P-factor Effects can be very Serious

Got a call during dinner from our insurance company. One of our pilots and his entire family had burned to death that afternoon at the South Lake Tahoe airport.


I would learn that it was P-factor. Specifically, he had failed to compensate for it.

P-factor is no big deal. Just keep your wings level with ailerons and your nose from turning with your rudder. That’s all there is to it.

When you compensate for P-factor your airplane flies more efficiently and is much better behaved.

When you don’t compensate for P-factor, it’s still no big deal – except when it is. Most of the time it’s not. Most of the time pilots ignore P-factor and get away with it. That’s why it’s so insidious.

The problem is that we all learned to drive cars before we learned to fly. As a result, we steer – we control the direction our airplane points – with our steering wheel. But it isn’t a steering wheel; it’s an aileron control. That’s hard to remember… using the wheel to steer is pounded into our subconscious every day.

If your propeller turns clockwise – and most do – then P-factor (when it is present) turns you to the left. When the pilot starts to steer with his ailerons, he drops his right wing. It is slipping to the right with the same turning force that P-factor is trying to turn the plane to the left. The result: the airplane climbs straight but, unfortunately, it is also cross-controlled. The pilot is happy.

He shouldn’t be. The airplane is in a slip; it has greater drag; it climbs slower; it’s cross-controlled. Still no big deal. The pilot probably doesn’t notice anything wrong. Wait until we add in a few more factors and it becomes more than a big deal, it becomes fatal.

That summer afternoon in the Sierra Nevada Mountains of Northern California our doomed pilot had loaded his wife, kids and camping gear into a new Cessna 182 and filled the long-range fuel tanks.

The pilot was in a heavy airplane with a powerful – 235 HP – engine at a high airport.

Okay, here are the relevant facts:

  1. P-factor is near it’s maximum when the airspeed is low and the power is high.
  2. The greater the uncompensated P-factor, the more cross-controlled the airplane becomes.
  3. When a cross-controlled airplane stalls, it is far more likely to spin.

This poor fellow never had a chance. He had been flying an airplane with a small engine and without rudder pedals. – He had no choice but to develop very bad habits.

The instructor who signed him off to fly a C182 with just one hour of instruction should have been drawn and quartered! (Sorry – I let my emotions get the better of me when fellow instructors don’t take their jobs seriously.)

The plane was too heavy and the air too thin for him to clear the trees at the end of the runway while climbing is a cross-controlled condition. Rather than abort the landing and wait for the air to cool, he tried to force the airplane up over the trees, stalled, spun, crashed, burned and killed his entire family.

You really need to know exactly what causes P-factor because you need to know when to expect it and how to compensate for. So I’ll get into it, complete with diagrams, in a future post.

Remember: P-factor is no big deal if you compensate for it.

In my next blog, I get back to basics in How to Takeoff and Climb without Chasing the Airspeed Needle. Look for it.

If there is a subject you’d like discussed, please leave a comment or contact me directly.

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