The number of mid-air collisions in recent months has led the FAA to update its Advisory Circular regarding the pilot’s role in collision avoidance.
The new AC, released Oct. 22, 2022, replaces one from June 2016, with updates regarding additional information regarding pilot actions, procedures, Notices to Air Missions (NOTAM), and aircraft technology to mitigate the risk of a pilot causing or being involved in a ground collision, in-flight collision, or near mid-air collision (NMAC).
“This AC is issued to assist pilots with their regulatory obligation to see and avoid other aircraft,” FAA officials say in the AC’s introduction. “Specifically, this AC looks to alert pilots to human contributors to midair collisions and NMAC, and recommend improvements to pilot education, operating practices, procedures, and improved scanning techniques to reduce midair conflicts.”
“The most advanced piece of flight equipment in any aircraft is the human eye,” FAA officials say. “Since the number one cause of midair collisions is the failure to adhere to the see-and-avoid concept, efficient use of visual techniques and knowledge of the eye’s limitations will help pilots avoid collisions.”
The AC notes that your vision is influenced by a variety of factors, such as:
- Atmospheric conditions
- Glare
- Lighting
- Windshield deterioration and distortion
- Aircraft design
- Cabin temperature
- Oxygen supply (particularly at night), and
- Acceleration forces.
Additionally, a pilot’s vision is influenced by some characteristics of the objects you are viewing, including:
- Your distance from the object.
- The size, shape, and movement of the object.
- The amount of light reflected by the object.
- The object’s contrast with the surrounding environment.
One inherent problem with the eye is the time required for accommodation or refocusing, the AC points out.
“It takes 1 to 2 seconds for eyes to refocus from something up close, like a dark instrument panel 2 feet away, to a bright landmark or aircraft 1 mile away,” it continues.
This delay is significant, when the FAA estimates it takes 12.5 seconds to identify, react, and avoid a midair collision.
The AC also discuses other issues with vision and reaction time, including:
- Empty-Field Myopia. If there is little or nothing to focus on, the eyes tend to not focus. This usually occurs on vague colorless days above a haze or cloud layer when no distinct horizon is visible.
- Binocular Vision: Binocular vision means using two eyes with overlapping fields of view, allowing good perception of depth. Binocular vision and our perception can be affected when an object is visible to only one eye but hidden from the other by a windshield post or other object, for example. That makes it essential for pilots to move their heads, not just their eyes, when scanning around obstructions.
- Narrow Field of Vision/Tunnel Vision. Another inherent problem with human vision is the narrow field of vision/tunnel vision phenomenon. Although our eyes accept light rays from an arc of nearly 200°, they can only focus on and classify an object within a relatively narrow area of approximately 10° to 15° degrees. As a result, the eye cannot accurately identify what is happening in the distance when experiencing tunnel vision or narrow field of vision, even when the eye senses movement by its peripheral vision. That leads pilots to not believe what they see out of the corner of their eyes.
- The Blossom Effect: In aviation, the “blossom effect” refers to the visual phenomenon where two aircraft on a collision course will appear to be virtually motionless to each other. The other aircraft will remain in a seemingly stationary position, without appearing to move or grow in size for a relatively long time, and then suddenly bloom into a huge mass filling one of the windows. Given that we need motion or contrast to attract our eyes’ attention, this effect becomes a frightening factor when you realize that a large bug smear or dirty spot on the windshield can hide a converging plane until it is too close to be avoided.
Tips
The AC also offers a myriad of tips on staying safe during airport ground operations, operations at non-towered airports, formation flights, training, and effective scanning techniques during flight.
“Effective scanning is accomplished with a series of short, regularly spaced eye movements that bring successive areas of the sky into the central visual field,” it advises. “Each movement should not exceed 10° and each area should be observed for at least 1 second to enable detection. Although most pilots seem to prefer horizontal back-and-forth eye movements, each pilot should develop a scanning pattern that is most comfortable and then adhere to it to ensure optimum scanning.”
Pilots can compensate for blind spots and enhance identifying other aircraft in a climb by adjusting the aircraft’s pitch attitude to improve visibility over the nose of the aircraft (which optimizes your scanning for traffic ahead).
When in level cruise or descending, execute gentle shallow bank turns left and right for a clear view of traffic ahead and from either side.
Scan the rear of the aircraft by scanning from behind the right wing through the windscreen to the back of the left wing.
In the traffic pattern, the FAA recommends that pilots continue to scan for other aircraft and check blind spots caused by fixed aircraft structures, such as doorposts and wings.
High-wing airplanes have restricted visibility above, while low-wing airplanes have limited visibility below. The worst-case scenario is a low-wing airplane flying above a high-wing airplane.
Banking from time to time can uncover blind spots. The pilot should also occasionally look to the rear of the airplane to check for other aircraft.
You can read the entire AC below.
Could NOT find him.
This summer coming from the south into Laramie, WY, non-towered airport I heard a plane approaching from the north announce his position and intent to land. I looked at my ADS-B display and could find him. We kept talking back and forth. He never saw me. I finally saw him just as he was over the numbers. We could have easily swapped paint.
I asked if he had ADS-B and he said yep but he always turned on only were mandated.
My home airport is near KDEN Class B and a couple busy Class D’s and the fish finder is one from engine start. It’s saved me from collision many times. It’s hard to understand the mentality of pilots who refuse to use one of the greatest safety advances in flying.
….and some won’t even talk on the radio in the pattern.
Perhaps a practice area runway outside the normal airport transit flow for those doing patterns.
Similar to limited access interstate vs surface roads.
I notice the outrage about the straight in twin and the 152. But I also see where the FAA stated that …beyond 5 miles…is not considered on final. The twin was at 3 when the 152 turned in front of it.
It seems the folks most offended in the pattern are the same folks that can’t deal with the reality of that incident.
For clarification, that means aircraft anywhere up to 5 miles are on final, which also means aircraft on downwind up to 5 miles from the runway threshold are also in the pattern as well, and at ???? feet/miles abeam the runway. Now who all is where in the pattern and Do You See Me? Probably not.
ADSB = Another damn stupid boondoggle. Heads down and locked.
That, and from the current data, only 53% of GA aircraft are equipped with ADS-B-out.
So, you had better be looking outside and use the comm radio….but hten, there are some NORDO aircraft out there too.
Quite honestly, I read the entire AC as an exercise that someone (or several someones) created to justify their job. The only useful comments I saw in it are the 10° segmented scanning method and the benefit of cleaning bug splatters off the windshield—both of which are valuable if somewhat obvious. Bottom line: I believe that publishing this AC will have zero effect, positive or negative, on mid-air collisions.
The responses to this article make for interesting reading. I fly a steam gauge 150 so am automatically one of the slowest airplanes in the pattern (except for Cubs). I am continually amazed at how many pilots are still attempting non standard pattern entries at non-towered fields, in spite of the lessons from recent tragedies – I’m thinking of the mid-air with a C150 at Watsonville with a Cessna Twin coming straight in at 179 knots!!
Last week we went to Paso Robles and there was a pilot announcing that he was going to join right base for a runway that was left pattern. Another pilot called him on it and he sheepishly changed to a standard mid pattern entry to downwind. My beef with the FAA is that when you are saturated with flying the airplane in the pattern, relying totally on “see and avoid” is simply not realistic. Why are we so reluctant to embrace the huge safety advance offered by ADS-B traffic on the iPad. I know its not perfect and may not “see” all airplanes but it does capture 90% of them, at least where I’m flying near Monterey CA. The most effective ways to reduce mid air collision risk are 1) fly standard pattern entries at non-towered fields (and I mean no straight ins unless it is post 9/11 and no other aircraft are in the air), 2) use a combination of screen target acquisition and eyeball scanning to achieve real-time situational awareness of the traffic around you – don’t rely solely on visual spotting! We have the technology – just use it! And by that , I don’t mean staying glued to the screen – its all about balancing the resources we have available – digital and human.
I read a case of a Part-135 jet making a right base entry and someone complained. The pilot claimed he was making a straight in. The ruling was he was not far enough from the airport (I think it was minimum 5 miles) to consider it a straight in and it cost the pilot dearly (suspension but don’t remember if a fine was also included). I think that example would get a lot of attention if it were included in training material.
As far as straight-in’s, think about the alternative, which would be twins and jets entering on the 45, some at your altitude and some 500ft above you (at some airports all twins are TPA +500). They are low wing and can’t see you if above. You may be high wing and can’t see them. All are faster than you and some will be following at TPA. Now, if one is higher than you, who goes first and how are you going to coordinate. If the higher one goes first, he will descend through your altitude. How will you maintain safe spacing and avoid wake turbulence? A lot of these aircraft shoot instrument approaches – should they really be circling? Remember the recent crash of the Lear in CA. I’d rather hear them call a straight-in so I can extend the downwind and watch them safely go by.
Of course airplanes should approach the runway at a reasonable speed and not push into an established traffic pattern and we should be aware of vision issues. But some hazards don’t fit into the usual guidelines. Some airplanes are really fast – I’ll never forget being on the downwind at Oxford-Waterbury, CT before it went towered. There were Part-135 operations of larger executive aircraft calling a long (more than 10) mile final, way out of sight but at 2 times my groundspeed or more. No way I was going to turn in front of them. When I extended the downwind, they were passing by in very little time. If it’s a Skyhawk on a ten mile approach, that’s one thing. But with twins and jets, I extend the downwind.
The directive only points the pilot to information, which is already known or needs to be reaffirmed. Ongoing training is what prevents these kind of accidents.
The A/C alone is not meant to prevent anything. It’s obvious intention is to direct pilots to the info they need to be more pro active in their training and flying and become better pilots overall.
Complacency and poor planning are the #1 killers in aviation.
Ref: “The AC notes that your vision is influenced by a variety of factors, such as ……..”
They forgot to add “Mounting your iPad(s) on top of the glare shield where it blocks your field of view.”
It does seem a bit unrealistic for FAA to think it can change pilot behavior by issuing a directive. They’ve managed to nitpick flight instruction to death, issued so many tasks (explained to the n-th degree for rote spit-back) and taken so much common sense out of pilot training that I, for one, saw this coming. Train people to fly first, primarily stick and rudder skills and outside references, then layer the other stuff in – gradually. Too many students are taught that the in-cockpit tasks are prerequisite to flying the airplane.
Very well said!
While the new AC is thorough and applicable to the mid-air collision problem, such documents fail to address the root cause of the problem: some GA pilots are far too casual in their approach to aviation, and more specifically place undue reliance of the new ‘glass’ gadgetry in the cockpit which offers a false sense of security surrounding aviation and navigation. I see the same thing happening in current generation high-end cars featuring the camera systems alerting the driver if the car strays across the stripe painted on their lane and the adjacent one. Pilots and drivers can text and engage in other distractions with the comfort of knowing the electronics will keep them safe. Wrong. Dead wrong.
In earlier times of ‘steam gauges’ and stick shifts in cars, the operator of either conveyance needed to bond with the vehicle and be aware of its function and operation, alert for wild and dangerous readings on the gauges and engine noises from under the car hood. But those days are gone. We’ve surrendered the need for that critical man/woman-machine interface bond to dazzling electronics creating the accompanying false sense of security, believing we’re in the ‘good hands’ of the glass. Dead wrong.
Decades ago, ‘stick and rudder’ pilots could put a bi-wing airplane through an open barn, walk on the wing and reliably ferry US mail across the Fruited Plain. Many of today’s pilots can’t land a Cessna 172 in a cross-breeze. That long-gone earlier generation of white scarf pilots is spinning in their graves at the idiocy of today’s tech-reliant generation of pilots. Every time I read of a mid-air, I wonder out loud ‘how could they be so blissfully unaware of the other plane?’ Then their mortal lives end in seconds and the question is forever moot.
What? You mean the government-imposed, expensive ADS-B gadget didn’t end mid-air collisions? We have to go back to what worked in the past – keeping our head out of the cockpit? Can we get our money back?
Expensive? Hardly. Easily the best aviation dollars I’ve spent.
I agree! Money well spent. And I lost friends to midair collisions before the advent of ADS-B as well. Is it a panacea? Of course not. Just a very useful tool that can help save lives. Just like eyeballs. Use everything you have at your disposal to avoid disaster, including a flexible mindset.