I would of thought that CF is less safe , metals "crumple" to absorb some of the shock of impact. Carbon fibre breaks when put under stress. A cf Module is more likely to keep it's shape after impact and I guess if the occupant is completly surrounded by air bags it would be safer. Cars generally do not have any significant vertical force in accidents ( so fwd and side air bags help) , most helicopter accidents involve significant vertical force so unless you can make air bags below the pilot keeping the cockpit intact will not reduce severity of the injuries.