My 52 year-old husband owns a rental property. Sell? When?

My husband owns a house we rent. The tenants are great, but my husband is taking a cash flow loss (less than $400/mo). However, the equity is rising nicely – 14% last year, 54% over the last 5. I want him to easily pay off or pay down the mortgage I’m carrying on my house so he’ll be comfortable if/when I die. He’s 52 years old and I’m also concerned about capital gains, which I worry he’ll get hit with inheritance taxes since my house is worth over a million dollars. My question is should we sell the rental, and if so, when is the best time for tax purposes?