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Imtheking
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What is marginal stable airplane?
gutemine said:A wild guess is that you are facing a poor translation of the German term 'grenzstabil' which means on the border of beeing stable - which is typically when the lift of the wings are only matching the weight of the plane, or it could be the point of minimal speed or maximal upward pointing angle before stalling, etc.
Just a hint on such language problems - try to search the technical term in your local language Wikipedia. If it is what you are looking for you could be lucky and find the article already translated in the English Wiki with the correct technical wording instead of doing strange Google like translations.
But I could be completely wrong also ...
gutemine
Cyrus said:Why do you offer an answer if you don't know what you're talking about? Do you think this is helpful to the OP??
gutemine said:Because I looked at the only other post he had so far which was about the shallowest angle of glide in aircraft.
Asuming that both questions could be related and maybe caused by a translation problem ist not such a bad suggestion - as English is not my mother language either I have a little bit experience in this area. But as I already said - I could be totally wrong also.
OPs then can comment and then the answering is getting much easier.
gutemine
Imtheking said:I found the Stability Margin which is the "Distance between the Center of gravity and the Neutral point of airplae". But don't understand how this helps the stability...
gutemine said:Doubt is not a pleasant condition, but certainty is absurd.
— Voltaire
Cyrus said:I'm going to make it a point to use it in conversation to sound smart tomorrow, lol.
boneh3ad said:Every time I try to do this, I forget within about 30 minutes.
Cyrus said:Doubt is not a pleasant condition, but certainty is absurd.
— Voltaire
Danger said:Maybe I'm missing something here because I didn't start flying until 1975, but I have never heard of a "neutral point" in relation to an aeroplane.
dtango said:Of course you have! You just didn't know it. I'm sure you were taught about CG movement for an airplane and the need to be sure how far aft the CG may move- for instance as you add passengers and bags for a GA airplane.
CG moving aft of the neutral point means bad juju!
Danger said:Okay, yeah... I've never heard it called that, though.
mugaliens said:It's not. They're confusing it with the center of pressure. The neutral point and the center of pressure are very closely related, but they're not synonomous.
Cyrus said:No one's said anything about center of pressure here. I'm a bit confused about this post.
A marginal stable airplane is an aircraft that is designed to have a slight tendency to return to its original position after being disturbed, but is not completely stable on its own. This means that it requires constant input from the pilot to maintain its position and prevent it from deviating from its intended flight path.
The stability of an airplane is typically measured using the static margin, which is the distance between the center of gravity and the neutral point of the aircraft. A higher static margin indicates a more stable airplane, while a low or negative static margin indicates a less stable or even unstable aircraft.
The advantages of a marginal stable airplane include maneuverability and responsiveness to pilot input, making it suitable for aerobatic and military applications. However, the disadvantage is that it requires constant pilot attention and can be difficult to control in certain situations, such as during turbulence or when carrying heavy loads.
The stability of an airplane can be improved by adjusting the location of the center of gravity, adding stabilizing surfaces such as a vertical stabilizer or horizontal stabilizer, and using control surfaces such as ailerons, elevators, and rudder to maintain stability and control in flight.
Marginal stable airplanes are commonly used in aerobatic and military aircraft, as well as some types of gliders and experimental aircraft. They are also used in some commercial aircraft, particularly those designed for short takeoff and landing (STOL) operations. However, most modern commercial airliners are designed to be fully stable for the safety and comfort of passengers.