. at the end of a 201ccooling off 201d period ( unless an agreement is reached , a peb is established or action is taken by congress ) , the labor organization may exercise 201cself-help , 201d such as a strike , and the airline may resort to its own 201cself-help , 201d including the imposition of any or all of its proposed amendments to the cba and the hiring of new employees to replace any striking workers