Category: CFI Technique

Angle of attack (AOA) is the most misunderstood concept in aviation – just raise the topic casually in a hangar flying session to sample the confusion. Our previous two blogs on tail-down force and the basics of a turn demonstrated the many scary gaps in the average pilot’s knowledge.  Some CFI somewhere has failed these pilots in training. Ignorance and misunderstanding, along with lack of solid skills are at the heart of many of our fatal loss of control accidents. Most pilots are fine and happy in the limited “comfort zone” of their 5% flight envelope, but terrified when forced by surprise events to maneuver. (I highly recommend Rich Stowell’s Emergency Maneuver Training to every pilot. This book will fill many “gaps” and is written in wonderfully clear language)

Controlling AOA is the central tool in the generation of lift and essential to everything we do as pilots defying gravity. Understanding and managing AOA is indisputably the most important knowledge and skill set we (should) learn as students. But unfortunately, if AOA exists at all in a pilot’s vocabulary it seems to represent only  the feared excess of the stalled condition. And even the simple stall is clouded in mystery and fear and hidden behind an over-reliance on technological protections. Now that  minimum controllable airspeed (MCA) has been removed from the private pilot ACS, educators often don’t teach this important skill and sample “the feathered edge” of critical AOA. Learning to maneuver in MCA not only teaches coordination, it teaches all the kinesthetic cues of the impending stall.

I have been privileged to own a 7AC Champ for the last 30 years. This plane has no stall warning device at all – and no blue button or “envelope protection” either. Demonstrating AOA and teaching stalls is so easy in a Champ or Cub (or glider); pilots in training learn it early and fairly painlessly. Add all the distractions of a technologically advanced airplane and the slow flight/stall process can take longer and be disguised by distractions. Don’t get me wrong, technology is wonderful and necessary in a “go fast” machine, but the physics of lift is identical and more easily learned in a simple plane.

Angle of attack is most commonly confused with flight attitude (an aircraft’s relationship to the horizon) but there is no relationship between AOA and attitude. I think this misconception is a deeply embedded “natural” human assumption. And it is essential to eradicate these misconceptions during flight training. This requires knowledge, demonstration and practice; but we often don’t get there. Any plane can be in level flight attitude and stalled, be pointed straight down and also be stalled (both exceeding the critical AOA). Air France 447 was a landmark case study of a very experienced crew mishandling AOA.

As illustrated above, in a still photo of an aircraft, you just can’t determine the AOA from the outside view; it is invisible. To discern AOA you need motion and trend; it is the difference between where the airplane is pointed and where it is actually traveling. And that is another good reason for a pilot to keep their eyes outside for more than infrequent glances; you need to see the trend to achieve control. If it’s going down out of control you need to unload and push it further down to recover. “Unloading” (reducing AOA – especially when nose down already) is so unnatural and at first it is incomprehensible to new pilots.

A secondary stall is a excellent tool to illustrate the difference between AOA and flight attitude and train unloading – the student is confused p“the nose is down below the horizon but the plane is stalling? How can that happen?” This initial confusion (cognitive dissonance) is a “learning opportunity” for full explanation, full understanding and training muscle memory in the learner. And here the aviation educator has to be patient and kind but also somewhat relentless in achieving understanding and proficiency (DPEs do not evaluate this skill on flight tests). If pilots do not fully grasp this “unload” concept, they will never be safe in emergencies.

My personal familiarity with AOA is largely from many hours of “dual given” watching people misunderstand and mishandle the physics of flight. And my passion is guiding them back to comfort, knowledge and control in their aircraft. But this takes commitment on both sides of this instructional relationship. Our natural human tendencies (called “naive rendition”) of how flight works is initially all wrong. Our intuition fails when it tries to “do physics.”

Everyone seems to “know” the nose high aircraft is “high AOA” (the crime of flight school demonstrations). But nobody seems to comprehend that a nose-low A/C can have an equally “high AOA” and be just as close to a stall (it mistakenly appears safe). The untutored knowledge that is “natural” to new pilots does not work and only gets worse when fueled by fear in an upset (pull away from the ground). Flying is largely applied physics and requires proper counter intuitive knowledge and understanding. Flight training is a careful process of discovery as we overwrite what humans intuitively guess is going on. And that takes trust and willingness on the part of the learner and requires a strong CFI/learner relationship to work through these issues completely – also rare.

After many years of flying and teaching, we know most people can drive a plane down the center of the flight envelope with very little guidance  – “look mom I learned to fly in a week!” We’ve all seen this on the cover of Popular Mechanics and I would love it if it was that easy. Unfortunately, if these marginally trained pilots experience displacement from “normal” or are startled, loss of control is a certainty. Even the most experienced pilots can fall into AOA traps. The video below is of an Air Force Thunderbird F-16 that suffered a very predictable LOC  problem. Watch carefully and see if  you can figure out why this happened (no one was severely injured here and the pilot ejected in time)

I often present this video at gatherings and call this “the perfect stall.” It demonstrates that even the most amazing military machine with endless power can’t make an airplane do the impossible and defy physics. Below is a screen shot that looks like a “fly by” – but in a static picture AOA is invisible – it takes motion and trend of a video to reveal the 7G stall.

And the question we left you with in last week’s blog; What is the AOA device installed in every airplane? AOA corresponds with how much chrome you see on your yoke (how far you are pulling back); and how much back pressure you feel on the stick (right side up). “Unloading” (overcoming that dangerous “monkey pull”) allows the reduction of AOA and is the first step to recovery of control (or don’t go there in the first place). To me personally, this huge, universal AOA device is more obvious and compelling in an emergency than a small electronic AOA device hidden somewhere in a busy panel.  But there are many good Upset Recovery Schools for you to try this for yourself and decide while experiencing upsets safely.  There is also excellent technical guidance on LOC-I in our SAFE public resource center (available to everyone) and in the FAA Airplane Flying Handbook. We will have a full syllabus of skill-building maneuvers at our SAFE CFI-PRO™ Workshop at AOPA, October 2&3. Fly safely (and often)!

Join SAFE to support our safety mission of generating aviation excellence in teaching and flying. Our amazing member benefits pay back your contribution (like 1/3 off your annual ForeFlight subscription)! Our FREE SAFE Toolkit App puts required pilot endorsements and experience requirements right on your smartphone and facilitates CFI+DPE teamwork. Our CFI insurance was developed specifically for CFI professionals (and is the best value in the business).

We discussed the turning stall in the last SAFEblog and revealed the (often surprising) fact that in coordinated flight, with lift equal on both wings, a stall simply falls away from the lift vector and is very benign. There is only a burble and a drop of the nose, but no rolling or sudden departure from controlled flight that many people expect (and fear). This maneuver is in the private pilot ACS and should be comfortable for every aviation educator. This maneuver not only builds skills and confidence, but also creates a powerful opportunity to promote the need for coordinated flight and the value of correct rudder usage. Since there is no spin tendency in a turn when we are coordinated, this has a super safety value to every pilot; it opens their minds and gets their attention. But we then need a method to achieve better intuitive rudder coordination.

There is lots of confusion about the airplane’s rudder and its function in flight.  Remarkably, when Rich Stowell surveyed pilots he found 70% thought the rudder was used to turn the aircraft. This is dramatically wrong and should be a wake-up call to every CFI. Quite simply, the rudder cancels unwanted yaw created by the adverse effect of ailerons, power application, or rapid pitching moments. Most commonly, the downward moving aileron creates yaw, pulling the airplane away from the desired turn direction with “adverse yaw.” This can be *very* pronounced in an older (often tailwheel) aircraft but is largely designed out of modern (control blended) aircraft. That is a nice way of saying modern planes mostly tolerate and disguise “flat-footed flying.” Unfortunately, moving the rudders appropriately and learning coordination is the key to safety and preventing LOC-I.

The critical skill is to anticipate yaw not just reactively cancel it after it has occurred. That’s why the advice “step on the ball” – though correct – is too late and creates more problems than it solves. “Step on the ball” means you already created the yaw problem – slewing the plane – and are subsequently forcing it back into balance with a time-consuming, mechanical input. People who utilize this advice not only have their eyes inside but also fly like bad robots in a jerky and uncomfortable fashion. In addition to being clumsy, we just do not have enough mental bandwidth while flying to be cogitating about “stepping on the ball” (which lags badly anyway). It is essential to tune up our kinesthetic yaw sensing and develop automatic anticipation of adverse forces. This will also makes you an amazingly smooth pilot that your passengers will appreciate.

I recommend all flight instructors (and pilots who want to get sharp) demonstrate (observe) a brisk application of power, aileron, or pitch applied independently at a safe altitude. In each case you will see the nose yaw in reaction to this force applied (physics in action).  With practice you can predict which way this will occur (physics!) and discern how much rudder to apply to maintain coordination. I have my primary students initially move the throttle hand and the right rudder together to develop some “muscle memory” while on the ground sitting in the cockpit (works for “chair flying too). This yaw correction will become automatic pretty quickly with directed focus and practice (but is much easier to teach initially than to correct from a bad habit). There is a lot more to this art of learning/teaching rudder and our SAFE CFI-PRO™ workshop has many time-honored CFI tricks to tune up rudder usage.

“As the power increases, you’ll simultaneously press on the right rudder pedal knowing that the entire universe (specifically the airplane’s power induced left turning tendencies) is doing everything possible to yaw the airplane’s nose to the left. But you’ll have none of this nonsense because you are in command of your airplane, right? Right! So step on that right rudder pedal.” Stick and Rudder Mutter, by Rod Machado

But let’s get on to this “cross-controlled bogeyman” we started with. If after we demonstrate that turning stall we ask why the plane did not spin (as expected) in the turn the logical follow up question is “what would cause a stalled plane to spin?” And I guarantee the answer will be “if you stall when you are cross-controlled.” So I demonstrate a stable full slip (power off) and bring the plane to a stall. I love this demonstration, because though the plane is balanced and stable, every pilot anticipates a violent spin entry. In fact with a well rigged trainer, nothing at all happens (except the student finally begins breathing again). Another learning opportunity; why no spin? Because the slip configuration is stable (with no power) with the rudder yaw opposing aileron roll force (perform this only with an experienced instructor and know your plane). This illustrates that the obvious bogeyman is not “cross-controlled” but rather the pro-spin inputs of a skidding turn (ironically the force 70% of pilots think turns the plane) The skid is an excess rate of turn. This usually is created with the rudder but can also be uncompensated force from a go-around attempt (well represented in the NTSB files). The skid is the evil form of “cross-control” and often occurs when people fight yawing force inappropriately with aileron (“driving” again). If there is one aerodynamic principle every pilot must understand this is it; understand thoroughly the difference between a slip and a skid and why one is safe and one will kill you . This is the essence of safety in the pattern. More detail is in this Aviation Safety article I wrote.

Three incidents personally persuaded me to demonstrate these maneuvers and promote this understanding to every pilot. First was repeated flight tests where applicants did not want to “slip to land” because it was “cross-controlled and dangerous.” Then I discovered a website by a respected airline pilot (with great popular following and gravitas) that advised (completely incorrectly) to convert the base to final turn into a slip by applying aileron out of the turn as you lined up on final; “you already have the wing down.” This is of course a skid and very dangerous (pro-spin: do not try this!). The final incident was a young CFI applying for a job at our flight school who demonstrated a massive skid (intending to slip) and confessed he thought you “just cross the controls” to create a slip. This level of confusion is obviously killing pilots and needs to be corrected by every conscientious aviation educator. Again, more here.

Next weekend SAFE will be at the AOPA Fly-In at Frederick, MD (and we would love to meet you there). This blog will cover another misunderstood (and potentially dangerous) aerodynamic force; AOA, CG and pitch (“planes don’t stall, but pilots stall planes”) Fly safely (and often).

Join SAFE to support our safety mission of generating aviation excellence in teaching and flying. Our amazing member benefits pay back your contribution (like 1/3 off your annual ForeFlight subscription)! Our FREE SAFE Toolkit App puts required pilot endorsements and experience requirements right on your smartphone and facilitates CFI+DPE teamwork. Our CFI insurance was developed specifically for CFI professionals (and is the best value in the business).

Presenting seminars at public events like Sun ‘N Fun is a fascinating opportunity to both meet people and also sample the aerodynamic understanding of our pilot (and CFI) population. Having been a DPE for many years, I often ask a lot of questions while presenting to get a sense of the understanding level of my audience. Reliably, 70% of pilots are usually confused about which control actually turns an airplane. Pilots (and CFIs) are unfamiliar with the actual aerodynamic forces at work on our wings during a basic coordinated turn. And no one seems to know that *every* aircraft has an AOA indicator installed – which every pilot controls. Let’s unpack a few of these ideas; because they are essential to the safety of every pilot and especially essential for every aviation educator to understand completely.

I usually ask audiences about the balance of lift on the wings of an airplane in a stable, level altitude turn:  In a level, coordinated 30-degree turn, is the lift equal on both wings? – Please make YOUR choice at this point before going further.

Reliably, more than half of the pilots in every audience will say lift is unequal on the wings in a level coordinated turn. For an educator, this is the classic “learning opportunity” to present a startling follow-up question. If lift is unequal in a stable turn, wouldn’t your plane would still be rolling? Presented that way it seems to make sense to pilots; lift is equal on the wings. Inevitably, someone always posits that the outer wing has “more lift because it is traversing a longer arc” (over banking tendency). But obviously if this was true your plane would still be rolling. I think what confuses pilots is the asymmetric lift used to create the roll initially, and I think also (surprisingly) the flight attitude is still somewhat scary to many pilots since we all spend most of our time straight and level. The fact that 70% of pilots are confused is also an opportunity to improve the understanding of our flight training community (see SAFE CFI-PRO™) We have great tools for teaching this area of flight.

So simply prove this to yourself the next time you go flying. Roll into a 30 degree bank and add enough nose up trim (and a touch of power) to maintain a stable level altitude hands off. Fold your arms and smile; your plane will happily continue to fly in a hands-off stable turn until it runs out of fuel (assuming it is properly rigged). Every CFI needs to  demonstrate this stability and explain the underlying aerodynamics very early in pilot training. This is not an automobile or a boat and ignorance of essential aerodynamics is responsible for many LOC-I accidents.

The natural follow up question is of course, what will happen if we stall in a coordinated turn? This is a very powerful question for every aviation educator to ask (and demonstrate) as soon as a student is comfortable with straight-ahead stalls. Student pilots predictably grab the seat cushion and start to sweat when I first demonstrate a turning stall in an aircraft during training (despite a full ground briefing). >70% of pilots (and CFIs) predict a spin entry as the inevitable result of a turning stall. But if lift is equal on the wings (we are coordinated), a stall in a turn will very simply drop away from the lift vector. Try this with an experienced CFI and you will see that the stall break is even less pronounced than the straight-ahead stall. This is a way of expanding your flight envelope and proving to yourself how the basic aerodynamics of turning an airplane works. A turning stall is a very empowering maneuver for every pilot to experience. And the turning stall is an element in the private pilot ACS for this reason; it is an essential learning experience for safety and understanding.

And for that last mystery question; which control is active in a level turn? The ailerons are neutral in a 30 degree turn – take a look out at your ailerons while turning and try wiggling them. And the rudder is also neutral  – because all it does is “cancel the adverse yaw” as ailerons are added to roll the plane. The active control responsible for the turn is what you added with the trim; your elevator! And over 25% of pilots guess the rudder is turning the plane – and that would be a skid and responsible for pro-spin force – a dangerous assumption. The actual control responsible for turning in level flight is the elevator. A more complete explanation of  the aerodynamics of turning are on Rich Stowell’s “Learn To Turn” course on community aviation. The fact that pilots are confused here is one reason we are providing expanded education for CFIs during our  SAFE CFI-PRO™ workshop. A YouTube of Rich Stowell at the NTSB is available here.

The (largely unknown) AOA indicator we all have in an upright airplane is how much chrome is showing on your yoke (how far back you have pulled the yoke or stick). This will reliably show your angle of attack and also is the first thing to reduce in an upset – unload! Next week we will talk about the fact that planes don’t really stall – but in fact pilots are responsible for stalling planes.  Stay tuned – and fly safely out there.

Join SAFE to support our safety mission of generating aviation excellence in teaching and flying. Our amazing member benefits pay back your contribution (1/3 off your ForeFlight subscription)! Our FREE SAFE Toolkit App puts required pilot endorsements and experience requirements right on your smartphone and facilitate CFI+DPE teamwork. Our CFI insurance was developed specifically for CFI professionals (and is the best value in the business).

Our SAFE CFI-PRO™ initiative was well received by the press and industry on April 3rd at Sun ‘N Fun and we had an  amazing show here in Florida. See all the industry visitors to our booth on our SAFE Facebook. There are many livestream videos from our booth with manufacturers like Piper, Cirrus, Lightspeed, Bose, Appereo and industry partners like Patty Wagstaff and Richard McSpadden.

We announced the date for our initial CFI-PRO™ workshop on October 2nd and 3rd at AOPA in Frederick, MD. This ambitious program is the ultimate expression of our SAFE mission of elevating aviation educator excellence. The purpose of these workshops is to codify and transmit the knowledge and skills that make a CFI professional truly proficient – far beyond the perfunctory FAA initial training. We are addressing the “CFI Gap” between “good and Great!” The heart of this workshop is our “Envelope Expansion Maneuvers.” We will present these in detail and explain the aerodynamics behind them. We hope to also fly them at the workshop so we can ultimately transmit these to every pilot at every airport (though our  CFI-PRO™ cadre) and expand pilot’s abilities to reduce the incidence of Loss of Control accidents.

There are great learning opportunities at this two-day course for every CFI. For new CFIs we will provide the “missing manual” of skills and techniques to elevate each educator from “good to great” taking you far beyond the FAA minimum standards. For the more experienced CFI we will reveal new and modern concepts of scenario-based training and testing and also focus on client-centered instruction. Everyone will also love the networking opportunities with some of the best educators in the country. A passion for excellence is energizing and a shared mission for improvement is  contagious.

What we mean by “expanding the flight envelope” is getting away from just scenario-based training and exploring flight outside the standard 5% “comfort zone” where we all fly. By definition “scenarios” are pretty tame flying. Envelope expansion maneuvers are non-operational, skill-building techniques and focus on full control authority. As an example, take a normal steep turn at the commercial level and reverse the heading after 180 degrees of turn. After you gain proficiency with this, reverse after only 90 degrees of turn. These 60/90s have been a standard tool of senior CFIs to build proficiency for many years.

As another example, perform a standard power off turning stall and recover in the turn without adding power – just reduce the angle of attack; what a confidence booster for both CFI and pilots. A normal turning stall is a required maneuver on the Private Pilot ACS but seldom taught by CFIs or well known by most students sent to a private pilot test. How about a power off stall in a full slip…what will your plane do? If you don’t know you are a good candidate for SAFE CFI-PRO™. We will cover the aerodynamics of this situation and also teach the maneuver in flight. You will become a more proficient CFI-PRO™. As we travel this program, we will depend on our growing cadre of professionals to spread these SAFE Expanded Envelope Maneuvers to other CFIs and our general aviation pilot population. Moving every pilot out of their complacent “comfort zone” by refocusing on confident “yank and bank” maneuvering is the antidote for LOC-I.

More people die in every sector of aviation due to LOC-I than to any other cause. The NTSB has been excellent at keeping this fact in front of the public until we figure out how to change the way we train pilots.” Realistically, however, Brooks adds, “If we look at how we spend our training time versus the LOC problem, there’s a huge gap, yet we continue training pilots the way we always have.”

The secret of success for SAFE CFI-PRO™ is teaching a syllabus of maneuvers that can be flown in a any standard part 23 training aircraft (no parachutes or exotic aerobatic planes required). This program is scalable to every pilot at every airport in the hands of a skilled CFI-PRO™ and ends up being highly effective at building skills. Pursuing an Upset Prevention and Recovery Course as the next step would be a great addition. Find more information here and please enter your contacts to receive more details as they become available. Registration will be available in about a month; stand by for a great educational experience.

In the meantime, fly safely (and often) and keep in touch. Together we are going amazing places.

Join SAFE to support our safety mission of generating aviation excellence in teaching and flying. Our amazing member benefits pay back your contribution (1/3 off your ForeFlight subscription)! Our FREE SAFE Toolkit App puts required pilot endorsements and experience requirements right on your smartphone and facilitate CFI+DPE teamwork. Our CFI insurance was developed specifically for CFI professionals (and is the best value in the business).