DG Flugzeugbau LS4 - Installation of the Wing Water Ballast Bags

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
4-14
4.5.3 Installation of the wing water ballast bags
Dump valve version 1:
- Place bag with seam to leading edge, roll bag lengthwise and push into
root rib cutout, pull cautiously on intermediate rope.
- Grease the thread at the dump valve body with Vaseline to prevent
seizing of the thread due to water contamination.
- Use mounting tool 4F5-111 item 2 to pull the valve body into the
holder mounted inside the wing. The pins protruding out of the valve
body must be inserted into the notches of the holder.
- Screw on the cap nut by hand. Then tighten the cap nut using the valve
opener tool part no. 4F5-111 item 1. Don’t tighten too much.
Dump valve version 2:
- Place bag with seam to leading edge and valve discharge port 45° down-
ward to the trailing edge, roll bag and push into root rib cutout, pull
cautiously on intermediate rope.
- Screw brass nut from the outside through ballast dump port using water
valve key 4F05-82 to assemble valve.
- Reinstall large PVC-nut at root rib, tigthen nut only by hand.
Both versions:
- Pretension rope with about 100 N (45 lbs), place end knot as shown in
sketch in section 4.5.2. Fix rope end (about 0.5 m <20 in> long) at root
rib, do not cut off.
- Check adjustment of water valves as outlined in section 4.4.
- Fill bags according to instructions given in Flight Manual, check for
tightness, proper discharge function and discharge time.
- If discharge time exceeds 4.5 minutes, the bag may be twisted. If the
bag is not tight, water may drip from one of the drain holes.
Disassembly is required again to find and solve the problem in order to
clear the plane for flight!