Linked Questions

52
votes
4answers
20k views

Why are the F/A-18 rudders deflected in opposing directions during takeoff?

Looking at some videos and photos of F/A-18 Hornets and Super Hornets taking off from carriers and from airfields, I recognised that the left rudder is pointing right, and the right rudder pointing ...
30
votes
2answers
143k views

What is the difference between centre of pressure, aerodynamic centre and neutral point?

I have just started learning some aerospace concepts, and I am not able to understand the difference between the three terms centre of pressure, aerodynamic centre and neutral point. What are their ...
11
votes
3answers
3k views

Does static longitudinal stability require download on the tail?

After having encountered this meme too often for comfort, I ask myself today in order to have the possibility to explain the issue in detail.
5
votes
4answers
2k views

Does the tailplane have a positive/negative camber?

I've read that the tailplane produces negative lift, so does that mean it would function like an inverted wing (has negative camber)? The image below is the best illustration I could come up with. ...
12
votes
2answers
1k views

Is the differential between the forward and aft CG limits indicative of the overall stability of an airplane?

Studying up on the Cessna 162 Skycatcher POH to take my checkride in soon and I noticed the differential between the maximum and minimum CG's is a mere 2.5 inches from one to another. I got curious ...
3
votes
3answers
2k views

Why can't Centre of pressure and Centre of Gravity coincide?

I understand that normally CG is placed ahead of COP so that a tail down force can make the aircraft stable. But why can't the COP and CG be placed in the same position so that there needn't be a tail ...
9
votes
3answers
829 views

Does cargo balance affect fuel efficiency in commercial aviation?

Positioning cargo such that the center of gravity of the plane is within a certain range is essential, but is there any advantage to having the center of gravity closer to some ideal point within the ...
8
votes
1answer
4k views

What is the aerodynamic centre and how does it relate to the pitching moment?

Okay so I have been trying to get my head around the Aerodynamic centre and the Pitching moment. Wikipedia really isn't helping much but from what I can gather the Pitching moment is a force caused by ...
4
votes
2answers
404 views

Why does not the lift produced by main wings create pitch moment?

Pitch moment is created by lift created by the horizontal stabilizers via the elevators. But then main wings also create lift, why does not this lift enough to create pitch moment?
2
votes
5answers
594 views

Why does instability in pitch lower trim drag for an aircraft with a tail?

I have a hard time figuring out why a longitudinally unstable aircraft has a lower trim drag. This seems to be a thing especially in fighter aircraft, so does it have to do anything with supersonic ...
4
votes
1answer
289 views

Does a tandem ultralight need flaps on the rear wing if the front wing has flaps?

Does a tandem ultralight need flaps on the rear wing if the front wing has flaps? I understand that most Rutan canards don't have flaps as I was told if the main wing has flaps, the canards need one ...
1
vote
2answers
249 views

Can the back tail of an airplane move the neutral point backwards?

I'm currently in the process of designing a prototype aircraft and since I don't have very much experience with this I have the following question: I know that the center of gravity of an airplane ...