My students often have concerns about setting up for slow flight when practicing and perfecting their skills for a checkride. So this lesson isn’t about so much how to do slow flight as maybe an easy plan to setting up and its relationship to the rest of our flight.
It’s a demonstration of controlling the relationships of Lift and weight and thrust and drag or the relationship of you controlling your minimum airspeed (or whatever speed requested to use)through angle of attack with the power creating just the right amount of thrust over drag to not sink or climb unless called for. Usually this happens in the so called dirtiest configuration of your aircraft such as max flaps in my C152 trainer.
So my recommended set up is to start as if setting up for a landing. Start by pulling your power to or close to your normal power setting or other recommended setting that you use to get ready to lower the airspeed into white arc and lower flaps. This will mean raising the nose some to prevent loss of altitude, but we reduce power so we don’t climb either. You can see the similarities already. (You can sometimes go straight to full flaps if can keep up with the ballooning tendency and power requirement to prevent altitude loss etc, but in the beginning you probably need to take it in steps, and for a checkride your under stress anyways so take the steps.) As the plane begins to stabilize and approach the slow speed desired, usually go ahead with next set of flaps. Do expect a slight more ballooning affect then be prepared to add some power to prevent loss of altitude. This means you will likely have to use some muscle of maintaining the slower settings. Then at this point usually adding the last of your flaps unless you have the lucky plane that have that fourth setting. Now don’t forget the power, just enough to prevent a loss of altitude. Don’t forget to trim the plane to keep the controls within your comfortable feeling of pressure, don’t try to muscle the plane which you will often over control. I usually have mine trimmed for the typical climb which is well above the minimum speed so if you let go of the controls the plane will drop the nose to gain speed but start trying to hold that speed say in my C152 of 70-80kts. This means you will likely have to use some muscle of maintaining the slower settings. Everyone may have a slightly different preference but I d prefer a student to not set trim trying to relieve all pressure you must know what the little details feel like the buffeting, the mushy controls and not too much trim you struggle to push the nose over to recover, most trainers this isn’t an issue but can be in some planes. Think moving your fingers for tiny airspeed corrections rather than whole ar movements
My version of practice is to take the speed as a slow as just the edge of turning on the stall indicator, that’s a typical 5kt buffer from actual stall. If it is turbulent I will end up using a higher number then and when extra calm its right at that just chirping the stall horn in my plane. We practice with horn blaring occasionally seeing how slow of airspeed might get before actual stall is induced. (The new standard has changed, but I have my methods and if can do my method of the slowest without a stall then you’ll pass that portion of the test easily.) Then you must make some turns. Now without adding power sometimes you will begin a descent or even induce a stall if used the yoke first to stop the sink or turned too steep initially. Turning with a very shallow and slow turn with rudders usually works best. Yes likely still using a bit of aileron, but this is slowest flight so these turns should be just as slow as the slowest turtle you can be too.
This lesson is to teach how your power can be manipulated minutely to make small corrections, this is a finesse skill your learning. Anytime you’re at your slowest and or the closest to the ground finesse is called for. Good coordination of ailerons and rudders and elevator and feathering of your speed and power. It’s not about perfection either, but seeing the indications of unwanted changes and adjusting to stop them and even reverse them if required or even do a full recovery and start over. Always stop the unwanted from getting worse before correcting it. Think making those corrections as if hoping your DPE or Instructor won’t notice (we do but if you’re smooth we might not let it count against you) or correcting so you don’t disturb your passenger from their nap or their Facebook live video.
Real World Scenario applications
Now in setting up this maneuver we did not do pattern turns. Yet this is exactly when you may find yourself slow flying either intentionally or unintentionally which should be avoided or corrected ASAP. Improper handling of your airspeed and altitude and directional control during reduced speed and power settings is when Loss of control incidences occurs. Usually you have become distracted with radio calls or worrying about someone else’s plane and not yours. Often happens in a Towered field if tower asks you to extend downwind or give other traffic space. Know what your slowest safe speed is beforehand like my C152 I say its 65kt which means I can safely make steeper turns avoiding stall conditions. Yes it will go slower but if I’m still possibly maneuvering the pattern or traffic avoidance this speed is that minimum speed. This is also applies to an uncontrolled field in which your also giving other traffic room for their landing etc. You might even find yourself flying a photographer wanting photos which they prefer slow flying so knowing what your safe zone to allow them to get their best shot but not endanger you when they want you to turn back or closer or lower etc… set your limits before flight and there will be less issues in flight.
It applies when find yourself dealing with a high density altitude takeoff/climb that you forgot to check for… understanding that feel helps you both not pull nose up and stalling, but also if need to maneuver to return to a landing or even land off field and or maybe avoid an obstacle. Course once that ordeal is over you likely won’t forget that lesson on density altitude! Or maybe you’re dealing with a loss of some power but not yet all. Many reasons and when and where this could be happening.
Understanding how to slow fly will help with you understanding and making those soft field landings also. Learning to just barely have enough power to barely sink through that ground effect yet not firmly tap the ground and keep that nose in that angle of attack so you don’t let it touch the ground too soon… yeah that skill! Ok now you’re just showing off!
Now go have a great relationship with slow flight and your airplane!