Tag Archives: FAA – Federal Aviation Administration

Not paying your pilots can be deadly

“Human Factors” statistically has contributed to more than 70% of all commercial aviation hull loss accidents. Initially human factors were considered strictly a flight operations issue, which is now classified as “Pilot Error”, but now include the aircraft maintenance, air traffic control operations and few other areas. You can read more about Human Factors on the wiki.

Airlines based in India

In simpler words, more accidents have happened, where the technology was not at fault, and it was a human error, where incorrect decisions were made. FAA implemented the Crew Resource management (CRM) and Maintenance Resource Management (MRM) programs to counteract human errors. There are many external sources that can and do affect a pilot’s judgment skills and abilities. Many have been identified by the FAA and have been incorporated in the training of the pilots.

Illness, Medications, Stress, Alcohol, Fatigue, Emotions (IM SAFE checklist) are some of the culprits interfering with a good Aeronautical Decision Making process (ADM). I’d like to talk more about Stress here. Many things can cause stress; NOT GETTING PAID at your JOB definitely is STRESSFULL. This is the current situation with many airlines in India, including the state owned Air India!! Many pilots have not received a pay check in months!

Can we look at this simply as a labor code violation, or do you think this can be an accident waiting to happen? Flying an airliner thinking about how you are going to provide for your family? Would you like to be a passenger in one of these airlines, where the pilots have not received their paychecks in months? Probably not. How would you like these airlines to operate in our airspace?

What’s even more disturbing is FAA’s category 1 aviation safety rating for these airlines. FAA does not consider “not paying your pilots” as a threat to safety.

Since 1992 FAA implements a program called International Aviation Safety Assessment (IASA) and grades countries based on aviation safety rating, and India happens to have category 1 rating, which allows their airlines to fly in and out of our airspace freely. Obviously IASA’s category 1 rating, meaning, India’s oversight of it’s airlines (including the one owned by itself) meets the ICAO standards, and not paying it’s pilots in months is not a safety oversight!!

Amazing NTSB (Animation) US Airways Airbus Crash Ditching in Hudson

NTSB’s investigation hearings of the Jan 15th, 2009 US Airways’ Airbus Flight 1549 bird-strike incident which led to the ditching of the aircraft in Hudson river have generated some potential recommendations – developing an on-aircraft anti-bird technology for rounding-up and wiping-out thousands of Canada Geese. At the hearings, Airbus test pilots supported Captain Sullenberger’s decision; to ditch the aircraft in the river instead of trying to make LaGuardia or Teterboro airports.

Airbus’ fly by wire system was commended for allowing Capt. Sullenberger to maintain the best airspeed for the ditching simply by holding the joystick in full aft position and letting the computers do the the rest; not letting the aircraft stall while he simply maintained the wings level.The hearings also reviewed and made public a rather compelling NTSB video animation with overlay-ed ATC audio and CVR content (textual). A board member’s call for more research into onboard bird-repellant or bird-deterrent technologies is supported by at least one study, conducted by Qantas and Precise Flight, which concluded that aircraft equipped with pulsed landing light system resulted in fewer bird strikes.

2004 Tests conducted by the U.S. Agriculture Department were less definitive; but further research (specifically, into flash frequency and light wavelengths) may be recommended by the NTSB.

Automatic Dependent Surveillance Broadcast (ADS-B) and General Aviation

NextGen, ADS-B and General Aviation

The other day I wrote about how the JDPO is working hard to design the future of aviation, and how the NextGen is going to address the issues related to the safety, capacity and efficiency of the national airspace system while providing a flexible, expandable platform to accommodate future air traffic growth. You can read my article on NextGen Air Transportation System by clicking here.

JDPO is a group of government bodies, and the industry partners include Lockheed Martin, UPS, and a few other major aviation giants.

What I did not realize was that even General Aviation, and Flight Training institutes like the Embry Riddle (ERAU) are such an active partners in this program. As a matter of fact, after I saw this video I realized that as a matter of fact, this time around, this newer technology was handed over to the general aviation community even before the commercial airlines were able to get their hands on it.

In fiscal year 2006, the FAA approved funding for the implementation of Automatic Dependent Surveillance – Broadcast (ADS-B) at eight sites. ADS-B is surveillance, like radar, but offers more precision and additional services, such as weather and traffic information. ADS-B provides air traffic controllers and pilots with much more accurate information to help keep aircraft safely separated in the sky and on runways.

Here is a link to my previous article on ADS-B.

ADS-B Applications for Aircraft

  • Enhanced Visual Acquisition: provides the flight crew with enhanced traffic situational awareness in controlled and uncontrolled airspace/airports.
  • Enhanced Visual Approaches: enhances successive approaches for aircraft cleared to maintain visual separation from another aircraft on the approach.
  • Final Approach and Runway Occupancy Awareness: reduces the likelihood of flight crew errors associated with runway occupancy and improves the capability of the flight crew to detect ATC errors.
  • Airport Surface Situational Awareness – Conflict Detection: reduces the potential for deviations, errors, and collisions through an increase in flight crew situational awareness while operating an aircraft on the airport movement area.

Avionics Technician Careers

The more I am learning about this, the more I worry about that who is going to fix all these avionics when they break down. There is already an extreme shortage of aviation mechanics, and these guys are not even trained to repair avionics! And to be able to repair avionics, one doesn’t even have to be an aircraft or aviation mechanic.

And, from my 20 some years of aviation experience, I know that the avionics technicians are much harder to find nowadays, and they make a lot more money as well. So I started to look around to see who all offer Avionics Training, and I was surprised to find that there are quite a few options out there.

One excellent option is Redstone College in the Denver area. Redstone and Lockheed Martin even have a joint scholarship program for Avionics Training. If I had the choice to go back in time, I know what I would do.

Automatic Dependent Surveillance Broadcast (ADS-B)

In one of my previous articles we talked about the NextGen; Next Generation Air Transportation System, and how it is working towards making the future of the air navigation in aviation industry better, safer and automated. We have also talked about how the future of aviation is getting more environment friendly and greener. If you have not read those articles, I suggest you read those as well to get the most accurate and complete information on this topic.

One of NextGen’s most promising initiatives with potential for broad operational applications is Automatic Dependent Surveillance-Broadcast (ADS-B), a technology that could revolutionize air navigation and surveillance, and be the backbone of the future system.  In fact, some companies, such as United Parcel Service (UPS), are already using ADS-B in their operations, and are realizing savings in jet fuel and faster delivery schedules.

ADS-B uses GPS satellites and ground-based equipment to allow aircraft to broadcast their transmissions with greater frequency and accuracy than the current land-based legacy radar systems.  With ADS-B, pilots will see exactly what the air traffic controller sees.

The Capstone program is a long-term, highly successful application of ADS-B in a non-radar environment.  ADS-B, one of NextGen’s essential foundational technologies, will continue its development with the goal of deployment throughout Alaska.  Since initial deployment, general aviation accidents have decreased by 40%.  The practical information provided by this FAA program has also proven invaluable in guiding the development of NextGen.

The United Parcel Service (UPS) is using ADS-B in trials at its hub in Louisville, Kentucky. The company is realizing savings while simultaneously reducing the adverse environmental impact of its flight operations.  The traditional “step-down” landing approach requires planes to use high thrust to level off at different stages, resulting in more fuel burn and additional noise and pollution.  ADS-B allows for an improved landing procedure called Optimized Profile Descents.

Taking advantage of improved situational awareness, Optimized Profile Descents permit planes to constantly descend from cruise altitude all the way to touch-down.  Using Optimized Profile Descents, UPS reduced flight time, allowing more planes to land, while cutting back on emissions and noise.  Once ADS-B is fully implemented, UPS anticipates an annual fuel reduction of 800,000 gallons.  Furthermore, the company forecasts a 30% decrease in noise and an emissions reduction of 34% in the vicinity of airports (3,000 feet or below).

The FAA signed a Memorandum of Agreement with helicopter operators, and oil and gas platform owners in the Gulf of Mexico to improve air traffic control in the region.

Currently, most helicopters operating offshore in the Gulf cannot communicate or be seen by air traffic controllers, requiring pilots to rely mostly on visual flight rules.  As a result, helicopter service to offshore platforms is severely curtailed in poor visibility conditions.

With ADS-B equipment installed on aircraft and platforms, helicopters are able to transmit critical position information to the Houston Air Route Traffic Control Center, resulting in improved communications.  This allows for continued helicopter activity on platforms in poor visibility in contrast to periodic weather-related stoppages.

Network-Enabled Operations (NEO) refers to the ability to link together information from a wide range of sources.  It is a high priority for JPDO and NextGen partner agencies.  NEO provides a platform for interested parties to have consistent, up-to-date, secure, and simultaneous access to the same information.

Next Generation Air Transportation System – NextGen

The Future of Aviation

NextGen, shorthand for the Next Generation Air Transportation System, refers to a wide-ranging initiative to transform the air traffic control system. It focuses on leveraging new technologies, such as satellite-based navigation, surveillance, and networking. The initiative involves meaningful collaboration among government departments and agencies as well as companies in the aerospace and related industries.

Currently, the U.S. air transportation system handles roughly 50,000 flights over a 24-hour period. By 2025, air traffic is projected to increase two-to-three fold, equating to 100,000-150,000 flights every 24 hours. It is acknowledged that the current U.S. air transportation system will not be able to meet these air traffic demands.

In transforming the national airspace system, JPDO is working with the FAA , NASA , the Departments of Transportation , Defense , Homeland Security , Commerce , and the White House Office of Science and Technology Policy .

The Senior Policy Committee of JPDO directs the NextGen initiative. The committee is chaired by the Secretary of Transportation, and includes the Undersecretary for Policy of the Department of Transportation; Administrator of the Federal Aviation Administration; Administrator of the National Aeronautics and Space Administration; Secretary of the United States Air Force, representing the Department of Defense; Deputy Secretary of the Department of Commerce; Deputy Secretary of the Department of Homeland Security; and the Director of the White House Office of Science and Technology Policy.

There are nine capabilities that will enable the transformation of the national air transportation system. The NextGen capabilities are as follows:

  1. Integrated NextGen Information
  2. Separation Management
  3. Capacity Management
  4. Trajectory Management
  5. Security
  6. Flow Contingency Management
  7. Environment
  8. Safety
  9. Flexible Airport and Surface Operations

Providing a high level of security in air transportation is a major goal for NextGen, which envisions a layered, adaptive security system.  This means a system that depends on multiple technologies, policies, and procedures that adapt to individual situations, and can change according to the threat level.  Other security measures will be in place as additional roadblocks to neutralize the threat, whether it is in the airport, on the plane, or in the air.

Intercontinental travel is, of course, a key element of the world’s air transportation system.  “Global Harmonization” is the technical term for coordinating NextGen activities with our counterparts throughout the world.

The FAA entered into an agreement with the European Commission (EC), which formalized cooperation between the NextGen initiative and its European counterpart, the Single European Sky Air Traffic Management Research (SESAR) program.  The FAA and EC are following through to identify opportunities and, as appropriate, establish timelines to implement common, interoperable, performance-based air traffic management systems and technologies.

And by the way, the ability to track any flight, whether commercial airline flights, or privately owned Cessna aircraft, from the convenience of your computer is already available, and I have talked about it in my other post – Live Flight Tracking. And it is Free.

ADS-B; Automatic Dependent Surveillance Broadcast is one of the initiatives of the JPDO’s NextGen program. You can read all about it here; and watch the video as well. It is pretty cool!

FAA Medical Certificate online application

Whoa! I just bumped into this information accidentally while doing some research on Airparks. Somehow I ended up on Rosamond Airpark’s website, and guess what I found? As just about everything else is migrating online (internet), FAA has already moved the FAA pilot medical certificate application online as well. I had no idea about this. I know the pilot practical test application (form 8710) was made available online a while back, but had no clue that the student pilot certificate and/or pilot medical certificate application can also be completed online at this site: https://medxpress.faa.gov/.

So, you can complete your medical application online, and the FAA Aero-medical examiner (AME) can review the application on his/her computer when you go visit for the medical. Yup. You still have to go see the AME. Maybe in the future there would be ways to save the trip and do the entire thing online. But for now, I think this is great! I am so liking this that I think I am going to go get me another medical anyways, even though I have about 4 more years before I need a renewal.

And yes, we will talk about medical certificate regulations in some other post sometime. I know this would be a good topic for the future.

An Aircraft in each household – a dream or reality?

Aviation has completed over a century of dynamic growth and advancement, resulting in the present air transportation system dominated by the commercial airline industry’s hub and spoke system. The initial 50 years of aviation were a chaotic, rapid evolutionary process involving disruptive technologies that required frequent modifications. The second half century produced a stable evolutionary optimization of services based on achieving an objective function  of economical operations. In the ongoing 50 years of what I call Aviation 3.0, there is a potential for aviation to transform itself into a more robust, scalable, adaptive, secure, safe, affordable, convenient, efficient, and environment friendly system. Read more about environment friendly aviation initiative in my “Green is the future of Aviation as Well” article.

However, such a global optimization requires not only the ability to perform analysis of larger system of system impacts, but also the ability to consider new value propositions that involve different infrastructures and business models that those which are currently the norm of the present aviation industry. While many obstacles exist, including technology, regulations, and perception; the Aviation 3.0 has the potential to mirror other on-demand market revolutions that have taken place over the past half century.

Highly successful innovators like Henry Ford and even Wright brothers believed that aviation would one day be capable of reaching an everyday impact in our daily lives. Yet after many years of rather empty promises, ranging from road-able aircraft to a a helicopter in every garage, the aviation community remains transfixed in a highly centralized world of very expensive, and not cost efficient aircraft.

Pessimists of the personal aircraft vision say that the aviation market evolution has brought us to the logical solution. Optimists of the vision respond that government regulations and the conservatism of the aerospace community have inhibited the industry. Both are correct, and as is typically the case, the answer lies somewhere in the middle. However, with a long-term viewpoint of demand and utility, it seems inevitable that in the very near future small aircraft will have a far more significant daily impact in many of our daily activities.

Sport pilot regulations, training and certification of the pilots, and the sport aircraft are a result of such an initiative from the government and the industry. If you desire to experience the spirit of what I am trying to express here in this article, find some time during your busy lives, visit your local GA airport, and ask someone in one of those FBOs to arrange for a demo flight for you in one of their Sport Aircraft. And then come back here and give this article and second read. And leave me a comment here underneath.

Alcohol and Aviation

I was reading an article about when do you have to report a DUI or DWI related action (in a motor vehicle) to the Federal Aviation Administration (FAA)? You can read it here. It is true that any arrest, and/or conviction has to be reported to the FAA within 60 days, as required by FAR 61.15 . Some pilots have a misunderstanding that they only need to report the conviction and not the arrest, and, the others think that they have to report only when they go back for their Pilot Medical Certificate renewal. Both these are far from the truth.

Another thing we need to understand is that honesty here is always the best policy. FAA does occasionally check the National Driver Register against pilot, mechanic and other FAA certificate holder names. And if you have failed to report your incident within the applicable time frame, which is 60 days, and FAA comes across your name during it’s driver record search, you will definitely have something much bigger to worry about.

It is common for the FAA to not take any action against the offending pilot on the first instance of a driving DUI/DWI. Subsequent ones, I don’t know. I have not come across such a  pilot or a mechanic yet! If someone out there knows of such a dare-devil, please drop me a comment there with a contact information so I can enhance my knowledge from his/her experiences.

8 hours bottle to throttle is the minimum, as per FAR 91.17 .  That’s right, no matter how small the sip, you stay away from that ramp until at least 8 hours has elapsed. And that’s not all. 04% alcohol concentration in the blood or breath is enough to get you in trouble with the FAA as well. Perhaps it takes less that that .04% concentration for you to be affected. Or have you considered how badly you’re likely to perform while hung over? Quite a few studies have documented the loss of performance, judgment, and reaction time you can anticipate even after your blood alcohol content has dropped back down to acceptable levels.

So, remember, alcohol and aviation, for that matter just about anything physical, ;-), yes that too, is not a good combination and should be avoided at all times. Alcohol is to be consumed and enjoyed very responsibly.

Oh by the way, the ol’ pilot rule of the thumb to remember this (in case you are a forgetful person) is called Whiskey Compass rule. We’ll talk about it some other day.

History of Flight

From prehistoric times, humans have watched the flight of birds, longed to imitate them, but lacked the power to do so. Logic dictated that if the small muscles of birds can lift them into the air and sustain them, then the larger muscles of humans should be able to duplicate the feat. No one knew about the intricate mesh of muscles, sinew, heart, breathing system, and devices not unlike wing flaps, variable-camber and spoilers of the modern airplane that enabled a bird to fly. Still, thousands of years and countless lives were lost in attempts to fly like birds.

The identity of the first “bird-men” who fitted themselves with wings and leapt off a cliff in an effort to fly are lost in time, but each failure gave those who wished to fly questions that needed answering. Where had the wing flappers gone wrong? Philosophers, scientists, and inventors offered solutions, but no one could add wings to the human body and soar like a bird. During the 1500s, Leonardo da Vinci filled pages of his notebooks with sketches of proposed flying machines, but most of his ideas were flawed because he clung to the idea of birdlike wings. [Fig 1] By 1655, mathematician, physicist, and inventor Robert Hooke concluded the human body does not possess the strength to power artificial wings. He believed human flight would require some form of artificial propulsion.

The quest for human flight led some practitioners in another direction. In 1783, the first manned hot air balloon, crafted by Joseph and Etienne Montgolfier, flew for 23 minutes. Ten days later, Professor Jacques Charles flew the first gas balloon. A madness for balloon flight captivated the public’s imagination and for a time flying enthusiasts turned their expertise to the promise of lighter-than-air flight. But for all its majesty in the air, the balloon was little more than a billowing heap of cloth capable of no more than a one-way, downwind journey.

Balloons solved the problem of lift, but that was only one of the problems of human flight. The ability to control speed and direction eluded balloonists. The solution to that problem lay in a child’s toy familiar to the East for 2,000 years, but not introduced to the West until the 13th century. The kite, used by the Chinese manned for aerial observation and to test winds for sailing, and unmanned as a signaling device and as a toy, held many of the answers to lifting a heavier-than-air device into the air.

One of the men who believed the study of kites unlocked the secrets of winged flight was Sir George Cayley. Born in England 10 years before the Mongolfier balloon flight, Cayley spent his 84 years seeking to develop a heavier-than-air vehicle supported by kite-shaped wings. [Fig 2] The “Father of Aerial Navigation,” Cayley discovered the basic principles on which the modern science of aeronautics is founded, built what is recognized as the first successful flying model, and tested the first full-size man-carrying airplane.

For the half-century after Cayley’s death, countless scientists, flying enthusiasts, and inventors worked toward building a powered flying machine. Men, such as William Samuel Henson, who designed a huge monoplane that was propelled by a steam engine housed inside the fuselage, and Otto Lilienthal, who proved human flight in aircraft heavier than air was practical, worked toward the dream of powered flight. A dream turned into reality by Wilbur and Orville Wright at Kitty Hawk, North Carolina, on December 17, 1903.

The bicycle-building Wright brothers of Dayton, Ohio, had experimented for 4 years with kites, their own homemade wind tunnel, and different engines to power their biplane. One of their great achievements was proving the value of the scientific, rather than build-it-and-see approach to flight. Their biplane, The Flyer, combined inspired design and engineering with superior craftsmanship. [Fig 3] By the afternoon of December 17th, the Wright brothers had flown a total of 98 seconds on four flights. The age of flight had arrived.

Pilot Vision

Vision is a pilot’s most important sense to obtain reference information during flight. Most pilots are familiar with the optical aspects of the eye. Before we start flying, we know whether we have normal uncorrected vision, whether we are farsighted or nearsighted, or have other visual problems. Most of us who have prescription lenses—contacts or eyeglasses—have learned to carry an extra set of glasses with us when we fly, just as a backup. But, vision in flight is far more than a lesson in optics. Seeing involves the transmission of light energy (images) from the exterior surface of the cornea to the interior surface of the retina (inside the eye) and the transference of these signals to the brain.

Anatomy of an Eye

  • Light from an object enters the eye through the cornea and then continues through the pupil.
  • The opening (dilation) and closing (constriction) of the pupil is controlled by the iris, which is the colored part of the eye. The function of the pupil is similar to that of the diaphragm of a photographic camera: to control the amount of light.
  • The lens is located behind the pupil and its function is to focus light on the surface of the retina.
  • The retina is the inner layer of the eyeball that contains photosensitive cells called rods and cones. The function of the retina is similar to that of the film in a photographic camera: to record an image.
  • The cones are located in higher concentrations than rods in the central area of the retina known as the macula, that measures about 4.5 mm in diameter. The exact center of the macula has a very small depression called the fovea that contains cones only. The cones are used for day or high-intensity light vision. They are involved with central vision to detect detail, perceive color, and identify far-away objects.
  • The rods are located mainly in the periphery of the retina — an area that is about 10,000 times more sensitive to light than the fovea. Rods are used for low-light intensity or night vision and are involved with peripheral vision to detect position references including objects (fixed and moving) in shades of grey, but cannot be used to detect detail or to perceive color.
  • Light energy (an image) enters the eyes and is transformed by the cones and rods
    into electrical signals that are carried by the optic nerve to the posterior area of the brain (occipital lobes). This part of the brain interprets the electrical signals and creates a mental image of the actual object that was seen by the person.

The Anatomical Blind Spot

The area where the optic nerve connects to the retina in the back of each eye is known as the optic disk. There is a total absence of cones and rods in this area, and, consequently, each eye is completely blind in this spot. Under normal binocular vision conditions this is not a problem, because an object cannot be in the blind spot of both eyes at the same time. On the other hand, where the field of vision of one eye is obstructed by an object (windshield post), a visual target (another aircraft) could fall in the blind spot of the other eye and remain undetected.

The “Night Blind Spot” appears under conditions of low ambient illumination due to the absence of rods in the fovea, and involves an area 5 to 10 degrees wide
in the center of the visual field. Therefore, if an object is viewed directly at night, it may go undetected or it may fade away after initial detection due to the night blind spot.

The Fovea

The fovea is the small depression located in the exact center of the macula that contains a high concentration of cones but no rods, and this is where our vision is most sharp. While the normal field of vision for each eye is about 135 degrees vertically and about 160 degrees horizontally, only the fovea has the ability to perceive and send clear, sharply focused visual images to the brain. This foveal field of vision represents a small conical area of only about 1 degree. To fully appreciate how small a one-degree field is, and to demonstrate foveal field, take a quarter from your pocket and tape it to a flat piece of glass, such as a window. Now back off 4 ½ feet from the mounted quarter and close one eye. The area of your field of view covered by the quarter is a one-degree field, similar to your foveal vision.

Now we know that you can see a lot more than just that one-degree cone. But, do you know how little detail you see outside of that foveal cone? For example, outside of a ten-degree cone, concentric to the foveal one-degree cone, you see only about one-tenth of what you can see within the foveal field. In terms of an oncoming aircraft, if you are capable of seeing an aircraft within your foveal field at 5,000 feet away, with peripheral vision you would detect it at 500 feet. Another example: using foveal vision we can clearly identify an aircraft flying at a distance of 7 miles; however, using peripheral vision (outside the foveal field) we would require a closer distance of .7 of a mile to recognize the same aircraft. That is why when you were learning to fly, your instructor always told you to “put your head on a swivel,” to keep your eyes scanning the wide expanse of space in front of your aircraft.

Types of Vision

  • Photopic Vision. During daytime or high intensity artificial illumination conditions, the eyes rely on central vision (foveal cones) to perceive and interpret sharp images and color of objects.Mesopic Vision. Occurs at dawn, dusk, or under full moonlight levels, and is characterized by decreasing visual acuity and color vision. Under these conditions, a combination of central (foveal cones) and peripheral (rods) vision is required to maintain appropriate visual performance.
  • Scotopic Vision. During nighttime, partial moonlight, or low intensity artificial illumination conditions, central vision (foveal cones) becomes ineffective to maintain visual acuity and color perception. Under these conditions, if you look directly at an object for more than a few seconds, the image of the object fades away completely (night blind spot). Peripheral vision (off-center scanning) provides the only means of seeing very dim objects in the dark.

Factors Affecting Vision

  • The greater the object size, ambient illumination, contrast, viewing time, and atmospheric clarity, the better the visibility of such an object. During the day, objects can be identified easier at a great distance with good detail resolution. At night, the identification range of dim objects is limited and the detail resolution is poor.
  • Surface references or the horizon may become obscured by smoke, fog, smog, haze, dust, ice particles, or other phenomena, although visibility may be above Visual Flight Rule (VFR) minimums. This is especially true at airports located adjacent to large bodies of water or sparsely populated areas where few, if any, surface references are available. Lack of horizon or surface reference is common on over-water flights, at night, and in low-visibility conditions.
  • Excessive ambient illumination, especially from light reflected off the canopy, surfaces inside the aircraft, clouds, water, snow, and desert terrain can produce glare that may cause uncomfortable squinting, eye tearing, and even temporary blindness.
  • Presence of uncorrected refractive eye disorders such as myopia (nearsightedness — impaired focusing of distant objects), hyperopia (farsightedness — impaired focusing of near objects), astigmatism (impaired focusing of objects in different meridians), or presbyopia (age-related impaired focusing of near objects).
  • Self-imposed stresses such as self-medication, alcohol consumption (including hangover effects), tobacco use (including withdrawal), hypoglycemia, and sleep deprivation/fatigue can seriously impair your vision.
  • Inflight exposure to low barometric pressure without the use of supplemental oxygen (above 10,000 ft during the day and above 5,000 ft at night) can result in hypoxia, which impairs visual performance.
  • Other factors that may have an adverse effect on visual performance include: windscreen haze, improper illumination of the cockpit and/or instruments, scratched and/or dirty instrumentation, use of cockpit red lighting, inadequate cockpit environmental control (temperature and humidity), inappropriate sunglasses and/or prescription glasses/contact lenses, and sustained visual workload during flight.

Focusing

The natural ability to focus your eyes is critical to flight safety. It is important to know that normal eyes may require several seconds to refocus when switching views between near (reading charts), intermediate (monitoring instruments), and distant objects (looking for traffic or external visual references).

Fatigue can lead to impaired visual focusing, which causes the eyes to overshoot or undershoot the target, and can also affect a pilot’s ability to quickly change focus between near, intermediate, and distant vision. The most common symptoms of visual fatigue include blurred vision, excessive tearing, “heavy” eyelid sensation, frontal or orbital headaches, and burning, scratchy, or dry eye sensations.

Distance focus, without a specific object to look at, tends to diminish rather quickly. If you fly over water or under hazy conditions with the horizon obscured or
between cloud layers at night, your distance focus relaxes after about 60-80 seconds.

If there is nothing specific on which to focus, your eyes revert to a relaxed intermediate focal distance (10 to 30 ft). This means that you are looking without actually seeing anything, which is dangerous. The answer to this phenomenon is to condition your eyes for distant vision. Focus on the most distant object that you can see, even if it’s just a wing tip. Do this before you begin scanning the sky in front of you. As you scan, make sure you repeat this re-focusing exercise often.

Dark Adaptation or Night Vision Adaptation

Dark adaptation is the process by which the eyes adapt for optimal night visual acuity under conditions of low ambient illumination. The eyes require about 30 to 45 minutes to fully adapt to minimal lighting conditions. The lower the starting level of illumination, the more rapidly complete dark adaptation is achieved. To minimize the time necessary to achieve complete dark adaptation and to maintain it, you should:

  • avoid inhaling carbon monoxide from smoking or exhaust fumes
  • get enough Vitamin A in your diet
  • adjust instrument and cockpit lighting to the lowest level possible
  • avoid prolonged exposure to bright lights use supplemental oxygen when flying at night above 5,000 ft (MSL)

If dark-adapted eyes are exposed to a bright light source (searchlights, landing lights, flares, etc.) for a period in excess of 1 second, night vision is temporarily
impaired. Exposure to aircraft anti-collision lights does not impair night vision adaptation because the intermittent flashes have a very short duration (less than 1 second).

Visual Scanning

Scanning the sky for other aircraft is a very important factor in avoiding midair collisions, and it should cover all areas of the sky visible from the cockpit. Most of us are instinctively alert for potential head-on encounters with another aircraft. Actually, a study of 50 midair collisions revealed that only 8% were head-on. However, 42% were collisions between aircraft heading in the same direction. So, compared with opposite-direction traffic, your chances of having a midair are over 5 times greater with an aircraft you are overtaking or one that is overtaking you. It is necessary for you to develop and practice a technique that allows the efficient scanning of the surrounding airspace and the monitoring of cockpit instrumentation as well. You can accomplish this by performing a series of short, regularly spaced eye movements that bring successive areas of the sky into the central (foveal) visual field. To scan effectively, scan from right to left or left to right. Begin scanning at the top of the visual field in front of you and then move your eyes inward toward the bottom. Use a stop-turn-stop type eye motion. The duration of each stop should be at least 1 second but not longer than 2 to 3 seconds.

To see and identify objects under conditions of low ambient illumination, avoid looking directly at an object for more than 2 to 3 seconds (because it will bleach out). Instead, use the off-center viewing that consists of searching movements of the eyes (10 degrees above, below, or to either side) to locate an object, and small eye movements to keep the object in sight. By switching your eyes from one off-center point to another every 2 to 3 seconds, you will continue to detect the object in the peripheral field of vision. The reason for using off-center viewing has to do with the location of rods in the periphery of the retina for night or low-intensity night vision (peripheral), and their absence in the center of the retina (fovea). Pilots should practice this off-center scanning technique to improve safety during night flights.

A Word about Monocular Vision

A pilot with one eye (monocular), or with effective visual acuity equivalent to monocular (i.e. best corrected distant visual acuity in the poorer eye is no better than 20/200), may be considered for medical certification, any class, through the special issuance procedures of Part 67 (14CFR67.401) if:

  • A 6-month period has elapsed to allow for adaptation to monocularity; during the adaptation period to monovision, an individual may experience hazy vision and occasional loss of balance.
  • A complete evaluation by an eye specialist, as reported on FAA Form 8500-7, Report of Eye Evaluation, reveals no pathology of either eye that could affect the stability of the findings.
  • Uncorrected distant visual acuity in the better eye is 20/200 or better and is corrected to 20/20 or better by lenses of no greater power than ±3.5 diopters spherical equivalent.
  • The applicant passes an FAA medical flight test.

A Word about Contact Lenses

Use of contact lenses has been permitted to satisfy the distant visual acuity requirements for a civil airman medical certificate since 1976. However, monovision
contact lenses, a technique of fitting older patients who require reading glasses with one contact lens for distant vision and the other lens for near vision, ARE NOT ACCEPTABLE for piloting an aircraft.

The use of a contact lens in one eye for distant visual acuity and a lens in the other eye for near visual acuity is not acceptable because this procedure makes the pilot alternate his/her vision; that is, a person uses one eye at a time, suppressing the other, and consequently impairs binocular vision and depth perception. Since this is not a permanent condition for either eye in such persons, there is no adaptation, such as occurs with permanent monocularity. Monovision lenses, therefore, should NOT be used by pilots while flying an aircraft.

The Eyes Have It

As a pilot, you are responsible to make sure your vision is equal to the task of flying—that you have good near, intermediate, and distant visual acuity because:

  • Distant vision is required for VFR operations including take-off, attitude control, navigation, and landing
  • Distant vision is especially important in avoiding midair collisions
  • Near vision is required for checking charts, maps, frequency settings, etc.
  • Near and intermediate vision are required for checking aircraft instruments

Learn about your own visual strengths and weaknesses. Changes in vision may  occur imperceptibly or very rapidly. Periodically self-check your range of visual acuity by trying to see details at near, intermediate, and distant points. If you notice any change in your visual capabilities, bring it to the attention of your Aviation Medical Examiner (AME). And, if you use corrective glasses or contacts, carry an extra pair with you when you fly. Always remember: Vision is a pilot’s most important sense.

KEY POINTS

  • The sharpest distant focus is only within a one-degree cone.
  • Outside of a 10° cone, visual acuity drops 90%.
  • Scan the entire horizon, not just the sky in front of your aircraft.
  • You are 5 times more likely to have a midair collision with an aircraft flying in the same direction than with one flying in the opposite direction.
  • Avoid self-imposed stresses such as self-medication, alcohol consumption, smoking, hypoglycemia, sleep deprivation, and fatigue.
  • Do not use monovision contact lenses while you are flying an aircraft.
  • Use supplemental oxygen during night flights above 5,000 ft MSL.
  • Any pilot can experience visual illusions. Always rely on your instruments to confirm your visual perceptions during flight.

Medical Facts for Pilots Publication: AM-400-98/2 (revised 8/02) Written by: Melchor J. Antuñano, M.D. Prepared by: Federal Aviation Administration Civil Aerospace Medical Institute Aerospace Medical Education Division