Which way each tube points and where it sits. Tap a tube to highlight it; tick the boxes as you hang + test. ← cut planner
Two checks per tube — both = done: hung connected & tested
The rule: every brain output feeds a zig-zag chain of 3 tubes (two 2-tube chains mid-Main-lobe). In a chain: 1st & 3rd tube point ↑ AWAY from the feed side, 2nd points ↓ BACK. At chain boundaries two neighbouring tubes point the SAME way — that is correct, don't flip them. ⌂ marks the feed end (cable from the case).