slips

[Sky-Pidgeon]

When getting my private certificate i had several different instructors.. who had different opinions. One of the things we talked about were slips in the pattern. One of my instructors said never, ever make a slip while turning base or turning in general. According to him X controlled during a turn could lead to a spin.

However at the end of my check ride my instructor pulled power on downwind and said.. OK land the plane on the first half of ruwnay, do a slip on your base turn and you're a pilot.

What are your thoughts on this. When are slips a bad idea? If i recall i put in flaps prior to slipping.. is that a bad idea? Just curious.

 

[fgcason]

Always maintain flying speed. As long as you have flying speed, you can make the plane do what you want it to do.

If the wing doesn't stall, it won't spin. Don't stall at 400 agl whether you're cross controlled or not.

 

[poadeleted20]

My feeling is that if you have to do a slip in the base turn to make the runway, either you're landing in one of those "bottom of a coffee cup" airports or you're on fire or you screwed up the approach. In the first two cases, you do what you gotta do to get the plane on the ground safely. In the latter case, I recommend going around and trying it again so you can make a more stabilized approach and eliminate the unnecessary risk associated with any approach which must be salvaged by extraordinary techniques.

 

[jesse]

My feeling is that if you have to do a slip in the base turn to make the runway, either you're landing in one of those "bottom of a coffee cup" airports or you're on fire or you screwed up the approach. In the first two cases, you do what you gotta do to get the plane on the ground safely. In the latter case, I recommend going around and trying it again so you can make a more stabilized approach and eliminate the unnecessary risk associated with any approach which must be salvaged by extraordinary techniques.

Chances are if you've never tried it before you won't do it in an emergency. There is little risk with slipping through the pattern *just make damn sure you're slipping and not skidding* (hint...step on the sky in the turn). If you keep the nose below the horizon you'll be fine.

Practice all of this at altitude to learn your particular aircraft.

Spinning from a turning slip in a 172 or similar aircraft is incredibly difficult. It must stall, then roll the opposite direction, past wings level, and into the spin. It gives you plenty of time to react..and generally won't even happen.

Here is a video of me doing aggressive slipping turns while stalling the aircraft that I made several years ago:

 

[EdFred]

I suggest to go attempt turning slips at altitude (3000-5000'AGL) at a similar airspeed to see how hard it is to enter a spin. If you don't want to do it alone, find an instructor who will go up with you and let you experiment. It sounds like your instructor who said never ever ever was either 1) not very knowlegeable about slips, skids, spins, and stalls, and just parroted to you what was told to him by his not so knowledgeable instructor, or 2) didn't feel like trying to explain to you the nuances and differences sbout slips, skids, spins, and stalls, other than the hand wave coverage in the Jeppesen books. Either way he did you a disservice.

 

[RotorAndWing]

I use to slip the B727 when ATC brought us in too high on a visual approach. MCO Runway 18R in VFR they would hold you up until crossing Orlando Executive. Since on the '72 you can't deploy speed brakes with any flaps out a slip worked rather well.

 

[pmanton]

I'm not an instructor by any means. I do LOVE a left hand slipping turn to final. I like being high and slipping off my excess altitude on the turn to final. I'm high, so if the fan should quit, making the runway would be a non event. Left is my favorite because my plane is side by side. Yet I did this giving a buddy a lift and he squawked because the ball was out of the cage. I said "IT'S A SLIP". He wasn't convinced.

Cheers:

Paul
N1431A
2AZ1

 

[Capt. Geoffrey Thorpe]

When getting my private certificate i had several different instructors.. who had different opinions. One of the things we talked about were slips in the pattern. One of my instructors said never, ever make a slip while turning base or turning in general. According to him X controlled during a turn could lead to a spin.

However at the end of my check ride my instructor pulled power on downwind and said.. OK land the plane on the first half of ruwnay, do a slip on your base turn and you're a pilot.

What are your thoughts on this. When are slips a bad idea? If i recall i put in flaps prior to slipping.. is that a bad idea? Just curious.

What's the problem with slipping? So what if you are not flying in a straight line? What's the difference?

Cross controlled stalls can result in spins, turning or not.

 

[Sky-Pidgeon]

What's the problem with slipping? So what if you are not flying in a straight line? What's the difference?

Cross controlled stalls can result in spins, turning or not.

i mean a forward slip to lose altitude - . Not to crab the airplane. THanks for the help - its interesting to get different opinions. I felt like that particular instructor occasionally would say bull-****.

 

[PittsDriver]

Cross controlled stalls can result in spins, turning or not.

With the caveat that a skid is spin prone and a slip is pretty close to spin proof. I can hold a full stall, stick full back to the stop in a slip and never spin while I'm falling like a rock. The coloring book level of instruction that says "cross controlled stalls cause spins" leave this bit of aerodynamics out which causes the confusion of the OP.

 

[tonycondon]

slipping turns are part of the private PTS for glider pilots. the airbrakes on my glider suck so if i fly a normal airport style pattern i almost always use some sort of a slip on the approach

 

[Ted]

I've slipped the Aztec into LOM pretty well on final. I believe the response from the helicopter pilot was "Wow, I don't think I can lose altitude that fast."

Don't see a safety issue. Skidding turns in the pattern, yes, that's bad. Jesse's tip is a good one, and what I use to remind myself as it's easy to remember.

 

[dmccormack]

I slip just about every landing in the Chief cause it's fun (and I don't have flaps).

These older airplanes were designed to slip.

It also gives me great visibility out the open side window, as opposed to the old, somewhat wavy plexi windscreen (yeah, gotta replace it).

The big wings, barn door ailerons, and huge rudder make slips in this old taildragger a thing of beauty -- and downright fun.

Any CFI who says "don't ever slip in the pattern" will be up a certain creek when he/she tries to squeeze the can into a parking lot when the fan up front stops.

As others have said -- practice at altitude, get comfortable, then use it whenever you need it.

 

[Ted]

Any CFI who says "don't ever slip in the pattern" will be up a certain creek when he/she tries to squeeze the can into a parking lot when the fan up front stops.

And as R&W pointed out, even on a 727 there are occasions when it's useful.

I've used slips in a bunch of cases to lose altitude when, for whatever reason (typically traffic or helping ATC out) I end up high and fast. Light twins still do it fine, and apparently so do heavy triplets.

As others have said -- practice at altitude, get comfortable, then use it whenever you need it.

Yep!

 

[Capt. Geoffrey Thorpe]

With the caveat that a skid is spin prone and a slip is pretty close to spin proof. I can hold a full stall, stick full back to the stop in a slip and never spin while I'm falling like a rock. The coloring book level of instruction that says "cross controlled stalls cause spins" leave this bit of aerodynamics out which causes the confusion of the OP.

I guess what I was trying to point out was that it doesn't really make any difference if you ease up a bit on the rudder to let the aircraft turn... The OP's instructor seemed to be saying it was OK to slip down a straight line, but not in a turn.

 

[skidoo]

With the caveat that a skid is spin prone and a slip is pretty close to spin proof. I can hold a full stall, stick full back to the stop in a slip and never spin while I'm falling like a rock. The coloring book level of instruction that says "cross controlled stalls cause spins" leave this bit of aerodynamics out which causes the confusion of the OP.

Say you have full slip rudder and the bank to turn. Then you suddenly release full rudder. Does that temporarily turn into a skid until it stabilizes out?

 

[Skip Miller]

Say you have full slip rudder and the bank to turn. Then you suddenly release full rudder. Does that temporarily turn into a skid until it stabilizes out?

Of course. But unless your plane has a lot of rotational inertia in the yaw axis, the overshoot as your tail swings back to a neutral position and beyond will be small. She'll come right back to neutral. This is not going to cause a spin.

-Skip

 

[whifferdill]

Say you have full slip rudder and the bank to turn. Then you suddenly release full rudder. Does that temporarily turn into a skid until it stabilizes out?

Of course. But unless your plane has a lot of rotational inertia in the yaw axis, the overshoot as your tail swings back to a neutral position and beyond will be small. She'll come right back to neutral. This is not going to cause a spin.

No, you can't skid without adding opposite rudder compared to what you held while slipping. Simply releasing rudder will still leave you with a slight slip if you still have aileron in. Furthermore, there's no danger of spinning if you've released the rudder. I don't know of any airplane that will spin without using rudder. Much more dangerous in a slip would be to release the AILERON, without also reducing the aft stick and rudder. That WOULD turn into a skid and possibly a spin depending on your airspeed and amount of aft stick.

Many instructors harp on keeping the ball centered at all times (especially during stalls) so you don't spin. What seems to go unmentioned is that you'll only spin if the ball is off to the side as a result of USING (skidded) rudder, rather than due to LACK OF rudder.

I remember Rod Machado (of AOPA Pilot...if you're into that rag) getting some heat for what he wrote in one of his articles...to the effect that it's safer not using the rudder at all on the base-to-final turn than using it. I don't recall the article, and I doubt he was actually recommending this practice as good flying technique, but rather making the point that too much rudder (skidded) is a lot worse than too little (slipped).

I don't understand why anyone would say slips are a sign of a poorly-executed approach. How about slips are a great way to consistently put the airplane where you want, while reducing the likelihood of your having to add power to make it to your landing spot? Use all the tools available to you. I can't remember the last time I had to add power to clear trees/runway threshold in the Pitts. It's not due to awesome flying skills, it's due to the fact that the Pitts slips so well it's almost like cheating.

 

[dmccormack]

Many instructors harp on keeping the ball centered at all times (especially during stalls) so you don't spin. What seems to go unmentioned is that you'll only spin if the ball is off to the side as a result of USING (skidded) rudder, rather than due to LACK OF rudder.

EXCELLENT POINT!

I can't remember the last time I had to add power to clear trees/runway threshold in the Pitts. It's not due to awesome flying skills, it's due to the fact that the Pitts slips so well it's almost like cheating.

So true...

 

[Dan Thomas]

In a descending turn the inside wing is at a higher angle of attack than the outer wing, due to the difference in helix angles that the two wings describe. The stall is dependent on angle of attack, of course, so in a descending turn the inside will will stall first.

If we slip the airplane, the AOA on that inside wing decreases and reduces the difference in AOA between the two wings. As other posters have noted, spinning out of a slip is extremely difficult. A skid, on the other hand, increases the AOA on that inside wing and brings the possibility of a spin much too close. In Canada spin training is mandatory, and we teach spinning out of various maneuvers like skidding descending turns, full-power climbs and turns, and so on. You soon learn what to avoid, and a skidding turn is one of them.

Dan

 

[timwinters]

I recommend going around and trying it again so you can make a more stabilized approach and eliminate the unnecessary risk associated with any approach which must be salvaged by extraordinary techniques.

I really didn't know that anyone considered a slip in the pattern an "extraordinary technique". My primary instructor (a retired Vietnam era full bird colonel) made sure I was quite competent doing slips to landing before sending me off for my check ride and we did quite a bit of work on this before he even let me solo.

Opinion: Any primary instructor who doesn't make sure his/her student is fully comfortable with using a slip to loose altitude in the pattern is setting them up for failure. And in the pattern isn't a place where you really don't want to fail.

 

[dmccormack]

Opinion: Any primary instructor who doesn't make sure his/her student is fully comfortable with using a slip to loose altitude in the pattern is setting them up for failure. And in the pattern isn't a place where you really don't want to fail.

Most heartily concur.

The whole "stabilized approach" mantra can be taken too far. Sure, it may prep kids on their way to fly big iron, but the rest of us need to be able to use every tool at our disposal. A slip is not only a tool -- it's a required maneuver on the Private PTS (and comes in handy on the Comm power off 180 accuracy landing task).

 

[Doggtyred]

Chances are if you've never tried it before you won't do it in an emergency.


(and)

Practice all of this at altitude to learn your particular aircraft.

I'd do that all day every day in a Cessna.. You couldn't pay me to do it in a Mooney or a Tiger.

And as for emergencies... absolutely agree. You practice for them so that when you need to put out, you do it right.

 

[dmccormack]

I'd do that all day every day in a Cessna.. You couldn't pay me to do it in a Mooney or a Tiger.

Bonanzas (A36 and -35) slip well. The V-tail not as much. Plus, you're fighting against rudder-aileron bungie interconnect.

Still, no adverse aerodynamics in those airplanes.

What's the problem with Mooneys and Grummans?

 

[TMetzinger]

Mooneys slip well too.

 

[Ted]

I slipped the M20F I used to fly. Considering how slippery the plane was naturally (full flaps and gear down was about as much drag as the Aztec when clean), a slip was a good way to get you a little extra drag. No problems with that.

 

[Capt. Geoffrey Thorpe]

Most heartily concur.

The whole "stabilized approach" mantra can be taken too far. Sure, it may prep kids on their way to fly big iron, but the rest of us need to be able to use every tool at our disposal. A slip is not only a tool -- it's a required maneuver on the Private PTS (and comes in handy on the Comm power off 180 accuracy landing task).

Comes in handy when you run your 767 out of fuel and land on a drag strip as well.

 

[Ted]

Comes in handy when you run your 767 out of fuel and land on a drag strip as well.

That sure puts a damper on your day.

 

[Capt. Geoffrey Thorpe]

That sure puts a damper on your day.

Could have been worse without the slip.

 

[whifferdill]

I slipped the M20F I used to fly. Considering how slippery the plane was naturally (full flaps and gear down was about as much drag as the Aztec when clean), a slip was a good way to get you a little extra drag. No problems with that.

There's a CFI at the airport that I fly out of that saw me slipping the Pitts in and told me if you do that in a Mooney, "you'd die". Hmmm...

 

[EdFred]

There's a CFI at the airport that I fly out of that saw me slipping the Pitts in and told me if you do that in a Mooney, "you'd die". Hmmm...

Sounds like that's what needs to happen to the CFI so he quits propagating that myth.

 

[Ted]

There's a CFI at the airport that I fly out of that saw me slipping the Pitts in and told me if you do that in a Mooney, "you'd die". Hmmm...

I guess I'm invincible.

The Mooney slipped great. It was never an issue. Full flaps and gear. I didn't die, I had positive control at all times. I also kept the speed around 110 mph when I did it, so there was plenty of air going over the surfaces.

The biggest thing I would notice with the Mooney would be if you got it too slow on the back side of the power curve it would drop like a rock, and it wouldn't necessarily be easily perceptible until you got closer to the ground. I found it to be an enjoyable and docile airplane to fly, though.

 

[SkyHog]

There's a CFI at the airport that I fly out of that saw me slipping the Pitts in and told me if you do that in a Mooney, "you'd die". Hmmm...

Sounds about right for most Mooney drivers....

 

[tonycondon]

i believe that you haven't slipped until you do a full slip in an ASK-13 sailplane. I thought I was going to get thrown out the side of the canopy. wowser.