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Old 01-02-2012 | 07:29 AM
  #14  
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Cubdriver
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From: ATP, CFI etc.
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Originally Posted by UAL T38 Phlyer
...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.
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.
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