Rotating labyrinth M-seal

A seal for a gas turbine engine, comprising:

• a plurality of lands;
• a barrel coupled to the lands and formed from a plurality of segments;
• and
• a plurality of knife edge seals coupled to the plurality of segments, the plurality of knife edge seals extending in a first radial direction so that at least one knife edge seal of the plurality of knife edge seals is disposed radially above at least one land of the plurality of lands,
• where the segments are coupled to one another such that the barrel is substantially non-linear,
• wherein a first of the plurality of segments and a second of the plurality of segments between the knife edge seals together form a ‘V’-shape, the ‘V’-shape extending in a second radial direction so that a peak of the ‘V’-shape is disposed radially below at least one land of the plurality of lands, and where the barrel is substantially ‘M’-shaped, and
• wherein the seal is configured to open on both of a first end and an opposing second end of the seal when the seal rotates.