Trhottle control?

Question

Does the throttle of a plane alone make it climb or nose up? Exclude VTOL planes.

Answer 1

Throttle controls engine which usually increases speed. (that part is simple)

Elevators control pitch (nose up down).

If you have enough speed pitch-up (stick back) will cause you to climb.

In *some* planes a pure increase in speed will cause the plane to climb (Cessna). In aerobatic planes and ACM planes a simple throttle advance will only make you go faster as their wing is semi-symmetrical (su-26, F16, T-28, SR-71, others). You have to change the angle of attack to increase lift and climb. A plane that is design to climb with an increase in speed makes it harder to manage as sometimes you want to cruise instead of climb.

Quick summary: It depends on the design of the particular plane and factors such as flaps, CG, ground effects, etc.

Answer 2

You've got some pretty good answers there already. This is a complex question with many variables, such as the type of plane, the wing geometry, angle of attack, center of gravity, flap/slat settings, airpseed, etc.

There are 4 forces acting on an aircraft in flight:

1. gravity
2. lift
3. thrust
4. drag

When an aircraft is in a constant speed, constant altitude flight, then gravity=lift and thrust=drag. Exactly. Changing any one of the variables will affect at least one of the other variables. Some people might say gravity is constant, but its not, because fuel is consumed in flight, and that makes the aircraft progressively lighter during a flight.

The engine(s) provides thrust, and the wings provide lift. When an aircraft is in a horizontal attitude (ie, clean configuration, no flaps, normal cruise power setting), adding throttle will make the plane go faster, and that indirectly causes the plane to climb because of increased lift due to Bernoulli's Principle. For a commercial jet flying at greater than about mach 0.60, adding more throttle will not increase the amount of lift, and that has to do with the wing shape - very complex aerodynamics that I won't get into here.

In a nose high position, such as on take-off or landing (with flaps and slats set), then increasing the throttle(s) will directly and indirectly cause the aircraft to climb because (1) part of the engine's thrust vector is downward and thereby creates lift, and (2) it creates more speed which makes the wings more efficient and that adds even more lift.

If you took an aircraft in level, constant speed flight and shut the engine(s) down, and didn't do anything else, then the aircraft would lose airspeed due to drag until the wings stall and you would very rapidly plummet to earth. So in that sense yes the throttle does affect the climb.

In the same line of thinking, if you pulled up the nose and didn't do anything else, the aircraft would also slow down until it stalled.

For a normal climb, the pilot would set the power, speed, and flap/slat settings as recommended by the flight manual depending on the speed, altitude and gross weight. So its a combination of engine thrust and wing lift that keep an aircraft airborne under normal flight conditions.

The results of adding throttle only depends on many variables, but clearly throttle is required for sustained flight.

Answer 3

Good question about air dynamics. The throttle control is only part of the story. Lift is caused by Air Flowing over the wing, which in turn causes a partial Vacuum. The pressure under the Wing becomes greater than the pressure on top, thus the wing is pushed upward. Increasing the Throttle will cause the plane to speed up, thus causing a greater air flow over the wing. and that would relate the Throttle to Lift. or Climb. Normally Climbing is caused by the position of the Elevator on the Tail of the plane.

Answer 4

Yes it does. The aircraft is trimmed for a specific angle of attack (which relates directly to airspeed in 1G flight). When the throttle is advanced the plane speeds up, produces more lift, and noses up until the speed decreases to roughly what it was before.

In reality, the aircraft will pitch too high, then pitch too low and so forth until it stabilizes. These are called phlugoid oscillations and are normally prevented by the pilot controlling the atitude of the aircraft with the elevators.

Aircraft with high mounted engines (like the Goose, Lake Amphibian, etc) will pitch down first due to the thrust being above the centre of gravity and drag, but they will eventually pick up speed and climb.

Answer 5

The mantra in ground school is "Attitude controls airspeed and power controls altitude." It actually does work that way in practice; when you cut power on final approach your sink rate DOES increase but you may have to compensate with a bit of nose down pitch to keep your airspeed on the numbers.

That all works fine until you strap on a military fighter. There's just so damn MUCH power available that you have to reverse your thinking to stay in one piece.

Answer 6

NO,aileron's do the work basically