Why is ADF required on ILS approach?

"David Brooks" wrote in message
...

"Leland Vandervort"
wrote
in message ...

Also most holding procedures in the Europe use NDBs as the holding
fix. (there are currently NO operationally published GPS approaches
in the UK, and the CAA and even JAA are tending to be somewhat wary of
implementing GPS procedures for instrument approaches.)

Is there a single rationale for this wariness?

No, as MLS airborne equipments use GPS derived DME.

The obviously compelling
reason is that other nations would be reluctant to throw the future of
their
air navigation into the hands of a system controlled by the US military -
we're allies now, but alliances change within the lifespan of an
aeronautical system.

The really compelling reason for building Galileo is to bridge a technology
gap, unfortunately TACAN stations interfere with the proposed Euro Nav
signal.

Or is there something more mundane: the incremental
cost causing slow adoption, or the decision to put more INS systems into
European planes before GPS came along, or roll out MLS faster than the US,
or what?

Working MLS uses GPS, so the reasoning has to be somewhat convoluted. Then
again, if Galileo provides binary stars, the Europeans will be ahead of the
US in space based Navigation.

John P. Tarver, MS/PE