Maintenance Manual LS4
Issued: May 2011
Copyright DG Flugzeugbau GmbH - any copy or publishing prohibited
Manual valid with the up-to-date cover page only
4.6 Removal and installation of the tail fin water ballast tank (Option)
4.6.1 Tail fin water ballast tank removal
- Disconnect operating cable from cockpit distributor at position , see
sketch in section 4.4 and extend with approx. 6 m (20 ft) of thin nylon
cord
- Loosen clamp (or cut bonding) at right lower rudder cutout, holding
discharge tube, push stiff tube of approx. 7 to 8 mm (0.28 to 0.32 in)
outside diameter and 1.5 m (5 ft) length into discharge tube.
- Dismount 2 bolts holding upper tank end (and horizontal tail bracket), 8
mm thread, LN9037, width over flats 13 mm.
- Cut silicon rubber sealing at upper end cautiously with sharp knife.
- Pull tank upward and push auxiliary tube from lower end accordingly.
Remove tank from auxiliary tube and nylon cord , which must stay in the
tail fin for re-installation.
4.6.2 Tail fin water ballast tank installation:
- Before installation, check valve tightness using water, also tightness with
valve fully open, but discharge tube held closed. Total valve travel
between 7 and 9 mm (0.27 to 0.35 in). (In fully open position spring coils
are solid)
- Push auxiliary tube into discharge tube, cover joint with tape to avoid
edge catching at ribs or webs.
- Connect drive cable with auxiliary cord.
- Insert tank into vertical tail fin upper end, at the same time guide auxiliary
tube and pull carefully on cord from cockpit.
- Valve must be inserted into a cutout in the lower tail fin rib, use caution to
avoid valve damage.
- Seal upper tank edge with silicon rubber to surrounding structure.
- Mount 2 bolts holding upper tank end (and horizontal tail bracket), 8 mm
thread, LN 9037, width over flats 13 mm. When tank is combined with
battery box, these bolts also hold the battery box cover.
- Clamp end of discharge tube (or fix by bonding with hot-melt adhesive) in
right lower rudder cutout.
- Adjust valve operation according to section 4.4.
Operation Check:
a) Watertight with valve closed
b) Opening before wing system
c) Tightness during filling (back to front via funnel). With valve open, water
level in filling tube must remain constant.
To Next Page
Loading...