micheal_can
Senior Member
Complete guess as I have no idea. Heck it could be 20 years. The real problem is not my guess, but how long the legacy fleet can last before they need to be removed from revenue service. The longer Via waits to order more,the more there is a risk of a loss of frequency.I suspect you are pulling that time frame out of your ear, unless you have knowledge of their order book and production rate.