However , due to the lack of other orders , the production line was shut down on 15 December 1975 .
At this point , the break - even point was anticipated to be around 125 -- 150 aircraft .
Due to the lack of other orders , the production line was shut down on 15 December 1975 .
At this point , the break - even point was anticipated to be around 125 -- 150 aircraft .