Linked Questions

0 votes
1 answer
3k views

How comes lift is less than weight on take-off? [duplicate]

If $$lift=weight * cos(angle)$$ this means that lift is less than weight during takeoff. Could someone please explain me why it is so
VISHAL's user avatar
  • 21
0 votes
1 answer
537 views

Can an airplane lift off the ground when lift is equal to weight? [duplicate]

Can a plane lift off the ground at the point when there is the same amount of lift as weight? Or does lift have to be greater?
tainehu's user avatar
  • 197
25 votes
9 answers
28k views

Does lift equal weight in a climb?

This subject keeps coming up in the discussions and questions such as this one, which asks if lift equals weight in level flight. Good answers there, pointing out that upwards force has many sources. ...
Koyovis's user avatar
  • 61.8k
32 votes
9 answers
9k views

Is excess lift or excess power needed for a climb?

As answered in this question, aircraft need excess power - not excess lift - to climb. This is plausible when the aircraft's thrust vector has a vertical component (its nose and engine points upwards),...
Chris's user avatar
  • 983
18 votes
4 answers
4k views

Do any airplane designs exist that don't involve a flight surface that provides downforce?

Most aircraft maintain longitudinal stability by balancing three forces: The down force acting through the center of gravity (CG) The lifting force acting through the center of lift The down force ...
ryan1618's user avatar
  • 14.9k
8 votes
6 answers
9k views

Does lift equal weight in level flight?

Does lift equal weight in level flight? Or does it equal weight + down pressure on the tail? Added) Let's say the total weight of the aircraft on the ground was 100,000 lbs, and when it took off and ...
lemonincider's user avatar
  • 7,565
6 votes
4 answers
4k views

How can lift be less than thrust that is less than weight? [duplicate]

Physics in schools teaches two contradictory and mutually exclusive things: That the upward lift force on an airplane in flight equal its weight (Lift = Weight = Mass x Gravity). This is based on ...
Nick's user avatar
  • 77
14 votes
4 answers
28k views

How do planes descend for landing?

I fly occasionally on a pretty short route on a turboprop (DHC-8). When the airplane descends for landing, I can look through the window and see the ground below getting closer over time. However I ...
Jacek Prucia's user avatar
7 votes
3 answers
3k views

What is the relationship between power and fuel efficiency?

We were having a discussion in our ground school that power will make the plane ascend or descend and that you use the stick for speed, forward for higher speed and back for slower speed. So does that ...
yankeemike's user avatar
7 votes
5 answers
3k views

Under what conditions do airplanes stall? [duplicate]

I've seen somewhat conflicting information on when planes stall. I've seen references to "stall speed," apparently a speed below which the airplane will stall, but stalling also seems to be ...
Someone's user avatar
  • 7,097
15 votes
3 answers
2k views

Is trimming for constant speed equal to trimming for constant angle of attack?

My understanding of trim: When you say you have trimmed an aircraft for a constant speed, say 100 mph, you are actually trimming the horizontal stabilizer so that there are no forces on stick (or tail ...
user2927392's user avatar
  • 2,359
19 votes
1 answer
3k views

How frequent is the use of spoilers during descent?

Having flown a number of flights as a passenger recently, I observed that: Roughly 50% of pilots used spoilers above FL180 Almost everybody used spoilers to pass the 10,000 feet / 250 knots mark ...
kevin's user avatar
  • 39.8k
17 votes
4 answers
2k views

Why do planes not fly "backwards" (up from the planes POV) when in a vertical climb?

As suggested by a user in this question, I'd like to ask this question: One of the most basic aerobatic maneuvers is a vertical climb. This can be achieved by just pitching up to what appears to be ...
Maverick283's user avatar
  • 3,941
8 votes
3 answers
3k views

Does an accelerating airplane also start climbing?

Assume that an airplane is flying level. If I understood correctly in this situations there are four forces acting on it: weight, thrust, drag and lift. Lift depends on air density, airspeed, wing ...
MLeal's user avatar
  • 81
4 votes
5 answers
2k views

Is there any part of a flight where the pilot would pitch down?

Would the pilot ever pitch down (even slightly) during a flight, or would he/she simply reduce power to reduce altitude? This question is not similar to Why do airplanes lift up their nose to climb? (...
Madhav Sudarshan's user avatar
7 votes
3 answers
4k views

Is there always a stall if you exceed a specific angle of attack?

So lets consider that the stall angle (=Cl max) of a B747 is at 16° (in clean configuration). Does this mean, that, at whatever speed you are flying (i.e. 500 knots), you would stall if you go on a ...
John Jordan's user avatar
3 votes
3 answers
2k views

Does adding high thrust prevent a plane from stalling?

I am convinced that fighter jets (every flying object) do stall. So from quora, Why don't fighter jets stall? But most of the fighters have thrust:Weight ratio > 1 which means that they are not ...
Auberron's user avatar
  • 1,567
5 votes
3 answers
1k views

What does the pressure distribution over a glider's wing look like?

Can someone explain the design of glider wing airfoils and the subsequent pressure distribution over them? I hypothesize that: The pressure distribution should form a resultant force in the forward, ...
Guha.Gubin's user avatar
3 votes
6 answers
2k views

What produces thrust along the line of flight in a glider?

After reviewing discussions and vector diagrams of gliders in flight, the vertical lift component and the vertical drag components seem to produce a steady state, 0 acceleration balance with gravity. ...
Robert DiGiovanni's user avatar
1 vote
2 answers
4k views

What happens at the wings when the yoke is pulled backwards?

What happens at the wings and vertical stabilizers when the yoke is pulled backwards or forward on typical airliners like the Boeing 747-800. Is it any different for smaller similarly shaped aircraft ...
securitydude5's user avatar
3 votes
4 answers
583 views

Can a plane still climb even if it has exceeded the critical AoA?

According to this answer here, an airplane requires less lift for a climb than horizontal flight because the thrust of the engines will point up. Now if the wing was in a stall condition, could the ...
Aviation Enthusiast's user avatar
6 votes
1 answer
455 views

Can this vane prevent/delay wing stall?

Given that a stall results from the airflow over the top of the wing separating from the wing at high angles of attack, would it be possible to prevent, or at least ameliorate, a stall by deflecting ...
Vikki's user avatar
  • 28.4k
4 votes
1 answer
625 views

Is all the extra lift from flaps added upstream where the spars sit?

Flaps can significantly increase the lift for a wing, is all that extra lift added upstream where the spars sit? I ask this question because the flaps in airliners seem to be only connected by a few ...
Mridul's user avatar
  • 1,222
2 votes
1 answer
3k views

How does angle of attack vary during climbing flight?

I'm a little confused by the angle of attack of an aircraft during climbing flight. Suppose you have an aircraft in level flight which then rotates to some angle x. Just after rotation, I would assume ...
imveryconfused's user avatar
1 vote
3 answers
656 views

Can plane climb without increase pitch angle?

As I know plane climb "with nose up", but can plane climb without change pitch angle? Can I force plane to climb like this: If I fly in straight level flight at 100km/h and now increase ...
user avatar
3 votes
1 answer
1k views

How to calculate the lift starting from the vertical speed?

Is it possible to calculate the lift of an aircraft knowing its speed (IAS,TAS and GS), its vertical speed, its altitude and its weight? Because if we look at the force of an aircraft in flight: the ...
Afe's user avatar
  • 1,501
3 votes
1 answer
895 views

Does angle of attack change in a sustained climb?

I saw this question on a closed Facebook group, generating wildly differing answers. So I thought I would ask it here. You're in a C172 flying straight and level at 5000 feet and 100 knots IAS. You ...
Ben's user avatar
  • 14.6k
0 votes
1 answer
1k views

What are the opimum values of Cl during descent?

Statistical Analysis of A320 aircraft shows the Cl values to be as under: cl_value. L is assumed to be 0.5*MaximumLandingWeight of A320 as the Aircraft is about to land. The Units used are: Flight ...
Nooradila Noordin's user avatar
0 votes
1 answer
260 views

Zenith-Add horsepower, NASA-add drag: to create lift. How is this possible?

Available horsepower and adding drag to an airplane both create extra lift? How is that possible? Available Horsepower According to the Zenith, available horsepower not used to overcome form drag ...
Fred's user avatar
  • 1,415
-2 votes
3 answers
259 views

Can one trim same AOA at a higher airspeed to climb? [closed]

There has been some discussion in recent questions regarding climbing technique and optimization of the Lift vector (and the resultant vertical Lift vector). Some writers claim the lift vector must ...
Robert DiGiovanni's user avatar

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