or a training center
certificated under part
this chapter is eligible under this subpart to conduct training, testing, and checking under contract or other arrangement to those persons subject to the requirements
of this subpart.” Any training vendor who does not hold an Operating Certificate and OpSpecs for the same type of operation for which training is provided or does
not hold a 14 CFR part
center certificate, with approved courses applicable to the training provided, must be qualified as a pilot and flight instructor for operations by the certificate
holder. Policy pertaining to NVG contract flight instructors and contract NVG check pilots is covered in
Volume 3, Chapter 54, Section 5. This
section also applies to vendors (other part
holders) who provide outsourced contract training and checking. Additional guidance pertaining to outsource training can be found on the Air Carrier Training Systems and
Voluntary Safety Programs Branch (AFS-280) website at
3) The POI should observe all ground and flight training curricula with the operator’s initial cadre crewmembers. This procedure
allows the responsible inspectors to evaluate and make recommendations for improvements in training in a very timely manner.
4) The final portion of this phase is completion of the qualification segment. An FAA aviation safety inspector (ASI) or NRS will
conduct or observe the conduct of the initial cadre pilot qualification checks, including any check pilot evaluations for the initial cadre of check pilots. The ASI/NRS
must be current in the general helicopter tasks and the HNVGO tasks as required by Order
order to accomplish qualification checks.
D. Certification Phase. In this phase, OpSpecs are issued to the operator authorizing HNVGO. OpSpecs A050 and D093 are NVG-specific.
Program Tracking and Reporting Subsystem (PTRS) records should be completed and the surveillance plan established according to the requirements in the Comprehensive
Assessment Plan (CAP). A certification report should not be required if proper PTRS reporting procedures are followed by all specialties. This action is necessary to
ensure that the Flight Standards Service (FS) is able to satisfy its oversight responsibilities in providing clear and effective national policy guidance for both agency
and consumer use concerning approval of NVG in part
E. OpSpecs. Once the certificate holder has revised the applicable sections of its GOM, maintenance manual, and training program, and
the rotorcraft has completed the NVG STC requirements, the POI and PMI may approve the HNVGO with the issuance of OpSpecs A050 and D093.
F. OpSpec Currency Requirements.
1) In order for a pilot to act as a pilot in command (PIC) using NVGs while carrying passengers, the pilot must have performed and
documented within the 2 calendar-months preceding the month of the flight, three HNVGOs as the sole manipulator of the controls during the period that begins 1 hour
after sunset and ends 1 hour before sunrise. These HNVGOs must be performed in the same category and class in which HNVGOs will be performed. Each HNVGO must include,
at a minimum, the tasks listed by OpSpec A050. If a pilot has not performed and documented these tasks, the pilot will be allowed an additional 2 calendar-months to
perform and document them, but will not be allowed to carry passengers using NVGs during that time. If the pilot has still not performed and documented these tasks
during the 4 calendar-months preceding the month of the flight, the pilot will be required to pass an NVG proficiency check in order to act as a PIC using NVGs. The
proficiency check will consist of the NVED/NVG maneuvers contained in
Volume 3, Chapter 19, Section 7, Table 3-71.
2) During the Demonstration and Inspection Phase, oversight of the operator’s recordkeeping is essential. Certificate holders
must develop a system to track and document NVG operating experience.
3) The reliability of the NVIS and safety of flight operations is dependent on the operators adhering to the instructions for continued
airworthiness (ICA). These ICAs are developed by the NVG manufacturer and the STC applicant and will be referenced in OpSpec D093.
4) A common misconception in pilot NVG qualification requirements is that qualified NVG pilots must always be trained and checked
in “each rotorcraft” approved for NVG use on an annual basis.
Section 135.293 requires part
to have completed an annual written or oral test, and a competency check in each rotorcraft type. Furthermore, §
that each pilot must be tested on the installed major appliances and contents of the RFM or equivalent. Section
the regulations refers to helicopter type as “basic make and model” when completing pilot testing. This language has led operators to believe that training
and checking of NVG-qualified pilots in each NVG-approved make and model (M/M) rotorcraft was always required on an annual basis. However, there are limitations to
the number of §
that are necessary to meet the NVG qualification and currency requirements.
5) In addition to the checking requirements outlined in §
order and OpSpec A050 provide supplemental information for NVG currency requirements. These documents require NVG-qualified pilots to meet recency-of-flight requirements
when conducting NVG operations, and such currency is limited to “category and class” (i.e., rotorcraft/helicopter).
6) The NVG requirements are determined to be similar within most helicopters (i.e., there are no M/M-specific NVG currency requirements).
7) Regarding initial and recurrent pilot testing requirements, such testing shall be conducted in accordance with §
in M/M for helicopters. Similarly, NVG checks can be alternated between rotorcraft during each successive §
(after the initial NVG competency check in that M/M), thereby eliminating redundant NVG checks thereafter.
8) If an NVG-qualified pilot receives NVG-only differences or transition training in the same duty position on an additional M/M
rotorcraft, in which they are already qualified under part
VFR-day/night operations, they are required to have an initial NVG competency check in that rotorcraft. However, once the initial competency check is completed, the pilot
may alternate between other M/M rotorcraft during each successive §
9) At a minimum, operators should ensure that pilots receiving transition training or differences training on other M/M rotorcraft
receive NVG ground and flight training in the following special emphasis areas: specific lighting considerations, switchology, rotorcraft configuration (e.g., wheel
or skid gear and single or multiengine), and rotorcraft ergonomics that are applicable and relevant to the safety and efficiency of NVG operations in that rotorcraft.
Once the pilot completes the initial NVG check for that M/M rotorcraft, the pilot may alternate NVG checks between rotorcraft in subsequent checks to meet the annual NVG
checking requirements, unless the operator chooses to conduct all required §
events during HNVGOs to satisfy both the §
(to include §
and HNVGO requirements simultaneously. Combining the rotorcraft-specific and HNVGO events may be desired to eliminate unnecessary additional checking, while still
providing an equivalent level of safety (ELOS) and standardization.
10) Guidelines for NVG check pilot and instructor approvals should follow the same principles cited above. However, the NVG check pilot
and instructor must still meet the regulatory requirement to remain a qualified crewmember in the same types of operations for which he/she holds check pilot or
instructor authority. Observations of check pilots conducting NVG checks in multiple rotorcraft should be alternated between rotorcraft when possible.
RESERVED. Paragraphs 4-1129 through 4-1135.