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### An airplane has an engine that pushes its flight. What force pushes a glider to fly? [duplicate]

An airplane has an engine that pushes its flight. What force pushes a glider to fly? Is it gravity? I think the flight of a glider is driven by gravity, but some people disagree with me. They say ...
18k views

### Why do airplanes lift up their nose to climb?

Is it right that basically an airplane just needs to accelerate to climb? Greater velocity of an airplane leads to greater lift - and since its weight remains constant (or even decreases) - a greater ...
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### 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. ...
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### 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),...
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### How does an aircraft descend without its nose pointing down?

I have seen many cockpit videos of airplanes landing, and nearly none of them have their nose down for losing altitude. How does this happen? and how does an airplane, such as A320, descend without ...
3k views

### Can hang glider hover straight into wind and keep same position? [duplicate]

Isnt resultant force allways pointing slighlty backward at every wing,so why hang glider is not push downwind by the wind? From theory that cant be possible,so does wind somehow coming at him at ...
1k views

### What exactly happens when power is reduced in trimmed, straight and level flight?

I understand that trimming an aircraft at a particular airspeed e.g. 100kts will keep the aircraft flying at that airspeed (100kts) even if you were to e.g. Lower power. This is apparently ...
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### How can an airplane keep going forward if it has no thrust?

Every pilot is familiar with the basic model of aircraft forces: If lift is greater than weight, the plane climbs, if less, descends. If thrust is greater than drag, the plane accelerates, if less, ...
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### Is lift force less than weight during a descent?

In the above image lift is the same during a climb and during a descent. Is lift force not supposed to be less than weight during a descent? Secondly, does descending at an airspeed much lower than ...
2k views

### Are we changing the angle of attack by changing the pitch of an aircraft?

For example: if I pitch the airplane up, but also increase power and am able to maintain the same speed, then no, the AoA hasnâ€™t changed, although it may have varied in the transition between one ...
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### 'Gravitational' power vs. engine power

A glider gets the power it needs to fly from the decrease of gravitational potential energy associated to the descent. My question is: for the same weight $W$, airspeed $V$, and a prop efficiency of ...
636 views

### What is the purpose of the propeller?

The propeller generates thrust, but what is the purpose of thrust of propeller? Is it to help the aircraft move forward or to produce lift to rise up?
442 views

### How does retracting flaps help extend the glide of an aircraft?

As per the video from Smithsonian channel BA flight 38's captain retracted the flaps of the Boeing 777 by 5 degrees to extend glide, to travel further. Why?
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### How can I calculate the maximum range of an aircraft descending with power (not gliding)?

Let's assume I have an aircraft, for which the thrust is not enough to keep the altitude. So over time I will lose some altitude. But it will still go further then it would without having an engine (...
250 views

### Is an increase in induced drag always caused by an increase in the angle of attack?

In this video at 2:57 they increase the AoA to maintain lift, which normally also increases the drag. Now, imagine that we don't increase the AoA: the drag will not increase but we will not have ...
239 views

### When do the lift and drag vectors contribute a force component along a glider's path of travel as seen from the ground?

It is often said that the lift vector helps to propel a glider forwards. The lift vector has no component acting parallel to the glider's trajectory through the airmass, but in many cases the lift ...