ANSW was a good example of a finely tuned, profitable commercial operation sent into the red by the Fat Man. It owned all its F27s, most of them (the -500s) relatively new, which were about as close to a perfect fit for its large network as an operator could ask for.
The Fat Man presented them with the unasked for F50s - and the costs of paying for their leases. And into the bargain, he opted for the 'cheap and cheerful' AN version (like no other F50 in the world) - without an APU - which was a bit like buying a new limo today to use to carry paying customers in really hot conditions and having the distributor remove the air con, to say nothing of the problems with repeatedly powering up and powering down an aircraft that ran almost everything on AC electrical systems.
Why buy (or lease, actually) unnecessary new aircraft? Shades of Lucius Tan at Philippine Airlines, because when you buy a swag of new aeroplanes, you sell (and pocket the cash) the wholly owned old ones. And of course, someone (I wonder who?) pockets the 2% commission on the price of the new ones.