23
votes
Accepted
Why do flying wires hum louder in a sideslip?
Here is one reason.
It once was common for suspension wires to be flattened rather than circular in cross-section, to reduce drag. those wires were then aligned with the airflow past the wing and ...
- 22.1k
18
votes
Accepted
Is it dangerous to do a skidding turn to lose altitude without increasing airspeed?
As Ron Beyer pointed out in a comment, your instructor was showing you a forward slip - a pretty standard maneuver for light aircraft.
A spin would involve full rudder and a stalled wing, which ...
- 6,989
15
votes
Accepted
Does slipping in turns allow higher climb rates?
Source: Wikipedia.
Origin of the theory
Klaus Holighaus, one of the famous glider pilots of the 70s, and himself a glider designer at Schempp-Hirth, is at the origin of a controversy when he ...
- 76.7k
9
votes
Accepted
Why does a turn and slip indicator matter?
The turn and slip instruments are combined for convenience and by convention more than anything else, slip is important whether you are in a turn or not. When you slip it means one wing is more ...
- 54.2k
9
votes
Why does elevator input move the turn coordinator ball in steep turns?
In a steep turn you are making power changes, pitch changes and also making constant corrections with aileron to hold the bank angle, without even realizing it. Once established in the turn some ...
- 134k
9
votes
Why should one not slip a Cessna 172 with flaps extended?
The basic problem is that sideslip induces a cross flow over the fuselage that can increase the local negative AOA and flow disruptions beyond that already caused by the turbulence and downwash being ...
- 134k
8
votes
Accepted
How is a sideslip maintained (aerodynamically)?
(Source)
Here's a representative image of the variation in lift coefficient with respect to angle of attack. The same airfoil is considered in a "clean" configuration, with a deflected flap, and ...
- 3,661
7
votes
What causes the ball to not be centered in a slip/skid?
It is the same thing that makes you slide sideways in your seat going around a corner in your car.
Or the same thing that would cause you to slide sideways the other way if you were driving straight ...
- 27.2k
7
votes
Do aircraft pitch down even at very low angles of attack (below 0°) in a strong sideslip?
As John K was alluding, AoA of -10 or -15 are not really practical and do not correspond to a powered dive like you think.
Even in a descent or a dive, most aircraft will have positive AoA.
You are ...
- 15.6k
6
votes
Accepted
How can using split throttles help when landing twins in crosswinds?
The use of asymmetric thrust when landing a twin in a crosswind effectively accomplishes the same thing that rudder input does. It induces a yawing moment about the aircraft’s vertical axis, the same ...
- 74.5k
6
votes
Is it dangerous to do a skidding turn to lose altitude without increasing airspeed?
I just want to go back to the OP's concern that rudder one way and aileron the other way is related to a spin - it's my understanding that this is a cross-controlled situation, and that is something ...
- 249
6
votes
Why should one not slip a Cessna 172 with flaps extended?
There could be several reasons for such recommendation, but specifically for C172, its POH explains it as follows (section 'Normal Landing'):
Steep slips with flap settings greater than 20° can ...
- 9,103
5
votes
Is it dangerous to do a skidding turn to lose altitude without increasing airspeed?
Slipping an aircraft is mostly perfectly safe. I say mostly because there are exceptions:
Some aircraft operator's manuals explicitly forbid slipping. This might be because of the general handling or ...
- 2,164
5
votes
How do uncoordinated turns (skid, slip) affect a helicopter's turn radius?
Given your assumptions about bank angle and airspeed and my assumption that coordinated turn is determined by acceleration inside aircraft pointing downward "perpendicular to the floor" (if you mean ...
- 2,766
5
votes
How does sideslip indicator react during crosswind?
1. Answer to original OP
In a stable airmass, the amount of sideslip/skid indication is irrespective of the wind strength and orientation; it is a function of the relative velocity of the airplane ...
- 11.1k
5
votes
Accepted
What does the balance ball actually indicate?
1. Preamble
The ball reacts to the body force (or acceleration), with the exact same working principle as a bubble level. In airplane frame, the force is expressed as:
$$Y+mg\cos{\theta}\sin{\phi}=m(...
- 11.1k
5
votes
Is drift and sideslip angle the same in the accompanied figure?
The answer to the title question is no, sideslip angle and drift angle are not the same thing. (in this figure, or any other...)
What the diagram shows is drift angle, and drift angle only. If you ...
- 27.2k
4
votes
Accepted
Finding Angle of Attack/Angle of Sideslip using East/North/Up Coordinates
What you've proposed is a reference frame translation of the aircraft velocity, so instead of the velocity referenced to East, North, and Up (ENU), it's referenced to the direction the aircraft is ...
- 6,803
4
votes
What is the relationship between the UH60 Blackhawk stabilator function lateral sideslip and pitch coupling?
The sideslip to pitch coupling is a result of the canted tail rotor and the asymmetry of the main rotor downwash. The tail rotor thrust pushes the tail to the right and upward (pitch down). The main ...
- 20.1k
4
votes
Which way (if at all) do the ailerons need to be deflected in a full-rudder sideslip in a Cessna 152 or 172?
Yes. If you apply full rudder with no aileron, you initially just get a flat skid, but then differential lift starts to have an effect and the inside wing drops because that wing has slowed down, the ...
- 134k
4
votes
In which direction will an aircraft drift after taking off in a crosswind?
The DPE is correct, the airplane will drift in the direction of the wind.
If you are piloting a boat across a river, and point the bow at the opposite side of the river with the rudder amidships then ...
- 54.2k
4
votes
What does the balance ball actually indicate?
When you see inclinometers placed at different locations like that it's for measuring level on the ground for fuel and center of gravity measurement or other leveling purposes.
The one on the ...
- 134k
4
votes
Viable to slip onto the center line?
I’m not totally sure how you’re orienting that, are you talking about aligning the aircraft up on final approach from a base leg, then doing a slip to final alignment on the runway CL for final ...
- 74.5k
4
votes
Accepted
What happens to tip vortices in a sideslip?
The following quote is from "Oblique Flying Wings: An Introduction and White Paper" from Desktop Aeronautics, Inc., available at https://www.desktop.aero/library/ofwwhitepaper.pdf.
2.2.2 ...
- 23k
4
votes
Accepted
Why does induced downwash vary across a wing in a sideslip?
This effect is really only substantial for swept wings.
Here is the lift distribution on an un-swept rectangular wing at 10deg AoA at 0 and 10 deg Beta.
Notice the general slight reduction in lift - ...
- 15.6k
3
votes
How can using split throttles help when landing twins in crosswinds?
In General Aviation light twins, when landing in heavy crosswinds,
what are some considerations to using asymmetric (or Split) throttles
to induce a sideslip, to align the fuselage with the ground ...
- 23k
3
votes
In which direction will an aircraft drift after taking off in a crosswind?
You drift downwind unless you turn into it. In a normal crosswind takeoff, say with the wind from the left, at rotation, you have left aileron to keep the left wing from lifting and right rudder to ...
- 134k
3
votes
Why does a turn and slip indicator matter?
The "slip" part of the Turn and Slip Indicator (T/S) measures the lateral (transverse) acceleration of the airplane. When the slip indicator is centered, the pilot and passengers will feel gravity ...
- 11.1k
3
votes
Is a high alpha sideslip possible and safe?
You would be risking your life. Cross controlled approaches should only be done well above stall speed and only after testing at a higher altitude. Increasing AOA will slow your plane down. If you ...
- 20.9k
3
votes
Is a high alpha sideslip possible and safe?
Let's assume that to first approximation, a given rudder deflection (say, full deflection) creates a given slip angle of the fuselage. So for a given rudder deflection, don't you generate a lot more ...
- 23k
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