Piper Arrow IV Turbo Maintenance Manual page 48

STATION REFERENCE LINES.
In order to facilitate the location of various components of the airplane which require maintenance and
servicing, a method utilizing fuselage station (Sta.) wing station or buttock line (BL), and water line (WL)
designations is frequently employed in this manual. (Refer to Figure 6-3.) Fuselage stations, buttock and water
lines are reference points measured by inches in the vertical or horizontal direction from a given reference line
which indicates station locations of structural members of the airplane. Station O of the fuselage is 44.5 inches
ahead of the lower edge of the firewall; station O (BL) of the wing and stabilator is the centerline of the
airplane; and station O (WL) of the fuselage vertical stabilizer and rudder is 20.5 inches below the cabin floor
as measured at the rear wing spar with the airplane level.
PIPER AIRCRAFT
PA-28RT-201 / 201T
* MAINTENANCE MANUAL
THIS SPACE INTENTIONALLY LEFT BLANK
1B24
6-20-00
Page 6-07
December 1, 1978