The conversion from purchase to lease often occurs. It may not in itself release large amounts of cash, but could have a positive tax advantage (varies country to country).
My understanding is that Virgin's cash position is limited due to finance guarantees which effectively restrict access to "cash in the bank".
In other words, the business as a going concern really needs to be cash flow positive and that includes VA as well.
If it's not ( and that is almost certainly the case right now), then it's only a matter of time.
I wouldn't place too much emphasis on the share price in such a turbulent market. What is important are the company fundamentals and cash reserves.