From -
http://www.mindef.gov.sg/nps/technical/paper1.html
"LALEE
38. A UAV designed for a continuous coverage mission will require
the operating cost per flying hour to be very low, below US$1,000,
to be affordable. A continuous coverage station will require the
flying of about 10,000 hours per year. The capital cost of
acquiring the platform and payload, say at US$50m will be overtaken
by the operations and maintenance cost after five years of
operations. The US Navy is studying the MRE (Multi-Role Endurance)
UAV to perform this mission. We have just completed a 3 year long
study of LALEE which is an integrated airborne surveillance and
communications system designed to provide continuous temporal
coverage over a very large area. Providing a task group operating
in the littorals with continuous surveillance from the air with
this class of UAV will be considerably cheaper than operating
current generation of surveillance and communications platforms.
The technology is there but whether Navies will to want to invest
in this class of UAV will depend on their perceived need for a
continuous coverage platform."