Boeing said on Sunday it remains on track to deliver two new Air Force One jets in 2028, but meeting that target will require additional spending on a program already years behind schedule and billions of dollars over budget.Boeing was awarded a $3.9 billion contract in 2018 to build the aircraft, though costs have since ballooned to more than $5 billion. The aircraft are intended to replace the current Air Force One planes, which entered service in 1990.“We’re on track for 2028,” Steve Parker, CEO of Defense, Space & Security, told reporters ahead of the Farnborough Airshow in the UK,…