This wheel presentation is helpful for the detection of potential amphipathic helices

Helical wheel representation of a 15 amino acid long alpha-helix

Amphipathic helices have a polar and a non-polar side and this plays a crucial role in helix-helix interaction and in the interaction of small peptides that have a helical conformation with the interaction with membranes, air-water interfaces, and self-assembly processes.

Projecting a peptide in alpha-helical form onto a plane along the helix axis allows for the circular distribution of the amino acid side chain direction away from the center. If the first amino acid is hydrophobic, and then amino acid at positions 4, 5, 8, 11, 12 and 15 are hydrophobic and the rest hydrophilic, the helix obtains an amphipathic character, with the upper half of the helix being hydrophobic and the lower half being hydrophilic. The distribution of hydrophobic residues follows the loose rule that every 3rd and/or 4th residue is hydrophobic in nature.