Wesley Beard on Jan 06, I prefer to give out the lift equation to explain something like this. So if the air density decreases, either you need to have a higher angle of attack or your TAS must be increased. Since we know TAS increases with altitude anyway, it helps balance with the decrease in density altitude.
Angle of Attack also increases as the airplane goes higher in the atmosphere. This all assumes we have a constant indicated airspeed. Steve Pomroy on Jan 06, Hi Jane. The part in brackets, half the density times the speed squared, is the dynamic pressure. The dynamic pressure is what your airspeed indicator actually measures — even though it indicates speed.
The ASI is calibrated to indicate speed based on the assumption of standard sea level air density. If you are at sea level on a standard day, the ASI will indicate your airspeed accurately — in other words, your true airspeed and your indicated airspeed will be the same.
However, if you are at higher altitudes, the changed reduced air density will create a discpepancy between your indicated and true speeds. This true v. But your true stalling speed will be higher at higher altitudes. So after all of that, the short answer to your question is: Yes, true stalling speed is higher at higher altitudes, but No, indicated stalling speed does not change with altitude. Lift is not reduced at higher altitudes.
Lift has to balance your weight and load factor no matter what altitude you are at. So, at different altitudes, you produce the same amount of lift but under different conditions. So indicated and calibrated airspeed are the same thing. Low speed buffet and high speed buffet are more relevant at those altitude and must be understood by the pilots who are flying at max computed altitude where maneuver margin is very less ,thats why that region is known as coffin corner.
This region can easily be identified in EFIS aircraft. When you bank while maintaining altitude, your stall speed increases. It's something that you need to be aware of, especially when you're in the traffic pattern.
So why does stall speed increase when you start rolling left or right? When you're flying straight and level, the lift that your wings produce points straight up, opposing gravity. At this point, your lift vector is pointed to the left. And as you can see in the diagram above, you now have two components of lift: a vertical component, and a horizontal component. When you combine the two, you get a total or resultant lift vector.
The horizontal component of lift is what makes your airplane turn, and the vertical component is what makes your airplane maintain altitude.
Let's say you enter a 30 degree banked turn and you don't change the amount of lift your wing is producing. In the banked turn, some of the lift that was keeping your plane at altitude is now working to turn your plane, and you have less vertical component to maintain altitude. So how do you turn and maintain altitude? You need to increase the total amount of lift your wing is producing.
And to do that, you need to pull back on the yoke, which increases the angle-of-attack that your wing is flying at. This part is important, because when you increase your angle-of-attack, you get closer to critical angle of attack, which is the point when your wing stalls regardless of airspeed or attitude.
Load factor is measured in Gs. So if your load factor in a turn is 2 Gs, you feel twice as heavy as you really are and your arms want to flop down to your seat. The same goes for your airplane - it 'feels' twice as heavy. But what does load factor have to do with stall speed? News: To better serve our users and the aviation safety community, SKYbrary is transitioning to a new, more flexible platform mid-November , providing users with a better service and easier access to the wealth of safety knowledge it offers.
If you wish to access the latest content from the SKYbrary team, please visit and bookmark www. Stall is defined as a sudden reduction in the lift generated by an aerofoil when the critical angle of attack is reached or exceeded. A stall occurs when the angle of attack of an aerofoil exceeds the value which creates maximum lift as a consequence of airflow across it.
At the stall, the airflow across the upper cambered surface ceases to flow smoothly and in contact with the upper surface and becomes turbulent, thus greatly reducing lift and increasing drag. Changing the effective configuration of a wing by the deployment of leading edge or trailing edge devices will directly alter the angle of attack at which an aerofoil stalls. However, all this assumes a clean wing and for any aerofoil, contamination of the normally smooth surface by frozen deposits will result in a change to the angle of attack at which a stall will occur.
The Angle of Attack of an aerofoil — the incidence of the wing to the incident airflow - is not the same as the pitch attitude of the aircraft as displayed on the corresponding primary flight instrument and many aircraft do not have an instrument which displays angle of attack.
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