Preheat oven to 400°F.
Lightly oil a large sheet tray. In a bowl, mix turkey, onion, sweet
potato, 3 tablespoons barbeque sauce, 1 teaspoon salt and 1/4 teaspoon
pepper. Form into four loaves, brush with remaining 1 tablespoon
barbecue sauce and bake on sheet tray for 20 minutes.
In a large bowl, toss green beans with maple syrup, oil and remaining 1/2 teaspoon salt and 1/4 teaspoon pepper. Arrange on sheet tray next to meatloaves and roast until tender and meatloaves are cooked through (165°F), 20 to 25 minutes more.