• Fly Accurately: Know your pitch/power for all maneuvers…think “total energy”
  • Practice Often: Too much “enroute autopilot”? Go “yank and bank” (steep turns, “dutch rolls,” slips) Challenge yourself!
  • Stay Sharp and Avoid LOC: Practice out of your “comfort zone” with a CFI…become “bulletproof!”

The most pressing area of concern in general aviation safety is  I-LOC; “In-flight Loss of Control.” This sounds like a new and surprising problem, as if the plane will jump out of your hands but it really is a problem that has dogged aviation safety for years:  “maneuvering flight”. Whatever you call it, over 40% of pilot accidents happen in an area of flight where we only spend 5% of our time; maneuvering flight and usually below 1000ft agl. This would of course include that inherently tricky area of take-off and landing.

As a long time CFI and DPE let me assure you that flying is safe and what we are addressing here are the frustrating and almost predictable accidents that seem to happen regardless of training and interventions. In aviation safety, we have harvested all the low-hanging fruit; our planes are now super safe and we have incorporated all kinds of technology to help. We have displays with current weather and other planes in the cockpit and GPS to drive us  precisely to our destination. What does not seem to be “fixable” however is the pilot handling the controls when the demands of the task are suddenly overwhelming. Stall/spin accidents account for 21% of fatalities in aircraft…we need to learn to control our aircraft correctly for safety not just in the center of the control envelope but also toward the edges. This involves both basic aerodynamic knowledge and recent and correct practice at the controls of the aircraft. This Vg diagram depicts the maneuver envelope for a GA aircraft. The yellow oval is where we spend 95% of our time…safe and comfortable with little real demands of pilot skill. Pilots who spend all their time here are are not prepared if they are suddenly displaced from their “comfort zone!”VgCenter

The problem starts with the fact that the fundamental physics of safe aircraft control is not all intuitive. Flying safely requires deeply embedded trained responses based on extensive knowledge and good habits. Piloting skills need to be correctly taught initially and fully assimilated but also practiced regularly to be available, in fluid form, when a sudden upset demands action. Flying only in the center of the flight envelope will not keep you sharp enough to be safe…you need to be challenged with some dual flight on a regular basis. If a pilot wants to climb in a plane, just pulling on the yoke will not work (for long). If you want to turn, mashing a rudder in that direction will not work (for long). To be safe in a plane and avoid I-LOC, you must bank the plane in a coordinated fashion and understand and manage angle of attack. Mishandling both of these control inputs together is the heart of I-LOC…an aerodynamic stall (excessive AOA) with a lot of yaw (turning with the rudder)!

Angle of attack cannot be easily explained in an blog article, it really has to be demonstrated to be effective. Suffice to say here that AOA is usually almost invisible to the pilot. A plane in a snapshot in a level flight attitude could be climbing or descending or even stalled and falling, but its impossible to tell without movement. The trend would reveal the AOA as would the position of the yoke. The amount of back pressure and the extent of geometric pitch is a good rough estimate of AOA. Pilots absolutely must practice and understand this critical part of aircraft operation.This classic diagram from Aerodynamics for Naval Aviators clearly diagrams this problem.

NavyAOA

 

The recent “seawall approach” into SF international in a Boeing 777 was a classic student pilot level error in aircraft control. It is what we call “naive rendition” in the flight instructor world: what you *think* should make the plane do what you want…just pull up the nose and it will climb…NOT! Actually, nose pitch controls airspeed primarily and adding power is necessary to arrest a descent and “stretch a glide” to the airport when low on final…not intuitive! In this photo, both the nose high (scary) Aircraft A and the nose low (friendly) Aircraft B have the same angle of attack. The plane can quite easily stall with the nose below the horizon with G-forces induced by a turn.

Cessna152AOAdemo

Turning coordinated using balanced rudder and ailerons seems to be increasingly rare in the pilot community and it is the heart of avoiding I-LOC. This essential skill is often missed in initial pilot training due to all the other “important” items that have to be covered in flight training…is my sarcasm showing? Nothing is more important than turning coordinated with balanced rudder and aileron! Pilots in training often miss this due to focus on glass panel avionics and other “shiny toy” distractions. Find a good instructor and practice this vital skill in your plane. Watch directly out over the nose when rolling the plane and the coordination will be immediately apparent. Watching the ball is absolutely the wrong place to focus…you are already behind the machine. “Dutch rolls” on a point will give you a good feel for the rudder and develop confidence in the outside visual cues.

Understanding slips and skids are also essential to safety in an airplane…but I doubt more then 10% of pilots could describe the process. (Keeping the plane from turning with the rudder is a slip and aerodynamically  stable…read this). Often used to land in a crosswind or add drag to increase the descent rate, a slip is a required maneuver for all private pilots candidates….learn and practice this maneuver with a good CFI.

Ultimately what I am am recommending here is a solid aerodynamic understanding of flight (AOPA course is excellent for this) and good “stick and rudder skills” to be safe and avoid I-LOC. Maintain a regular recurrency flight routine to stay sharp. Participation in the FAA Wings program is an excellent way to do this. Spend some time in our tail wheel aircraft to acquire an understanding of correct rudder usage. Practice some dutch rolls on your annual check-out. Above all stay sharp with your maneuvering skills…just droning on autopilot in the center of the flight envelope will not maintain the requisite pilot skills for safety. As the professionals joke “safety is not an accident” it take regular practice to stay safe.    ©2015, David St. George

 

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2 thoughts on “Fly Accurately, Practice Often, Avoid LOC!

  1. It’s all about the relative wind verse the AOA. And the relative wind does not even have to be straight at your nose…. It could be coming up at the belly as is the case with spins. 🙂
    ✈✈✈✈✈✈✈✈

    Yeah… I guess how far back the stick/control wheel is…. Is a good indicator of AOA. %)

    1. Yes, the position of the stick and the pressure (in a part 23 certificated plane) are pretty good indications of AOA. I once had a CFI candidate on a check ride unintentionally demonstrate how failure to lower the nose rapidly (and stay coordinated) in a power on stall could take you directly into a spin…oops!

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