Mailing List lml@lancaironline.net Message #43335
From: <Sky2high@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: What causes stall/spin -- Why do so many engines quit?
Date: Fri, 03 Aug 2007 21:22:29 -0400
To: <lml@lancaironline.net>
In a message dated 8/3/2007 5:56:45 P.M. Central Daylight Time, j.hafen@comcast.net writes:
I agree that if an engine quits, either a recip or turbine, you need to be
all over both the AOA AND airspeed to get the craft safely (hopefully) to
the ground, and survive.  A guy needs to resist his normal tendencies of
"level flight" since he is now without power and is flying a glider, that
doesn't "glide" like a glider. So the first thing he should do is push the
nose down (against his instincts) to maintain airspeed -- which is hugely
counterintuitive to those of us with powered flight time versus glider time.
But that is what you have to do if you lose power.  You can either approach
the ground under control and with speed, or without speed and out of
control.  No argument there.

If engines didn't quit, you wouldn't have to worry about "technique" (the
academic argument of maintaining proper airspeed versus proper AOA) in an
emergency power off descent.

So my question is, why do so many engines quit?
John,
 
You forgot the second immediate thing you must do if you have a CS prop - pull it to coarse pitch - the difference in sink rate at best glide is incredible. 
 
If you have your wits about you, during a test flight, go ahead and reduce power to zero thrust (close to idle) and establish best glide speed while the prop is in cruise pitch.  Check the VSI.  Then, pull the prop back to coarse pitch (feather if you can) and maintain best glide.  Check the VSI again.  Report back here as to the Lancair type and the difference in descent rates -- go ahead if you dare.
 
Forget the reasons an engine quits and know what to do if it does.
 
I can't relate what to do if it seizes as that is hard to simulate.
 
Scott Krueger AKA Grayhawk
LNC2 N92EX IO 320 SB 89/96

One thing for sure is that you are going down.  How that proceeds is important.




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