Timeline for Does lift equal weight in level flight?
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
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| Dec 14, 2018 at 3:15 | comment | added | AirCraft Lover | From this discussion, I got several very important things: 1). Most horizontal stabilizers generate negative lift, but some (e.g. the A380) generate positive lift. 2). If power is lost the airplane is in nose down attitude, which is safer, rather than nose up, which can lead to stall aka unsafe 3). The fuselage does produces lift. Thank you to all my friend here, especially @kevin and vasin1987. I do understand now why is recommended to put the fatter passenger in front seats and the slimmer in rear seats. We have to anticipate the worst, which to maintain the airplane still fly. | |
| Sep 25, 2017 at 13:46 | vote | accept | lemonincider | ||
| Jul 12, 2017 at 13:33 | comment | added | MSalters | @asawyer: Because of a nasty effect on stabilization. If the nose is up quite a bit, and the plane is flying slowly, the horizontal stabilizer may stall in the turbulent air behind the wing. With negative lift, the loss of negative lift helps to stabilize and level the plane. But if the horizontal stabilizer would have been providing positive lift, its loss would lead to the tail sinking even further, which might be unrecoverable. | |
| Jul 12, 2017 at 3:11 | comment | added | David | Ah, when you put it that way it makes perfect sense. | |
| Jul 12, 2017 at 2:20 | comment | added | vasin1987 | @David yes it would cause upward pitching moment. However when airplane losing speed, say engine out, the upward pitching moment would be lesser make airplane to pitch down and gain airspeed. | |
| Jul 12, 2017 at 1:39 | comment | added | David | @vasin1987 I'm confused by your comment... if the horizontal stabilizer produces negative lift i.e. a downward force on the tail, wouldn't that result in an upward pitching moment? | |
| Jul 11, 2017 at 19:26 | comment | added | kevin | @CodyP the latter. | |
| Jul 11, 2017 at 18:14 | comment | added | asawyer | @vasin1987 Ah that makes sense. Thank you! | |
| Jul 11, 2017 at 18:09 | comment | added | vasin1987 | @asawyer so that if power is lost the airplane is in nose down attitude, which is safer, rather than nose up, which can lead to stall aka unsafe. | |
| Jul 11, 2017 at 18:03 | comment | added | asawyer | "Most horizontal stabilizers generate negative lift" Why is that? | |
| Jul 11, 2017 at 16:12 | comment | added | RealAnswersNotAI | Can you clarify "Modern aircraft designs use software to take that [fuselage lift] into account." Do you mean the lift predictions in the flight control software use fuselage lift, or that modern aircraft shape and structural design includes calculations of fuselage lift? | |
| Jul 11, 2017 at 11:45 | history | answered | kevin | CC BY-SA 3.0 |