I really appreciate that! You have really nice way to make it understand. If you would make it more deep on the lateral stability that could be perfect
Nice Video, Quite useful to refresh everything. I just have to comment on one thing: -At 13:00 you talk about dorsal and ventral fin. If I'm correct, the ventral fin would have a destabilizing effect as it is situated below the Center of Gravity. If it is submitted to the same lateral component of the flow, it would create a right rolling moment on your drawings. In fact, it is the opposite of the dorsal fin. Anyway, nice work and continue to share the knowledge with people!
+James HIREL-WEBSTER Thanks a lot.. I hope the following will clarify your comment. Now ventral fin can play two roles. The one I was talking about was directional stability. At high angle of attack, the relative airflow is blocked by the fuselage and in this case directional stability is enhanced by the ventral fin. The planes with high tail stabilizer are laterally very stable and have difficulty in rolling. In such cases, the ventral fins induces some lateral instability. So the words are directional and lateral stability, which are two different things altogether. I hope it is clear now, if not let me know. Thanks
Thanks. It was a mistake due to a low level of arousal maybe hehe. Thanks for clarifying though, and it might be useful to other RUclipsrs! Keep doing your work sir!
Depends on type of aircraft you fly actually. Small aircraft rudder helps Bigger aircraft rudder can aggravate spin because of the size unless you control it very well
21:44 you mentioned that with increase in wing area (flaps) rolling moment will decrease (because of reduced coefficient of roll=more stable laterally) ....then how flaps reduce lateral stability ....less stable means aircraft rolls easily right(less lateral stability)
Very useful thank you... 21:40 point 5... If flaps and anhedral reduce rolling moment, then there is less likelyhood the aircraft will roll - does that not mean it is more stable?
+Ali Baylav No but the other factors make it unstable so overall it is not all that stable. If you discuss on the basis of single points then anhedral and flaps reduce rolling moment. And Welcome! :)
+Ali Baylav Yes thats the reason on approach and landing, flaps and anhedral give a stabilized approach and giving a better laterally stabilized aeroplane which doesn't roll easily :)
you mentioned a point in the video , that if the forward cg limit is exceeded the aircraft will have a nose down pitching moment...so my question is ,if the cg moves more forward how can the aircraft have a nose down pitching moment??
+Dolridge Rumao CG is where your weight acts, if your aircraft CG is forward, your weight is forward and when your weight is forward your nose will go down. I hope that clarifies it.
Im still having a little bit of confusion 1) So when a question is asked regarding stability about the lateral axis, its talking about longitudinal stability and longitudinal stability is controlled by wing dihedral? but isn't it suppose to be the horizontal tailplane. 2) Longitudinal stability you said is mainly by the fin, wouldn't it be mainly the wing dihedral considering the first question 3) Lastly, So wing dihedral provides lateral stability? Meaning stability about the longitudinal axis is wing dihedral? I think when i see a question i get confused when they put such answer; Elevators, Alierons, Wing Dihedral, The fin, The Horizontal tail plane.
1) Longitudinal stability is with design and position of the tailplane. 2) Directional stability is by the fin. 3) Increasing dihedral gives increased lateral stability.
Lateral stability is simply to do with rolling moment. If you aircraft has the tendency to roll or have higher rolling moment then it is laterally less stable and vice versa.
can you tell me how the wing which is going down has higher angle of attack, during rolling with respect go wing having a dihedral? imagine for a positive sideslip and the aircraft is rolling to the left(due to swept back of wing) will it create stabilize or destabilize roll from dihedral perspective?
The wing going down will have higher effective increases in lift due to sideslip. Geometric dihedral always is a powerful contributer to lateral stability. A wing with dihedral will develop stable rolling moments with sideslip. If the relative wind comes from the side, the wing into the wind is subject to an increase in angle of attack and develops an increase in lift. This change in lift gives a rolling moment tending to raise the into-wind wing.
+Даниил Коломиец Alright you might be better at this but here are few points -> Flaps ALWAYS increase the camber. -> SOME Flaps increase both area and camber. -> Flaps NEVER decrease the area. The Fowler flap, which is the most commonly used flap in modern jets, gives an increase in area and camber. And hence using that equation which I explained at 21:15 clarifies the same. Hopefully this helped, if not kindly upload your video with the same :)
Lateral stability is about the roll axis. It is improved by various components of the aeroplane. A wing with geometric dihedral will develop stable rolling moments with sideslip. It contributes to stable roll due to sideslip. The contribution of sweepback to dihedral effect is important because of the nature of the contribution. If the wing is at a positive lift coefficient, the wing into the wind has less sweep and an increase in life and the wing out of the wind has more sweep and a decrease in life, a negative rolling moment will be generated, tending to roll the wings towards level. In this manner the swept back wing contributes a positive dihedral effect. The contribution of sweepback to dihedral effect is propotional to the wing lift coefficient as well as the angel of sweepback. Because high speed flight requires a large amount of sweepback, an excessively high dihedral effect will be present at low speeds (high CL). An aircraft with a swept back wing requires less geometric dihedral than a straight wing.
+Ganesh Tamatta Sweep is the angle of the wing wrt the fuselage of the aircraft. Slide of aircraft I'm wondering if you're talking about evacuation slides or something else. Kindly let me know in what reference.
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I'm studying for the FAA Airframe Certificate oral exam, and your videos really help me refresh my mind. Thank you!
+Carlos Peralta I'm glad it helped! My Pleasure! Stay tuned for more! :)
Brilliant summaries, just what I needed for my ATPL's. Cheers fella!
You're Welcome! Glad it helped, stay subscribed for more! :)
Thanks for saving my day, dude! Fantastic summaries.
I really appreciate that! You have really nice way to make it understand. If you would make it more deep on the lateral stability that could be perfect
Thanks for clearing the doubts related to stability over positive and negative👍👍👍
Welcome
Favourite teacher watched almost all your videos thank you
You're welcome!
Thank you very much Sir,all my doubts on Stability has gone
Nice Video, Quite useful to refresh everything. I just have to comment on one thing:
-At 13:00 you talk about dorsal and ventral fin. If I'm correct, the ventral fin would have a destabilizing effect as it is situated below the Center of Gravity. If it is submitted to the same lateral component of the flow, it would create a right rolling moment on your drawings. In fact, it is the opposite of the dorsal fin.
Anyway, nice work and continue to share the knowledge with people!
+James HIREL-WEBSTER Thanks a lot.. I hope the following will clarify your comment.
Now ventral fin can play two roles.
The one I was talking about was directional stability. At high angle of attack, the relative airflow is blocked by the fuselage and in this case directional stability is enhanced by the ventral fin.
The planes with high tail stabilizer are laterally very stable and have difficulty in rolling. In such cases, the ventral fins induces some lateral instability.
So the words are directional and lateral stability, which are two different things altogether. I hope it is clear now, if not let me know. Thanks
Thanks. It was a mistake due to a low level of arousal maybe hehe. Thanks for clarifying though, and it might be useful to other RUclipsrs! Keep doing your work sir!
+James HIREL-WEBSTER Your most welcome! Expect a few more videos in the coming month ;) Stay tuned. Cheers.
all keel surfaces increase directional stability.
ur doing great job to the aerospace students
what a great video, keep it up...
Thank you
I also wanted to know which one is the primary control for spin recovery? Is it rudder
Depends on type of aircraft you fly actually.
Small aircraft rudder helps
Bigger aircraft rudder can aggravate spin because of the size unless you control it very well
angle of attack in lateral case....is between wing chord and airflow, but u marked between something else
21:44 you mentioned that with increase in wing area (flaps) rolling moment will decrease (because of reduced coefficient of roll=more stable laterally) ....then how flaps reduce lateral stability ....less stable means aircraft rolls easily right(less lateral stability)
Flaps reduce lateral stability because the centre of lift of each wing will now be closer to the wing root reducing the moment arm.
Thank you Sir 👍👍☺️☺️
You're welcome
Very useful thank you... 21:40 point 5... If flaps and anhedral reduce rolling moment, then there is less likelyhood the aircraft will roll - does that not mean it is more stable?
+Ali Baylav No but the other factors make it unstable so overall it is not all that stable. If you discuss on the basis of single points then anhedral and flaps reduce rolling moment. And Welcome! :)
+Ali Baylav Yes thats the reason on approach and landing, flaps and anhedral give a stabilized approach and giving a better laterally stabilized aeroplane which doesn't roll easily :)
Does high wing have higher longitudinal stability than low wing?
More lateral stability for sure, doesn't roll easily.
Longitudinal stability is dependent on CG, so if the wing design is affecting CG then it does
Thank you so much!!
I also wanted to know which one is the primary control for spin recovery? Is it rudder
you mentioned a point in the video , that if the forward cg limit is exceeded the aircraft will have a nose down pitching moment...so my question is ,if the cg moves more forward how can the aircraft have a nose down pitching moment??
+Dolridge Rumao CG is where your weight acts, if your aircraft CG is forward, your weight is forward and when your weight is forward your nose will go down. I hope that clarifies it.
Im still having a little bit of confusion
1) So when a question is asked regarding stability about the lateral axis, its talking about longitudinal stability and longitudinal stability is controlled by wing dihedral? but isn't it suppose to be the horizontal tailplane.
2) Longitudinal stability you said is mainly by the fin, wouldn't it be mainly the wing dihedral considering the first question
3) Lastly, So wing dihedral provides lateral stability? Meaning stability about the longitudinal axis is wing dihedral?
I think when i see a question i get confused when they put such answer; Elevators, Alierons, Wing Dihedral, The fin, The Horizontal tail plane.
1) Longitudinal stability is with design and position of the tailplane.
2) Directional stability is by the fin.
3) Increasing dihedral gives increased lateral stability.
Thank you!
+Chabara Graham You're welcome!
Which wing gives more lateral stability bro...higher or mid or lower wing ....reply me quickly bro
High
@@poh thanks bro ..and another question.. which placement of wing gives minimum drag......please upload a video of wings
Co efficient of drag and co efficient of lift sign bro.. positive or negative...
How does low rolling moment reduce lateral stability????
Lateral stability is simply to do with rolling moment. If you aircraft has the tendency to roll or have higher rolling moment then it is laterally less stable and vice versa.
can you tell me how the wing which is going down has higher angle of attack, during rolling with respect go wing having a dihedral? imagine for a positive sideslip and the aircraft is rolling to the left(due to swept back of wing) will it create stabilize or destabilize roll from dihedral perspective?
The wing going down will have higher effective increases in lift due to sideslip. Geometric dihedral always is a powerful contributer to lateral stability. A wing with dihedral will develop stable rolling moments with sideslip. If the relative wind comes from the side, the wing into the wind is subject to an increase in angle of attack and develops an increase in lift. This change in lift gives a rolling moment tending to raise the into-wind wing.
@@poh thank you :)
I read stability chapter from EASA book 2846253 times but I didn't understand this shit at all . Thanks for video
+Cderfa Kdkdkda You're welcome :)
Can you please make video for longitudinal stability in deep concept to aircraft ...
+Ganesh Tamatta It'll be beyond my scope, engineering will be able to deal with it better.
how can dihedral be high wing aircraft
Why not? Infact Cessnas 152/172 etc have slight dihedrals only
Sir give MCQ also
Flaps not always reduce area of the wing
+Даниил Коломиец Flaps increase the area of the wing not decrease
+DGCA Technical and not always increase. Man, check your video
+Даниил Коломиец Alright you might be better at this but here are few points
-> Flaps ALWAYS increase the camber.
-> SOME Flaps increase both area and camber.
-> Flaps NEVER decrease the area.
The Fowler flap, which is the most commonly used flap in modern jets, gives an increase in area and camber. And hence using that equation which I explained at 21:15 clarifies the same.
Hopefully this helped, if not kindly upload your video with the same :)
how swept back wing helps in lateral stability?
Lateral stability is about the roll axis. It is improved by various components of the aeroplane. A wing with geometric dihedral will develop stable rolling moments with sideslip. It contributes to stable roll due to sideslip. The contribution of sweepback to dihedral effect is important because of the nature of the contribution. If the wing is at a positive lift coefficient, the wing into the wind has less sweep and an increase in life and the wing out of the wind has more sweep and a decrease in life, a negative rolling moment will be generated, tending to roll the wings towards level. In this manner the swept back wing contributes a positive dihedral effect. The contribution of sweepback to dihedral effect is propotional to the wing lift coefficient as well as the angel of sweepback. Because high speed flight requires a large amount of sweepback, an excessively high dihedral effect will be present at low speeds (high CL). An aircraft with a swept back wing requires less geometric dihedral than a straight wing.
And whts the different between sweep and Slide of aircraft ?
+Ganesh Tamatta Sweep is the angle of the wing wrt the fuselage of the aircraft. Slide of aircraft I'm wondering if you're talking about evacuation slides or something else. Kindly let me know in what reference.
anyone else that scream at around 38 second into the video?