While under administration, the administrator guarantees payment for any debt incurred AFTER he takes over. Therefore, as long as fuel, landing fees, crew wages, insurance, handling and ATC charges are paid the aircraft can fly as long as the maintenance release is current.
It is short term only, to keep the company alive to be sold as a going concern ,or possibly generate some more funds for the creditors if things are wound up. Attractive rates could be offered as the administrator isn't concerned with long term planning for major checks, engine overhauls and eventual fleet replacement. As long as he can turn a profit after covering the day to day costs, aircraft fly.
MK have a fleet of obsolete, fuel inefficient aircraft. The business model may have worked when oil was cheap, ie it burns more fuel but costs alot less to lease/buy. With the current fuel price this MAY have been turned on its head, airlines in the states are rushing to retire their MD80s, DC9s and 727/737-200, and replace them with modern economical types.
However if the creditors push for things to be wound up the aircraft are unlikely to realise much in a fire sale with oil at record highs and everyone else dumping older jets. It may be in their interest to forgive a % of MKs debts and allow a restructuring plan to get things going again. But modern freighters may be difficult and expensive to obtain with everyone else having the same idea, also an investor would need to be adventerous to invest in aviation at the moment.
Interesting times.