blastoff

Due to swept-wing aerodynamics, slipping an airliner is universally a very bad idea. These guys ran out of options:
http://en.wikipedia.org/wiki/Gimli_Glider

wizepilot

I had a boss many years ago who was rated in the Lear. He told me (not sure if this was BS or not) that when they practiced getting down to altitude from a catastrophic decompression, this was way before simulators, Lear 20 series, that they pulled the power, rolled the airplane inverted, dropped the gear and out with the speed brakes. This way going into it inverted, as the nose came down, they would only pull positive G's. He told me this story once, but like I said, I did not know if he was pulling my chain.

UAL T38 Phlyer

The two prerequisites for a spin (in any airplane) are a stalled wing, and yaw. Doesn't matter if the yaw is "Forward-slip" or "Side-slip."

I found that previous training colored my perception (and made for pre-conceived notions) regarding aerobatics and post-stall maneuving. I started flying in General Aviation. Stalls were straight-ahead to 30 degree bank maneuvers, and slow. Spins were something entered from low-speed, low-power, and deliberate (with full-aft wheel and full rudder).

The resultant aircraft behavior was also pre-conceived: in stalls, a Cessna 150 would pitch down (classic stall-break). Spins would increase bank, and settle at about 20 degrees down. And, I believed that once stalled, an airplane could not be maneuvered, per-se. (In my mind, the recovery was mostly about the addition of POWER, and trying to figure out how to stop that horrible Cessna stall horn from going "bleeehhhhhhh!")

It wasn't until I did the very thorough aerobatic training in the Air Force that I realized: I could stall in any attitude, at any speed. Spins: any attitude, and a wide range of speeds. And airplanes (depending on type) could be maneuvered after the stall.

Example: while doing a loop, you can stall while going straight up, upside down at the top, or when going straight down. The resultant (temporary) aircraft motion differs, but the principles are the same.

Do a loop while going straight-up, pull on the stick until the airplane is stalled, and stomp the rudder: you just entered a spin while going straight-up. Horizontal plane? Snap-roll. These resultant maneuvers are temporary, and given enough time, would end in a familiar stabilized spin.

Back to the two prerequisites. In a spin, usually the inside wing is stalled, and the other is not (or "Less-stalled"). The difference in drag on the two wings (more drag on the stalled side) is what keeps the yaw stabilized.

In most GA aircraft, the recovery is to unload (reduce AOA) to "un-stall" the inside wing, and apply opposite yaw. When it stops spinning, recover from whatever attitude you are in.

In jet fighter-types, it may be a little different: apply full-aft stick to make both wings equally stalled. Rudder-yaw may or may not be available (usually not) as fighters have short tail moment-arms, usually have limited deflection available when the gear is up (to prevent overstress at high speed), and are often in disrupted air behind the spinning fuselage.

You should be able to yaw a GA airplane for photos without worry. Slip a little, and if losing airspeed or altitude, add power. If you are at the max allowable power, slip less.

Learn it at higher altitude until it is natural before trying it down low.

Cubdriver

Yep, did it extensively in a job I had flying GPS grids for photo work at low altitude. The grids often ran right into hillsides and we would skid to turn around quickly. I had a huge post worked up telling all the gory details, then the software lost my work before I could post it. Could not even use the back button to find it. The lesson is to make small posts apparently.

Some points:

• Skidding creates tons of drag. Your airplane will probably start a gradual descent even using full power.
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• When you skid under full power, the prop disc will undergo partial stall. This creates huge stresses on the prop and makes a loud noise. It probably is bad for the prop but in hundreds of operational hours doing this on 3 blade props, I never saw a failure or got a bad report from a mechanic. Your mileage may vary.
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• Full-bore skidding is hard on the flight controls. You will see rising maintenance costs for rigging work.
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• You are much safer in regard to spins than you would guess. The airplane will mush before spin most likely. My photo firm tested this extensively, and found that only a gross attempt to stall the airplane in a skidding configuration with full power using back elevator would produce a spin. It was a safe maneuver even at low altitudes done with care.

JamesNoBrakes

I've done slips all the time in 182s with full flaps, just pitch down more, in fact most people do not do this enough because they are trying to replicate their "normal" landing pitch while slipping, and they tend to get slow. I'll even go as far to say that most people should not land these with 40 degrees of flaps and they do not make an approach that is appropriate. Why are you going to follow the VASI at 40 degrees of flaps and 12" of MP? How does it make sense to power in at a high-AOA and high power seting during landing? How much extra power will you now have when you hit some wind shear or downdrafts? If you are going to use the 40 degrees you need to come in at an AOA and speed that are approrpiate (usually going to be pretty steep). This airplane is a drag-queen with 40 degrees, but you can still slip. Don't get slow, think about your descent rate and transitioning to normal landing later on. Never had it "pitch down" on me like you describe in any situation. Think about it, how would that be possible?

You can find a lot of crazy things stated by examiners, less by inspectors, and less depending on the experience, knowledge and ability of whomever you are talking to. Realize that examiners are kind of out there "on their own" by contract from the FAA. They sometimes have some pretty interesting/crazy ideas. Think about their reasoning and do some research.

JamesNoBrakes

Newer single engine cessnas only go to 30 degrees because it's way too hard to power out of a rejected landing with 40 degrees in certain conditions. I can fly that old C182 with 40 degrees at some pretty crazy slow speeds given it's weight and size, but with that much induced drag you just can't maintain altitude at all. With these aircraft there was also the issue of the flaps blanking out the tail when speeds decrease during landing, resulting in flat/hard landings as well. Limiting to 30 degrees helps with both. I don't believe it had anything to do with slips.

JamesNoBrakes

Hopefully with good instruction students won't have to wait until an experience like this to make this realization. When I do spin training I deliberatly pull up from the resultant dive fast enough that I'm getting some accelerated stall buffeting, to minimize building up load factors. I'm basically on the edge of a stall while pointing straight down. And then there's the accelerated stalls that can demonstrate the point IF you do them correctly (one IP taught to do them in a bank and simply get slow in the bank until you stall..great for not scaring people, um...poor to demonstrate the point that you can stall at any pitch attitude). You can even do these things with a cessna 150, although it helps to have an aerobat

UAL T38 Phlyer

Cub:

That's happened to me, too (when APC times-out on me while writing a lengthy diatribe, and I mis-type my name or password getting back in).

Solution (at least, what I have done):

Write your post in Word, then copy and paste.

2nd best pilot

"Example: while doing a loop, you can stall while going straight up, upside down at the top, or when going straight down. The resultant (temporary) aircraft motion differs, but the principles are the same.

Do a loop while going straight-up, pull on the stick until the airplane is stalled, and stomp the rudder: you just entered a spin while going straight-up. Horizontal plane? Snap-roll. These resultant maneuvers are temporary, and given enough time, would end in a familiar stabilized spin."

That's a very good point. I was meaning to point out, from a straight and level perspective, that "the slip" is relatively stable while "the skid" is not (in high wing stable airplanes). Once again the example is the falling leaf maneuver.

"Never had it "pitch down" on me like you describe in any situation. Think about it, how would that be possible? "

I actually have no idea. I'd lightly slip all the time with 40 degree flaps because it was a very tight runway. The nose down would usually happen if I applied full rudder and held it. Assuming a CG at its forward limit and airspeed constant.

Cubdriver

A REAL internet guru can read a thread, log on, work up a 1,000-word content-perfect post in 10 minutes or less, hit the little "send" button and be back to the ladies before the server even thinks about dumping their little discourse on the subject. That's the test of internet manhood. I'm getting old.