FINAL REPORT - Stakeholders - Ofcom

Notes:
• The costs are not dependent on whether the change is to P-RNAV or RNP
RNAV. The cost difference between these upgrades is dependent upon the
number of additional units required.
• For T0/T1 it is assumed that a combined GPS/RNAV computer is purchased
rather than separate GPS and FMS.
• This cost would be zero for J2 and J3 if the requirement for AFM change is
removed.
• Maintenance is only included for new avionics.
• Database costs are additional to current costs.
• Military costs are not presented, due to lack of information.
Cost Recovery: CAA DAP, acting as agent for Ofcom, charges licence fees for
navigational aids in the UK. This fee is charged by the number of frequencies used by
each individual navigation aid at the declared location. In addition, the ATSU also pays for
the purchase of the navigation aid, and any maintenance or upkeep necessary.
The recovery of all costs on ground-based radio-navigation aids has traditionally been via
route or airport charges on the aircraft using the service; this is likely to remain the case in
the future.
For route charges, the difficulty is examining exactly what factor ARNS plays; they are
calculated based on the overall service, and not only with reference to the navigation
aids, since for RNAV there is no way to identify which en-route navigation aids are used
by each individual aircraft.
For the airport domain, the charge structure is easier since the tower should have records
of which approach procedure each aircraft uses; navigational aids are generally tied into
approach procedures, and therefore use of navigational aids can be calculated – e.g. ILS
approach will use ILS (localiser and glideslope) and possibly DME; NDB non-precision
approach will only use an NDB etc.
Airborne equipment costs, where retrofitting is required, are recovered as part of
customer charges. The obvious exceptions are the military and GA communities, where
little or no primary cost recovery exists. This then presents a problem in encouraging
these communities to move to new, more spectrally efficient, technologies.
Regulatory impact
Regulatory Authorities: The regulatory authorities involved with the lobbying and
promoting of aviation RF requirements have traditionally taken a defensive stance when
dealing with the allocation of spectrum. This is not necessarily unreasonable since the
safety criticality of a civil aircraft’s navigation systems is very high, particularly in the
landing phase of flight.
From ICAO’s ‘Position for ITU WRC2003’ document:
“The ICAO position aims at securing availability of radio frequency spectrum to meet civil
aviation requirements for current and future safety-of-flight applications. In particular, it
stresses that safety considerations dictate that exclusive frequency bands must be
allocated to highly critical aeronautical systems and that adequate protection against
harmful interference must be ensured.”
In the UK, a balance is struck between the MoD and CAA DAP in determining the
assignment of ARNS applications to spectrum. In general, this partnership works in
providing equitable use of the frequency to each user.
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