Mailing List lml@lancaironline.net Message #54730
From: Colyn Case at earthlink <colyncase@earthlink.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: More on Ed Smith's accident
Date: Mon, 22 Mar 2010 11:59:44 -0400
To: <lml@lancaironline.net>

good point.
I did it for my airplane, which is very forward CG.
If I load it up to max weight, max rear CG that I can come up with, losing prop and oil puts me 3% out the back.
----- Original Message -----
From: Bill Wade
Sent: Monday, March 22, 2010 10:16 AM
Subject: [LML] Re: More on Ed Smith's accident

  I did some calculations- don't forget that the prop FELL OFF. That and the loss of oil changed the W&B immediately and dramatically.
 
  I don't know how the plane was loaded so I used W&B figures for a IV-P that Lancair had sent me and added guesses of my own for fuel and baggage:
 
                     Weight         Arm                Mom                 Station
 
Empty-          2377                               214876                  90.40
 
Pilot-               170             98                16660
 
Co-pilot-           170             98                16660
 
50 gal fuel         300            94.8              28440
 
25# backseat       25          129                  3225
_________________________________________________________
 
Total                3042                            279,861                91.99
 
So far so good. Now lose the prop.
 
Prop-                 78              9 (est)             702
 
Spinner                2              9                      18
 
Flange & bolts      2            12 (est)               24
 
8 qt oil               14             30 (est)             420
_____________________________________________
 
                         96                                  1,164
                       ____                               ______
 
Result:            2946                               278,697              94.6
 
I estimated the weight of the spinner and flange, the prop weight is Hartzell's value for a PHC-H3YF. I also made my best guess of the arms from Hartzell and TCM info. Oil is a guesstimate based on what I use in an IO-550. The CG limits for a IV-P are 86.5- 94.5.
 
  If the Smiths weighed more than 340# combined or if they had baggage in the rear the results would've been worse.
 
 Now imagine you're trying to fly a plane that's out of the envelope, has known stall issues, and keeps trying to raise its nose. All you could do would be to keep speed up to maintain elevator authority. In addition, the engine oil would have immediately pumped out of the crankshaft onto the windshield until the engine seized up.
 
  I hope I never have to try to match Ed's accomplishment. I don't know what the situation was on the beach but I think there was a combination of circumstances that led to the tragedy through nobody's fault.  -Bill Wade          
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