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74 votes
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Does lift equal weight in a climb?

It depends on exactly how you define "lift" and "weight". You might say intuitively that lift is all the forces acting on the aircraft in the upward direction, like this: In this case, lift must ...
Phil Frost's user avatar
  • 1,073
41 votes
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Why is this plane struggling to gain altitude?

According to the video's information: EMB-721 Sertanejo heavy and insane takeoff in Carlos Prates This is "EMB-721 Sertanejo heavy and insane takeoff in Carlos Prates. Full fuel, 6 on board plus ...
PcMan's user avatar
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38 votes
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Can a plane bank without turning?

Yes it can. The steady-heading sideslip (SHSS) maneuver is used in flight testing to demonstrate static lateral/directional stability (similar maneuvers exist as sideslip approach in crosswind, or ...
JZYL's user avatar
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34 votes
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How do "tip jet" helicopters cancel the torque effect of the main rotor?

This is a basic physics question, involving Newton's third law of motion (For every action, there is an equal and opposite reaction.) When a centrally mounted engine applies force to turn the rotor, ...
jamesqf's user avatar
  • 2,577
33 votes

Flying upside down without feeling it

This sounds like a barrel roll. This is a corkscrew-like flight path in which the airplane rotates around an axis between its longitudinal and pitch axes by flying along a path which lies on the ...
Peter Kämpf's user avatar
32 votes

What is a skidding turn (vs slipping turn)?

The terms "slip" and "skid" refer to two different types of uncoordinated turn - neither has much to do with the elevator, instead both depend on what the rudder is doing: Skids In a skid you have ...
voretaq7's user avatar
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32 votes

Without wind, would a plane go straight if the pilot let go of the controls?

If the airplane is properly trimmed, the airmass is smooth, and the aircraft is inherently stable in its design, then yes - many airplanes are capable of flying straight with only very light and ...
Michael Hall's user avatar
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30 votes
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Does a sudden drop of the velocity of the headwind affect the airspeed by lowering it?

Your airspeed does not remain constant because of inertia: it takes more time for the airplane to adapt to the new relative wind, compared to the time it takes for the wind to change. Example One: ...
kevin's user avatar
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30 votes
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Why is the ball no longer centred in a multi-engine airplane with inoperable engine?

Asymmetric thrust means now you have more thrust on one side than the other. A yawing moment results. You want to balance this yawing moment in order to still fly straight. This means the airplane ...
Peter Kämpf's user avatar
29 votes
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Why do airplanes usually pitch nose-down in a stall?

You are quite close to the answer And indeed, if the wings stalled before the tailplane, I would expect the downforce produced by the tailplane to be dominant, and the nose to pitch even further up. ...
Sanchises's user avatar
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27 votes
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How do elevons work to roll a flying wing?

Good question! There's a bit of a misconception: when the elevon moves up, it actually decreases lift. It pushes air up which pushes the wing down. This explains the roll behaviour, but how does ...
Sanchises's user avatar
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27 votes
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Plane that always flies into the wind?

The short answer is no. All the glider feels is its flight relative to the air. What the ground is doing beneath it is not relevant, the wind could be blowing a hundred kilometers an hour and the ...
Guy Inchbald's user avatar
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27 votes
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Do airliners reduce their angle of attack to maintain lift = weight as fuel burns off during cruise?

Yes. As fuel is burned the airplane will want to climb, so the autopilot (which is flying the plane 99% of the time and will normally be in altitude hold mode once you're at your clearance Flight ...
John K's user avatar
  • 132k
25 votes

What does it mean when an aircraft is statically stable but dynamically unstable?

Static stability means that a deviation from a trimmed state produces forces which return the system to this trimmed state. If these forces produce an overshoot which increases over time, such that ...
Peter Kämpf's user avatar
25 votes
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Which Provides a Faster Turn - A Horizontal Turn or a Vertical Loop?

Bottom line: you need to keep the aircraft as close as possible to its "Corner Velocity", which is the highest point on its energy maneuverability diagram. (Note, all this comes from an ...
Charles Bretana's user avatar
24 votes
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Can a barrel roll really be executed at a constant 1G?

You are absolutely right, a load factor of greater than 1 is impossible to avoid in a proper barrel roll. The barrel part of its name comes from the spiral path the aircraft needs to perform in order ...
Peter Kämpf's user avatar
24 votes

Can gliding your plane save fuel?

This approach of using an engine is called pulse and glide. It generally works because each engine has an optimal power setting at which it converts fuel into power most efficiently. If the most ...
h22's user avatar
  • 12.1k
23 votes

Does lift equal weight in a climb?

In an aircraft that is climbing at a constant vertical velocity, the total of the upward-directed vertical forces is the same as the total of the downward-directed vertical forces. Were it not so, ...
xxavier's user avatar
  • 11.1k
23 votes

Can an encapsulated airfoil generate enough lift to lift the capsule?

Consider Newton’s third law - for any action there is an equal and opposite reaction. If the action is to lift the enclosure then what is the reaction? It has to be pushing against something. You ...
Frog's user avatar
  • 1,852
23 votes

Why a kite flying at 1000 feet in "figure-of-eight loops" serves to "multiply the pulling effect of the airflow" on the ship to which it is attached?

The giant kites mentioned aren't the quadrilateral kites kids fly. They are airfoil shaped parachutes with open noses that generate lift as they move through the air. Ram air pressure inflates them ...
Pilothead's user avatar
  • 20.2k
22 votes

Can we see evidence of "crabbing" when viewing contrails?

Yes, you can see evidence, but it isn't the angular misalignment you are picturing... The aircraft does not crab relative to the airmass, it crabs relative to the earth. So, you will never see the ...
21 votes

Can hang glider hover straight into wind and keep same position?

The ground is not flat, and indeed slightly angled. This is enough to "hover". Specifically, the ground slope should be equal or more than the max L/D ratio of the hang glider at the current ...
Sanchises's user avatar
  • 13.4k
21 votes

Why does a sudden tailwind/headwind change IAS?

Why that happens is due to the aircraft's inertia. Consider a fairly simple case: an aircraft is flying due north, straight & level, with a constant 100 knots of indicated airspeed (KIAS) and a 10 ...
Ralph J's user avatar
  • 51.8k
20 votes

Do airliners reduce their angle of attack to maintain lift = weight as fuel burns off during cruise?

It's almost always more economical to fly higher if you can. So, as an airliner burns off its fuel load, it will naturally want to climb higher, and the pilot will request clearance to do so in stages ...
niels nielsen's user avatar
20 votes

Terminology: is the "normal acceleration" (nz) considered to be 1 G, or 0, when an aircraft is at rest on the ground with fuselage horizontal?

At zero G, you're floating (Vomit Comet ride). At 1 G, you have normal weight. At 2 G's, you seem to weigh twice as much as usual (60 degree banked turn). The normal aviation convention is that 1 G is ...
Ralph J's user avatar
  • 51.8k
19 votes

How can an aircraft turn if the horizontal force component is zero?

It is easier if we look only at the forces experienced by the aircraft, and in an inertial frame of reference In this revised diagram, the vertical component of the lift balances the weight, which is ...
ProfDFrancis's user avatar
19 votes
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What does it mean when an aircraft is statically stable but dynamically unstable?

If an aircraft is statically stable, it will always return to equilibrium after a disturbance. But what happens after can either show instability or stability. This is where the dynamic stability ...
Anas Maaz's user avatar
  • 1,963
18 votes

Can we see evidence of "crabbing" when viewing contrails?

Crabbing is the misalignment of the aircraft's longitudinal axis with the direction of travel over ground, caused by crosswind. The crabbing cannot be seen by looking at the angle at which the ...
DeltaLima's user avatar
  • 83.5k
17 votes

Can a plane bank without turning?

Yes, it's entirely possible. You can use the rudder to oppose the turn induced by the roll, and thus fly straight. However, doing so means that your nose is pointed off at an angle from your direction ...
HiddenWindshield's user avatar
17 votes

Can gliding your plane save fuel?

Here is one thing that WILL save fuel-- where possible-- such as when flying VFR. Note that this strategy only applies within the layer where thermal convection or orographic uplift are significant, ...
quiet flyer's user avatar
  • 22.7k

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