While vacation bookings to Cape Cod are off 30 percent for this summer compared to last year, executives at the regional carrier Cape Air aren’t too worried about the drop. The airline, which operates a fleet of twin-engine Cessna 402s, is cutting flights on some of its vacation routes and using the planes to expand service to Baltimore, White Plains and New Hampshire, the Provincetown Banner reported. Cape Air is considering enlarging its Caribbean and Florida service, and may even expand to Cuba if travel restrictions there are lifted. Cape Air hasn’t laid off any of its 700 employees in the current downturn. A bigger concern is what to do with its aging fleet of 402s, which company executives expect have 10 to 15 more years of life in them. With the 402 out of production, Cape Air has been buying up used ones to scrap for parts. The airline hasn’t settled on a replacement aircraft for its fleet, but it wants to stick with a smaller plane like the 402, which seats nine passengers.