DG Flugzeugbau DG 202, Flight Manual

Page: 62 / 212

Manual Compass 46--MFK--1 BOHLI MAGNETTECHNIK AG
Edition 01.2007 Page 12 of 16
By turning the two lower adjustment screws (US), the N--S axis of the compass is now turned
to be exactly in line with the center line of the fuselage. For turning the scale to the right screw
(US) must be loosened and the left screw (US) tightened and vice--versa. After the sailplane
has been prepared in this manner, it is moved to a compass compensation spot which is ali-
gned to the magnetic pole. Levelling of the compass and, at the same time, compensation
(swinging) are then a simple matter.
Fig. 12
Assembly of cardan joint
hook in
move down
drill
secure with resin
Ø 2.5 -- 2.7 mm
First, with the wings held horizontally, the sailplane is aligned to face exactly towards magnetic
North. The fuselage pitch angle is not important here, as it only causes the indicator to move
along the N--S axis. Using the turning knob, the compass is now adjusted so that the N--axis
will cut centrally through the red marker dot. Slight tapping on the knob will eliminate friction
on the compass needle. This tapping must be done during the entire compensation procedure
(in flight, friction is automatically eliminated by the ever--present vertical and horizontal acce-
lerations). Now the bank indication scale is adjusted so that its 0--mark is exactly aligned with
the N--S axis.
The center point of this circle lies now exactly on the N--S axis of the scale. Now, the center
point must also be brought onto the E--W axis.
The plane is turned to face exactly towards magnetic West. In this position the pitch angle of
the fuselage is important. By unscrewing the upper screw (OS) and tightening the center
screw (ZS), or vice--versa, the W--axis is moved exactly above the red mark. In order to have
easier access to the screws, the compass may be banked to position 45
° “R”. The red mark
is then somewhere near the E--axis and the centering adjustment may be completed by using
this axis. Make sure to remove the screw--driver from the compass for every reading in order
to eliminated interference. When bringing the compass back to level, the red mark must now
be located exactly on the W--axis.