Performance and Limitations PART I (ACS)
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- เผยแพร่เมื่อ 13 ก.ย. 2024
- A discussion of performance and limitations oral exam prep located in the Airmen Certification Standards (ACS).
We discuss the five types of altitudes: Pressure altitude, density altitude, indicated altitude, true altitude and absolute altitude. We also discuss the four types of airspeed: Indicated airspeed, calibrated airspeed, true airspeed and groundspeed. Last we discuss V speeds including maneuvering speed.
We discuss how pressure and temperature effects performance.
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You have to keep posting content. Teaching is awesome.
Why does VS1 (clean with no flaps) stall speed show so high? I don't stall a 172M until almost 40 knots or less indicated with just me and full fuel. In other words, I can slow flight clean well under the green arc.
Separate question, why are no power landings under 30 degree flaps get taught so often to private pilots? Flying during my instrument rating, a power on landing at 1700 rpm by controlling a stabilized approach with configuration (flaps) and pitch is way more comfortable. Not yo-yoing up and down and not so steep of an approach angle. Is it due to pattern work vs straight in? Inexperience of the pilot? Easier? Could it reduce or eliminate the need to slipping to lose altitude producing a more controlled approach?
Sorry for so many questions. Hopefully, they are understood.
So if you watch performance and limitations Part II video it will explain why. It’s because of the difference between indicated and calibrated airspeed. Look in your AFM/POH in the performance section to determine the difference in IAS and CAS. For example our 172M when it indicates 40, calibrated airspeed is 53! Also the stall speed on the airspeed indicator (Vs) is at max gross weight. So of course stall speed chances with weight (also explained in performance and limitations Part II video), meaning wings level at 1g, if your not a max weight, the stall speed would be lower than published Vs1.
To me, every landing is a power off landing, except for a soft field landing when power may be needed to make a smooth touchdown.
The way I teach landings is to fly as close to the runway as possible and not let it touch. It’s a transition on short final to slow flight and then to a power off stall. This prevents porpoising when landing with an airspeed that the wings still want to fly. It’s a much better way to keep from damaging the airplane via porpoising for students and low time pilots. Once you gain more skill then you can easily do what you are suggesting and not damage the nosewheel/ still land on the mains. So basically I’m saying, doing a power off stall just above the runway is a better way to initially teach landings in my opinion.
A second thing about the forward slip to landing. I agree with you that the slip to landing is unstabilized. In the modern day aircraft, we have flaps now, so there is no reason to slip the airplane. I feel as though, if you have to slip the airplane with flaps, then the approach is unstabilized, and you should do a go around. I feel as though a forward slip is only reserved for the emergency approach and landing to be able to use flaps and slip to put it down on a spot in an emergency situation.