Slips and skidding turns

Velocity173 said:
I still don’t think he’s getting much, if any aerodynamic benefit from the skid. He’s not doing this skidded turn immediately after takeoff because he knows better. He’s building speed to probably 80 kts and throwing it into a skid when there’s no need to do that. Could’ve gotten the same if not better and safer result but flying a coordinated Vx early, then transitioning to Vy. Even with a steeper coordinated bank, while it might be adding drag and increasing stall speed, a skid is doing the same. Either way it’s a trade off but I think the altitude gained with Vx and slower airspeed in a coordinated turn will beat his technique every time.

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Yeah. I don’t disagree with any of that. I’ve flown out of this airport a few times and I give it a skid during the departure off RW02 The preferred departure is to turn left and fly over the river bed for noise abatement. Before going any farther, no, I will never let ‘noise abatement’ make me do anything I feel is unsafe. The reason I give a little extra rudder and skid it for a few seconds is to make the turn with less bank. I think it can be a little less intimidating to my passengers. Sitting right next to me there very close to the CG, they aren’t going to ‘feel’ the skid. But a think a steep bank at low altitude can be a little disconcerting to some. So I do it that way. I’m way above stall speed and if something starts happening, like the engine sputters or whatever, I can be out of the skid and coordinated in a fraction of a second.

EDIT: thought I was gettin a pic attached but doesn’t seem to be working. It’s 6K5, Sisters Eagle Airport
 
motoadve said:
Not clear of the term in English.
What I do is lower one wing and apply opposite rudder , enough amount so the airplane does not start to turn, to loose altitude without gaining speed.

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For the landing, that's exactly what the crew of the Gimli Glider did to lose altitude when they could no longer control the flaps in their Boeing 767. You're in good company. (I also use forward slips frequently in my PA-28, even together with flaps).

https://en.wikipedia.org/wiki/Gimli_Glider

I can't watch a video where I am, but other commenters are mentioning a skid on takeoff. If so, that's very dangerous. Outside of aerobatics or dogfighting, there's no legitimate reason for a skid, ever.
 
David Megginson said:
For the landing, that's exactly what the crew of the Gimli Glider did to lose altitude when they could no longer control the flaps in their Boeing 767. You're in good company. (I also use forward slips frequently in my PA-28, even together with flaps).

https://en.wikipedia.org/wiki/Gimli_Glider

I can't watch a video where I am, but other commenters are mentioning a skid on takeoff. If so, that's very dangerous. Outside of aerobatics or dogfighting, there's no legitimate reason for a skid, ever.
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It’s a C182 in the back country departing off of a gravel bar in a river. There are tall trees straight ahead and close. The river bends and he needs/wants to follow it. He needs to start the turn very soon after lifting off. He chooses to be in a skid with a shallow bank rather then staying coordinated with a steeper bank.
 
luvflyin said:
It’s a C182 in the back country departing off of a gravel bar in a river. There are tall trees straight ahead and close. The river bends and he needs/wants to follow it. He needs to start the turn very soon after lifting off. He chooses to be in a skid with a shallow bank rather then staying coordinated with a steeper bank.
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I think that's a bad idea—the skid gives the illusion of a quick turn because the nose moves, but it actually takes longer for the airplane's direction to change than it would with a coordinated turn, so it's only a comforting self-delusion. Lots of info on that in the old classic, Stick and Rudder.
 
David Megginson said:
I think that's a bad idea—the skid gives the illusion of a quick turn because the nose moves, but it actually takes longer for the airplane's direction to change than it would with a coordinated turn, so it's only a comforting self-delusion. Lots of info on that in the old classic, Stick and Rudder.
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Yeah. I don't think the goal is so much 'tightning' the turn as it is getting it done with less bank. @motoadve ????
 
luvflyin said:
Yeah. I don't think the goal is so much 'tightning' the turn as it is getting it done with less bank. @motoadve ????
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Less bank and keeping coordinated would get the turn done in the same or less distance. A skid is a useless risk and the airplane is NOT going where the nose is pointing. Someday he might find that out when he skids into the trees.
 
It's time to review some stuff. A lot of folks seem to want to skid to avoid too much bank. Afraid of stalling. The risk presented by the skid is greater than the risk of stalling, if we're that close to stall speed. Look at this:

uDeQ6g0DaBjpEIV__R2Efi7TaZWYQf8cEoVGwAaE7X9aX_waUiiM3Ybz5CRdfSMgYXfPTZ5n6U8Dsgty6VxDUyYrNgJHmQ6Q-d0GNIVY3fz0yUBJdd2n-h4LuUdJDIn5QDZMcS9s82A

In a 30° bank, your stall speed rises by the square root of the load factor, which at 30° is about 1.15, so the stall increases by about 7%. If your stall is, say, 55 MPH, the bank will increase it to a little less than 59 MPH. If you're that close to the stall in the climb, you're already an accident waiting to happen. If you're climbing at Vy, which would be around 75 or 80 MPH, stalling in a 30° bank is less likely than running into trouble in a skid.

But if you're one of those guys that likes to bank at the same time you're pulling up hard, you are combining two factors and could easily stall. Here's some more stuff:
serveimage


If you pull back and get a 2G loading, your stall speed is now 1.41 times normal, or 77 MPH. If you add that 30° bank, it compounds to get 82 MPH. If you do that spectacular 45° bank, your stall goes to 1.19 x 1.41 x 55 = 92 mph. This kills guys that buzz their friends and pull up hard while banking. The airplane enters a nasty accelerated stall, flips over into a spin and it's all over.
 
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Nevil Shute has a scene in one of his novels (from the late 1920s) where the narrator—a WWI vet who hadn't flown since 1918—takes a plane up, get scared that banking is dangerous, tries to turn with the rudder alone on approach, and spins in. The narrator (who survives, with serious injuries) excuses himself by saying that he hadn't been following advances in the understanding of flight since the war, and they had only a vague understanding of what caused spins back then.

Now, almost 100 years (and over 75 years after Langweische tried to stomp out the idea forever in Stick and Rudder), it seems there are still pilots who think it's safer to do "boat turns", trying to turn the plane using the rudder alone.

It isn't. Ever. Period.
 
David Megginson said:
Nevil Shute has a scene in one of his novels (from the late 1920s) where the narrator—a WWI vet who hadn't flown since 1918—takes a plane up, get scared that banking is dangerous, tries to turn with the rudder alone on approach, and spins in. The narrator (who survives, with serious injuries) excuses himself by saying that he hadn't been following advances in the understanding of flight since the war, and they had only a vague understanding of what caused spins back then.

Now, almost 100 years (and over 75 years after Langweische tried to stomp out the idea forever in Stick and Rudder), it seems there are still pilots who think it's safer to do "boat turns", trying to turn the plane using the rudder alone.

It isn't. Ever. Period.
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Even my 20’ boat banks into a turn, lol.
 
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