The FAA has conducted extensive research into the area of occupant safety and
occupant restraint in aircraft.  The Civil Aero-Medical Institute (CAMI) in
Oklahoma City is charged with  this responsibility.  Their findings and
recommendations are available to everyone in Advisory Circular AC21-34.  This
can be downloaded from the  www.faa.gov website.

To prevent spinal compression, and still provide the occupant with maximum
restraint, AC21-34 recommends a shoulder harness installation angle between
-5 degrees and +30 degrees.  It states: "the 30 degree elevation angle is the
maximum angle which will provide effective restraint by the shoulder belt."  
The rationale for this conclusion is provided in the Advisory Circular;  in
short, an excessive angle creates  excessive loads (on the airframe and
harness webbing), and permits excessive motion of the occupant (resulting in
head and neck injuries).

Now, back to the Legacy ........ take a moment to measure the angle of the
shoulder harness from the factory-installed hard points in your Legacy.  What
angle do you come up with?   On my Legacy, the angle is over 40 degrees.  
However, if the attach point is moved aft to just in front of the baggage
wall bulkhead, the angle is reduced to approximately 17 degrees which falls
well into the optimum range.

There are several other geometry considerations when installing seat belts
and shoulder harnesses.  AC21-34 is an excellent publication devoted to this
topic.

John Kleber
N83JK   LEG2/G