While the technologies involved in aviation night vision goggles have been steadily increasing, some limitations come along with them.
Therefore, pilots and operators must be aware of both the advantages and limitations of using aviation night vision goggles.
Enhancing Night Flight Operations
Pilots and operators who utilize aviation night vision goggles know the acute advantages that these devices bring. Aviation NVGs improve the operator’s visual acuity and ability to see at night, enhancing their night flight operations.
On the other hand, pilots and operators may be less aware of the limitations that aviation goggles impose on night visual acuity.
As the use of aviation NVGs in helicopters continue to increase, it’s essential that pilots and operators fully understand the capabilities and limitations of these night vision devices.
Most importantly, pilots and operators must be aware of the misleading effects of night vision goggles on image perception.
A Safe and Effective Flight
Pilots and operators’ visual reference to the outside environment is imperative for a safe and effective flight mission. During the daytime and depending on the visual meteorological conditions, the situational awareness of pilots and operators rely on the scope of the view outside the windshield.
Also, the visual structure of pilots and operators is amplified by the avionics system.
This provides the navigation, communication, flight control, mission, communication, and aircraft systems information.
When it comes to night flying, pilots and operators face a different set of challenges. This is why night vision advancements were initiated to aid operators during night flying.
Night flying is defined as the flight operation between the end of evening twilight and the start of morning twilight. In simpler terms, night flying operations are conducted between sunset and sunrise hours.
The flight crew utilizes binocular devices such as aviation night vision goggles that augment ambient light. These aviation night vision binoculars enhance the operators’ visual acuity to the surface of the night.
The Basics of Night Vision Imaging System (NVIS)
During night flight missions, night vision imaging systems (NVIS) can significantly improve the out-of-the-windshield visuals of pilots and operators.
NVIS is engineered to conduct a comprehensive integration of all the elements needed to safely and effectively operate aviation night vision goggles. The system comprises of the binoculars device, NVIS-compatible cockpit lighting, and other essential components.
Along with these components, there is a set of guidelines and regulations that must be followed. These guidelines are aptly named Night Visual Flight Rules (NVFR). These rules enumerate the conditions – weather, safety, terrain, water at night, and other related conditions – under which a pilot or operator can favorably conduct night flight operations.
While NVIS was built to enhance flight safety, its use may also characterize some flight safety hazards due to unavoidable circumstances.
Some of these factors include the following:
- Poor flight operation
- Equipment operational failure
- Incompatible equipment
- Inexperienced flight crew
- Insufficient standard operating procedures
- Supervisory oversight
Effects of NVIS Threats
Failure to control or avoid the threats we’ve listed above could lead to severe aircraft accidents. Some of the common dangers in a failed NVIS operation include recency, flight crew amateurishness, helicopter/aircraft compatibility, flight weather considerations, and aviation night vision goggles failure.
Steps You Can Take to Avoid NVIS Threats
Weather condition predictions, along with the planned flight path, must meet the minimum Visual Meteorological Conditions (VMC) requirements – or better.
The weather forecast must include illumination calculations (starlight, moonlight) and risk of diminished visibility in the haze, blowing snow, wind, or dust.
Helicopters and aircraft must also meet the guidelines outlined by the Instrument Flight Rules (IFR). ON top of that, the aircraft must be proficient for dual IFR operations following the corresponding regulatory procedures.
Before any NVG activity takes place, a risk assessment is needed. The flight crew must conduct and document this test before the flight.
Failed and Inefficient Device
All aviation night vision devices must be certified to TSO-C164, which is the minimum standard equal to ANVIS-9 systems with Omnibus 4 image tubes.
Night vision goggles released before TSO-C164 must pass the operational conditions outlined by RTCA/DO-275. Typically, aviation NVGs are battery-powered. These devices don’t need the aircraft to supply electrical power for them.
The devices are also generally built with automatic change-over in the power supply or a minimum of 30 minutes to one-hour battery warning to the operator.
All flight crews must use the same type, brand, and model of night vision goggles. On top of that, there must be a spare set of NVG devices of the same type, brand, and model – readily accessible and used by the flight crew.
Helicopter or Aircraft Compatibility
To be able to use aviation NVGs successfully, the helicopter or aircraft must be compatible with the device. You can achieve this by adding the necessary NVIS modifications to the helicopter or aircraft.
When done correctly, you can get approval from the Federal Aviation Administration along with one of the following:
- NVIS Certification with a Supplementary Type Certificate
- FAA AC 29/2C MG 16
- FAA AC 27-1B MG16
- Or any equivalent
Two pilots must man the aircraft along with two controls and equipment. This is required so you can get the complete IFR functionalities. On top of that, the helicopter or aircraft needs to have a preferably infrared steerable (or movable) searchlight. The searchlight must be operated from either of the two-pilot stations.
Furthermore, the helicopter or aircraft must have either dual radar altimeters (independent) or two output ones. These altimeters are built with aural and visual height forewarnings. They must also come with alterable height warnings that the flight crew can set.
You must also meet the requirements set by TSO-C194, which is also referred to as the Terrain Avoidance and Warning System (TAWS). There is a three-bloc autopilot to alleviate the workload of the flight crew.
When applicable for the type of aircraft, the moving map features must be tailored to improve the crew’s situational and visual awareness.
You only use multi-engine helicopters and aircraft when flying with aviation night vision goggles.
Flight Crew Skill and Experience
All flight crew members must each have a minimum of 50 hours of night unaided flight operations. The pilot-in-command (or the flight commander) must have logged at least ten hours of NVG flying. Role-based scenarios for the aviation night vision crew is needed in a CRM recency setting.
When the application calls for specialist NVG operations – such as, for example, hook, hoist, confined area, marine pilot transfer, etc. – the flight crew must meet the necessary qualifications as mandated by each role. Moreover, each of these roles must be certified by the aviation night vision goggles training provider.
The flight crew education, checking, and training must be in strict compliance with the comprehensive syllabus prepared by the equipment operations manual.
The aviation NVG flight crew training must have the following essential items:
- NVIS working methodologies
- Eye physiology
- Night vision
- Night flight limitations and how to overcome them
- Preparation of NVIS systems and equipment
- Testing of NVIS systems and equipment
- Standard operating procedures
- Emergency procedures
- NVIS inefficiency modes
- Failure modes and rectification steps
- Upkeep of unaided night flight operations
- Crew coordination in compliance with NVIS guidelines
- Risk analysis, mitigation, and supervision
Furthermore, the flight crew training syllabus must consist of night flight efficiency checks. The emergency measures to be taken on NVIS operations should be clearly outlined.
It would be best if you placed particular emphasis and consideration on the NVIS flight path, local area meteorology, in-flight guidelines, transitions to NVG, transitions from NVG usage, and crew coordination guidelines following NVIS systems.
Other Threats that May Affect the Use of Aviation Night Vision Goggles
Other contributing factors may interject on the effective use of aviation NVGs. These factors include complacency, recklessness, stress, and fatigue.
Pilots and operators must fully understand the importance of paying attention and following all NVG flight missions’ guidelines.
Not doing so could lead to severe implications.
A complacent operator has a reduced attention span. They are also less vigilant. They tend to overlook the minor yet essential details of specific processes. Routine but critical tasks are disregarded.
When an operator feels like they already know what needs to be done during an NVG operation, they over-estimate the functionalities and features of the NVIS, which could then lead to recklessness and poor performance.
Stress and Fatigue
Physiological constraints associated with nighttime – along with certain drawbacks of using aviation night vision goggles – could significantly impact NVIS operations.
Some of these inadequacies are often the result of stress, fatigue, eyestrain, not working within the operators’ normal circadian rhythm, and other human factors.
You can mitigate these constraints with adequate training and education, exercises, adaptation techniques, risk management, and most important of all, taking enough breaks and rests.
Aviation night vision goggles offer an enhanced ability in seeing the terrain, objects, and the horizon during night flight missions. However, it is essential to remember that there are risks, constraints, and limitations that come with using them.
These could be mitigated with proper training, preparedness, and taking the appropriate safety and technical measures associated with the use of aviation NVGs.