Yield with the E-jet is no where near enough to cross the finish line with cash in the bank.
This is the crux of Virgin's trouble. Effectively the cash reserves are feeding the yield gap that:
1. Has been generated by the jungle jets.
2. Will be generated by the 777.
With these 2 factors alone, it will take some very creative accounting to try and stay afloat. Also remember that lines of credit will have dried up to the point that any available funds for this type of high risk venture will attract extremely high interest rates.
In other words if the cash flow isn't there, yield management becomes irrelevant.
Something has to give here if the core brand is to be saved.