But from everlasting to everlasting the LORD's love is with those who fear him and his righteousness with their children's children . . . Psalm 103:17

Sunday, May 13, 2012

CFI Checkride and Autorotations

Practicing a "power recovery" autorotation.
I (Gavin) have my checkride for my helicopter Certified Flight Instructor rating on Wednesday this week. I will be driving up to Louisburg, NC on Tuesday and will fly with the Flight Examiner on Wednesday morning after practicing some full-down autorotations (emergency engine failures to a landing) with another instructor.

If you think of it, please pray for safe travel to Louisburg,  good weather, good preparation for the test, and a good transition into an unfamiliar aircraft.  There are many different things that I can be tested on during the oral exam and during the flight exam.  It is hard to know what exactly to focus my studies on in the last few days in order to be best prepared, but the Lord knows.

Another autorotation recovery

Autorotations?  

For those of you who are interested, read on.  This has nothing to do with pregnancy, quintuplets, or waist girth . . . .

Yes, helicopters can and do "glide."  If the engine fails, that does not necessarily mean it's all over and you are going to crash.  Just as in an airplane, pilots need to be trained how to correctly respond with the flight controls when an engine failure occurs.

In a helicopter, a pilot must react quickly if the engine fails.  If he does, the helicopter is fully controllable, but will be descending much quicker than an airplane.  The rotor blades, instead of being driven by the engine, are being driven by the air that is flowing upward through the blades as the helicopter descends.  This aerodynamic phenomenon is called autorotation.  If the pilot is able to conserve the energy that is in the spinning rotor blades all the way to the ground, that inertia can then be used as the helicopter approaches the ground to slow the descent rate and forward speed.  This will allow the helicopter be lowered to the ground before the blades slow down to the point where they can no longer support the helicopter.

That's one of the things we practice repeatedly in training.  We do not shut the engine down, but just roll off the throttle so that the engine is no longer driving the rotor blades.  Typically we only do an autorotation to a "power recovery," which means we practice the maneuver down to the point where we are a few feet off the ground, but then we roll the engine power back on.  We never actually touch the ground during the maneuver.  It still teaches the pilot the necessary aspects of safely landing a helicopter after an engine failure, but removes on of the potentially dangerous portions of the autorotation- the actual touchdown.

The reasoning is this.  Statistically, more accidents have happened due to practicing autorotations to the ground than from actual engine failures.  Therefore we usually just practice the power recovery autorotation.

In order to be a helicopter flight instructor, we need to be proficient in full-touchdown autorotations, so that is part of the test that I will be taking on Wednesday.  We don't practice that maneuver in our organization's helicopter due to insurance reasons, so that's why I'll be going to another location for the test.  I'll do some training initially with a regular instructor, practicing the full-touchdown autos, then will take the test with the actual examiner.

Thanks for your prayers!

Gavin

2 comments:

  1. Well, you just gave Thor to tell all of his crashing helicopter stories from the Marine Corps. Scary!

    ReplyDelete
  2. But he walked away alive?! Or was he not in the helicopters? I think of Black Hawk Down . . . Glad Cousin Thor is safe at home nowadays! Love to you all.

    ReplyDelete

Gavin, Carrie, Isaac, Will, David, Marcie, Seth, & Grace Jones

Gavin, Carrie, Isaac, Will, David, Marcie, Seth, & Grace Jones