Investment Property Tax Deduction Scenerio

[Phil M.]

So, my parent's are going in on a multifamily investment property (Non owner occupied). Now, there will likely be vacancy for a few months they clean up the property and look for suitable tenants. Their only other income is a pension and social security. My question is: Will they be able to deduct losses against their other ordinary income? From what I understand the law is that you have to be considered a "Real Estate Professional" to be able to deduct against other income. But since they are both retired, and will be using considerable time towards this investment (Possibly 750 hours or more as required), would it be feasible to be considered Real Estate Professional and be able to make deductions (losses) against their other ordinary income (Pension and social security)? 

If not, are there any investment property deductions that they could make against their other ordinary income sources?