2016-04-08 : When Neglected Heirloom transforms, it remains attached to the creature it’s attached to. If the equipped creature transforms into a noncreature permanent, Neglected Heirloom will become unattached before it transforms into Ashmouth Blade.

2016-07-13 : For more information on double-faced cards, see the Shadows over Innistrad mechanics article (http://magic.wizards.com/en/articles/archive/feature/shadows-over-innistrad-mechanics).