"This compares to $18,900 for the Boeing AV-8B Harrier II and Boeing F/A-18A-D, the aircraft types the Joint Strike Fighter will replace.Although NAVAIR projects the F-35 will fly 12% fewer flight hours than the AV-8B and F/A-18A-D fleets, the agency expects the modern aircraft to cost as much as about 25% more to operate at peak rates, the briefing says.The unexpected cost increases mean the F-35" . . . .