Mailing List flyrotary@lancaironline.net Message #20530
From: Jarrett & Heidi Johnson <hjjohnson@sasktel.net>
Subject: Re: [FlyRotary] Motor Mount Loads??
Date: Tue, 19 Apr 2005 23:39:35 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Bill I just looked this up in Martini Hollman's book 'Modern Aircraft Design Vol.-1'  here's a direct quote from Pg 78. 
 
"During a normal landing touch down is on the two main wheels and a limit landing load factor for these wheels should be greater than 2.67 per 14CFR, Part 23. From my experiance, both shock and rigid mounted landing gears can be designed to a limit landing load factor of 3 to 5.5 depending on the size, shock system and landing speed of the a/c. We are allowed to subtract out a lift factor of 0.667."
 
Also you had asked if I'd done any checking on the motor mount depicted in some of my pictures. I did a quick and dirty check to see what happens w/ the basic load and wasn't quite satisfied so I upped some of the mat'l thicknesses and am re-running it as I write this. If you want, I'd be glad to pass on what info I have to you. { off list }
 
I haven't found any info on motor mount loads as of yet but will pass them on if I come across them. I just used 9g+ and 4.5- for mine w/ a small side load [ the first check] the second one is a bit more in depth w/ a torque load also.
 
Jarrett Johnson
----- Original Message -----
From: Bill Dube
Sent: Monday, April 18, 2005 9:18 AM
Subject: [FlyRotary] Motor Mount Loads??

When designing an engine mount, what loads should you design to?

Of course, the mount must withstand the ultimate loads of +9 g and -4.5 g, but what about gyroscopic loads imposed by the spinning engine and prop during abrupt maneuvers?

What landing gear loads would be prudent?

Thanks in advance,

Bill Dube'

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