KENNYR,
I assume what you mean by "graduated low flying" is an allocation of hours based on experience? Chinooks, like other SH, do fly below 50' IAW the JHC FOB - we don't always carry USL!
But at the moment we have no idea of who does what, once we do maybe we could discuss just how much we do need. The current practice is fill your boots - can we justify that approach?