Can Somone Explain The Local 109 Seniority System In The CBA? Will  

It will be based on the agreed negotiations between Local 109, current members, AMC, and the Check Airmen. They may get DOH, modified DOH, stapled to the bottom of the list, any or all.  Keep in mind those who are currently on the seniority list may not be happy to loose seniority by having CA placed above them. 

Here is my weird example. Hired as a base pilot in 2014 and placed on the seniority list. Base closed in 2016. Left the company for 5 months. Rehired as a relief pilot. Company seniority was 2014 hire date. Bidding seniority for union positions was original hire date plus 5 months. So I lost the 5 months I was gone. That's fair. Then after 2 years as a relief pilot I became a per diem part time pilot. Non union position. Did that for a year. Finally left the company for good.  So I spent 5 years with the company but my union time was only 3.5 years. Make sense? No really